eChapters

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 (Plate 209).

Dairy: It is a room, building, or establishment where milk is kept and butter / cheese is made or it is the department of farming / farm that is concerned with the production of milk, butter, and cheese or an establishment for the sale / and distribution of milk and milk products.

Dairy husbandry: It deals with care, breeding, feeding, milking of the diary cattle and the production and sale of the milk. It is the economical management of a dairy, including looking after the dairy cattle breeding and proper disposal or sale of milk and milk products.

Dairy products: These are the milk preparation, including butter, cream, cheese, ghee, yoghurt, pasteurized milk, tonned milk, butter milk etc processed and prepared in dairy. Ice cream and kulfi or sweets are not included in this.

Damage: Damage is a physical spoilage, often a partial deterioration, are subjectively judge and very difficult to measure and usually reported as per cent damage.

Daminozide: It is a growth regulator which is used for red colour development in apple.

1. Introduction

Milk and milk products constitute essential dietary components for a vast majority of the population. India with annual production of more than 135.6 million tonnes has emerged as leading milk producing nation. The per capita per day availability of milk in India is more than 290 g. Buffalo milk accounts for 57% of the total milk produced in India. Ethnic dairy products account for 90% of all dairy products consumed (Aneja et al., 2002). Many health benefits have been attributed to fermented dairy products and probiotic microorganisms (Salminen et al., 1998). The market for functional foods, nutraceuticals, wellness foods and beverages is fast growing. The harmful effects of synthetic drinks have propelled health conscious consumers to go for natural and traditional drinks. In search of better returns, the Indian dairy industry is widening its focus to include traditional milk products, and these are emerging as new profit centres for the organised sector.

Traditional dairy products have several advantages. They require low capital investment and give high profit margin. They are more appealing to the Indian palate. Dahi or curd is the most popular indigenous fermented dairy product. There are numerous references to dahi in vedic literature. The Prevention of Food Adulteration Act (Anon, 1976) describes dahi as a product obtained from pasteurized or boiled milk by souring (natural or otherwise), using harmless lactic acid or other bacterial cultures. Indian dahi and its western counterpart yoghurt differ considerably in terms of cultures used and their bouquet and flavour profiles (Aneja et al., 2002). The major flavor compound in dahi is diacetyl. Dahi made from buffalo milk has a firm body and white glossy appearance, with a cream layer on top. Mixed mesophilic cultures of Lactococcus lactis subsp. lactis, Lactococcus lactis subsp. cremoris, Lactococcus lactis subsp diacetylactis along with Leuconostoc species are grown together for production of dahi.

Dairy byproducts constitute an important segment of dairy industry. An important criterion in the economic choice of any process is the efficient utilization of byproduct that is produced along with the main product. The main byproducts of dairy industry are skim milk, buttermilk, whey and ghee residue. Each and every component of milk must be judiciously processed into edible form not only to improve the profitability of dairy industry but also to make best use of the unique nutritional value of the precious milk constituents on one hand, and to prevent environmental pollution, on the other. However, dairy plants, particularly in India, are usually confronted with the problem of byproduct utilization, especially that of whey and ghee residue in economical manner.

Skim milk is a byproduct obtained during the manufacture of cream. It is rich in solids-not-fat content and has high nutritional value. In dairy plants, it is mostly utilized either in standardization for the manufacture of main dairy products or preserved by removing moisture in milk powder form. The skim milk when utilized in either of these two forms or consumed as liquid, is not considered a byproduct. It is regarded as a byproduct only when it is either not economically utilized or utilized for derived byproducts, like casein and other related products, co-precipitates, protein hydrolyzates, etc.

Buttermilk is the byproduct obtained during butter manufacture. Sweet cream buttermilk resembles skim milk in gross chemical composition and is usually admixed with bulk of skim milk for further spray drying or even product manufacture in dairy plants. Desi buttermilk, on the other hand, has long been an important domestic beverage in India. It has high nutritive and therapeutic value. It also finds its way in the preparation of a host of culinary dishes such as kadhi, dhokla and idili. Also a number of federations and private plants sell salted and spiced buttermilk in 200 ml pouches.

30.1 Introduction
Every food processing facility, especially those that produce several products, generates trash in various forms. The food products are rich in carbs, proteins, lipids, and mineral salts. During the process of flushing and washing various equipment, nutrients are released into the drainage, promoting the growth of both anaerobic and aerobic bacteria. Consequently, the water that is flushed might have a highly unpleasant smell and could become a challenge for disposal in the municipal sewer system.

30.2 Definition of Waste Management
Waste management encompasses the collection, transportation, processing, recycling or disposal, and oversight of waste materials.

30.3 Types of Wastes in a Food Processing Plants
Waste produced in food processing plants can be categorized based on their form and origin, whether they are avoidable or unavoidable, their value, or their potential for reuse.

30.3.1 Based on the forms: Wastes based on forms can be classified as
1. Solid wastes,
2. Liquid wastes,
3. Oily wastes,
4. Gaseous wastes/water vapors.

Milk processing plants involve processing of raw milk into products like market milk, cheese, butter, ice cream, condensed milk, dried milks and traditional dairy products. The by-products processing includes buttermilk, whey and its derivatives. Dairy effluents contain dissolved sugar, protein, fat and minerals. Spills and leaks of products or by-products, residual milk or milk products in piping and equipment before cleaning, wash solutions from equipment and floors, condensate from evaporation processes and cheese trimmings are some of the sources of dairy effluents in a dairy plant. The key parameters are the biological oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids, total dissolved solids etc. Common dairy waste techniques include grease traps, oil water separators for separation of floatable solids, equalization tanks. Biological treatment consists of aerobic and anaerobic process.

Introduction
Demand of dairy products is on the rise in India. India‘s demand forecast for milk and milk products is more than the current supply of these products. To meet this demand entrepreneurship initiatives are need of the hour. Further, younger generations of India are more interested in commercial dairy farming rather than subsistence based farming. Therefore, scientific as well as commercial dairy entrepreneurial training to farmers about advanced technology used in breeding, feeding, housing and healthcare is essential.

a. Barriers for Entrepreneurship in dairy

An average dairy entrepreneur faces several barriers to start a new enterprise. Some of them are as under

    1.    Lack of financial support: A major stumbling block for many dairy farmers to expand production or diversify into new high value enterprises is lack of access to finance. Farmers who are starting new enterprises often face difficulty raising investment capital.

Dairy Industry in India
Milk holds a deeply symbolic place in Indian culture, far beyond its role as a mere food item. It is intricately woven into the cultural and historical identity of the nation, with the dairy industry serving as a cornerstone of India’s economy. The sector is a driving force behind rural development providing a crucial pathway to prosperity for millions of small-scale farmers. It plays a significant role in alleviating poverty and generating employment opportunities. The dairy sector by empowering farmers, developing modern infrastructure embracing technological advancements, and promoting sustainable practices, fostering widespread socio-economic progress in rural India. In the 1920s, modern milk processing and marketing technologies were introduced in India. The National Dairy Development Board (NDDB; founded in 1965), implemented Operation Flood (1970-96) to modernize the dairy sector through cooperatives. This led to the rise of dairy cooperatives countering the exploitation by private milk plants. The cooperatives followed the Anand model, a three-tier structure comprising village-level societies (producers), district-level unions (milk collection and processing), and state-level federations (marketing). Originating in Anand, Gujarat in 1946, the model was later adopted nationwide. The progress termed as White Revolution transformed India from a nation struggling with milk shortages into the world’s largest producer and consumer of milk. By 1997, India became the global leader in milk production with a volume of 70.9 million tons, surpassing the United States (FAO data rearranged by Our World in Data). Further in the year 2014, for the first time, it beat the entire European Union. Since 1950, India’s milk production has seen tremendous growth, rising from 17 million tonnes in 1950-51 to 230.58 million tonnes in 2022-23. The per capita availability of milk increased from 124 g/day in 1950-51 (PIB 2022) to 459 g/day in India during.

Introduction
 
Dairy ingredients are of significant importance in the formulation of many food products. Additionally, the incorporation of dairy ingredients, comprehensively recognized by the consumer as “natural” intensifies the odds of success of packaged foods and adds functional properties of the dairy ingredients in the targeted product. Dairy ingredients can be extracted from fluid milk in the form of cream, butter, condensed milk, dry milk, cheese, and whey products [1]. They provide beneficial functionality to foods, such as delivery of key nutrients, water management, fat-holding capacity, emulsification capability, viscosity creation, gel formation, and foam generation apart from providing desirable attributes of texture and flavour. Various ingredients and claims associated with dairy foods are shown in Table 3.1.

Milk is nutritious and essential food for human beings and also serve as good medium for microbial growth and contamination. Milk is a single, most nearly complete, natural food. Primarily it is meant for nourishing the newborns but man has exploited it for human consumption since long. Today milk has become indispensable integral component of our diet. About half the milk produced is consumed as fresh milk, the rest going into a variety of products including evaporated and condensed milk, dried milk powder, butter, cheese, malted milk, ice cream, yoghurt, lactose and casein. Milk is very important from a nutritional standpoint since it contained all the essential food constituents (carbohydrate-lactose, protein-casein, fat-butter, minerals- calcium, potassium and vitamins- A, B, C, D, E, and K) required in human diet in about the proper proportions. India is the second largest producer of milk in the world. India has exhibited unprecedented rate of growth in dairy development in last 30 years mainly due to sustained efforts of dairy technologists in Operation flood Programme introduced by the National Dairy Development Board. Dairy microbiology deals with aspects like shelf life and spoilage microbes, public health significance and food borne pathogens, and production of fermented dairy products.

DAIRY BUSINESS

Most ambitious young men at some time or another are likely to develop an interest in going into business for themselves. This is prompted not only by the thought that a person owning his own business is more independent but also by the hope of increasing personal income. However, when these same young men look about them and see the general existence of “big business” in practically all lines of endeavour, they often lose courage and decide to remain as workers with some company where they can enjoy a certain degree of security. 
The general condition is an important factor in determining the success of new business enterprises. Similarly, innovations like the creation of new products or the development of new methods of merchandising often gives rise to opportunities for a new business enterprise. The introduction of “Softy” ice cream and other soft-served frozen products made it possible for several hundred small businesses to get established in our country. The advent of single- service paper container was the spark that started several milk-plant operations which later grew into companies of considerable size. Ironically, the paper milk container also spelled the doom for many older independent plants that could not or did not adjust soon enough to this new way of packaging. The chocolate-coated ice-cream bar idea started a number of new enterprises which grew from small companies going to concerns of considerable size. Vending machines made it possible for many small companies to get started selling milk, ice cream, candy and lassi etc. 

Introduction

The dairy industry is a cornerstone of worldwide agricultural economies, underpinning nutrition, employment, and rural development. India stands out among nations with thriving dairy sectors, accounting for approximately 23% of global milk production (Prasad et al., 2023). With advent of Operation Flood in the late 1970s, India’s dairy industry has undergone transformative changes. This movement revolutionised milk production, rural income, and the organisation of cooperatives. The Indian dairy sector is still unorganized and only 18-20 per cent of the total milk produced is handled by organized sector (Gowda, 2023). There is rising trend of value addition along with rising demand of processed dairy products in India. These changes underscore the importance of effective dairy plant management systems, where strategic oversight of milk procurement, processing, and product manufacturing ensures quality, efficiency, and sustainability.

The GOI is pushing to strengthen infrastructure for the production of quality milk, as well as for procurement, processing, and marketing of milk and milk products through the following Dairy Development Schemes:

6.1. Dairy Entrepreneurship Development Scheme (DEDS)

Dairy Entrepreneurship Development Scheme (DEDS) was started in September 2010. This scheme is being implemented through NABARD which provides financial assistance to commercially bankable projects with loans from Commercial, Cooperative, Urban and Rural banks.

Objective of the scheme

To generate self-employment and provide infrastructure for the dairy sector, to set up modern dairy farms and infrastructure for the production of clean milk, to encourage heifer calf rearing for conservation and development of good breeding stock, to bring structural changes in the unorganized sector so that initial processing of milk can be taken up at the village level, to upgrade traditional technology to handle milk on a commercial scale, to provide value addition to milk through processing and production of milk products.

1.1. Global Dairy Scenario

Global milk production is forecast at 852 million tonnes in 2019, an increase of 1.4 per cent from 2018 (DAHD, 2019) – a smaller rate of growth, reflecting downward revisions made for India and the European Union. Much of the anticipated output expansion will originate in India, Pakistan, China, the European Union, and Brazil, partially offset by declines in some countries including Australia, Colombia, and Argentina. In India and Pakistan, herd expansions drive output growth, while in China, farm efficiency improvements underpin higher growth. The output is increasing in the European Union, although slowly as dry weather limited the supply of milk during the summer, whilst rising dairy herds and stable milk prices are supporting higher production in Brazil. By contrast, the output may decline in Australia and Colombia due to dry weather, whereas in Argentina, rising feed costs and restrained consumer demand may dampen production. Elsewhere, in the United States, higher milk yields hold up the growth momentum, whereas, in New Zealand, favourable weather corroborates a positive production outlook (DAHD,19).

    1.    The heifer is bred (naturally or by insemination) before the age of two years.

    2.    The gestation period is nine months and one week.

    3.    After calving, the cow gives milk for 10 months.

    4.    1 – 2 months after calving the cow will again be bred.

    5.    The cow then continues to give milk for about 300 days. This period is known as lactation.

    6.    Milk should preferably be handled in a closed system, to minimise the risk of contamination. It must be cooled to 4 °C as soon as it is produced.

    7.    The content of protein, lactose and ash is somewhat higher in buffalo milk than in cow milk. Buffalo milk contains vitamin A, but lacks b-carotene, which is present in cow’s milk.

    8.    When milk and cream turn to butter, there is a phase inversion from an oil-in-water emulsion to a water-in-oil emulsion.

    9.    In milk, the whey proteins are in colloidal solution and the casein in colloidal suspension.

Date-palm (Phoenix dactylifera L.). belongs to family Palmae and is the most common tree of desert and dry areas. Date palm is one of the oldest trees known to man kind. Date-palm is believed to have originated in the countries around Persian Gulf. It is extensively grown in Iraq, Iran, UAE, Saudi Arabia, Algeria, Egypt, Libya, Yemen, Mauritiana, Morrocco, Tunisia, Baharin, Sudan, USA, Spain, Australia, Pakistan, South Africa, Somalia, Oman and some parts of the South America. Date is a staple food of the people of the Western Iraq and North Africa. In India, it has been believed to be introduced by soldiers of Alexander the Great in 4^th century B.C. In India it is commercially cultivated in Rajasthan, Punjab, Hariyana and Gujarat.

Cultivars: Deglet Noor, Halawy, Khadhrawi, Hayani, Majhul, Zahidi, Khalaeh.

Uses

Date palms produce many products that are useful to human beings. The primary product is the date fruit, which can be eaten fresh, dried, or in various processed forms. In North Africa and the Middle East, some dates are harvested and consumed during the Khalal stage, when the fruit are still very astringent with a high tannin content (Dowson and Aten, 1962 ; Glasner et al., 2002; Kader,1992). Dates can be used in cereal, pudding, bread, pressed cakes, cookies, candy bars, ice cream, and date shakes (a California specialty). Date fruit also can be made into juice, vinegar, wine, beer, sugar, syrup, honey, chutney, pickle, paste, dip, and food flavoring (Barreveld, 1993; Glasner et al., 2002).

It is said that there are as many uses of dates as there are days in a year. The trunk and wood of date palms can be used as timber, wood, or fuel. Fiber from the trunk and leaves can be made into bags, baskets, camel saddles, cords, crates, fans, food covers, furniture, mats, paper, ropes, trays, and twine. Dried bundles of leaves (‘‘Barusti’’) can be made into shades, roofs, separating walls, and enclosures. Ribs of the leaves can be used to build boats (small fishing boats called ‘‘Shasha’’) or fishing traps. The base of the leaves and fruit stalks can be used for fuel. The pith of the palms can be made into date palm flour. Terminal buds (palm heart) can be eaten as a salad or as a cooked vegetable. Date seeds can be used as feed for livestock or strung as beads for decoration. Oil from date seeds can be manufactured into soap (Chao and Krueger, 2007). Dates are considered a balanced and healthy diet and have several medicinal uses. Leaves are source of fibre used for making ropes baskets and cordage. Walking sticks are made from leafstalk.

Ice cream defects can result from formulation imbalance, poor ingredient quality, processing deviations, inadequate freezing or hardening, packaging problems, storage conditions, and cold-chain failures. This chapter provides a systematic framework for understanding, classifying, diagnosing, and correcting defects affecting flavour, body, texture, melting, colour, appearance, packaging, and storage stability. It emphasizes that a visible defect in the finished product may originate much earlier in the production or distribution chain. Examples include iciness caused by slow freezing or temperature abuse, weak body associated with formulation or overrun, and flavour problems originating from raw materials or microbial activity. Defect analysis therefore becomes an important tool for troubleshooting, quality improvement, training, and preventive action.

25.1 Introduction
Cream, butter, anhydrous milk fat, ghee and fat preserves, cheese, condensed milk, evaporated milk, skim milk, and whole milk powder are among the dairy products that have been extensively examined.
25.2 Defects in market cream
In the market, there are a variety of creams, including half cream, single cream, coffee cream, cultured cream, whipping cream, heavy whipping cream, aerosol cream, double cream, clotted cream, and high-fat creams (also referred to as plastic cream). The defects related to market cream are detailed in Annexure-I
1. Flavour defects in cream: Any flavor imperfections originally present in whole milk may become more noticeable in separated cream. Volatile compounds that are fat-soluble tend to concentrate in the fat portion, which can amplify these defects, such as an oxidized taste. Common flavor defects associated with cream include feed, cooked, malty, musty, utensil, weed, acid, bitter, and oxidized/rancid flavors. These flavor defects are further described in the section discussing flavor issues in Table butter.
2. Specific defects in cream
• Serum leakage, creaming, reduced overrun in whipping cream: Serum leakage typically results from partial churning (overwhipping), causing an unattractive liquid pool around the whipped cream or sogginess when applied to cakes. Excessive whipping leads to the formation of large fat globule clusters, which can break bubble-enclosing membranes, initiate bubble coalescence, and reduce overrun. This process may lead to an irreversible phase inversion, turning the cream into a greasy water-in-oil emulsion, visible as butter granules. Unfavorable creaming and serum separation can be delayed by lowering fat content (within legal limits), adding stabilizers like carrageenan, emulsifiers, or protein ingredients, or through post-UHT homogenization. Using a mix of kappa and iota carrageenan can help reduce creaming during storage and minimize whipped cream drainage.

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

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.

Materials Required

Dehydrator, balance, thermometer, sulphur dioxide, blanching pan, fruits / vegetables, polythene or aluminium bags.

Procedure

    1.    Select sound fruits or vegetables 
    2.    Record their initial weight and wash them properly in plain water to remove any dirt or extraneous matter. 
    3.    Peel with stainless steel knife (as the case may be) and cut into thin uniform pieces or slices of  0.2-0.5 mm thickness
    4.    Blanch the slices in boiling water for 1-2 min. to inactivate the enzymes followed by immediate cooling.
    5.    Treat the slices with sulphur (sulphuring or sulphiting) in order to prevent darkening of the product during drying. 
    6.    Dry the slices in a mechanical air dehydrator at about 55 + 5oC temperature.
    7.    Record the weight of the product after every 2 hr till it becomes (almost) constant i.e. when there no more (significant) loss of moisture from the product.
    8.    Pack the product in ploythene or aluminium laminated pouches and seal them air tight. 
    9.    If it is to be converted into powder, the dried product can be ground in a grinder before packing.
    10.    Label the packages and store them in a cool dry place.
    11.    Plot the drying rate curve of the product on a graph paper and analyse it.
    12.    Record the initial and final moisture content of the product (as discussed in Exercise No. 19).