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Milk is a highly perishable commodity. The shelf life of raw milk is in hours. In order to harness its full potential for the well being of the humanity, it is essential to extend its shelf life not only in days but also in months and years. This can be achieved by judicious application of processing and preservation technologies.

Preservation is any purposeful treatment or processing of a food which prevents spoilage and extends the shelf life of raw material to a longer than its natural keeping quality.

During storage and distribution foods are exposed to a wide range of environmental conditions. Environmental factors such as temperature, humidity, oxygen and light can trigger several reactions that may lead to food deterioration. As a result foods may be altered to such an extent that they are either rejected by the consumer or are harmful to the person consuming them. It is, therefore, essential that the good knowledge of different reactions that cause food deterioration is gained prior to understanding the principles of food preservation.

The deterioration in foods may be caused either due to internal or external chemical or microbial reactions occurring in milk. The changes may be either latent to senses of consumer, or they may be discernible by the human senses. The consumer cannot perceive latent changes visually, olfactorily or otherwise, and laboratory measurements are the only method to detect them. Still the nutritional value of such materials may be seriously impaired. Such changes include fermentation, oxidation of lipids, loss of vitamins and changes in the contents and composition of nitrogenous substances.

Non-microbial changes in foods, perceptible to human senses, may often lead to serious deterioration noticeable to the average consumer. These include discolouration and changes in odor, taste and consistency. Microbial changes may result in alteration of original properties of milk making it unfit for further processing, deterioration in flavour quality, loss of nutrients and toxin production.

Microorganism is a collective term for all living organisms, which are not visible to the eye, and occupy an intermediate position between the vegetable and animal kingdoms. They are found every where in the atmosphere, in water and in the soil and, as they break down organic materials, they play a very important role in the cycle of the nature.

There are thousands of species which are important to the life and economic structure of the human race. For example, certain species form simple chemical elements during the break down of dead organic material which plants can use again. They increase soil fertility and crop production which results in more food.

Other species are present, and essential, in animal intestines, helping in the digestion of food.

Some microorganisms are used in many food processes, e.g. dahi, yoghurt, cheese, pickles, beer and wine as well as in the acid production to preserve foods. There are microorganisms that produce toxic substances which kill other organisms, e.g. the mould penicillium which produces the substance penicillin.

Many microorganisms cause diseases in animals and plants with a subsequent reduction in the nation’s food supply, whereas others cause food deterioration such as mouldy foods, tainted foods, etc.

Milk is a complex colloidal dispersion, the physical and physicochemical properties of which depend on intrinsic compositional and structural factors, extrinsic factors such as temperature, and post-milking treatment.

There is no clear dividing line between physical properties and physicochemical properties. However, physical properties may be thought of as the measure of the bulk behaviour of milk and of how milk interacts with energy, while physicochemical properties are measures of how bulk behaviour and energy interactions depend on the constituent colloidal particles, molecules, atoms and ions in milk.

Knowledge of physical properties is of importance particularly in the technological and engineering design and control of milk processes and processing equipment. Knowledge of physicochemical properties provides the basis for the design of modern methods of milk analysis, determination of milk microstructures and elucidation of the complex chemical reactions that occur in milk.

In the dairy industry measurements of the physical properties of milk and milk products are made to secure data necessary for the design of dairy equipment (e.g., heat conductivity and viscosity) to determine the concentration of a component (e.g., specific gravity to estimate solids-not-fat or freezing point to determine added water), or to assess the extent of a physical or chemical change (e.g., titratable acidity to follow bacterial action or viscosity to assess aggregation of protein micelles or fat globules). The great advantage of physical measurements for such purposes is their speed and simplicity as well as their potentialities for automation.

Use of physical property to measure concentrations or changes in degree of dispersion demands knowledge of the contribution of the several components to that property. Furthermore, the natural range of variation of the property in milks or products is of major interest. The precision and suitability of possible methods of measurement are also of prime importance.

“Tell me what you eat and I will tell you what you are. The destiny of people depends on the nature of its diet.”

A. Brillat-Savarin

Milk is the only product which is considered nature’s almost perfect food. It is treasure house of unlimited nutrients. It is considered best and ideal food by virtue of possessing almost all the nutritional factors, viz., fats, proteins, carbohydrates, minerals and vitamins. They are not only of higher quality but are present in milk in such form and proportion that their digestion and assimilation in the body is very efficient. Milk also plays a supplementary role in our nutrition. If it is included in our diet it enhances digestion and assimilation of nutrients of other food products. This is the reason that it is kept in high esteem as a food and is called the nectar for living beings.

Milk is the first taste of food for whole mankind. It establishes the mother-infant bond and is a life promoter. Of the many fluids that biology offers milk is perhaps the most versatile in terms of its use– as food, as a growth stimulant and as a defense package to the user. To the infant mammal – be it a mouse, calf or a human child, mother’s milk is more than a source of energy and nutrients. It contains a wide variety of substances that defend the growing infant against infections.

Milk, a perfect blend of nutrition and palatability, plays an important role in preserving mental and physical health. Milk has long been recognized as the most wholesome and complete single food available in nature for health and as a medicine, both preventive as well as curative. Ancient chronicles as recorded in the Upnishads, Puranas and Vedas extol the beneficial and therapeutic properties of milk and milk products. It has been stated that cow milk, dahi and ghee impart knowledge and radiance, cure heart trouble and anaemia besides other bodily diseases.

1.1. General Discussion of Milk

“The cow is the foster mother of the human race. From the days of the ancient Hindoo to this time have the thoughts of men turned to this kindly and beneficent creature as one of the chief sustaining forces of human life”.

William Dempster Hoard (1836-1918)
Former Governor, State of Wisconsin, USA (1889-1891)
Founder of Hoard’s Dairyman (1885)

The oldest written records of the human race are in Sanskrit and are preserved in India. At the time these records began, about 6,000 years ago, milk had already become an important article of food. In fact, so important was the cow to these early people of South and Central Asia that wealth was measured in numbers of cattle, and the cow was in time made a sacred animal and is still so considered in India.

According to the best authorities, the domestication of cattle must have occurred somewhere between 6,000 and 10,000 years ago. The cow was worshipped in Babylonia, and in Egypt about 20,000 B.C. Over fifty references to cows and milk are found in Old Testament and the Promised Land was described as “a land flowing with milk and honey”.

Milk is the only food of the young mammal during the first period of its life. The substances in milk provide more energy and the building materials necessary for growth. Milk also contains antibodies which protect the young mammal against infection. A calf needs about 1000 litres of milk for growth, and that is the quantity which the primitive cow produces for each calf. There has been an enormous changes since man took the cow into his service. Selective breeding has resulted in dairy cows which yield more than 5,000 litres of milk per calf, i.e. five times as much as the primitive cow. Some cows can yield 10,000 litres or more.

Introduction of Food Industry

India is one of the major food producers in the world. The food sector contributes to about 28% of India's GDP. India stands at 1st position in the world for production of cereals, milk, livestock, banana and Mango, 2nd in producing fruits and vegetables and ranks amongst top 5 in producing rice, wheat, groundnut, tea, coffee, tobacco, spices, sugar and oilseeds. India's share in global production of fruits is 10% and vegetables are 13.7%. The current consumption of fruits and vegetables is approx Rs.2 lakh crores at current prices with an estimated growth rate of 11% per annum. The growth rate is higher than cereals and milk and comparable to meet consumption

Status of Food Processing Industry

The food processing industry in India is still in a sorry state. The rural population comprising 70% including small cities, consume less than 10% of the processed foods and vegetables, whereas 60% of the processed food is consumed in four major metropolitan cities and 30% in the state capitals and big cities. Another fact is that 40% of the processed food and vegetables produced in the country in terms of value are bought by institutional buyers like Hotels, Restaurants and Defense etc. The highest growth in domestic market has been in fruit drinks, tomato ketch up and Jams.

There is another fact that India is the largest milk producer in the world, however, organized industry accounts for less than 15% of the milk produce in India. It is estimated that there may be a total production of 1100 million tons of production of food products mainly food grains, oilseeds, sugarcane and fruits/vegetables during 2011-12 and leaving marketable surplus of 870 million tons.

Purpose of Law

The Food Laws or Regulations are made in order to protect people consuming these foods from undue risks, which may arise from processing, transport, retailing and consumption of food products which may undergo contamination, spoilage, inclusion of harmful chemicals/microbes or at harmful levels. Besides safety, consumers are also protected by these laws with respect to quality, quantity and substance that the food products are supposed to represent. Finally, laws also aim to protect the consumers from Nutrition and Health considerations with special consideration being given to vulnerable group such as infants, pregnant women etc.

Food additives are chemical substances added to foods to improve flavour, texture, colour, appearance and consistency or as preservatives during manufacturing or processing. Herbs, spices, hops, salt, yeast, water, air and protein hydrolysates are excluded from this definition.

In many countries, the use of food additives is regulated, and food additives must be declared on food labels by using their chemical names or numbers. the use of any new additive in a particular food, they ensure that:

Importance of Food Storage

Food storage is both a traditional domestic skill and is important industrially. Food is stored by almost every human society and by many animals. Storing of food has several main purposes:

•Storage of harvested and processed plant and animal food products for distribution to consumers

•Enabling a better balanced diet throughout the year

•Reducing kitchen waste by preserving unused or uneaten food for later use

•Preserving pantry food, such as spices or dry ingredients like rice and flour, for eventual use in cooking

•Preparedness for catastrophes, emergencies and periods of food scarcity or famine

•Religious reasons (Example: LDS Church leaders instruct church members to store food)

•Protection from animals or theft

Definition

Packaging is the science, art, and technology of enclosing or protecting products for distribution, storage, sale, and use. Packaging also refers to the process of design, evaluation, and production of packages. Food packaging is packaging for food. It requires protection, tampering resistance, and special physical, chemical, or biological needs. It also shows the product that is labeled to show any nutrition information on the food being consumed

Packaging may be defined as co-ordinated system of preparing foods for transport, distribution, storage, retailing and their use. It is also a means of ensuring safe delivery of goods to the consumer in sound condition without affecting adversely the quality of the product packed in it at a reasonable cost. Packaging thus has as “techno-economic function” aimed at maintaining the quality of food stuff packed, with a view to retain the quality for a reasonable period.

Packaging plays a vital and dominant role in marketing, in maintaining quality and in preserving the food.

Consequent to the increase in the consumer awareness of the healthy hazards, which may be posed by different types of packaging material. It becomes inevitable for the packers to use better quality, hygienic packaging material which could retain the quality of the product for a longer time without posing any health hazard. The choice of a suitable packaging becomes all the more necessary for a number of factors like physico-chemical characters and acceptability of the commodities packed in any packaging material. Apart from this the package should be of the right shape and size and must attract the consumer's eye which could offer an absolute confidence regarding the wholesomeness of the products pack in it.

Importance of Food Additives

Food additives are chemicals, biochemical ingredients etc., which are added to food products for their technological benefits. These benefits may be to preserve the quality of food, to maintain and improve its appeal, to ensure its nutritional value and to provide innovations in new products with consumer appeal and satisfaction. Additives are also added to maintain uniform quality and to enhance quality parameters such as flavour, colour, texture etc. in large-scale production. They and their by-products ultimately become part of the food that is consumed and so they must be safe.

Additives may be direct additives, which are added deliberately to improve its sensory quality, nutritive value, stability, ease in processing and retention of quality during handling and retailing. There are also indirect additives, which are not added intentionally but get included into foods incidentally during handling, processing and packaging.

There are some guiding principles for the use of food additives. They should be justified for their technological effectiveness and purpose. They should be safe for use. There should be maximum adequate levels, absolutely necessary levels of usage and ADI (Acceptable Daily Intake) properly evaluated while considering its safety and permitted usage levels in foods. They should not be added with the intention of misleading consumers about quality. They should also not significantly affect adversely the nutritional quality of food products.

Importance

The dairy products, which have originated in India, are called indigenous dairy products. The products can be broadly classified in to khoa based and channa based. The importance of the dairy products were known to Indians since time immemorial or it could be roughly estimated to be around five thousand years ago and the development could be considered as an art.

Tamarind (Tamarindus Indica)

Introduction

The fruit of tamarind a pod 5 to 15 cm long, 3 to 10 seeds surrounded with edible pulp which is principal souring agent for sauces, chutney, in beverages and in general cooking. Pulp is carminative, laxative, given as infusion in biliousness and febrile conditions. It is also used in dyring and tanning and for polishing and cleaning metal ware. The tartaric acid is extracted from unripe fruits. The polysaccharide (jellose) is extracted from seeds, which is used as a sizing material in the cotton and jute industries. Besides, polyose obtained from the seed is good substitute for fruit pectin in the preparation of jam, jelly or marmalade. The bark and leaves are used for tanning. Tamarind balls are prepared after taking out seeds from the fruit. Tamarind paste and tamarind juice concentrate are the other commercial products.

The fruits, flattish, bean-like, irregulary curved and bulged pods, are born in great abundance along the new branches and usually vary from 2 to 7 in long and from 3/4 to 1 1/4 in (2-3.2 cm) in diameter. Exceptionally large tamarinds have been found on individual trees. The pods may be cinnamon-brown or grayish-brown externally and, at first, are tender-skinned with green, highly acid flesh and soft, whitish, under-developed seeds. As they mature, the pods fill out somewhat and the juicy, acidulous pulp turns brown or reddish-brown.

Introduction

The tropical root and tuber crops are comprised of crops covering several genera. They are staple foods in many parts of the tropics, being the source of most of the daily carbohydrate intake for large populations. These carbohydrates are mostly starches found in storage organs, which may be enlarged roots, corms, rhizomes, or tubers. Many root and tuber crops are grown as traditional foods or are adapted to unique ecosystems and are of little importance to world food production. Others such as cassava (Manihot esculenta Crantz) and white-fleshed sweet potato (Ipomoea batatas L.) are known worldwide. Several of these crops have been termed under-exploited and deserving of considerably more research input

Potato and Banana chips: Potato chips are one of the popular snack foods consumed throughout the country. Chips are mostly prepared by small scale artisans / confectioners, and sold in plastic film or paper packs. Recently, however some of the companies have installed plants having relatively large capacities and have started marketing chips in attractive packs. The fat content generally ranges between 25-40% and moisture content between 2-4%. Potatoes having high total solids, low reducing sugars and low amylase activity are most suitable for chips manufacture.

Banana chips are prepared from varieties rich in starch having very low levels of soluble sugars and polyphenol - oxidase activity. These are mostly processed and marketed in Southern States especially in Kerala. Previously, the chips were fried in coconut oil, but now other vegetable oils are also used in their processing. Relatively, banana chips are harder in texture than potato chips.

Importance of Fruits and Vegetables in Human Life

Fruit is the edible, and more or less juicy, product of a tree or plant and consist of the matured ovary including its seeds and adjacent parts. Usually fruits are sweet, with a wide range of flavours, colours and textures.

Composition

Fruits are very poor source of protein and fat. Avocado is the exception containing 28% fat. Fruits contain high amount of moisture hence they are highly perishable. They are also good source of fiber. Fruits are not very good sources of calories. Fruits like bananas give fairly good amount of calories. Ripe fruit contains a higher percentage of sugar than unripe fruit does and the sugar is chief in the form of sucrose, fructose and glucose. Generally fruits are poor source of iron, Mangoes are excellent source of carotenes. Oranges are fairly good source of beta carotene. Guavas are the best source of vitamin C. Citrus fruits are good source of vitamin C. Cashew fruits are inexpensive and rich in vitamin C, although there is variation of vitamin content from fruit to fruit most fruits in the raw state contain some ascorbic acid. If fruits are bruised, peeled, cooked or exposed to air, large amounts of the vitamin may be oxidized. Apples are not only expensive; they contribute little to the nutritive value. They give fiber to the diet.

Importance of Traditional Foods

Traditional convenience food, or tertiary processed food, is commercially prepared food designed for ease of consumption. Products designated as convenience foods are often prepared food stuffs that can be sold as hot, ready-to-eat dishes; as room-temperature, shelf-stable products; or as refrigerated or frozen products that require minimal preparation (typically just heating).

These products are often sold in portion controlled, single serve packaging designed for portability for “on-the-go” eating. Convenience food can include products such as candy; beverages such as soft drinks, juices and milk; fast food; nuts, fruits and vegetables in fresh or preserved states; processed meats and cheeses; and canned products such as soups and pasta dishes.

Traditional Foods

Preparation of Vadagam and Appalam

Vadagam is a traditional product mostly prepared from rice flour and also sago. It is an deep fat fried product and consumed as a side dish in the meals. Papad also known as appalam or papadam in South India, is essentially a thin wafer like product, usually circular in shape rolled from a dough made out of pulse, cereals, edible vegetable oil, alkaline and mucilaginous additives. It is normally consumed in toasted or fried form. In India, papad has been associated and deeply entwined with social customs/ rituals and has been developed into culinary art.

Importance of Foods

The word “instant” has been used in widely different types of premixes to specify the products either as ready-to-eat food or semi processed foods. The instant premixes available in Indian market were classified as Indian products and Westernized or sophisticated products. The instant mixes included under Indian market products are spice mixes, snack mixes and desert and sweet meat mixes. The Westernized products (instant mixes) contained soup mixes, beverage mixes, desert mixes and soft drink mixes.

Convenience foods are gaining popularity in recent years as they are very easy to handle, require minimum storage space and are attractive. Convenience foods have emerged as a new set of products in the international market. Most of the traditional foods that are commercially available in our country are being prepared / processed by cottage industries and by some of the multinational companies. The various types of convenience foods/ instant mixes that are presently being processed, marketed and consumed all over the country. Supplementation with protein-rich sources and preparation of acceptable ready-to-eat snack foods would not only correct its nutritional inadequacies, but would also provide a variety.

Instant mixes were high in nutritive value especially needed for armed forces, light in weight, easy to carry and prepare. Rapid industrialization and urbanization and changes in eating habits of Indian people led to very high demand for ready-to-use snack foods. The convenience instant foods are meeting the urgent and exigency situations of offering hospitality to unexpected guests.

Changing life styles and values are at the root of considerable changes in eating habits over the last few years. Hand-in-hand with a strong demand for fast and take away foods, there has been a marked upturn in popularity for convenience foods in India. The major reasons for this trend are: the decline of the family meal time, growth in disposal incomes (only in cases of city dwellers), the desire for more leisure time and demand for “foreign” or “sophisticated” dishes inspired by the media and increased travel.

Over the past several years, there has been significant change in consumer perception on quality and food safety. Consumers are demanding healthy, nutritious and cost-effective products processed under controlled hygienic conditions. Food safety concern, in recent years, has become dominant and important. The requirement of food safety and quality assurance has never been so demanding as it is now. Globally food safety is being addressed independent of food quality. In anticipation of consumer demands on food safety, food sanitary standards at national and international levels are under constant review. Several inter governmental agencies/organizations are engaged in work related to quality assurance and food safety. Amongst these World Health Organization (WHO) and Codex Alimentarius Commission (CAC) play the major role in protecting public health and defining standards of quality and safety aspects of foods for regional and or world wide usage.

Abstract

Grains in present context are food grains. The PFA Act includes cereals, millets, and pulses in food grains. At times, seeds of certain oilseeds like soybean are also referred to in the discussion of food grains. Grains have been cultivated for thousands of years. We have Grain Standards as established by the International Organization for Standardization (ISO), which are considered as International Standards. Another source is Codex Alimentarius Commission (Codex) under the aegis of FAO (UN), which operates a Committee to formulate standards that are referred to as Codex Standards. Many countries have a National Standards Institution, which develops National Standards for their main grain crops and other commodities and issues specifications along with methods of testing and analysis. Several countries, which are in developing status, adopt or modify international standards into their national system. The Grain Standards have been evolved and established for a variety of purposes but primarily to grade produce in agricultural marketing largely to facilitate the movement of grain, provide both sellers and buyers with guidelines to support financial transactions, and ensure that the produce will meet up with end-use requirements, or, increasingly to protect the consumers.

Abstract

A survey of various wheat milling units (atta chakki) available around Indian Agricultural Research Institute, New Delhi was conducted to study the performance of these. The mills of various sizes (12", 16", 18", 20", 24" and 30" stone disc diameter) with horsepower ranging between 2 to 20 are in operation. Both horizontal and vertical disc types of mills are in use. The capacity of these units ranges between 10 kg/h to 200 kg/h. The stationary sieve, hand sieve, pedestal/exhaust fan are used for cleaning. The average wheat cleaning cost is Rs. 200 per ton. A small room of 8' x 10', 10' x 10' and 10' x 12' size is used for running the mills and storage of wheat grains. The grinding charges (Rs./q) of wheat, coarse grains (maize, sorghum, millet etc) and spices are 100, 200 and 1000, respectively. Sample of 500 g of wheat and flour were collected from each chakki and were analysed for wheat grain and flour quality. Infested, damaged grains were observed to be in 2-10% range. Sieve analysis of the flour was done and the average particle size, fineness modulus and uniformity index of the flour were calculated. Average particle size, fineness modulus and uniformity index were found in the range 0.1875 to 0.2023 mm, 1.052 to 1.297 and 0:1:9, respectively. Average particle size of the flour obtained from horizontal mills was found to be higher than vertical mills. Temperature of the flour at the outlet was observed in between 45 and 50°C at room temperature of 18.5°C.

Abstract

There is an urgent need to – create market driven linkages rather than do it alone by building new infrastructure. A lot needs to be done to improve infrastructure in terms of reducing the logistics cost, eliminating middlemen influence and eliminating the wastage of basic inputs. There is a need to blend technologies based on principle of dovetailing production for masses with the advantage of mass production, particularly in the area of grain processing, packaging and marketing which would help combine livelihood, security with agricultural competitiveness. Risk in crop production is not new to any age and the farmers have been bearing it since times immemorial. The farmers should be allowed to maximize their grain. High performance continuous and batch dryers remove moisture in a way that is predictable and reliable. The problems associated with moisture content may be harmful to international trade in grain and need to be addressed adequately by the standardization institutions.