eChapters

INTRODUCTION

Food is the basic need of human beings. It gets spoiled primarily due to microorganisms and enzymes. Energy is required for microbial growth and enzymatic reactions. At low temperature, the rate of biochemical reactions is slow resulting in prolonged storage life of food. It must have been observed long back that food could be stored for longer period without deterioration during the winter months. Since then this principle is being used to extend the storage life of foods. A sea change can be observed in development of low temperature preservation technology. It has travelled a long journey to reach this stage; however, a major break through took place in twentieth century. Low temperature technology is of two types; refrigeration and freezing. In refrigeration storage, water is in liquid phase and temperature is maintained above freezing point. In freezing technology, the food is stored below freezing point and water gets converted into ice. The former is short term preservation due to slow growth of microbes and lower enzymatic activity while the later is long time preservation due to inactivation of enzymes during blanching and inhibition of microbial activity due to unavailability of free water and much lower temperature. Low temperature preservation is widely accepted and is of commercially important in food supply chain.

INTRODUCTION

Food being the basic need of all humans and other living organisms, the production and processing of food is a continuous activity with several new procedures and technologies adoption; thereby the quality of food needs an emphasis which also protects the consumers by providing safe and suitable food. The contaminated foods, food borne illness outbreaks though at times referred to poor consumer handling, commitment for provision of safe food to consumers is also a Governments concern. In the recent years, food safety measures through Food Safety programmes and increase in awareness are being followed. The food production in our country is the most promising sector which is the cause for white revolution and green revolution. India ranks first in the world in production of cereals and milk and second largest producers of fruits and vegetables. India stands second in inland fish production. It is second largest exporter of rice and so on. Food processing sector has a great potential which covers a wide spectrum of products encompassing agriculture, horticulture, plantation, animal husbandry and fisheries. But the growth of food processing industries in our country is rather slow. However, to encourage, the government is providing lot of incentives in the recent years.

INTRODUCTION

A food may have three attributes (1) Provide energy and nutrition (2) Give pleasure, i.e., enjoyable aroma, colour, and taste and (3) Health benefits. Functional food has physiological benefits and reduces the risk of chronic disease beyond basic nutrition.

Functional foods, also reported as ‘nutraceuticals’, ‘medical foods’ or ‘designer foods’ in the literature, were first described by Roberfroid (1999) as ‘Food similar in appearance to conventional food that is intended to be consumed as part of a normal diet, but has been modified to subserve physiological roles beyond the provision of simple nutrient requirements’. Examples are iodized salts, vitamin A and vitamin D fortified milk and yoghurt, folic acid enriched bread, soy products, wheat bran and oats products.

INTRODUCTION

Food processing as a technological regime is undergoing a revolutionary change in terms of conception, product and process design and energetics. The conventional approach of a food processor is to develop products with a long shelf-life in user friendly packaging systems. Food processors are usually bothered about sensory attributes and microbiological profiles without much emphasis on the fate of heat labile nutritional and nutraceutical components. The changing consumer perception is slowly but steadily leading towards emergence of novel technologies without depending upon conventional thermal processing. A few years before, non-thermal techniques have emerged for food processing and preservation, but these techniques were restricted to framing of fundamentals with regard to the inactivation of vegetative and reproductive bodies of microbes and the deteriorative enzymes.

INTRODUCTION

Packaging is an important aspect in modern life and in fact the word ‘packaging’ developed a literal value indicating presentation of an issue or material in a comprehensive and compact manner. Food packaging has become a revolutionary trend and plays a dominant role in the promotion of marketing of various fresh and processed food products. The reason could be a number of aspects inclusive of protective, legal and aesthetic elements. The industrial revolution in the late 18th century caused major impact on manufacturing process. Without appropriate packaging no food is acceptable and even in the common household food packaging is being practiced in its own way to render food safety and convenience for various culinary operations. Therefore, food packaging needs to be considered as an essential element of food processing and marketing and it is one of the key areas in food technology making rapid strides in research and development.

INTRODUCTION

For thousands of years fermentation processes were largely natural phenomena exclusively identified with food preservation throughout the world. Fermentations can play a significant role in meeting the ever growing food requirements of world population providing benefits in the form of innovative food products with improved nutritional value and food quality along side better safety. Fermentations can be used to address a large variety of food related problems and in the development of processes to meet the demand for food. In the wake of estimations made by international organizations that global food demand and population would increase by two-fold by the year 2050, much emphasis has been placed over the ways and means to increase food production and preservation.

INTRODUCTION

Fruits and vegetables are historically important constituents of human diet and the growing awareness of consumers about the beneficial effects of these commodities could result in enhancement of global trade involving fresh and processed fruits and vegetables. Emergence of postharvest handling of fresh fruits and vegetables facilitated global trade of these commodities. The developed countries started realizing the export potential of these commodities by development of adequate value addition in terms of pretreatments, shelf life extension and packaging besides grading and other associated packing house operations. However, the trade concerning fresh fruits and vegetables could never come out completely from problems related to pesticidal residues, spoilage, bulkiness of the commodities involving transportation of inedible portions and excessive packaging costs arising out of bulkiness. The other problems associated with fresh produce include mandatory requirement of specific storage temperatures with refrigeration as the primary means of regulation of metabolic rate.

INTRODUCTION

Now-a-days, food products with maximum health benefits and ease in preparation are gaining popularity globally, the reason being changing awareness level about food and dietary habits. Since ages, a number of methods like cooking, baking, drying etc. have been used to thermally process the food materials. Electrical sources of electromagnetic waves are very promising because of advances in nuclear and hydroelectric power as well as ongoing cost rises in traditional forms of fuel, of which there are only restricted reserves. The heating aids include use of wooden fuel, gaseous fuel, electric energy etc.; but the new era of electromagnetic rays had introduced new horizons of food processing by utilizing it in various unit operations (Sakai and Hanzawa 1994). Though, these radiations are gaining popularity in various walks of life; their destructive impact is much dominating. Hence, one should handle these radiations with utmost care as well as comprehensive understanding of the know-how and control over the process.

INTRODUCTION

Radiation processing is a promising technology for improving hygiene and increasing storage and distribution life of food products. Ionizing radiation can be used to bring about beneficial changes in food stuffs (Urbain 1995) and it has been suggested as a method of ensuring safety of meat products (Patterson and Stevenson 1995). Ionizing radiation interacts with an irradiated material by transferring energy to electrons and ionizing molecules by creating positive and negativities (Moseley 1989).

INTRODUCTION

Preservation of food by drying or chemical means as by alcohol or acid fermentation and that by the use of ice is long recorded in history. With the advancement of science and the knowledge governing various unit operations in food processing, these food preservation techniques employing thermal, radiation, or low temperature or a combination of these have only got further refined as regards their viability and commercial applications. Process foods of different genre and cuisine, which include frozen foods too, are increasingly becoming popular the world over for reasons of quality, safety and year round supply of nutritious foods to cater to different niche segments of human society. Increasing health consciousness is buoying those processed foods which are preserved and stabilized using non-thermal technologies as these ensure retention of food nutrients to a better definition. Interest in frozen food also stems from need to deliver safe and nutritious foods with extended shelf-lives.

INTRODUCTION

Drying or dehydration is defined as the removal of moisture from its initial level to a level which renders food materials safe for subsequent storage. It is a simultaneous heat and mass transfer operation in which heat is supplied externally to evaporate moisture and air is forced through the bed to carry away the moisture. Drying is the oldest technique to preserve food materials. Advantages of drying include reduction in water activity, enhancement of shelf life, maintenance of flavor and nutritive value, and reduction in packaging and transportation costs. When the water activity of the dried product is reduced to below 0.6, most microorganisms do not grow and the rates of other deteriorative reactions are substantially reduced.

INTRODUCTION

A mixture is a combination of two or more elements or compounds in any proportion so that the components do not lose their identity. Most materials in our world are mixtures and very few materials are pure substances. Foods are complex mixtures of compounds and the extraction or separation of food components is fundamental for the preparation of ingredients to be used in other processes. Separations usually aim to remove specific components in order to increase the added value of the products, which may be the extracted component, the residue or both. Purposes include cleaning, sorting and grading operations, extraction and purification of fractions such as sugar solutions or vegetable oils, recovery of valuable components such as enzymes or flavour compounds, or removal of undesirable components such as microorganisms, agricultural residues or radionuclides. For example, cooking oils from oilseeds or gelatin from connective tissue; or for retrieval of high value compounds, such as enzymes (e.g. papain from papaya for meat tenderisation or rennet from calf stomachs for cheese making). Other types of separation methods are used to sort foods by separating them into classes based on size, colour or shape and to clean them by separating contaminating materials.

INTRODUCTION

The concept of hurdle technology has been developed as a new way to realize safe, stable, nutritious and economical foods. It employs combination of different preservation techniques to achieve a multi-target, mild but reliable preservation of foods. The application of hurdle technology in food preservation is increasing rapidly worldwide. Over the years, insight into the hurdle effect has been broadened and the application of hurdle technology has been extended. A better understanding of the occurrence and interaction of food preservative factors (hurdles) in foods is the basis for improvements in food preservation. If the hurdles for the microbes are known, the microbiological stability and safety of this food might be optimized by changing the intensity or quality of these hurdles. Using the proper combination of hurdles, it is possible to improve not only the microbial stability and safety but also the sensory and nutritive quality as well as the economical aspects of food. The hurdle concept is also referred to as food preservation by combined methods, combined process, combination preservation or combination processing techniques. The hurdle effect is of fundamental importance for the preservation of foods. The illustration of hurdle effect was first introduced by Leistner in 1978. Based on the understanding of hurdle effects, the concept of hurdle technology was derived (Leistner 1985).

INTRODUCTION

By the turn of the century, consumers have been more demanding, sophisticated and discretionary. They want much safer, higher quality, and more convenient to foods. The food processor need to get the best from their existing processing technology in addition to looking for newer ones. New and alternative food processing methods and/or novel combinations of existing methods are continually being investigated by the industry in pursuit of producing better quality foods more economically. Thermal processing is one of the most important food preservation techniques that was first introduced at the beginning of 1800 and has evolved itself in to one of the most scientific mature food processing techniques of recent times. Both science and technology have gone through tremendous transformation in the last two centuries and today it is the most reliable method to assure food safety and stability. Developments in thermal processing and evolution of non-thermal processing technologies like high pressure processing, pulsed electric field, pulsed light etc. have enhanced the utility of thermal processing principles and increased the awareness of possible alternative processing technologies.

INTRODUCTION

Food processing is necessary for the conversion of raw food products in to finished products with desired textural, sensory and nutritional attributes. This is required to be done mainly due to seasonal production and facilitating non-seasonal availability of different commodities. Stages of processing are primary and secondary. In primary processing raw material is converted into food commodities, while in secondary processing commodities are converted into edible products. Processing is mainly done to convert the products into edible forms, to extend shelf life, availability, accessibility and also to provide variety into the form of value added products. Processing of products destroys inhibitors, microorganisms, retards physico-chemical and biochemical deterioration, maintains good sensory properties, preserves and enhances the nutritive value. Unit operations involve phase changes and sometimes chemical reactions also, which are undesirable as they cause inferior quality of the product (Gekas 1992). Different processes like separation, assembly, preservation and packaging are broader classification for unit operations in food processing (Saravacos and Kostaropoulos 2002).

Food Science is one of the ancient sciences and the genesis originates to the very beginning of human civilization. The advent of food science was associated with practice and observation by humans before establishment of scientific concepts. The ancient man knew that roasting or smoking of meat improves the edible quality and digestibility. As a consequence, he started practicing the same much before the reasons for the same could be established. Many of the modern preservation concepts had their origin in prehistoric period itself as humans could use techniques such as dehydration, fermentation and pickling to their advantage to improve the sensory attributes of the products and also to enhance their shelf life. Humans during the Pre-Neolithic period about 2,50,000 years before used fire for cooking meat. During the Paleolithic period humans not only roasted food but also developed grinding, pounding and drying. During the Mesolithic era, humans were desperate for food and got involved in extensive hunting and fishing. During the same time domestication of animals took place and animal husbandry became a reality (Stewart and Amerine 1982). The Neolithic period made qualitative changes in the food habits of humans and they changed from a food gathering and hunting society to one of food production (Heizer and Elsasser 1980).

Z -distribution : It is a probability density function and a normal distribution that has a mean equal to zero and a standard deviation equal to one and that is used in testing hypotheses about means or proportions of samples drawn from populations whose population standard deviations are known.

Zeatin : Zeatin is a cytokinin C₁₀H₁₃N₅O first isolated from the endosperm of Indian corn.

Yabby : It is one of the burrowing Australian crayfishes (Cherax destructor) that are used for food.

Yakitori : A bite-size marinated pieces of beef, seafood, or chicken on skewers is called yakitori.

Yam : It is edible starchy tuberous root of plants (genus Dioscorea of the family Dioscoreaceae) used as a staple food in tropical areas.

Xanthan / Xanthan gum : It is a polysaccharide that is produced by fermentation of carbohydrates by a gram-negative bacterium (Xanthomonas campestris) and is a thickening and suspending agent used in pharmaceuticals and prepared foods. It is also called xanthan. Xanthan is a stabilizer produced by Xanthomonas compestris. Xanthan is not hydrolysed or degraded by humans.

Wafer : A thin crisp cake, candy, cracker or chips is known as wafer.
 
Waffle : A crisp cake of batter baked in a waffle iron is called waffle

Warner-Bartzler Shear : It is one of the oldest but commonly used devices used to measure the tenderness of meat. It is used to test the quality in the cooked meat.

Vacreation : The pasteurization of the milk or cream under reduced pressure by direct steam is called vacreation.

Vacuum : The state of negative pressure. It is equal to atmospheric pressure minus absolute pressure.

Vacuum cooling : A technique of cooling vegetable (leafy vegetables, asparagus Brussels sprouts) having a high surface to volume ratio rapidly and uniformly by boiling off some of their water at 10C and at low pressure (5 mm of Hg) into a sealed container. The produce is cooled by evaporation of water from the tissue surface and is more rapid than hydro cooling.

U value : U value is a measure of the heat transmission through a building part (wall or window) or through a given thickness of a material (insulation). U values with lower numbers indicate better insulating properties.
 
Ubiquinone : It is one of the groups of lipid soluble quinones that are found especially in mitochondria and have a long isoprenoid side chain, and function in oxidative phosphorylation as electron carrying coenzymes in electron transport.

T A Spoilage : The spoilage of low and medium acid canned foods by Clostridium thermosacharolyticum which breaks sugars and form acid and gas (moisture of H₂ and CO₂) resulted in swelling and in severe cases even bursting of can may occur and the spoiled food usually has a sour odour.

Saccharides : A monosaccharide sugar or combination of sugars is called saccharides.

Saccharification : The process of breaking a complex carbohydrate (starch or cellulose) into its monosaccharide components is called saccharification.

Saccharimeter : A device (polarimeter) used for measuring the amount of sugar in a solution is called saccharimeter. It is also known as saccharometer. It is a hydrometer with a special scale.

R - enamel can : The acid resistant, gold coloured enamel treated can are called R enamel cans. It is used for canning of acidic food which have soluble colouring pigments.
R factor : It is a group of genes present in some bacteria that provide a basis for resistance to antibiotics and can be transferred from cell to cell by conjugation.
R value : R value is a measure of resistance to the flow of heat through a given thickness of a material (insulation) with higher numbers indicating better insulating properties.

Q fever : Q fever is caused by a rickettsia like organism (RLO), a parasitic organism falling between bacteria and viruses. It is a disease that is characterized by high fever, chills, muscular pains, headache, and sometimes pneumonia, that is caused by a rickettsia (Coxiella burnetii) of which domestic animals serve as reservoirs, and that is transmitted to humans especially by inhalation of infective airborne bacteria as in contaminated dust.

Pack inspection : It is similar to continuous inspection except that here inspector(s) may make in-process checks during different processing operations under contract but not required to be present all the times in the plant during operation.

Package : The package means a pre packed box, tin, barrel, pouch or can etc in which food article is packed.

Package store : A store that sells bottled or canned alcoholic beverages for consumption off the premises.

Obesity : A condition characterized by the excessive accumulation and storage of fat in the body. It is a physiological disorder having high body mass index (BMI), which can be expressed as a mathematical formula in which a person’s body weight in kilogram is divided by the square of his or her height in meters.

Naïve panel : It refers to the sensory evaluation panel that has not been trained specifically regarding the product evaluation being undertaken in the study.
Nano technology : It is the art of manipulating materials on an atomic or molecular scale to build microscopic devices. The word “nano’ meaning ‘dwarf” in Greek language refers to dimension / magnitude of the material / particle in the order of 10^-9. Nanotechnology is nothing but manipulating of particles into very small particles called nano-particles. These particles have dimensions in the scale of nano-meter and used to design / build materials and devices. Nanotechnology has been provisionally defined as relating to materials, systems and processes which operate at a scale of 100 nanometers (nm) or less. Nanotechnology is an anticipated manufacturing technology that allows through and inexpensive control of the structure of matter by working with atom. It will allow many things to be manufactured at low cost and with no pollution. The concept of nanotechnology was first given by Nobel Laureate physicist Richard P. Feynman in Southern California in 1959. Nanotechnology is sometimes termed as Molecular Manufacturing based nanotechnology “MNT”.

MAC : It stands for modified atmospheric coating.

Macaroni : Pasta made from semolina and shaped in the form of slender tubes.

Macaroni wheat : It is tetraploid wheat and is preferred for making macaroni, vermicelli etc.

Macaroon : A small cookie composed chiefly of egg whites, sugar, and ground almonds or coconut.

Mace : An aromatic spice consisting of the dried external fibrous covering of a nutmeg.

L - Ascorbic acid : It is a white crystalline compound with a slightly acidic taste. It is readily soluble in water, alcohol, glycerin, propylene glycol and is insoluble in oils, fats, ether, benzene, chloroform.

Lab coat : A loose white coat with deep pockets that is worn in a laboratory or medical office.

K ration : It is a lightweight packaged ration of emergency foods developed for the U.S. armed forces in World War II.
Kairomone : A chemical substance emitted by one species and especially an insect / plant that possess an adaptive benefit (stimulus for oviposition) to another species.
Kaiser rolls : A round crusty roll often used for sandwiches.
Kalamata /calamata : It is brine cured black olive grown in Greece.

Jaboticaba : It is a Brazilian tree (Myrciaria cauliflora) of the myrtle family cultivated in warm regions for its edible purplish fruit.

Jack salmon / walleye : A large vigorous American freshwater food and sport fish (Stizostedion vitreum) that has large opaque eyes and is related to the perches but resembles the true pike sometime also called walleyed pike

Jaggery : Raw brown / unrefined brown sugar in lump made from palm sap.

ICAP : It stands for International Centre for Alcohol Policies.

Ice Bank Cooler : Air forced cooler leads to desiccation of the produce. So use forced air high humidity cooler are known as Ice Bank Cooler. Ice bank Coolers are useful for strawberry.

Ice bank cooling : Storing of fruit and vegetable in storage chamber with positive ventilation and a system countries where ice formation is allowed during night time (as electricity cost of night is less as compared to the day time). Melting of ice occurs during day time and with proper air circulation by means of ventilation process, approximately 0.5-1^ºC temperature with 90% RH in the chamber is maintained.

HACCP : The Hazard Analysis and Critical Control Points (HACCP) is a scientific, rational and systematic approach to identify, assess and control hazards during production, processing, manufacturing and use of food. It ensures safety of the food. HACCP presents a good opportunity for the food industry for upgrading quality and bringing uniformity and consistency in their supplies to international market. or It is a systematic preventive approach to food safety that addresses physical, chemical and biological hazards as a mean of prevention rather than finished product inspection. It involves identification, evaluation and control of hazards which are significant for food safety.

Galactan : It is a polysaccharide in which major monosaccharide subunit is galactose and often found among the pectic substances of cell walls.

Galactoblast : It is also called colostrums. It is female’s first milk after parturition.

Galactometer : It is an instrument used for recording the specific gravity of the milk.

Galactorrhea : A spontaneous flow of milk from the nipple is called galactorrhea.

F- distribution : A probability density function that is used in analysis of variance and is a function of the ratio of two independent random variables each of which has a chi-square distribution and is divided by its number of degrees of freedom.

F₀ value : It is used to express F-value when z =10^ºC/18^ºF and the temperature is 121.1^ºC. It is the number of minutes at a specific temperature (250^ºC) required to destroy or kill a stated number of microorganisms and has specific z-value. It is also called reference value. 

E numbers : Each food additive used in the food industry has been given a specific number code for their identification. These numbers are called as E numbers. These E numbers are used within the European Union. The word prefix “E” stands for Europe. They are commonly used on the food label through out the European Union. These are not used in Australia and New Zealand. The different food additives are given different E numbers depending upon the type of food additive like E100-E199 (food colours), E200-E299 (preservative), E300-E399 (antioxidants), E400-E499 (thickners, stabilizers, emulsifier), E500-E599 (pH regulator, anticaking agent), E600- E699 (flavour enhancers), E700-E799 (antibiotics), E900-E999 (miscellaneous like waxes, synthetic glazes, packaging gases, sweetners, foaming agents), and E1000-E1099 (additional chemicals).

Dahi : It is the product obtained from pasteurized or boiled milk by souring, natural or by harmless lactic acid or other bacterial culture. It is also called Curd.
Daidzein : These are the substance from which daidzein is derived and are isoflavone C₁₅H₁₀O₄ found chiefly in legumes and esp. soybeans.
Dairy : It is a farm building often a single room in which milk is cooled and temporarily stored prior to collection for transportation to the commercial diary. Here the milk is treated and made into cream, butter and cheese. Or

C - enamel can : The sulphur resistant lacquer is golden coloured and the can coated with it are called C-enamel can or sulphure resistant can, used for packing non acid products.

CA storage : Storage of commodities under gaseous atmosphere like gas storage, where the composition of atmosphere is controlled accurately. MA and CA differ only in degree of control and CA is more exact. These storage methods in combination with refrigeration markedly enhance storage life of fruit and vegetables.

B cell : It is one of the lymphocytes that have antigen-binding antibody molecules on the surface, that comprise the antibody-secreting plasma cells when mature, and that in mammals differentiate in the bone marrow. It is also called B lymphocyte.

B.T.U. : It stands for British thermal unit. The heat required to raise the temperature of one pond of the water through 1oF is called BTU.

Baby back ribs : Meaty pork ribs cut from the lower back rib section.

Abattoir : An establishment where animals are butchered is known as abattoir. It is also known as slaughterhouse. 
Abiotic : Abiotic means any factor which is not biological / abiological and especially there is no involvement of the organisms in synthesis of certain compounds.

Abstract

Inspired by the human eye to brain assessment process, computer vision technology has demonstrated its potential for monitoring and controlling of several operations in food industry. Computer vision technology is, therefore, applied extensively in food drying process for monitoring nutritional value and sensorial characteristics because of its promising characteristics such as reliable objectivity and repeatability. In this chapter, after providing a brief explanation of the computer vision technology and its prerequisites and principles, an example is given to elucidate how this technology is used for monitoring the visual attributes of foodstuffs during drying process. Overall, monitoring the visual properties of food products like size, shape, color, and texture in off-line mode are the most popular issues to fascinate researchers’ attention to apply the computer vision technology in food drying. Nevertheless, industrial applications of the computer vision technology for real-time monitoring and control of food drying facilities as final goals of its introduction in food drying industry seem to be limited. For future studies, it is suggested to apply this unique technology along with advanced soft computing methodologies for in-line monitoring and control of food drying process in order to achieve high quality dried products. Finally, outlooks and potential employment of this technology in food drying domain are discussed as well.

Abstract

By loosely inspiring the actions of neurons in the human brain, artificial neural networks (ANNs) are widely accepted as a powerful nonlinear adaptive approach to tackle complex, dynamic, highly nonlinear, and ill-defined problems in an increasing number of fields of food industry.They have been used extensively in food drying to solve problems of nonlinear function approximation, pattern recognition, data description, optimization, simulation, pattern recognition, control, data sorting, clustering, and noise reduction, due to their massively parallel structure and capability to learn from examples. In this chapter, after providing a brief description of ANN technology and its principles as well as the structure of the most commonly employed ANNs in this context, an example is given to explain how the ANN technique is used for modeling and controlling food drying process. Generally, modeling, prediction, and optimization of heat and mass transfer, thermodynamic performance indicators, and quality parameters as well as physico-chemical attributes of dried foods are the most popular subjects to attract researchers’ attention to apply the ANNs in food drying industry.

Abstract

Packaging plays an important role in the food processing Industry. It makes food more convenient as well as gives the food greater safety assurance from microorganisms, biological and chemical changes such that the packed foods can have longer shelf life. In order to meet the huge demand of processed food with longer shelf life, various methods of preservation and packaging are being used in the food processing industry. Drying and dehydration is one of the method which helps preservation of a perishable commodity against deterioration or spoilage.

Abstract

Most dryers operate at low thermal efficiency. The development of models and control systems offers an opportunity to improve dryer operation and efficiency. Dryer control is very important and with deeper understanding of the drying concept, new “smart” dryers can be made more reliable and more cost-effective than classical dryers. This chapter will provide an overview of necessity of control and safety measure in food drying system, and terminology related with drying control system. Different control strategy includes conventional and advanced techniques implemented in drying operation are reviewed  here and simple outline of intelligence control system in drying technology are briefly described in succeeding section. Various hazards in drying process and risk and safety management will also be discussed.

Abstract

Water, the most important component of common foods, is considered to be desirable as well as undesirable in the different food systems. Water-solid interaction in food systems controls various biological, biochemical and biophysical reactions affecting their acceptability. The retention or release of water from solid has been quantified in the terms of sorption isotherm. Sorption isotherm techniques have been used to characterize and identify the type of water-solid interaction in different food products. Sorption isotherm provides various information useful in designing and optimization of drying, storage, packaging, predicting quality and shelf life of the product.

Abstract

Dietary antioxidants can be found naturally in various fruits, vegetables and food products.Typically, antioxidant phytochemicals commonly found in food products are Vitamin C, Vitamin E, carotenoids, polyphenols, melanoidins and indoles. The main characteristic of an antioxidant is its ability to scavenge free radicals and form stable end product which inhibit the chain oxidative mechanisms that lead to degenerative diseases which are harmful to human health. Drying is widely used in food processing to minimize food wastage and to extend food shelf-life. Pretreatment, drying methods and storage conditions are some of the processing parameters affecting the quality of dried products. Selection of processing conditions and storage environment are therefore critical in maximizing the retention of food antioxidants. This chapter aims to compile and summarize studies carried out for antioxidants namely antioxidant contents in dried food products, effect of processing parameters and quantification methods in the analyses of antioxidants.

Abstract
 
Spray drying is used as one of the best alternatives for extracting essential constituents of fruit and vegetables. Spray drying of fruits and vegetable juice/purees, which is an excellent source of bio-functional properties into a solid phase helps to enhance their stability and controlled release in different food matrices. Spray drying along with different carrying agents helps to retain essential active compounds in fruits and vegetables. Spray drying is generally carried in three steps viz. atomization of liquid feed by suitable atomizer; drying of droplets with the help of hot air and motion of droplets. Carrier agents like maltodextrin, wax starch, Gum Arabic and microcrystalline cellulose are added to the feed to increase glass transition temperature. Chapter presents the effects of different operating parameters of spray drying as well as effects of carrier agents on the physicochemical and functional properties of spray dried fruit and vegetables powders.

Abstract

Drying remained at the centre stage since the initiation of the food processing due to its promise to preserve agricultural products economically and add functionality to a food product unlike other thermal as well as non-thermal food processing operations. However, many existing drying techniques have their own limitations like nutrient loss, damage of the organoleptic quality, high cost etc. Therefore, research for better drying technologies is going on. Supercritical drying (SCD) is one such technology which utilizes higher dissolving power of super critical fluids (SCFs) to dry food products. The current chapter illustrates the mechanism of SCD as well as current state-of-art and promise of the drying technology. Also, some modelling approach of SCD has been included in the discussion to facilitate new designs and optimization of SCD for various food products.