eChapters

It is a discipline of science that describes handling, preparation and storage of food that can prevent food-borne diseases. When there are two or more cases of a similar illness from the ingestion of the same common food it is known as a food-borne disease outbreak (FSN, 2018). In order to avoid potential health hazards, food safety is very important. This needs safety between industry, market and the consumer. For food safety the labelling on food material is vital. This includes the origin of food, steps taken for food hygiene, food additives, pesticide residues, policies on biotechnology, food guidelines for the management of governmental import, export inspection and certification systems for foods. The food should be safe in the market with safe preparation and delivery of the food for the consumer. Foegeding et al., (1996) have done an assessment of risk factors with food borne pathogens.Warnock et al., (2007) have reported intervention to food safety.

When pathogens are in the food they may be transmitted to the consumer. It may result in an illness or death of the person or other animals. The pathogens include bacteria, viruses, molds and fungus. These multiply in the food medium. Joon et al., (2012) have found pathogenic bacteria in meat products of Korea. The developed countries have high intricate standards for the preparation of food; however, in the developing countries there are less standards and enforcement of the standards which are followed. Apart from food another major source of infection is water, which is very critical in spreading many diseases. It is possible to prevent food poisoning if good water is used for all purposes. However, it becomes difficult as in the food supply chain a large number of persons are involved apart from the fact that pathogens can be introduced into foods no matter how much precautions are taken. Cowden (2000) has studied the notification on food poisoning to improve health. Frenkel et al., (2015) studied the amount of wastes from food processing industries.

According to Futter (2001) it is very important the way we cook our food. If the cooking is inadequate it causes food poisoning. While cooking there can be cross contamination starting from raw foods. It includes hands or utensils which can cause food poisoning. Most foods, especially meat, poultry, fish and eggs should be cooked thoroughly to kill most types of food poisoning bacteria. Generally the food should be cooked to a temperature of 75 °C or hotter. When food is cooked, it should be eaten promptly, kept hotter than 60 °C or cooled, covered and stored in the fridge or freezer. Some people are more at risk from food poisoning than others. In order to buy safe food in the market like buying pre-cut produce as a half a watermelon or cut veggies from a salad bar, it is important to choose items that are refrigerated or surrounded by ice. They must be kept in separate bags. FDA (2019) has studied the contamination in lettuce. Shopping at a farmer’s market is a great way to get locally-grown, fresh fruit, vegetables, and other foods. However, safety of these produce needs to be checked. Many markets have their own food safety rules and vendors must comply with them along with the government regulations. Fruits and vegetables must be washed thoroughly under running water just before eating, cutting or cooking. Fruits and vegetables must never be washed with soap or detergent or using commercial produce washes. Even if it has to be peeled before eating, it is still important to wash it first. Any bacteria present on the outside of items like melons can be transferred to the inside when it is cut or peeled. They should be refrigerated within two hours after preparation. The juice or cider must be treated (pasteurized) to kill harmful bacteria. Pregnant women, children, older adults and people with weak immune systems should drink only pasteurized or treated juice. Raw milk can harbor dangerous microorganisms like Salmonella, E. coli, and Listeria. World India (2017) has looked into the food regulations. These can pose serious health risks. Pregnant women, older adults and people with weakened immune systems are at higher risk for illness caused by Listeria. One source for these bacteria is soft cheese made from unpasteurized milk. It is vital to check the label to make sure that it is made from pasteurized or treated milk. Make sure that eggs are properly chilled at the market. FDA requires that untreated shell eggs must be stored and displayed at 45°F. While buying eggs it needs to be ensured that the eggs are clean and the shells are not cracked. Meat should be properly chilled even in the market and kept in closed coolers with adequate amounts of ice to maintain cool temperatures. If it is brought in an insulated bag or cooler during transit it is very beneficial to keep the quality. It should be always kept separately from your other purchases, so that the juices from raw meat (which may contain harmful bacteria) do not come in contact with produce and other foods. Essays (2018) have written a very comprehensive overview of food safety.

Today, organic and local foods are preferred as they use less pesticides or fertilizers. However, these foods, like others, can be exposed to harmful bacteria during the growing and harvesting process. The farmers and distributors must use good sanitary practices to minimize food contamination. Consumers should cook food properly. The street food vendors are a traditional and indigenous fast food approaching in most countries of the South-East Asia Region. As these are economical they cater to millions of consumers. Among safe street foods there are many contributing factors that are associated with the safety of street food. WHO had conducted a survey in 1993 covering 100 street foods in 100 countries around the world. It revealed that the major health threat comes from raw and undercooked food, infected food handlers and inadequate hygiene practices in processing and storing such food. If the street food is cooked well and is served hot, then the chances of food poisoning is less. The water quality, hygienic conditions and the level of cleanliness especially in the summer season are the major factors for food poisoning. However improvements in physical infrastructure and hygienic conditions are growing as consumers are also demanding quality food. Michael et al., (2017) have looked into organic versus conventional foods.

In this century the usage of plastics had become very common. However, it is important to know as to what kinds of plastics are used for food handling and storage and the health hazards caused by using it. It has been observed that plastic packaging plays a significant role for the enhanced shelf life and in the ease of storage and cooking for many foods. Some kinds of plastic materials which are widely used for handling and storage of food and water include polyethylene terephthalate (PET). It is used in soft drinks, water, sport drinks, ketchups, salad dressing bottles, peanut butter, pickle, jelly and jam jars. This plastic is strong, heat resistant, resistant to gases and acidic foods. It can be transparent or opaque. It does not leach any chemicals that are suspected of causing cancer or disrupting hormones and can also be recycled.

Usage of High density polyethylene (HDPE) has been found to be common in milk, water, juice bottles, yogurt, margarine tubs, grocery, trash and retail bags. High-density polyethylene is stiff and strong but is not heat stable (it melts at a low temperature). It does not leach any chemicals that have a role in causing cancer or disrupting the hormones. HDPE can be recycled. Low-density polyethylene (LDPE) is used into making films of various types, some bread and frozen food bags and also in the making of squeezable bottles. Low-density polyethylene is relatively transparent. Many of the films are not heat stable either and may melt the food in case it is touching it. However, polypropylene (PP) is more heat resistant, harder, denser and more transparent than polyethylene and is therefore used for heat-resistant microwavable packaging and sauce or salad dressing bottles. Polycarbonate is clear and heat resistant. It is also durable and often used to make refillable water bottles and sterilisable baby bottles, microwave ovenware, eating utensils, plastic coating for metal cans. Tiny amounts of bisphenol A are formed when polycarbonate bottles are washed with harsh detergents or bleach (sodium hypochlorite). At high levels of exposure, bisphenol A is potentially hazardous as it mimics the female hormone estrogen. In addition, polystyrene (PS) and polyvinyl chloride (PVC) are also used during food material transportation and handling in supermarkets. Modern food safe plastic bags are plasticizer-free which do not leach harmful chemicals into the food during cooking.

Food adulteration is an unethical and often criminal malpractice. It is very common in countries of the South-East Asia region. It frequently occurs where informal food production and marketing services are predominant and enforcement of food regulation is weak. The prohibited substances are either added or used to partly or wholly substitute healthy ingredients. This creates the impression of freshness in old food artificially. Adulteration in food is usually done for financial gain. The high target is spices due to the demand and also their high price. Sometimes it can happen due to lack of proper hygienic conditions of processing, storage, transportation and marketing. The consumer is either cheated financially or becomes a victim of illness or disease. In case, the consumers take a lot of precautions at the time of purchase of such products it would help them in avoiding the purchase of such adulterated food. The whole spices: Dirt, dust, other seeds; chili powder: brick powder, salt powder or talc, powder. In ghee/butter: vegetable ghee, animal fat, mashed potato, sweet potato, etc. ; ice cream and beverages:saccharin; honey: jaggery, sugar syrup. Food contaminants are not added to the foods. They are present in foods as a result of the production (crop farming, animal husbandry and aquaculture), manufacture, processing, preparation, treatment, packing, packaging, transport or holding of such food or as a result of environmental contamination. Usually it includes the presence of harmful chemicals or microorganisms in food, which if consumed can cause several debilitating illnesses. Many times, unknowingly, the contamination may occur during the production, processing, storage and marketing.

When certain disease-causing bacteria or pathogens contaminate food, they can cause foodborne illness, often called “food poisoning”. Foods that are contaminated may not look, taste or smell any different from foods that are safe to eat. Salmonella, Campylobacter, Listeria and Escherichia coli are common bacteria causing foodborne illness. Some foodborne illnesses are mild where most people get better within a few days, but illness can sometimes be more severe and fatal. Bacillus cereus can form heat resistant spores. On cooking the food with these spores the heat resistant toxin is left at room temperature. Reheating or lightly cooking the food does not destroy these toxins. Most types of foodborne illnesses cause symptoms like nausea, vomiting, watery diarrhea, abdominal pain and cramps. Fever and/or the presence of blood or mucus in the stool are signs of bacterial infection that may require a medical consultation. Proper food handling is vital to prevent most foodborne illnesses and diseases. WHO has given keys towards safer food which should be followed. Unsafe food containing harmful bacteria, viruses, parasites or chemical substances, causes more than 200 diseases which range from diarrhoea to cancers. Foodborne and waterborne diarrhoeal diseases kill around 2 million people worldwide annually, including many children. A single foodborne bacterium can grow into more than two million bacteria in just seven hours under the right conditions. Foodborne pathogen called Listeria sp. can survive and sometimes grow on foods being stored in the refrigerator. Hepatitis A virus can cause long-lasting liver disease and spreads typically through raw or undercooked seafood or contaminated raw produce. It is estimated that more than 250 million people worldwide suffer food allergies. The boiling temperature (smoke point) of cooking oil is above 200 °C. The boiling point of water is 100 °C.

According to the World Health Day (WHO,2015) food contamination happens when food are corrupted with another substance. It can happen during the process of production, transportation, packaging, storage, sales and cooking process. The contamination can be physical, chemical and biological. Faulde et al., (2013) studied the infection caused to patients by mothfly

Even after public concern the scientists feel that the GMO foods are quite safe. According to them the genetically-engineered crops are very safe to eat as much as the non-GE of the same crop. According to them the environment has improved by reducing the use of pesticides. GMO stands for genetically modified organism. Soy, corn, or other crops are very common as GM crops which are made by genetically engineered DNA. Many have come to the conclusion that GM foods are safe, healthy and sustainable. However, some people are against them. There are many benefits of GM crops like less water or pesticides to be used. Genetically engineered crops fight diseases to save the foods. At the same time the industries/ farmers that grow them are also benefitted. These foods have higher nutritional profiles, both in the US and abroad like corn which is one of the most prominent GMO foods. Soy is found in tofu, vegetarian products, soybean oil, soy flour and many other products. The other major crops taken for genetic modification are Papayas, Canola and Cotton. For dairy products a lot of work is being done on the genetic engineering of animals in a big way. This is going to be the most intractable environmental challenge of the 21^st Century. Presently, around 92% of the U. S. corn (GE), 94% of soybeans and 94% of cotton are genetically engineered.

Due to the globalization of the food supply there has been a need to strengthen food safety systems in and between the countries. In this regard the World Health Organization (WHO) has promoted efforts in improving the food safety from farm to plate which started on World Health Day, 7 April 2015. The World Health Day 2015 slogan was “From farm to plate, make food safe”. The informal food production and marketing system is still strong in most countries of the South-East Asia Region, for the enforcement of food safety regulations. Traditionally, the preferences have been for hot and well-cooked food. These habits are partially responsible for preventing foodborne infections. In many countries street food has become very popular as it is cheap. Hygienic conditions are improving, provided that potable water supply and clean facilities are ensured by municipal authorities. Many waterborne and diarrhoeal diseases could be prevented with the introduction of bottled drinking water. The awareness and education on food safety by the consumers has strengthened in the enforcement of food standards. This has improved the hygienic practices and has helped in the prevention of foodborne illnesses. The “WHO Five keys to safer food” serves as the basis for educational programmes to train food handlers and educate the consumers. These help in preventing the foodborne illnesses. The important points are to keep food surfaces clean, washing of all utensils, plates and cutlery, keeping the raw food separate from the cooked food. Cooking food thoroughly to the appropriate temperature, keeping food at safe temperatures, both for serving and storage and using safe water and raw materials.

A process control system that identifies the hazardous points in the food production process is known as HACCP (Hazard Analysis Critical Control Point). It puts into place many stringent actions to prevent any hazards from occurring. In any food process if there is strict monitoring and controlling steps, the chances for hazards are minimum. Today, HACCP is an integral part of modern food industry that identifies and controls the major food risks. These are like microbiological, chemical and physical contaminants. These can also be practiced at home scale by checking proper storage, handling, cooking and cleaning procedures. These steps have resulted in industries taking greater responsibility for and controlling the food safety risk factors. This helps in better consumer protection, agriculture, the food processing industries and promotes domestic and international food trade.

The temperature of food storage is important. Below 4⁰C the food pathogens do not grow. Above 60⁰C some colonies begin to die. However, almost all die at 71⁰C. How hot is the food served is important for food safety. The size of the piece is important to how quickly it will cook all the way through. The smaller the piece the faster it will cook. Large or thicker pieces take a longer time to be cooked. Otherwise cooking for a longer time is better so that pathogenic microorganisms do not grow. In case of a thicker piece the color must be checked inside to outside after cooking which should be consistent. If the meat has the bone, check the color/temperature closest to the bone in the thickest part. In case of meat the contamination usually gets introduced while butchering and the practices used. The street food on a cart is perhaps the most contaminated as it has some level of bacteria in it. The meat in the decorated malls also has pathogenic bacteria. The environment plays a very pivotal role which can recontaminate the food even after proper cooking. The amount of harmful pathogens keeps growing in number with the passage of time. Fresh from the grill is the best, an hour or two is not ideal, half a day or overnight could make a person sick. Due to the reason that consumers do not know the time and temperature of cooking it is important to eat food which is freshly prepared.

Jay et al., (1995) and Joerger et al., (2003) have written the role of bacteriocins as an alternate to antibiotics. Bacteria produce bacteriocins which are proteinaceous in nature or peptidic toxins. These inhibit the growth of similar or closely related bacterial strain(s). There are different types of bacteriocins which are classified based on the producing strain, common resistance mechanisms and mechanism of killing. Ahmad et al., (2013) have isolated antifungal compound for food preservation. Martin et al., (2018) and Batish et al., (1997) found antibacterial compounds from fungus. Mahboubi et al., (2019) studied the potential of Zataria in IBS. There are bacteriocins from gram-positive bacteria known as the colicins, the microcins and the bacteriocins from Archaea (Cascales et al., 2007). The bacteriocins from E. coli are called colicins (formerly called ‘colicines,’ meaning ‘coli killers’). These have been studied widely. Earlier called colicin V and is now known as microcin V. It is very small and is produced and secreted in a different manner than the classic colicins. Adrienne et al., (2016) have studied the colicin resistance.

Josephson (1977) studied the effects of food irradiation and sterilization. In radiation sterilization of food (radappertization) the food is exposed in sealed containers to ionizing radiation at absorbed doses which are high enough (25-70 kGy) to kill all organisms of food spoilage and public health significance. Radappertization is analogous to thermal canning for enhancing the shelf stability. In dry products the radappertization process requires the food to be heated to an internal temperature of 70-80°C (bacon to 53°C) to inactivate autolytic enzymes which catalyze spoilage during storage without refrigeration. In order to reduce off-flavors and odors, undesirable color changes, and textural and nutritional losses from exposure to the high doses of irradiation the foods are vacuum sealed and irradiated frozen. Radappertozed foods have the characteristic of fresh foods prepared for eating. Irradiation can be a good substitute for some chemical food additives such as ethylene oxide and nitrites which are toxic, carcinogenic, mutagenic or teratogenic either wholly or in part. Till now, there is no evidence of any adverse effects of radappertization on the foods. Extensive research has taken place towards the space food. During the planning of Apollo missions, Space Food NASA Technical Reports Server (Space Food NASA Technical Reports Server, NTRS ,1994 ) conducted trials including freeze drying.

Henderson et al., (2010) have studied the different aspects of food regulation. The authors have looked into the perceptions of Australian consumers’ who is and should be responsible for food safety. Forty-seven participants were interviewed as part of a larger study on trust in the food system. Participants associate food governance with government, industry and the individual. While few participants can name the national food regulator, there is a strong belief that the government is responsible for regulating the quality and safety of food. Personal responsibility for food safety practices was also identified. Little evidence is found in the politicisation of food, reflecting a level of trust in the Australian food governance system that may arise from a lack of exposure to major food scares. According to Wood (1990) the marketing of food service program in an Ohio district is directed toward the students and also at the community, school administrators, teachers, and employees. Students are encouraged to follow a healthier way of eating.Jones (1998) studied the role of food safety in the food chain from farm to fork. In response to growing threat of food-borne illnesses the federal government had launched the Food Safety Initiative. A key element is the Hazard Analysis Critical Control Point’s system (HACCP). Under this it has been designed to make everyone in the food-delivery chain to be responsible for ensuring a safe food supply.

Food safety scientifically describes various methods of handling, preparation and storage of food to prevent any foodborne illnesses. However, it is important to check the safety between industry, market and the consumer. From the food industry to the market the practices relating to food labeling, food hygiene, food additives and pesticide residues are important to be looked into and the policies on biotechnology. The governmental imports and exports needs to be given proper guidelines. Certification systems and Inspection for foods need to be installed which should be clean and corruption free. When all this is properly considered the food could be safe in the market. This may allow for safe delivery and safe preparation of the food for the consumers. Many diseases are transmitted by food which serves as a growth medium for bacteria and cause food poisoning. In the developed countries it has been observed that there are many intricate standards for food preparation. However, in the developing countries the availability of adequate safe water itself is a question. It is possible to prevent food poisoning to 100%. An ordinance and code regulation in US (1943)was given.

For looking into the biosafety in research laboratories, agriculture and other food producing industries it is important to look into the numerous strains of lactic acid bacteria that are associated with food systems and are capable of producing bacteriocin or antibacterial proteins with activity against foodborne pathogens such as Listeria monocytogens, Staphylococcus aureus and Clostridium botulinum. Recently considerable attention has been given on the identification of these proteins and their biochemical properties including spectrum of activity, production conditions, purification procedures, aminoacid composition and mode of action. Advances in genetic engineering have facilitated the characterization of proteins at genetic level, providing information about protein synthesis, structure and cloning of bacteriocin genes into other organism. One problem in the use of bacteriocin in their applications as bio-preservatives is the emergence of resistant population. The understanding on the mechanism of resistance to bacteriocins is limited which limits the application in biopreservation. Much of the work on bacteriocin has been done under controlled laboratory conditions without the presence of adventitious microbial population. More research is needed to determine the efficacy of bacteriocin producing organisms and bacteriocins which are stable under commercial conditions. Foodborne illness is a major international problem and an important cause of reduced economic growth. The contamination of the food supply with the pathogens and its persistence, growth, multiplication and/or toxin production

1.1 Introduction and Background

In present scenario, the word “extrusion” refers to a process by which dry or semi-moist ingredients with varying in-barrel moisture are forced through varying barrel temperature, screw speed and screw configuration through a die opening of the desired cross section. In other words, extrusion is predominantly a thermo-mechanical processing operation that combines several unit operations, including mixing, coating, kneading, venting, shearing, heating, forming, partial drying or puffing, depending on the material and equipment used.

The origins of extrusion are in the metallurgical industry, where in 1797 Joseph Bramah patented the first extrusion process, wherein a piston driven device was used for making seamless lead pipes. The present understanding of extrusion technology and the developments or improvements in machine design are largely due to research carried out by the plastics industry. In food industry, this technology is in use since 1930 and its popularity is increasing continuously due to its efficiency, continuity and sustainability. In beginning, sausage extruders were developed in the nineteenth century as simple forming machines. One of the original developments which laid the foundation of the food extrusion was the use of pasta press termed as “cold extruder” in mid 1930s. Furthermore, in the late 1930s, General Mills, Incorporation., Minneapolis, MN, USA, first used a single screw extruder in the manufacture of ready-to-eat (RTE) cereals. Later in 1970s, twin screw extruders were used for the manufacture of moist pet-foods. Twin screw extruders were also adapted from polymer industry, as rising food quality and limitations of single screw extruders were demanding a more versatile process for the newer and higher quality products. After 1970s, the extrusion processing with simultaneous use of heat was popularized as a versatile and highly energy efficient with negligible wastage process. In all these years, number of changes has been noted in the extruder design such as changes in screw design, barrel design and also material used for the manufacture of these materials. Barrel liners availability along with already available segmented screws could further add more economics to the process and increased equipment lifetime. For better wearing characteristics, a number of screw elements of different materials are being used in addition to standard nitrided steel for customized processing needs, such as corrosion and wear resistant surface coated steels, stainless steel, satellite welded and bimetallic HIP (Hot Isostatic Press). JBL Feedscrews Limited, a UK based company recently introduced tungsten carbide coated screw in conjunction with a compatible bimetallic barrel. Likewise, a number of options for barrel metallurgy are available to withstand the higher internal pressure and temperature. Barrels lined with hard cobalt based alloy, typically Xaloy, to give abrasion and chemical resistance are also in use, although, the most common material is carbon steel with a nitride interior. Similarly, steam heated or jacketed barrels were used earlier for cooking purpose which gradually replaced by the electric induction heating elements. These HTST cooking extruders are versatile, highly productive and energy efficient processing machines. They can use a wide variety of raw materials and formulations to produce products with increased shelf-life and convenience.

2.1 Introduction

Food is one of the complex systems involving many constituents such as carbohydrates, lipids, proteins, vitamins, minerals and other phytochemicals. These all constituents are not present in the same relative proportion in every type of food and thus the foods are categorized and valued according to the presence of these constituents as protein rich foods, fat rich foods, etc. The specific type of food is in abundance with only one or at most two of these constituents and rest of the bulk is not valuable, commercially. So, if these active constituents which are present in the tissue surrounding inactive matrix, are separated, it is of great benefit with respect to increased purity, nutritive value, functional properties, reduction in volume, easy handling and transportation. On contrary some valuable food items contain undesirable constituents generally referred as anti-nutritional factors. Removal of these anti-nutritional factors enhances the food value and commercial utilization. Hence, the separation of phytochemicals and removal of anti-nutrients from the food matrices can be easily carried out by using a unit operation called as extraction.

Extraction involves the separation or isolation of active/desirable components of complex system viz., plant and animal tissues from the rest of inactive/undesirable components by using suitable means such as solvent or mechanical structure. The basic principle involved in the extraction process is partitioning of different components in accordance with the extracting agent. For example, in mechanical extraction, the partitioning is due to pressure and screen/apperature size where as in case of solvent extraction, the portioning of components from mixture takes place due to particular solubilizing power of solvent used.

3.1 Introduction

Energy comes in many forms like chemical, radiant, mechanical, electrical, nuclear etc and can transform from one type to another. Energy can also be transferred or moved from one object to another. Electromagnetic (EM) radiation is a form of energy that can take many forms, such as radio waves, microwaves, X-rays and gamma rays even sunlight is also a form of EM energy. Visible light is a small portion of the EM spectrum, which contains a broad range of electromagnetic wavelengths.

Electromagnetic waves, a self –propagating transverse radiation, are created when an atomic particle, such as an electron, is accelerated by an electric field, causing it to move. The movement produces oscillating electric and magnetic fields. The electric and the magnetic components of the wave are perpendicular to each other and also perpendicular to the direction in which wave is travelling in a bundle of light energy called a photon. Photons travel in harmonic waves at the fastest speed possible in the universe: 186,282 miles per second (299,792,458 meters per second) in a vacuum, also known as the speed of light. There are three important characteristics of the electromagnetic radiation, its frequency, amplitude and speed (Figure 3.1).

4.1 Introduction

The purpose of processing the food is to make it safe and healthy for human consumption. The term food processing refers technologically anything, which transforms raw ingredients into consumer ready products, with the aim of stabilizing food products by preventing or reducing deteriorative changes in quality. The objective of food manufacturers is to develop, modify and employ those processing technologies that retain or create desirable sensory qualities in food and eliminate or reduce undesirable changes due to processing.

The purpose of food processing is to increase the shelf life of food before spoiling (preservation); to remove, destroy or inhibit pathogens and toxins (food safety); to change flavor, texture, aroma, color or form (variety); to reduce preparation times and make food more portable (convenience); to restore and/or raise nutrient levels in food (nutrition).The various food processing methods used extensively in food industry include physical (high temperature, freezing, chilling, dehydration, packaging), chemical (control of storage gases, reduction of water activity, pH, addition of chemical additives or spices) preservation methods.

Traditionally, food preservation has been associated with thermal treatments alone or in combination with biochemical or chemical methods. For example, the thermal processing of milk is done various thermal treatments viz. at 63^oC for 30 min for low temperature long time (LTLT), 72^oC for 15 seconds for high temperature short time (HTST) pasteurisations and up to 140^oC for a few seconds for ultra high temperature (UHT) treatment. However, such thermal treatments effectively reduce level of microorganisms but in long-term preservation, it may lead to losses of desired organoleptic attributes and destruction of temperature liable nutrients and vitamins. The limitations involved with thermal processing has been overcome by employing chemical preservation, cool chain management and process hygiene in the formulation and production of food products.

5.1 Introduction

Food is the basic requirement of every living being and it provides physical, mental as well as emotional satisfaction. Globally, there are many food enterprises which provide this basic necessity across the nations irrespective of nature of origin and climatic condition. Food companies are required to provide products at certain quality parameters so as to maintain the uniformity in the food system. Hence, food quality can be defined as a total of traits and criteria which characterize food as regard to its nutritional value, sensory value, convenience as well as the safety for a consumer’s health. Food quality is the quality characteristics of food that is acceptable to consumers. This includes external factors as appearance (size, shape, colour, gloss and consistency), texture, and flavor; factors such as grade standards and internal (chemical, physical, microbial). Due to the various food risks, all over the world the quality regulation authorities have intensified the efforts to improve food quality. Some of the quality related systems are obligatory by law while other is voluntary which are to be implemented by the various food chain members.

Many companies are forced to improve safety and quality of their products by implementing the quality and safety assurance and management system because of growing consumers’ expectations and concerns as regards food quality and safety.

In order to attain maximum profit and decrease the flaws, a new system was developed and followed by various companies all over the world. This new system is known as Six Sigma. The application of this system has the capability to reduce the losses considerably by reviewing the process parameters and increasing the profit exponentially. It constitutes a systematic approach to assure that food products have particular traits at any stage of production and distribution.

6.1 Introduction

Consumer demand, regulatory guidelines and economic power of the consumer as well as ascertained profitability stimulated the need of novel food processing techniques. The concept of “fresh”, “natural”, or “organic” food also led to the development of environmentally sound and resource efficient food processing technologies. Thermal processes have been used for food preservation since a long time. These are not very energy efficient and can change the phase of food from fresh to cooked as well as it can alter the nutritional and sensory qualities. Thus, the quest for energy conservation by the manufacturers to reduce carbon footprint of the processes involved in food processing and preservation as well as to fulfill consumers’ requirement for fresh-like quality food have given rise to the development of innovative non-thermal food processing technologies i.e. ionizing radiation, high-intensity light pulses, high isobaric pressure, electric or oscillating magnetic fields, as well as pulsed electric fields (PEF).

Application of electric energy in food processing started in the early 1900s. In the beginning, electrical pasteurization inactivated microorganisms by increasing the temperature of samples by means of an electrical resistance (ohmic heating). Milk was the first electrically pasteurized product. In the late 1940s, electric fields were used to increase the permeability of fruits to facilitate the subsequent extraction of juices. The PEF technology as a non-thermal process is very effective for inactivation of microorganisms, increasing the pressing efficiency, enhancing the juice extraction, and for intensification of the food dehydration and drying process. The main effect of PEF technology is based on the phenomena that biological membranes are punctured under the influence of external electrical impulses. This process is often referred as non-thermal, since the structural damage to membranes is implemented at very low temperature compared to the conventional heating process. The PEF process is considered to be energy efficient because the electric energy is released in short pulses, thus total energy requirement is much lower than other continuous preservation technologies. The microbial inactivation can be achieved at ambient or moderately elevated temperatures by the application of short-bursts of high intensity electric fields to liquid foods flowing between two electrodes or to semi-solid/ solid food between some specialized electrode and treatment systems. Due to chemical/physical properties and presence of electrical charge, the liquid foods (e.g. milk or fruit juices) had different conductivity, which results in variable flux of electrical current through the food systems.

7.1 Introduction

Food processing has become one of the most competitive sectors in recent years. With increasing consumers’ demands, food industry needs to keep updating technology. These efforts are focussed at improving the organoleptic quality and nutrition of food and improve its keeping quality. This drives the industry to look for newer technologies which include new products as well as new processes. Some of the new processing technologies include non-thermal processes such as high pressure processing, pulsed electric fields and ultrasound processing. Advanced thermal processing techniques such as ohmic heating, inductive heating, extrusion and infrared heating have also been developed. Innovative methods for improving food quality through irradiation, removal of heat and moisture from food are now available. Newer packaging techniques now help to improve shelf-life and attractiveness of the food products and cater to the biodegradability of the packaging material. Hence, there is abundance of new products that have now become part of our daily life.

Food nanotechnology has its long history when the first step of revolution in food processing and improvement in quality of foods was introduced by Pasteur to kill the spoilage bacteria (1000 nm). Later, Watson and Crick’s model of DNA structure, which is about 2.5nm, opened the gateway of applications in biotechnology. Nanotechnology is defined as the design, production, and application of structures, devices, and systems through control of the size and shape of the material at the nanometer (10^-9 of a meter) scale. Nanotechnology is one such technology that has the potential to revolutionize the food industry. Taniguchi first used nanotechnology in 1974 to describe production technology at ultrafine dimensions. The word “nano” means “dwarf” in Greek and one nanometer is equivalent to 10^-9 m. Objects of this scale are not visible through the human eye or the ordinary optical microscope. A nanometer (nm) sized particle measures one billionth of a meter. A human hair measures 80,000 nm while a DNA strand is 2.5 nm wide whereas a protein chain is 5nm in diameter. Nanotechnology can be applied to develop nanoscale materials, controlled delivery systems, contaminant detection and to create nanodevices for molecular and cellular biology. Nanotechnology may be defined as the understanding and management of matter at dimensions of roughly 1-100 nanometers. Unique behavior of matter at the nanoscale enables novel applications. Nanoscale science, engineering, and technology can be used for imaging, measuring, modeling, and manipulating matter at this length scale. Range of sizes of nanomaterials in the food sector and their relative position on nanoscale/microscopic scale are listed below.

8.1 Introduction

Electron Microscopes were developed due to the limitations of Light Microscopes which are limited by the physics of light to 500x or 1000x magnification and a resolution of 0.2 micrometers. In the early 1930’s this theoretical limit had been reached and there was a scientific desire to see the fine details of the interior structures of organic cells (nucleus, mitochondria etc.). This required 10,000x plus magnification which was just not possible using Light Microscopes. The Transmission Electron Microscope (TEM) was the first type of Electron Microscope to be developed and is patterned exactly on the Light Transmission Microscope except that a focused beam of electrons is used instead of light to see through the specimen. It was developed by Max Knoll and Ernst Ruska in Germany in 1931. The first Scanning Electron Microscope (SEM) debuted in 1942 with the first commercial instruments around 1965. Its late development was due to the electronics involved in scanning the beam of electrons across the sample. Electron microscope has been a valuable tool in the development of scientific theory and it contributed greatly to biology, medicine and material sciences. This wide spread use of electron microscopes is based on the fact that they permit the observation and characterization of materials on a nanometer (nm) to micrometer (µm) scale. Electron Microscopes are scientific instruments that use a beam of highly energetic electrons to examine objects on a very fine scale. This examination can yield information about the topography (surface features of an object), morphology (shape and size of the particles making up the object), composition (the elements and compounds that the object is composed of and the relative amounts of them) and crystallographic information (how the atoms are arranged in the object). A scanning electron microscope (SEM) is a type of electron microscope that produces images of a sample by scanning it with a focused beam of electrons. The electrons interact with atoms in the sample, producing various signals that can be detected and that contain information about the sample surface topography and composition. SEM can achieve resolution better than 1 nanometer. The combination of higher magnification, larger depth of focus, greater resolution, and ease of sample observation makes the SEM one of the most heavily used instruments in research areas today.

9.1 Introduction

Food quality and safety are central issues in food economics today. A number of developed countries (EU, UK, US) has imposed a number of new regulations to track food products across the supply chain which is forcing the companies to invest in new automated approaches for their implementations. These solutions facilitate better process efficiency with more productivity, quality control in production lines, lower manufacturing costs with higher profit margins, and also help to achieve improved presentation as customers request. The high labour costs in developed countries make cost-cutting inevitable to remain competitive production. The growth in products packaged for the market, the increasingly strict hygiene regulations, the need to reduce risks at work, cut costs, and control product quality are all calling for the development of technologies that enable robots to be used for these tasks. In fact, robotics has a great opportunity in this industry. But the variation in physical properties of various food products and the necessity to avoid damaging them, make it necessary to seek flexible handling solutions for a wide range of products.

The robotics industry is looking into a bright future. As per the report given by the Statistical Department of International Federation of Robotics (IFR), it was projected that between 2014 and 2016 worldwide robot sales will increase by about 6% on average per year. Ten years ago, global sales figures were hovering around 80,000. So, three key factors for the boom - factory modernization, increases in production capacity and rising demand from a number of emerging markets.

10.1 Introduction

Food safety and quality are the two important factor which results in consumer food choices. Nowadays consumers are demanding food which is safe and of high quality in terms of nutrition due to a healthier life style. Food safety and quality are the terms used interchangeably. Food safety refers to all those hazards, that make food injurious to the health of the consumer and it is not negotiable. Food quality includes attributes that influences the product's value to the consumer. This includes both negative and positive attributes; negative attributes includes spoilage, contamination, discoloration, off-odours and positive attributes include colour, flavour, texture and processing method of the food. This distinction between safety and quality has implications for public policy and influences the nature of the food control system. Food control is defined as a mandatory regulatory activity which provides consumer protection and ensures food is safe, wholesome and fit for human consumption during production, handling, storage, processing, and distribution.

Despite the huge efforts made by the food safety authorities and industries, food safety still remains a critical issue. In food industries, producers have to satisfy both safety and quality criteria for their products to the consumer. Food processors have multiple options in terms of different quality and management systems, they have to choose the most appropriate one for its specific activity and should establish, document and implement effective systems in the processing area for managing quality and safety of the product. Over the past few decades, food-borne illnesses have raised great concern about the safety of food. Considerable steps are taken by the food processor for understanding and managing the risks of airborne diseases. Among various systems, Hazard Analysis and Critical Control Point (HACCP) is effective tool which focuses mainly on controlling hazards to ensure the production of safe and wholesome food. For maintaining the safety and increasing the shelf life of food, traditionally it has been preserved by thermal processing, freezing, salting and drying. But nowadays consumers are demanding convenient, innovative, fresh foods, including new "minimally processed" products. To meet consumers' expectations in the 21^st century, the food industries are implementing novel technologies whose purpose will be two fold: 1) to provide the new quality attributes demanded by consumers; and 2) to ensure the all important and often expected assurance of food safety. The novel technologies will include various minimally processed technologies like high pressure processing (HPP), pulsed electric field (PEF), ohmic heating, dielectric heating, microwave heating, ultrasound, modified atmosphere packaging (MAP) and cleanroom technology. Among these cleanroom technology have attracted great attention for maintaining the safety and quality of the food products as because it doesn't have any effect on the nutritional quality of the food being processed, it maintains the hygienic condition in the processing area, remove contaminants from the processing area and clean air in the processing area which in turn results in safe food product. The main objective of cleanroom technology is to eliminate airborne contaminants from the humans and/or from the environment. An air curtains and a positive air pressure is maintained in the processing unit using filtered air. Production personnel will use the special clothing which is preferred for cleanroom to reduce the contamination from both air- and human-borne microorganisms. In this chapter we will discuss about cleanroom technology, its historical background, its classification, layout of cleanroom, air handling, personnel and its clothing, regulations in cleanroom, and its application in food industries.

11.1 Introduction

Phytosterols or plant sterols are bioactive plant constituents having similar chemical structure and biological functions as cholesterol (cholest-5-en-3b-ol), but differ in their side chain configuration. They are non-nutritive compounds with chemical structure differing from that of cholesterol only by minor modifications like in the structure of their side chain by a methyl or ethyl group at C-24. Sitosterol and campesterol have an ethyl and a methyl group at C-24, respectively (Fig. 11.1). Phytosterols present a tetracyclic ring and side chains linked to C-17 that differ according to sterol compound same as cholesterol, to which they resemble structurally as well as biosynthetically. Saturated form of sterols referred to as stands, occurring in small amounts, mainly in cereals are represented by the absence of the double bond at the D5 position. Phytosterols represent a part of the broad group of isoprenoides and are 28- and 29-carbon atom steroid alcohols naturally occurring in plants. Phytosterols and phytostanols are triterpene compounds, found ubiquitously in plants which can only be synthesized by plants, whereas humans and animals obtain them from their diet.

12.1 Introduction

Micronization is a size reduction in which particles are reduced down to micrometer resulting in particle-size distribution is less than 10 microns. Acceleration of particles has been involved for particle-to-particle impact or impact against a solid surface. Micron technology is an emerging technology which has a great potential in nutraceuticals and functional foods. By increasing the surface area per unit mass, compared with larger-sized particles of the same chemistry, tiny particles are made more biologically active. A lot of attention has been gained by micronization in food research and development. Functional properties, surface areas and structures gets altered by reduction in particle sizes of different materials (e.g., metal salts, metal oxides, chitosan and organic compounds) by micronization or nanotechnology to micro- or nano-sizes and bring some new applications in the academic world as well as in food industry.

They absorb a large concentration (10-40 wt %) of C0₂ that either swells the polymer or melts it at a temperature below (10 to 50 °C) it’s melting/ glass transition temperature hence, this technique is useful for micronization of especially for polymers. Active substrate(s) in a polymer or other carrier substance can be used with suspensions for micronization process. In manufacturing advanced pharmaceuticals, coating materials, micro sensors, polymers and many other chemicals particle design has been gaining importance. Formulation homogeneity and control particle size can be improved by micronization. Moreover, bioavailability of poorly soluble APIs (active pharmaceutical ingredient) by increasing particle surface area and accelerating dissolution rates can also be improved. Because of the high impact velocities possible as a result of particle acceleration in a fast gas stream, fluid energy mills are used for micronization. Particle velocities in a jet mill are in the range of 300 to 500 meters per second, compared to 50 to 150 meters per second in a mechanical impact mill, in many industrial fields like food technology, pharmaceuticals, catalysts, pigments, and biopolymers, for example, are some categories of products that can be used as micro-sized particles, micronized powders are of great interest. High-temperature reactions that require high energies, on jet milling that is characterized by low efficiencies and mechanical stress, and on liquid solvents precipitation that has a poor control on particle size and can pollute the product comes under the traditional techniques for producing micronic powders. Generally, the control of the powder size and the span of its distribution are still very approximate. In recent years, many supercritical fluids-based techniques have been developed for the production of micronic and nanometric particles. Some particular properties of gases at supercritical conditions such as enhanced solubilization modulation and its power, large diffusivities, organic solvent reduced operation, and the connected possibility of controlling powder size and distribution resulted from this process. Important characteristics of powders like particle size and size distribution have significant effects on dissolution properties, flowability and release kinetics. Therefore, particle engineering is the most important step during processing of powdered foods. Lower micrometer range and sizes are needed for many applications particles with special requirements. Processes like jet milling, pearl milling or high pressure homogenization are used for micronization.

13.1 Introduction

A surfactant or surface-active agents are the compounds that lower the surface tension between the two liquids or between a liquid and a solid. Surfactants may act as detergents, wetting agents, emulsifiers, foaming agents and dispersants. Surfactants are normally organic compounds that are amphiphilic, meaning they contain both hydrophobic groups or hydrophilic groups. Therefore a surfactant contains both a water insoluble component and a water soluble component. Surfactant will diffuse in water and adsorb at interfaces.

The interfacial free energy is the minimum amount of work required to create that interface and the interfacial tension between two phases is determined as the interfacial free energy per unit area. The interfacial (or surface) tension is also a measure of the variance in nature of the two phases meeting at the interface (or surface). The greater the dissimilarity in their natures, the greater the interfacial (or surface) tension between them. A surfactant is therefore a substance that changes the amount of work required to expand those interfaces. Surfactants usually act to reduce interfacial free energy.

Surface active agents in the form of emulsifiers have a long history of use and are widely used in many products being used in everyday life. An extensive basic research is required to understand the reason of instability and methods to prevent the breakdown of emulsions. Emulsifiers can function as dough conditioners by improving tolerance to variations in flour quality, better gas retention resulting in lesser yeast requirements, increased uniformity in cell size, a finer grain, more resilient texture and improved slicing. Also, the characteristics of freshly baked bread like soft crumb can be retained longer, if the appropriate emulsifiers are added. Commonly used surface active agents in bread production are propylene glycol mono- and diesters, polyoxyethylene sorbitan monostearate, ethoxylated mono- and diglycerides, succinylated monoglycerides and Diacetyl tartaric acid, esters of monoglycerides. Cookie characteristics like top grain, volume and spread ratio can also be improved. Here surfactants used are sodium stearoyl fumarate, sucrose fatty acid esters, sodium stearoyl lactylate, sorbitan fatty acid esters, polysorbates and ethoxylated monoglycerides. In dairy products like Ice cream surface active agents play some important functions like to improve fat dispersion and control fat agglomeration, facilitation of fat– protein interactions, facilitate air incorporation, give smoother texture due to smaller ice crystals and air cells, increase resistance to shrinkage, improve melt-down and reduce whipping time. In candy products, the elimination of “bloom,’’ i.e., the transition of fat crystals is a key reason for the addition of surface active agents. In mixtures of triglycerides, surfactants like sorbitan esters (Spans) and ethoxylated sorbitan esters (Tweens) can control product viscosity in chocolates and in cream fillings and modify the crystal structure. Surface active agents have been utilized in the production of meat analog products also. In margarine, Emulsifiers fulfil several functions like modification of crystal structure in the vegetable fat, assistance in emulsion formation and antispattering. Here, a mixture of citric acid monoglycerides and monoglycerides or lecithin can be used. The properties and mode of action of these chemical surfactants is discussed in the following sections.

14.1 Introduction

Proteins are the substances formed from nitrogen containing amino acids and are principle structural components of body tissues and muscle. In addition, they are used to produce various hormones, enzymes and hemoglobin in human body. Due to the shift from agricultural to electronics and other fast paying industrial development, most of the countries around the world, ceased to be self-sufficient in their food production in particular protein, which is necessary to satisfy their optimum food demands. The biotechnology development and its usage to agriculture have brought hope to them. The need for food by modernization of agriculture has gained much attention throughout the world. However, the necessity for exploring unconventional and non-agricultural means of food production, especially of proteins rich food, cannot be over-emphasized due to the tremendous growth of human populations in several regions of the world. In addition to this, the importance of protein in food nutrient cannot be put aside because its shortage causes various malnutrition problems and the most lethal malnutrition problem is Protein-Energy-Malnutrition (PEM). The United Nations Food and Agriculture Organization estimates that nearly 870 million people of the 7.1 billion people in the world, or one in eight, were suffering from chronic undernourishment in 2010-2012. There are 925 million people undernourished in developed countries (FAO October, 2010). This situation has created a demand for the formulation of innovative and alternative proteinaceous food sources having high nutritional value. These sources have to be non-competitive with food for human consumption, economically feasible and locally available. This demands a search for new protein sources, with high nutritional value, economically feasible and locally available. Use of microbes as a food source is one of the biotechnological innovations that will certainly increase the availability of affordable protein in the world to solve the global food and feed problems.

In recent decades there has been an increased interest in the industrial production of microbiological protein for use in both human and animal nutrition. The main reason behind it is that there has been the shortage of low cost protein sources in view of the increasing human population and living standards, resulting in famine in some parts of the world and increased demand for animal protein in others.

15.1 Introduction

Color of food is the most sensitive part of any commodity as it is the one of the organoleptic characteristic to be noticed and one of the main ways of visually assessing a food before it is consumed. The people associate certain colors with certain flavors and the color of food can influence the perceived flavor in anything from confectionary to beverages. For this reason, food manufacturers add dyes to their products. Sometimes the aim is to simulate a color that is perceived by the consumer as natural, such as adding red coloring to glace cherries, but sometimes it is for effect, like the green ketchup that was launched by Heinz in 2000. If the flavor of a food product is inconsistent with the color, the flavor can often be perceived incorrectly, for example an orange flavored drink colored green could be perceived to taste of lime. In addition, the color of a food substance is important indicator of its freshness. While all of us are aware that food with bright or unnatural colors likely contains food coloring but only few people know that natural foods such as oranges and salmon are sometimes also dyed to mask natural variations in color. The color variation in foods throughout the seasons and the effects of processing and storage often make color addition commercially advantageous to maintain the color expected or preferred by the consumer. Some of the primary reasons include:

16.1 Introduction

Food safety is most important issue in today's global environment. To safeguard food supply is a very difficult and challenging responsibility, as a consequence of which the world's largest food companies, retailers, and manufacturers have placed very high food safety standards. Although the safety of food has improved exponentially but progress is uneven and food borne outbreaks due to microbial contamination, pesticides, antibiotics chemicals and toxins are common in many countries. International trade statistics (2007) by World Trade Organization (WTO) reported that Europe has accounted for 46% of world exports of agricultural products, where food represents 80% of agricultural exports. The trading of contaminated food among countries increases the risk for outbreaks and consequently, health risks due to microbial pathogens in food are of major concern to all governments.

Biosensors are an important option in the agricultural and food sectors to control production processes and ensure food quality and safety by dependable, fast and cost effective methods. Biosensors have plenty of advantages over conventional analytical tools since they offer advantages in size, cost, inherent specificity, selectivity, rapid response, accuracy and sensitivity. Food microbiologists are always in search of rapid and reliable automated systems for the detection of biological activity. Biosensors provide sensitive, miniaturized systems that can be used to detect unwanted microbial activity or the presence of a biologically active compound, such as glucose or a pesticide. Immunodiagnostics and enzyme biosensors are two of the leading technologies that have had the greatest impact on the food industry. The use of these two systems has reduced the time for detection of pathogens such as Salmonella to 24 hour and has provided detection of biological compounds such as cholesterol or chymotrypsin. The another useful application for biosensors, is detection of genetically modified organisms (GMO), since several countries have laws regulating the commercialization of GMO products and their derivatives. Biosensors are also useful in the implementation of hazard analysis and critical control points (HACCP) plans by verifying process developments and correcting errors in due time. There is joint application of Biosensor technologies and nanotechnologies in many food and agricultural applications such as the development of nano-scale tools for biosafety, nanoscale compounds for food packaging, and nano-sensors for pathogen detection in animals and plants. These are helpful tools in the detection and control of potential food contaminants by the agricultural and food industries.

Due to inadequate intakes of vitamins and minerals, half of the world's population suffers from micronutrient malnutrition. An adequate amount of wholesome as well as diverse foods are required for the proper growth and development. In addition to calories requirements, these foods should provide various nutrients. In India, ~70% of children do not get the required calories either due to lack of enough food or diverse food. This indicates that these children are also incapable of fulfilling their protein, minerals and vitamins requirements. Diets that lack diversity can be deficient in certain nutrients. Due to the micronutrient composition of the soil of a region, or because of the intrinsic insufficiency of the normal diet the staple foods of some region can lack particular nutrients. The individual plant foods are often deficient in certain nutrient components due to the varying level and composition of food nutrients in different food crops. Some crops are rich in one component but low in other. For example; legumes are usually high in protein, but deficient in essential amino acids like methionine whereas, wheat and rice are rich in carbohydrates but contain little essential amino acid such as lysine, iron, and lack provitamin A. Relying on a single food crop as major staple source of nutrients thus will not attain a nutritionally complete diet and result in malnutrition and deficiency diseases, which often occur in populations of developing countries, mainly due to poverty. Globally, over one billion people are undernourished and food security is a major issue with the world's population forecast reaching to nine billion by 2050.

18.1 Introduction

The Packaging Institute International describes packaging as the enclosure of items, packages or products in a wrapped pouch, box, bag, cup, can, tray, tube, bottle or other container for protection, preservation, containment, communication, performance and utility. To an engineer or a scientist, it is technical matter as it is a system designed for efficient delivery of safe food products with high quality, via each and every stage of distribution chain, from production of raw material to food manufacture, packaging, retail, wholesale, consumer, disposal and finally recycling or of resource resurgence. The extent of food packaging is literally broad as it encompasses technological activities such as graphic and machinery design, package manufacture and development, shelf life testing, distribution and marketing. Food packaging science is a discipline which applies principles from four major areas of science (materials science, food science, information science and socioeconomics) to understand the properties of packaging materials, packaging requirements of foods and the packaging system. Both material science and food science have been two major contributors for food packaging development. Material science is important to understand the mechanical strength, barrier properties, appearance and physical and chemical properties of paper, glass, metal, polymer and composite. Food science is important to understand the deterioration kinetics of foods (such as microbial growth, lipid oxidation, moisture loss or gain) governs the food shelf life. Food packaging technology is a science based solutions to address specific food packaging needs; examples are tamper evident packaging, microwavable packaging, modified atmospheric packaging, and controlled atmospheric packaging which are aimed at enhancing safety, quality and convenience for the consumer.

19.1 Introduction

Food safety is one of the important factor for food industry, regulatory agencies and consumers. Nowadays consumers are demanding food which is safe and of high quality in terms of nutrition due to a healthier life style. Food safety refers to all those hazards, that make food injurious to the health of the consumer and it is not negotiable. Food may be contaminated physically, chemically or microbiologically, mainly microbial contamination is of high concern in the food industries. Various pathogenic and spoilage causing microorganisms, viruses, insects can deteriorate the food products and cause food borne illnesses. Therefore, there is a need to eliminate these undesirable microorganisms from the food industries to ensure food safety to the consumer. Various methods are available to eliminate these undesirable microorganisms such as thermal technologies like pasteurization, dehydration, retort processing, freezing etc. and non thermal technologies like microwave heating, Pulsed Electric Field (PEF), High Pressure Processing (HPP), Pulsed Light Technology, Ohmic Heating, Ultra sonics, Pulsed X-Rays. But these technologies have certain disadvantages like thermal technologies lowers the nutritional value and leads to unwanted changes in the foods' sensory attributes of the food products whereas non thermal technologies retain better nutritional and sensory quality of food than thermal technologies but they are cost effective, required specialised equipments and trained personnel. Cold plasma technology (CPT) is a non-thermal green technology used now-a-days for variety of application in various industries especially in food industry. It is proposed to be an alternative method for eliminating microorganism from the fresh produce. This technology does not require extreme process conditions and can be used as a good alternative source for food preservation without affecting its nutritional and sensory attributes. Plasma is an ionized gas, consisting of active species like positively and negatively charged ions, electrons, free radicals, and gas atoms, metastable and quanta of electromagnetic radiation (photons). When the energy source is turned off, active species used to disappear immediately, therefore cold plasma technology is environmental friendly and fulfilling all ecological standards. Based on the properties of plasma, it can be applied in various fields like electronics, life sciences, textile, packaging and food industries. In food industries, it is showing promising application by retaining the nutritional, functional, and sensory characteristics thus ensuring the fresh appearance of the food product and satisfying the consumer need.

Abstract

Drying is a widely used method of food preservation. It leads to some structural changes in the dried material resulting in poor quality and rehydration. Freeze drying, though a costly process, reduces water activity without exposing the food material to high temperatures, eventually retains the original quality to a great deal. Moisture in the foods is frozen to ice which is sublimated under low pressure. Low pressure helps to vaporise the ice without transforming it to liquid, hence leaving the food structure porous in nature. The food is claimed to preserve the nutritional, sensory and re-constitutional qualities.

1.1 INTRODUCTION

Most food materials are composed of a very high percentage of water, which can be as high as 95%, and this makes them susceptible to microbial activity. Microbial activity spoils the products, leaving them useless for human consumption. It not only changes their taste and color but it may also develop toxins, thus making them unsafe. There are various methods for preserving food but in order to make them shelf stable, removing water from foods helps keep them from spoiling for a longer period of time.

Abstract

Drying is one of the most important industrial operations for preservation of food material. Due to the major limitations posed by convective drying methods, there is always a need for novel drying techniques which are technically, economically and environmentally sustainable. Based on the principle of moisture diffusion due to vapor pressure gradient, atmospheric freeze drying (AFD) offers a promising alternative to conventional drying systems. A cold gas with low water vapor pressure is used as drying medium to sublimate moisture directly from the frozen material at atmospheric pressure conditions. As a result the product gets dried at much lower temperature unlike convective drying. Thus, products dried with AFD retain better nutrition, texture and color and the process is also considerably cost effective. Major limitation of the AFD process is longer drying time, which can however be accelerated by using heat pump drying or new ultrasound technology. This chapter focuses on mechanism, benefits, limitations and comparative study of AFD with other drying methods such as hot air drying and vacuum freeze drying. It provides an insight regarding effect of AFD on properties of food material based on various studies reported in literature.

Abstract

Multiflash drying (MFD) process is based on the application of multiple cycles of heatingvacuum pulse to a solid food. Heat can be provided by convection (from hot air), conduction (by contact with a hot surface), microwaves, or by a combination of these methods. Due to the moderate temperatures applied to the drying food, and the sudden decompression step (vacuum pulse), MFD processes allow obtaining crispyanddried foods with very good nutritional and sensory properties. Vacuum pulses cause food texturization, which depends on the pressure drop rate during decompression. In fact, the dried products are similar to freezedried foods, but with more open structures, which result in higher crispness. The dehydration can be performed in relatively short processing times, when compared with traditional drying processes (e.g. solar drying, airdrying, vacuum drying and freezedrying). The short process time indicates clearly that this class of drying process presents a huge potential to the production of driedandcrisp foods at industrial scale.

Abstract

Airflow drying persists as the main dehydration operation. Indeed, the high expense of freeze-drying in term of equipment cost and energy consumption considerably restricts its use and confines its applications to high added value products (pharmaceutical products, cosmetics, etc.). However, airflow drying undergoes fundamental problems such as low operation performance, poor product quality and short reliability of the equipment. The time of drying is long; particularly at the end of the operation, which implies crucial energy consumption. The poor quality of the end product is related to thermal degradation and in particular to the compactness of texture as a result of the phenomena of shrinkage and case hardening. Another main problem common to all drying operations, including freeze-drying, is the safety of the end products. Swell-drying is defined as an operation that combines optimized hot air drying with instant controlled pressure controlled texturing. The improvement of texture, the preservation of sensory and nutritional quality, the possibility of manufacturing expanded granule powders and the reduction of drying time and energy consumption allow considering swell-drying as the most relevant drying process.

Abstract

This chapter presents the principle of fluidisation and its use in drying of food materials. Being a convective drying process, capacity and kinetics are limited by process conditions and material properties. The influences are discussed as well as presenting the main equations that describe drying in fluidised beds. The main focus lies on hot gas drying, additionally superheated steam drying as well as atmospheric fluidised bed freeze drying and microwave-assisted fluidised bed drying are presented and discussed.

Abstract

Increasing global demand for ‘fresh-like’ processed food products has forced food industries to investigate into various minimal processing techniques. Food processing in general has been associated with thermal processing, alone or in various combination with chemical and mechanical preservation and processing methods. However, thermal processing methods are energy intensive in nature and tend to reduce product quality and freshness at the cost of shelf-life gain. Advance technique such as microwave, radio-frequency and freeze drying do maintain the product quality but their implementation at industrial scale involves high operational and maintenance cost. An ideal processing method therefore would be one that can process food products without losing its quality, is energy efficient and is easily scalable. In this chapter, we discuss about ‘Electrohydrodynamic (EHD) Drying’, which is can be classified as a minimal processing technique. The heat and mass transfer principles involved in EHD drying have been extensively discussed and so has been the key consideration for designing an EHD drying system.

Abstract

Pulse combustors provide an advantageous superposition of unsteady gas flow and high intensity sound waves. Such a combination does not only accelerate drying rates because of increased heat and mass transfer but also allows processing of liquids, pastes and agglomerated solids in a dispersed state due to aerodynamic impact from the high intensity sound wave. Over last decades, applications of pulse combustion in drying have been exploited continuously and different pulse combustion dryers have been designed and fabricated. In pilot tests and technical reports on these dryers, short drying time, high energy efficiency and product quality are generally reported, which cause that pulse combustion drying is regarded as a technology of the future in convective drying.

This chapter attempt to introduce basic knowledge and state-of the art about this emerging technology and summarizes some recent studies in pulse combustion drying and equipment design. Following a concise description of pulse combustion and pulse combustor, the basic types of pulse-combustion dryers are presented, including spray dryers, fluidized bed dryers, impinging dryers, and dryers of special design. The existing commercial applications and pilot test projects are described and potential applications are identified.

Abstract

Foam Mat Drying (FMD) is an economical alternative to drum, spray and freeze-drying for the production of food powders. The raw material is converted into stable foam by adding foaming agent through beating or whipping in presence or not of foam stabilizers, and dehydrated by different classical airflow and thermal means. A high-quality food powder attributes can be obtained by the proper selection of foaming method, foaming agents, foam stabilizers, time taken for foaming, suitable drying method and temperature. FMD can be used for large production of food powders because of its suitability for all types of food materials, rapid drying at lower temperature, retention of nutritive value and bioactive compounds, good reconstitution characteristics and flowability and cost-effective for producing powders.

In this chapter, basics of foam and its structure, mechanisms of foaming, types of foaming agents and stabilizers for the production of stable foam have been discussed. The influence of foaming agents, foaming properties, thickness of foam and drying temperature on the drying characteristics of mat are also studied. This chapter analyzes the application of foam drying process for different food materials, the microstructure and whole quality attributes of obtained powder, and the energy consumption and costs of FMD as well.

Abstract

Application of ultrasound is one of the most promising uses of novel technologies in food processing. Use of ultrasound at various stages of drying has resulted in significant decrease in drying time and improvement in quality characteristics of dried products. The chapter discusses the principle behind use of ultrasound, general application in food industry with detailed description of various drying processes and equipments assisted by ultrasound.

Abstract

Cocoa and coffee are highly sought after commodity crops in the market owing to the distinct flavor and aroma characteristics. Cocoa beans are mostly used in the manufacturing of chocolates and various types of confectioneries while coffee is mainly consumed in the form of beverages. Both cocoa and coffee need to be dried and roasted in order to produce the flavor precursors which further develop into the desired flavor and aroma in the finished products. This chapter aims to provide an overview of cocoa and coffee processing with particular emphasis on drying and roasting aspects and its impact on product quality.

Abstract

Mushrooms are the fruiting bodies of fungi, a group of organism that is different from fruits and vegetables. They are a rich source of good quality protein having more essential amino acids and vitamins with low calories. There are about six commonly known edible mushrooms throughout the world with button mushroom (Agaricus bisporous) being the most familiar and commercially important variety. Mushroom is a highly perishable product with a shelf life limiting to a few days. Soon after harvest, it starts to undergo physiological disorders like shriveling, wilting, liquefaction, browning, textural as well as weight losses and flavour changes. The main responsible factors for the quality deterioration after harvest are respiration rate, browning, bacterial spoilage of mushrooms, temperature and relative humidity. Because of its limited shelf life under ambient conditions of temperature and humidity, the preservation of mushrooms is a matter of concern. Various techniques have been involved in the extension of shelf life of mushrooms including chemical treatments, cooling, modified and controlled atmospheric storage, radiation, drying etc. Drying is one of the most accepted and effective methods for the long term storage of mushrooms. Mushrooms preserved by drying have a pleasant flavour and are used as an important ingredient in several food formulations including salads, instant soups, meats and rice dishes. Various drying processes like sun drying, hot air drying, freeze drying, vacuum drying etc. can be used for the long term storage of mushrooms. As mushrooms are sensitive to temperature, determining the right drying method is the key for the successful and effective operation of the system. The different operating conditions involved in various methods of drying affect product quality considerably. The effect of drying methods on the process and the quality of the dried mushroom is explained in detail in this chapter.

Abstract

Vitamin C is one of the most important phytochemicals and can be found in almost all fruits and vegetables. Since it covers almost all eventualities, being water solute and prone to leaching from cells, thermally labile (one of the most labile vitamins), pH-, metal ion-, light-sensitive, as well as readily oxidizable by ascorbic acid oxidase, vitamin C is selected as the most frequently measured nutrient to evaluate the nutrients loss during thermal processing. It is generally accepted that if vitamin C is well preserved, the other nutrients are also well retained. Higher retention of vitamin C in processed products is highly desired. Herein this chapter reviews the degradation mechanism and kinetics of vitamin C of fruits and vegetables during thermal processing, such as blanching, drying, cooking and frying. It starts with an overview of the functions of vitamin C in human’s health. Then the current status for understanding of the degradation kinetics of vitamin C during thermal processing was outlined, followed by the discussion of its degradation mechanism. At last, potential strategies or alternatives to keep vitamin C are identified and discussed.

Abstract

Design, operation and optimization of dryers demands the calculation of energy consumption, in most cases in the form of thermal energy, equipment sizing, temperature and moisture distribution of solids as well as temperature and humidity distribution of drying air. Energy calculations are very important as drying is a widespread process in a variety of industries and is highly energy demanding. In the energy analysis of the process the first step is the estimation of the minimum energy requirement followed by the estimation of energy rejection through solids stream and especially through drying air. Increase of thermal efficiency is always willing and the two most common ways for its achievement is the application of heat exchange between cold feeding air and relatively hot rejecting drying air and hot air recirculation. The later is also employed for the adjustment of air temperature and humidity gradient through the dryer. The combination of a heat pump with the dryer decreases considerably the thermal energy consumption but demands electricity and the method can be beneficial in cases of excess electricity production in the process plant, e.g. by cogeneration. Utilization of exhaust hot air from the main drying unit for the predrying of wet solids can also decrease the total energy requirement. The application of humidity adsorption from the feed air increases its drying potential, but regeneration of adsorbent is required. Grand composite curve of the process plant can reveal potential heat sources from different unit operations.

Abstract

The increasing interest in polyphenolic compounds in industries has led to the exploration and exploitation of rich bio-compounds from natural sources, essentially plants and their by-products. Solid-liquid extraction is mostly applied for the recovery of these valuable compounds from plants. Since the extraction process is often difficult in a fresh matrix, a drying operation is needed to reduce the moisture content, and preserve the targeted valuable compounds. An uncontrolled drying operation will lead to product damage and hence, loss in quality, reason why, several studies have been carried out to understand and control the drying process. The present chapter aims to present some data on drying for bioactive compound recovery from plants and their by-products, mainly polyphenolic compounds. Our main interest is the mathematical tools used to model the drying process.

1.1. Introduction

The significance of milk as the most wholesome single food available in nature has never been debated. It is as ancient as mankind itself, as it is the substance created to feed the mammalian infant. All species of mammals, from the lowly rat to the mighty whale, produce milk for this purpose. Several centuries ago, perhaps as early as 6000-8000 BC, ancient man learned to domesticate species of animals for obtaining their milk for consumption. These included cows, buffalos, sheep, goats and camels, all of which are still used in various parts of the world for the production of milk for human use (Fig. 1.1 & 1.2).

Milk is the secretion of the mammary glands of animals. For human consumption, milk is that liquid obtained from the cow or the buffalo during the period following at least 72 hours after calving or until the milk is colostrums-free. It is a complex biological fluid consisting of seven main components: water, fat, protein, sugar (lactose), minerals, vitamins and enzymes. Milk is a white opaque fluid in which fat is present as an emulsion, protein and some mineral matters in colloidal suspension and lactose together with some minerals and soluble proteins in true solution. The opacity of milk is due to its content of suspended particles of fat, proteins and certain minerals. The colour varies from white to yellow depending on the carotene content of the fat. Skimmed milk is more transparent with a slightly bluish tinge. Milk of a good flavour has a pleasant, slightly sweet taste, and no odour. It is an excellent source of calcium, phosphorous and riboflavin. Vitamin A and D are currently added to whole milk, partly skimmed and skimmed milk.

Milk production in India is a subsidiary activity of agriculture in contrast to the organized dairy sector in the western countries. Farmers and landless labour maintain one to five milch animals. As a result, small quantities of milk are produced in a scattered manner. Due to this reason, milk procurement models from western countries, such as bulk cooling and bulk transportation are not applicable under Indian conditions. Collection of small amounts of milk is scattered over long distances and, therefore, poses a formidable challenge in maintaining the quality attributes and keeping costs down.

3.1. Rural Milk Collection

A systematic approach to rural milk collection suitable for the tropical climate and techno-economic conditions prevailing in India has been developed, based on the indigenous experience gained over the past few decades. In the first phase, extensive surveys are undertaken in the milkshed areas, where the milk plant is to be established. The second phase involves ‘route planning’ taking into account, availability of quantities of milk, access to roads for plying vehicles and distance from the site of dairy plant. Then zones are identified, representing equal costs of collection and transportation. In the third phase, planning is done for locating the primary collection centres as well as chilling centres, where, milk can be cooled to 4ºC before transporting to the milk plant. Milk may be collected from individual producers either by the contractor or by forming village level cooperative societies.