eChapters

Abstract

The interest in the utilization of industrial by-products is increasing day by day and is major reason for exploring different meat, poultry and fish industry waste and optimization of extracting conditions of different valuable compounds. Utilization of these by-products in effective manner can be positive for meat industry economy as well as environmental pollution of the country. Besides the potential revenue losses, non-utilized or underutilized by-products accounts for the extra cost for their disposal. Meat producers are converting these by-products into value added edible and inedible form. Among the most prominent current uses of meat, poultry and fish waste are food ingredients, water treatment, cosmetic and personal care products, biogas/biodiesel, biomedical and pharmaceutical application. Several studies have dealt with the production of several value-added products such as gelatin, collagen, enzymes, specific proteins, bioactive peptides, chitin, chitosan, and pigments fro m the meat industries waste. Recently, in the food and pharmaceutical industry, an increasing number of new applications have been found for products generated from meat, poultry and fish industry waste; in different products as foaming agents, emulsifiers, biodegradable film-forming materials, colloid stabilizers, and microencapsulating agents, in line with the growing trend to replace synthetic agents with more natural ones.

Abstract

India ranks in the world’s five largest producers of over 80% of agricultural produce items. Processing of agricultural produce generates substantial amount of crop residues which can have tremendous value to farmers. However, a large portion of the residues is burned on farm primarily to clear the field from straw and stubble; which affects the environment, soil health and crop yield.The conversion of crop residues to eco-friendly and valuable product like biochar is need of the hour. Biochar is an organic amendment which slowly releases C in the soil, and is stable over the years. Various applications of biochar like reduction in greenhouse gases emission, sequestering C in the soil, increasing crop yield, used as combusting fuel and livestock feedmakes it a promising candidate for sustainable agriculture and environment.

Abstract

Food lost during the production chain is referred to as postharvest loss. Reducing postharvest loss can effectively feed starving mouths while conserving resources and decreasing the pressure to produce more. There are five main areas where postharvest loss can be reduced – harvest, storage, transportation, processing, and retail. New approaches and technologies in each of these areas will increase the amount of food available for human consumption. The total loss due to poor post- harvest processing of agricultural products in India when valued in terms of monetary reflects a tremendous loss in the economy. Annual value of harvest and post-harvest losses of major agricultural produces at national level to be of the order of Rs. 92,651 Crore calculated using production data of 2012-13 at 2014 wholesale prices. Deficits in food items or financial loss should not have occurred if postharvest losses were reduced through proper processing and preservation from harvest to consumption. Both the government and private sector need to invest in research so as to improve and modernize post-harvest facilities for attaining more efficient market infrastructure and distribution channels. Research and extension activities have to be closely coordinated particularly in the public sector for the benefit of farmers, traders and consumers.

The dairy processing industry in India deals mainly with the fluid milk and/or short shelf life products, despite India being the largest producer of milk in the world, with an output bordering the 110 million ton mark. This feature offers immense potential in the area of R&D in dairy processing in terms of value addition. The potential gains are many, including higher returns for producers and advantages in terms of health, therapeutic, nutritional and/or gastronomy for the consumers. However, the Indian Dairy Industry can amass possible benefits by being a global contender in trade only when its products are at par with those available in the rest of the world in terms of price and quality. It is evident from the post-WTO scenario that for sustainability, Indian dairy industry will need to maintain wholehearted commitment to quality management right from the farm to the consumer, shedding its inhibitions and resistance to changes.

9.1. WTO Agreements and Food Industry

The General Agreement on Tariffs and Trade (GATT) was formed in 1947 and lasted until 1994, when it was replaced by the World Trade Organization (WTO) in 1995. The WTO is the only global international organization dealing with the rules of trade between nations. It provides a forum for negotiating agreements aimed at reducing obstacles to international trade and ensuring fair deal for all, thus contributing to economic growth and development. Currently, there are 16 agreements to which all WTO members are parties and two agreements to which only some WTO members are parties. WTO currently has 153 members, of which 117 are developing countries or separate customs territories. The Head Quarters of WTO is at Geneva (Switzerland) and the official languages are English, French and Spanish.

India has achieved a commendable position of being the highest milk producing country in the world. Nearly 110 million tons of milk per annum is contributed by small and marginal farmers having 2-3 milch animals which are scattered in lakhs of villages across the length and breath of India. The poor socio-economic conditions are serious constraints in producing raw milk of good quality. The quality of milk is further deteriorated during subsequent handling and transportation. Milk being a product of biological origin, is extremely vulnerable to attack by microbes. It is also a good vehicle for additives and adulterants without any apparent changes in its appearance. Thus, milk is susceptible to several post-secretion changes, some natural and some man-made.

Indian dairy industry faces a mammoth task to meet the world quality standards, particularly in the present context of globalization and increasing quality conscious consumers. In view of the highly perishable nature of milk soon after it is secreted, it is important to monitor its quality by having a firmly installed quality assurance programme along the entire production-to-supply chain. This can be possible with application of sensitive, accurate and rapid methodologies as a tool in quality assurance programmes.

Quality comprises of several attributes ranging from physical, chemical, technological and bacteriological through nutritional to aesthetic. All dairy plants have a quality assurance laboratory (Fig. 8.1) and usually follow chemical quality control with the intention of payments to contractors/producers, processing of milk and meeting mandatory requirements for end products. Quality is judged both by objective and subjective tests.

Cleaning and sanitisation are the two processes employed in dairy industry to ensure hygiene and product safety. The safety of milk and milk products is a very important aspect and every attempt should be made, during processing, to minimize contamination through handling and processing equipments. The accumulated dried milk solids (milk stones) consist largely of calcium phosphate, milk proteins (precipitated, coagulated and baked on by heat) and insoluble calcium salts from water and washing detergents. The surface can also contain biofilms, which are formed by the incorporation of bacteria into the accumulated inorganic and organic materials that attach to most surfaces. With time and in the presence of nutrients, a biofilm and the bacteria within the biofilm will grow and become strongly attached to the surface. The removal of dairy soil, milk stones as well biofilms is the prime objective of the cleaning process. International Dairy Federation (IDF) defines a clean surface as one which is free from residual film or soil that will not contaminate the food products coming in contact with it.

While cleaning refers to the removal of soil from the surface of the equipment, sanitisation implies destruction of all pathogenic and almost all non-pathogenic organisms. Cleaning and sanitisation are complimentary processes. Either of the processes alone will not achieve the desired result, which is to leave the surface as free as possible from soil and viable organisms. In actual practice cleaning and sanitisation overlap to some extent, as during cleaning a high proportion of bacteria are destroyed and others get removed in the detergent solution. Inadequate or faulty cleaning and sanitisation can have serious consequences, as milk is a prefect nutrient in which bacteria can multiply. A thorough understanding of the cleaning methods is, therefore, necessary for economic production of high quality food products.

Packaging is a tool that is used to contain the product, protect the product from environmental hazards and help in marketing the product. Examples of ideal natural packaging systems are that of a banana, orange, coconut and egg, where the packaging is provided by nature. The major step forward in the food processing arena has been the ability to protect and preserve products with packaging and hence ensuring the availability of fresh and processed products out of season and over long distances in various forms. Milk is a highly perishable product and is not uniformly available round the year to the whole country due to geographical and genetic variations. If dairy products are to be available all the year round the country, irrespective of the season and area, it must be presented in packages that are convenient to purchase and use.

Packaging has additional responsibilities of providing convenience, safety and facilitating, besides handling, storage and distribution of products. It should prevent spoilage of food by microbial or insect attack. It also preserves the quality and nutritive value of many foods by the exclusion of oxygen and the control of moisture loss or gain. It increases the shelf-life and ensures longer availability and contributes to the product image through structural and graphic design. Product information is also given out through the medium of labeling, which acts as a tool for marketing and advertising.

Milk, as secreted in the udder of a healthy animal is practically sterile, but during its transit to the processing plant, becomes heavily contaminated with a variety of micro-organisms. These may be responsible for spoilage of milk or for causing diseases in animals and human beings. It thus becomes imperative that adequate heat treatment is given to milk to destroy these micro-organisms, thus increasing the shelf-life of milk as well as making it safe. Varied heat treatments offer the potential of producing different kinds of processed milk to satisfy the needs of the consumer. To cater to the ever-increasing demand of consumers, several varieties of processed milk are available in the market, some of which are discussed below.

5.1. Pasteurised Milk

Pasteurisation was named after the renowned French scientist Louis Pasteur, who discovered that spoilage organisms could be inactivated in wine by applying heat at temperatures below its boiling point. The process was later applied to milk and remains the most important operation in the processing of milk.

It is the process by which every particle of milk is heated to such temperature-time combinations (usually to 63°C for not less than 30 minutes or to 72°C for not less than 15 seconds) and promptly cooled to 4°C or below so as to destroy any harmful bacteria that may be present without affecting flavour and food value. Pasteurisation does not involve the use of any additives. Apart from making milk safe to drink, pasteurisation increases the length of time it can be kept before it spoils. The nutrient losses due to pasteurisation are so small, that they are considered insignificant.

Milk, on reception at the dairy factory is subjected to various unit operations on its way to product manufacture. Processing is applied as a means to convert liquid milk into products or to render the milk (and products) safe from harmful organisms. The basic processing operations to which milk is subjected at processing units have been described in this chapter. The common processing operations employed are depicted in Fig. 4.1. Several of these operations are routine compulsory processes common to all dairies, while certain others are undertaken for specialized purposes in some dairies.

4.1. Filtration and Clarification

At the time of milking various foreign materials such as dirt, feed, manure, dandruff, hair, flies, dust particles, worn out cells, cell debris and many other undesirable substances may find their way into milk. The process of removal of this extraneous matter (solid particles of higher density than that of milk) is called filtration or clarification. This can be achieved either by simple filtration through specially woven filter cloth or continuous process of centrifugal clarification that helps

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.

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.

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).

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.

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

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

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

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

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

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

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.