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Article Manual Food Technology

By Arjun Shukla B.Sc Biotechnology M.Sc. Zoology (Entomology) Mitali Gupta B.E (Electrical & Electronic Engg.), M.E. Control System Purpose of its Maintenance and Product

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Introduction:

India derives nearly 33% of the gross Domestic population from agriculture and has 66% of economically active population, engaged in agriculture. The share of livestock product is estimated at 21% of total agriculture sector. The fact that dairying could play a more constructive role in promoting rural welfare and reducing poverty is increasly being recognized. production alone involves more than 70 million producers, each raising one or two cows/ buffaloes primarily for milk production.

The domesticated is one of the gentlest of all farm animals; hence it can be breeded easily. The dairy sector offers a good opportunity to entrepreneurs in India. India is a land of opportunity for those who are looking for new and expanding markets. Growth prospects in the dairy sector are very bright.

Dairy development in India has been acknowledged the world over as one of modern India’s most successful development programme. India is the second largest milk producing country with anticipated production of about 78 million tons during 1999- 2000. The production of milk products stood at 3.07 lakh tones in 1999-2000. Production of milk powder including infant milk food has risen to 2.25 lakh tons in 1999- 2000, whereas that of malted food is at 65000 tons. Off late market for milk products is showing a steady increase.

Dairy farming has been part of agriculture for thousands of years, but it was usually done on a small scale on mixed farms with little distinction between dairy and beef cattle. Today, dairy cows are specialized to produce large volumes of milk. Specialist scale is only viable where either a large amount of milk is required. DAIRY CATTLE Dairy farming in the United States is undergoing dramatic changes, driven by both supply and demand factors. Consumption is shifting from fluid milk, generally produced for local markets, toward manufactured products, such as , and dairy- based ingredients produced for national and global markets. Innovations in breeding and feeding systems have led to large increases in the

3 amount of milk that a cow produces. The location of milk production is shifting toward Western States such as California, Idaho and New Mexico. Finally, production is shifting to much larger farms. The number of dairy farms with fewer than 200 cows is shrinking rapidly while very large operations, with 1,000 to 30,000 cows on one site, account for rapidly growing shares of production. Large dairy farms first emerged in the Western States, but are now appearing in traditional dairy States as well.

History:

Milk producing animals have been domesticated for thousands of years. Initially, they were part of the subsistence farming that nomads engaged in. As the community moved about the country, their animals accompanied them. Protecting and feeding the animals were a big part of the symbiotic relationship between the animals and the herders. In the more recent past, people in agricultural societies owned dairy animals that they milked for domestic and local (village) consumption, a typical example of a cottage industry. The animals might serve multiple purposes (for example, as a draught animal for pulling a plough as a youngster, and at the end of its useful life as meat). In this case the animals were normally milked by hand and the herd size was quite small, so that all of the animals could be milked in less than an hour— about 10 per milker. These tasks were performed by a dairymaid (dairywoman) or dairyman. The word dairy harkens back to Middle English , from dye (female servant or dairymaid) and further back to Old English doge (kneader of bread).

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With industrialization and urbanization, the supply of milk became a commercial industry, with specialized breeds of cattle being developed for dairy, as distinct from before draught animals. Initially, more people were employed as milkers, but it soon turned to mechanization with designed to do the milking.

Historically, the milking and the processing took place close together in space and time: on a dairy farm. People milked the animals by hand; on farms where only small numbers are kept, hand-milking may still be practiced. Hand-milking is accomplished by grasping the teats (often pronounced tit or tits) in the hand and expressing milk either by squeezing the fingers progressively, from the udder end to the tip, or by squeezing the teat between thumb and index finger, then moving the hand downward from udder towards the end of the teat. The action of the hand or fingers is designed to close off the milk duct at the udder (upper) end and, by the movement of the fingers, close the duct progressively to the tip to express the trapped milk. Each half or quarter of the udder is emptied one milk-duct capacity at a time.

The stripping action is repeated, using both hands for speed. Both methods result in the milk that was trapped in the milk duct being squirted out the end into a bucket that is supported between the knees (or rests on the ground) of the milker, who usually sits on a low stool. Traditionally the cow, or cows, would stand in the field or paddock while being milked. Young stock, heifers, would have to be trained to remain still to be milked. In many countries, the cows were tethered to a post and milked. The problem with this method is that it relies on quiet, tractable beasts, because the hind end of the cow is not restrained. In 1937, it was found that bovine somatotropin (BST or bovine growth hormone) would increase the yield of milk. Monsanto Company developed a synthetic (recombinant) version of this hormone (rBST). In February 1994, rBST was approved by the Food and Drug Administration (FDA) for

5 use in the U.S. It has become common in the U.S., but not elsewhere, to inject it into milch kine dairy cows to increase their production by up to 15%.

Dairy Cattle Breeds:

Major Breeds of Dairy Cattle- Holstein Friesian (HF):

• Origin: Netherlands • Characteristics: – Distinctive black and white markings – Large framed – Calf weighs 90 lb at birth – Mature cow weighs 1500 lb – Tremendous milk production • 21,167 pounds of milk / yr • 3.2% • 3.4%

Jersey: • Origin: Island of Jersey, GB • Characteristics: – Color: very light gray, mouse color to a very dark fawn, almost black • Dark points – Medium to Small Frame Size (smallest dairy breed) • Cow weighs 800 to 1200 lb. – Milk with highest • Milk yield 16,223 lb / yr • Protein 3.9% • Fat 4.9%

Brown Swiss: • Origin: Switzerland • Characteristics:

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– Color: Brown-grey – Strong feet and legs – Docile – Milk Production • Milk yield 21,242 lb / yr • Protein 3.5% • Fat 4.0%

Shahiwal: • Origin: India-Pakistan • Characteristics: – Color: reddish brown to red – Heat tolerance – Tick and parasite resistance – Milk Production • Milk yield 2270kg /lactation • Protein 3.5-4.0% • Fat 4.5-5.0%

Why do Dairy Farming?

Dairying is an important source of subsidiary income to small/marginal farmers and agricultural laborers. The manure from animals provides a good source of organic matter for improving soil fertility and crop yields. The goober gas from the dung is used as fuel for domestic purposes as also for running engines for drawing water from well. The surplus fodder and agricultural by-products are gainfully utilized for feeding the animals. Almost all draught power for farm operations and transportation is supplied by bullocks. Since agriculture is mostly seasonal, there is a possibility of finding employment throughout the year for many persons through dairy farming. Thus, dairy also provides employment throughout the year. The main beneficiaries of dairy programmes are small/marginal farmers and landless laborers. A farmer can earn a gross surplus of about Rs. 12,000 per year from a unit consisting of 2 milking buffaloes. The capital investment required for purchase of 2 buffaloes is Rs. 18,223/-. Even after paying a sum of Rs. 4294/- per annum towards repayment of the loan and interest the

7 farmer can earn a net surplus of Rs. 6000 - 9000/- approximately per year. (For details see model scheme enclosed). Even more profits can be earned depending upon the breed of animal, managerial skills and marketing potential.

According to World Bank estimates about 75 per cent of India's 940 million people are in 5.87 million villages, cultivating over 145 million hectares of cropland. Average farm size is about 1.66 hectares. Among 70 million rural households, 42 per cent operate up to 2 hectares and 37 per cent are landless households. These landless and small farmers have in their possession 53 per cent of the animals and produce 51 per cent of the milk. Thus, small/marginal farmers and land less agricultural laborers play a very important role in milk production of the country. Dairy farming can also be taken up as a main occupation around big urban centres where the demand for milk is high.

Package of Common Management Practices Recommended for Dairy Farmers Modern and well established scientific principles, practices and skills should be used to obtain maximum economic benefits from dairy farming. Some of the major norms and recommended practices are as follows:

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I. Housing: 1. Construct shed on dry, properly raised ground. 2. Avoid water-logging, marshy and heavy rainfall areas. 3. The walls of the sheds should be 1.5 to 2 meters high. 4. The walls should be plastered to make them damp proof. 5. The roof should be 3-4 meter high. 6. The cattle shed should be well ventilated. 7. The floor should be pucca/hard, even non-slippery impervious, well sloped (3 cm per meter) and properly drained to remain dry and clean. 8. Provide 0.25 meter broad, pucca drain at the rear of the standing space. 9. A standing space of 2 x 1.05 meter for each animal is needed. 10. The manger space should be 1.05 meter with front height of 0.5 meter and depth of 0.25 meter. 11. The corners in mangers, troughs, drains and walls should be rounded for easy cleaning. 12. Provide 5-10 sq. meter loaf space for each animal.

13. Provide proper shade and cool drinking water in summer. 14. In winter keep animals indoor during night and rain. 15. Provide individual bedding daily. 16. Maintain sanitary condition around shed. 17. Control external parasites (ticks, flies etc.) by spraying the pens, sheds with Malathion or Copper sulphate solution. 18. Drain urine into collection pits and then to the field through irrigation channels. 19. Dispose of dung and urine properly. A goober gas plant will be an ideal way. Where goober gas plant is not constructed, convert the dung along with bedding material and other farm wastes into compost. 20. Give adequate space for the animals. (The housing space requirement of crossbred cattle in various categories/age-groups is given in Annexure-VII). II. Selection of Animal: 1. Immediately after release of the loan purchase the stock from a reliable breeder or from nearest livestock market.

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2. Select healthy, high yielding animals with the help of bank's technical officer, veterinary/ officer of State government/ Zilla Parishad, etc. 3. Purchase freshly calved animals in their second/third lactation. 4. Before purchasing, ascertain actual milk yield by milking the animal three times consecutively. 5. Identify the newly purchased animal by giving suitable identification mark (ear tagging or tattooing). 6. Vaccinate the newly purchased animal against disease. 7. Keep the newly purchased animal under observation for a period of about two weeks and then mix with the general herd. 8. Purchase a minimum economical unit of two mulch animals. 9. Purchase the second animal/second batch after 5-6 months from the purchase of first animal. 10. As buffaloes are seasonal calves purchase them during July to February. 11. As far as possible purchase the second animal when the first animal is in its late stage of lactation and is about to become dry, thereby maintaining continuity in milk production vis-a-vis income. This will ensure availability of adequate funds for maintaining the dry animals. 12. Follow judicious culling and replacement of animals in a herd. 13. Cull the old animals after 6-7 lactations.

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III. Protection against Diseases 1. Be on the alert for signs of illness such as reduced feed intake, fever, abnormal discharge or unusual behavior.

2. Consult the nearest veterinary aid centre for help if illness is suspected. 3. Protect the animals against common diseases. 4. In case of outbreak of contagious disease, immediately segregate the sick, in-contact and the healthy animals and take necessary disease control measures. (Vaccination schedule is given in Annexure IX). 5. Conduct periodic tests for Brucellosis, Tuberculosis, Johne's disease, Mastitis etc. 6. Deform the animals regularly. 7. Examine the faeces of adult animals to detect eggs of internal parasites and treat the animals with suitable drugs. 8. Wash the animals from time to time to promote sanitation.

• Good understanding of milk and dairy products

• Perceived to be the highest form of

• Dairy products are highly price and income elastic

• Consumption at home

 Across all regions of the country  Integral to the meal structure  Highly versatile usage of milk and its derivatives

• Dairy products fast becoming one of the major sources of protein -other than pulses

• Milk fat is a very valuable product – higher realization than SNF. Dairy Challenges in India

• Low milk yield of cattle • Limited use of farm management techniques

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• Only 15% of milk processed in the organized sector • Wastage is high  Distribution constraints  Climatic conditions  Poor refrigerated storage facilities • High bacterial count of milk • Parallel economy thriving on adulterated milk Scope for Dairy Farming and its National Importance

The total milk production in the country for the year 2001-02 was estimated at 84.6 million metric tones. At this production, the per capita availability was to be 226 grams per day against the minimum requirement of 250 grams per day as recommended by ICMR. Thus, there is a tremendous scope/potential for increasing the milk production. The population of breeding cows and buffaloes in milk over 3 years of age was 62.6 million and 42.4 million, respectively (1992 census) 2.2 Central and State Governments are giving considerable financial assistance for creating infrastructure facilities for milk production. The ninth plan outlay on Animal Husbandry and Dairying was Rs. 2345 crores.

Processing of milk in farm house

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In most Western countries, centralized dairy facilities process milk and products obtained from milk (dairy products), such as , , and cheese. In the US, these dairies usually are local companies; while in the Southern Hemisphere facilities may be run by very large nationwide or trans-national corporations (such as Fonterra).  Storage tank  Pasteurization  Microfiltration  Creaming & Homogenization  Packing

1. Storage tank:

In storage tank store milk, then go on process of pasteurization. 2. Pasteurization:

Pasteurization is used to kill harmful microorganisms by heating the milk for a short time and then immediately cooling it. The standard High Temperature Short Time (HTST) process produces a 99.999% reduction in the number of bacteria in milk, rendering it safe to drink for up to three weeks if continually refrigerated. Dairies print expiration dates on each container, after which stores will remove any unsold milk from their shelves.

A side effect of the heating of pasteurization is that some vitamin and content is lost. Soluble and decrease by 5%, thiamin and by 10% and by 20%.

Because losses are small in comparison to the large amount of the two B- vitamins present, milk continues to provide significant amounts of thiamin and vitamin B12. The loss of vitamin C is not nutritionally significant, as milk is not an important dietary source of vitamin C.A newer process, ultra pasteurization or ultra-high temperature treatment (UHT), heats the milk to a higher temperature for a shorter amount of time. This extends its shelf life and allows the milk to be stored unrefrigerated because of the longer lasting sterilization effect.

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3. Microfiltration:

Microfiltration is a process that partially replaces pasteurization and produces milk with fewer microorganisms and longer shelf life without a change in the of the milk. In this process, cream is separated from the and is pasteurized in the usual way, but the whey is forced through ceramic micro filters that trap 99.9% of microorganisms in the milk (as compared to 99.999% killing of microorganisms in standard HTST pasteurization). The whey then is recombined with the pasteurized cream to reconstitute the original milk composition. 4. Creaming and homogenization:

Upon standing for 12 to 24 hours, fresh milk has a tendency to separate into a high-fat cream layer on top of a larger, low-fat milk layer. The cream often is sold as a separate product with its own uses. Today the separation of the cream from the milk usually is accomplished rapidly in centrifugal cream separators. The fat globules rise to the top of a container of milk because fat is less dense than water. The smaller the globules, the more other molecular-level forces prevent this from happening. In fact, the cream rises in cow's milk much more quickly than a simple model would predict: rather than isolated globules, the fat in the milk tends to form into clusters containing about a million globules, held together by a number of minor whey .[13] These clusters rise faster than individual globules can. The fat globules in milk from goats, , and water buffalo do not form clusters as readily and are smaller to begin with, resulting in a slower separation of cream from

these .

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Milk often is homogenized, a treatment that prevents a cream layer from separating out of the milk. The milk is pumped at high pressures through very narrow tubes, breaking up the fat globules through turbulence and cavitations.

A greater number of smaller particles possess more total surface area than a smaller number of larger ones, and the original fat globule membranes cannot completely cover them. Casein micelles are attracted to the newly exposed fat surfaces. Nearly one-third of the micelles in the milk end up participating in this new membrane structure. The casein weighs down the globules and interferes with the clustering that accelerated separation. The exposed fat globules are vulnerable to certain enzymes present in milk, which could break down the and produce rancid flavors. To prevent this, the enzymes are inactivated by pasteurizing the milk immediately before or during homogenization.

Homogenized milk blander but feels creamier in the mouth than unhomogenized. It is whiter and more resistant to developing off flavors.

Cream line (or cream-top) milk is unhomogenized. It may or may not have been pasteurized. Milk that has undergone high-pressure homogenization, sometimes labeled as "ultra-homogenized," has a longer shelf life than milk that has undergone ordinary homogenization at lower pressures.

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Homogenized milk may be more digestible than unhomogenized milk.

Kurt A. Oster, M.D., who worked during the 1960s through the 1980s, suggested a link between homogenized milk and atherosclerosis, due to damage to plasmalogen resulting from the release of bovine xanthenes oxidase (BXO) from the milk fat globular membrane (MFGM) during homogenization. Oster's hypothesis has been widely criticized, however, and has not been generally accepted by the scientific community. No link has been found between atherosclerosis and milk consumption. 5. Packaging:

Glass milk bottles are now rare. Most people purchase milk in bags, plastic bottles, or plastic-coated paper cartons. Ultraviolet (UV) light from fluorescent lighting can alter the flavor of milk, so many companies that once distributed milk in transparent or highly translucent containers are now using thicker materials that block the UV light. Milk comes in a variety of containers with local variants.

Packing machine pack milk in different weight such as 1 lit, 2lit and then after supplied market and other district and country.

Indian dairy products: A variety of dairy projects are indigenous to India and an important part of . The majority of these products can be broadly classified into curdled products, like china, or non-curdled products, like . A is food produced from the milk of mammals.

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Dairy products are usually high energy-yielding food products. A production plant for the processing of milk is called a dairy or a dairy factory. Apart from breastfed infants, the human consumption of dairy products is sourced primarily from the milk of cows, yet goats, sheep, yaks, horses, camels, and other mammals are other sources of dairy products consumed by humans. Dairy products are commonly found in European, Middle Eastern, and Indian cuisine, whereas aside from Mongolian cuisine they are little-known in traditional Asian cuisine.

1. Curdled dairy products 2. Non-curdled dairy products 3. Fermented dairy products 4. Other dairy products

1. Curdled dairy products  is an unaged, acid-set, non-melting made by curdling heated milk with juice or other non- food acid, and then removing the whey and pressing the result into a dry unit.  Chena is like paneer, except some whey is left and the mixture is beaten thoroughly until it becomes soft, of smooth consistency, and malleable but firm.  is a confection made from china mixed with then grilled lightly to caramelize, but removed from heat and molded into a ball or some shape.  is a confection made from mixture of china and rolled into a ball and boiled in syrup.

2. Non-curdled dairy products  Khoa or Mawa is made by reducing milk in an open pan over heat.  Peda is a confection made by mixing sugar with khoa and adding flavoring, such as .  Barfi is a confection made by reducing milk and sugar until it solidifies and adding flavoring, such as pistachio.

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 Gulab jamun is a confection made by mixing khoa and sugar, caramelizing it by frying, and soaking it in syrup containing rosewater.  is made from slowly freezing sweetened . In comparison to ice cream, Kulfi is not whipped or otherwise aerated.  is type of clarified butter that is cooked long enough to caramelize the milk sugar and sterilize the liquid.

3. Fermented dairy products  is dahi (Indian ) mixed with sugar  is strained yogurt mixed with sugar, and often flavorings such as cardamom, , or fruit.  Whey it is an alcoholic beverage prepared by fermenting whey with yeast.

4. Other dairy products  is made by boiling rice or broken wheat with milk and sugar, and sometimes flavored with cardamom, raisins, saffron, pistachios, or almonds.  Murki is made by frying cubes of chhena to burn the outside, then soaking them in syrup flavored with cardamom.  Pantooa is like gulab jamun, except with some chhena mixed with the usual ingredients. Basundi is also made up from milk.

What is milk?

• 87% water

• 13% solids

• Our most nearly perfect food.

• No other single food can substitute for milk in diet and give a person the same nutrients that you get from a glass of milk.

• Servings (1 cup/8 fluid oz)

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• Children 4-8 3 servings

• Children 9-18 4 servings

• Adults 19-50 3 servings

• Adults 50+ 4 servings Nutrients:

• Protein - body building and repair

• - energy and warmth

• Fats - energy and warmth, carries fat-soluble vitamins ADEK

• Vitamins - Growth, prevents diseases

• Vitamin D - bones and teeth, prevents rickets

• - aids growth, prevents night blindness

• (Vitamin B2) - regulates production of energy from dietary fat, carbohydrates and protein.

• Minerals - strong bones and teeth, body regulation

• Calcium - bones and teeth, prevents osteoporosis

• Phosphorus - bones and teeth Types of Milk

 Whole Milk (3.25% fat) contains 150 and 8 grams (g) of fat per serving (8 fluid oz). Although not required, whole milk may be fortified with vitamin D at a level of 400 International Units (IU) per 1 quart. If vitamin D is added, the label must state this fact.

 2% Reduced-Fat Milk (2% fat) contains 120 calories and 5 grams (g) of fat per serving (8 fluid oz). Vitamins A and D are removed with the milk fat. For this reason, these vitamins must be added to 2% reduced-fat milk so that it contains at least 2,000 IU of vitamin A and 400 IU of vitamin D per 1 quart. The addition of these vitamins must be stated on the label.

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 1% Lowfat Milk (also called Light Milk) (1% fat) contains 100 calories and 2.5 grams (g) of fat per serving (8 fluid oz). Vitamins A and D must be added to a level of at least 2,000 IU of vitamin A and 400 IU of vitamin D per 1quart. The label must indicate the addition of these vitamins.

 Fat-Free Milk (also called Skim or Nonfat Milk) (0% fat) contains 80 calories and 0 grams (g) of fat per serving (8 fluid oz). Vitamins A and D must be added to a level of at least 2,000 IU of vitamin A and 400 IU of vitamin D per 1quart The label must indicate the addition of these vitamins.

 Chocolate Milk (fat-free,1% lowfat, 2% reduced-fat, whole milk) is milk to which chocolate or cocoa and a sweetener have been added. This milk is just as nutritious as its unflavored counterpart. Compared to plain milk, chocolate milk contains about 60 more calories per serving (8 fluid oz).

 Evaporated Milk

(6.5% fat) is made by removing about 60% of the water from whole milk. The milk is then homogenized, fortified with vitamin D to a level of 25 IU per 1fluid ounce, canned and heat sterilized. The addition of vitamin A is optional. If added, each fluid ounce must contain not less than 125 IU of vitamin A.

 Evaporated Fat-Free Milk (0.5% fat or less) is a concentrated, fortified (vitamins A and D) fat-free (skim or nonfat) milk that is canned and sterilized

 Sweetened Condensed Milk (8% fat or less) is a canned milk concentrate of whole milk to which sugar has been added. The sweetener used (usually sucrose) prevents spoilage. Sweetened condensed fat-free milk contains no more than 0.5% milk fat.

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Various Types of Milk Products:

Milk after optional homogenization, pasteurization, in several grades after standardization of the fat level, and possible addition of bacteria Streptococcus lactis and Leuconostoc citrovorum

1. Crème fraîche, slightly fermented cream  Clotted cream, thick, spoon able cream made by heating  , Central and Eastern European variety of 2. Cultured milk resembling , but uses different yeast and bacterial cultures 3. , fermented milk drink from the Northern Caucasus 4. /Airag, slightly fermented mares' milk popular in Central Asia 5. Condensed milk, milk which has been concentrated by evaporation, with sugar added for reduced process time and longer life in an opened can 6. Khoa, milk which has been completely concentrated by evaporation, used in Indian cuisine including gulab jamun, peda, etc.) 7. Evaporated milk, (less concentrated than condensed) milk without added sugar 8. , acidified whey, reduced in volume 9. Infant formula, dried milk powder with specific additives for feeding human infants 10. Baked milk, a variety of boiled milk that has been particularly popular in Russia 11. Butter, mostly milk fat, produced by churning cream

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12. • Cheese, produced by coagulating milk, separating from whey and letting it ripen, generally with bacteria and sometimes also with certain molds. Milk Products –Yogurt

Yogurt is a mixture of milk (whole, reduced-fat, low fat or nonfat) and cream fermented by a culture of -producing bacteria, bulgaricus and Streptococcus thermopiles.

Other bacteria (e.g., acidophilus) and other strains of the above bacteria may be added to the culture. Sweeteners (e.g., sugar, , and aspartame), flavorings (e.g., vanilla, coffee) and other ingredients (e.g., fruits, preserves, stabilizers such as gelatin) may also be added. Yogurt contains at least 3.25% milk fat and 8.25% solids- not-fat. The mixture of dairy products and optional ingredients, except bulky flavorings, must be pasteurized or ultra pasteurized. The milk in most is also homogenized. Some yogurts carry a seal on the label indicating that the yogurt contains a significant level of live, active cultures. Milk Products – Cream

Half-and-Half is a mixture of milk and cream containing at least 10.5% but not more than 18% milk fat? This product contains about 20 calories and nearly 2 grams (g) of fat per tablespoon.

Light Cream (coffee cream, table cream) contains at least 18% but less than 30% milk fat. This product provides about 30 calories and 3 grams (g) of fat per tablespoon.

Light Whipping Cream (whipping cream) has at least 30% but not more than 36% milk fat. This product can be used as is (unwhipped) or whipped. Liquid (unwhipped) whipping cream contains about 44 calories and 5 grams (g) of fat per tablespoon.

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Heavy Cream must contain at least 36% milk fat. This product is readily whipped and can retain its whipped state longer than that of light whipping cream. Heavy cream provides about 52 calories and 6 grams (g) of fat per tablespoon. Milk Products – Cheese

All cheese is made from milk, but different manufacturing and aging processes are used to produce the array of available today. Cheese can be made from many types of milk, cows, goat, and buffalo.

Cheese is made by coagulating or curdling milk, stirring and heating the , draining off the whey (the watery part of milk),collecting and pressing the curd,and in some cases, ripening.

Cheese can be made from whole, 2% lowfat, 1% lowfat or fat-free milk, or combinations of these milks.

About one-third of all milk produced each year in the U.S. is used to make cheese. In 1998, 9.7 billion pounds of natural and processed cheeses were produced. Milk Products – Butter

Butter is essentially the fat of milk. It is usually made from sweet cream (as opposed to sour cream) and is salted. To be called butter, it must contain not less than 80% of milk fat. Different types of butter:

Cultured butter - An unsalted butter made from cream to which bacterial culture has been added. This gives it a distinctive, delicate, tangy taste that some refer to as having "old-country flavor".

Whipped butter - Made by the uniform incorporation of air or inert gas into butter. It makes it softer and easier to spread. It does not have the

23 same density as regular butter; therefore, it should not be used in recipes calling for plain butter.

Churned butter or sweet butter - It is traditional, everyday butter.

Flavoured butter - Butter herbs and/or spices have been added during the process, for example garlic butter.

Farm butter - Called "beurre cru" (raw butter) in France, it is made from unpasteurized milk. It typically has a better taste, but does not keep well.

Ghee - A type of clarified butter that originated in Eastern cultures. It is simmered until the moisture evaporates and the butter caramelizes. Available in specialty stores.

Unsalted - Contains 0% salt, used in pastries and cake production Semi- salted butter or lightly salted In the USA Butter grades are determined by classifying the flavor, then rating the body, color and salt characteristics. The resulting score translates into a grade B, A, or AA. Health:

According to a 2013 study, breast cancer survivors who consume high- fat dairy foods have a higher risk of dying from breast cancer than those who eat little or no high-fat dairy.

Dairy products can cause health issues for individuals who have intolerance or a milk allergy. Some dairy products such as blue cheese may become contaminated with the fungus Aspergillus fumigates during ripening, which can trigger asthma and other respiratory problems in susceptible individuals. Dairy products if consumed after the expiry date can cause serious heart problems.

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Milk Testing Procedure

FAT & SNF

Fat & SNF of milk is tested for each batch for each silo milk for standardization purpose and also for finished milk so as to ensure that milk is ready for dispatch. Fat and SNF is tested using a milcoscan. The temperature of the sample should be 84 degree F Heat. It is a latest technical machine for scanning of milk and uses I.R rays to analyze milk for Fat, SNF, Protein, , TS. Homogenization Efficiency

• Draw milk sample from outlet valve and note the homogenization pressure.

• Take 10 ml milk in centrifuge and see for any fat separation.

• If doubtful, prepare a slide and observe under micro scope the size of fat globule should not be more than 2 microns.

• In case unsatisfactory, the matter and cause is seen into.

Methyl Blue Reduction Test (MBRT)

Principle:

This test is based on the principle that methyl blue (an oxidation- reduction dye or indicator) which is blue in its oxidized state, is reduced to colorless compound (leuco form) as a result of the metabolic activities of bacteria in milk. When a solution of dye is added, the organisms present in milk consume the dissolved oxygen and lower O-R potential to a level where methyl blue or similar indicators are reduced or decolorized.

Procedure:

Take 10 ml of milk in a sterilized MBR tube. Add 1 ml of MBR dye. Plug with a sterilized cork. Invert the tube to mix the contents and incubate at 370C in a water bath. Check the tube for de-coloration first after 10

25 minutes and subsequently every hour milk. For pasteurized milk time should be 5 hrs or at least 4 hrs. Whereas for raw milk time is 30min. Keeping Quality of Milk

Keep milk samples of first and final testing in sterilized 125 ml glass bottle in incubator at 37°C.Note the time. Check for COB after 3 hrs first and then every hour till it becomes COB positive. Note down the % TA. Note total hours taken for milk to become COB positive. Observe for any abnormality such as cream layer, fat or powder separation Titrable Acidity

Take 10 ml milk sample to it add 10 ml distilled water add Phenolphthalein and titrate against N/10 NaOH.

Acidity% = titrate value x.09

Titrable acidity of milk from PM silo should not be greater than .14. COB

Take 2 ml milk in a test tube and kept in a boiling water bath for 5 min. The formation of curd indicates the poor heat stability and hence the positive COB test. Neutralizers

To 2 ml Rosalic acid in a test tube add 2 ml of milk. Rose red color indicates neutralizer present in milk and formation of flakes indicates disturbed salt balance. The neutralizer test results of processed milk should be negative so as to ensure that there is no misappropriation or mishandling during processing. After ensuring that fat percentage is 3.05 and SNF 8.58 minimum and all other tests are giving satisfactory results the milk is send or marked for dispatch. Procedure for Final Inspection & Testing of Milk

(1) Samples are drawn from filled dispatch tankers parked in the hard parking bay. Normally temperature of milk in tanker is checked from the sample drawn from delivery valve. If temperature is found more than 7°C

26 it is confirmed by taking sample from the top. Sample of few tankers is checked from top also for observation, temperature and MBR.

(2) The sample are tested for neutralizer test and for fat and SNF. If sample meets the requirements, the tanker is accepted and recorded. Few tankers are also tested for MBRT and if the MBRT of a tanker is found to be less than 4 hrs, milk of tanker is called back from retain outlets.

(3) If it fails to meet Mother Dairy dispatch standards, the tanker is rejected and shift in charge is informed.

(4) The system is so made that weighment of milk for dispatch is done only when the test results are found correct so as to ensure that quality milk leaves Mother Dairy.

(1) Regeneration-I: The milk is pumped to the balance tank from there the milk is pumped to regeneration-I wherein it gets heated to about 40- 45°C because of outgoing milk and hence reducing its temperature. Regeneration system helps in energy saving both for heating as well as cooling milk.

(2) Clarification: Clarification is the process of removing suspended foreign by centrifugal sedimentation – clarifies are used for this purpose.

(3) Regeneration-II The milk from clarifier is sent to regeneration-II wherein the milk is further heated by the pasteurized milk hence raising the temperature of incoming milk and reducing the temperature of outgoing milk and also regeneration-II raises the temperature of milk so as to enable efficient homogenization which is the next step.

(4) Homogenization: - Homogenization is a process wherein fat globules are broken down to 2 microns or less under high pressure Homogenizer is a machine which causes sub-diversion of fat globules. It consists of a high-pressure piston pump that forces the milk and thereby subdivided into smaller particles of more uniform size.

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Effect of Homogenization:

The fat globules of milk are surrounded by a membrane 5-10 mm thick. The membrane has properties of an emulsifier and keeps the emulsion, milk stable. During homogenization the original membrane is destroyed and the first result is a rise in interfacial tension soon falls again. The new emulsion therefore remains stable even after homogenization.

Homogenization effect is produced by three collaborating factors:

1. Passage through the narrow gap in the homogenizer head at high velocity subjects the fat globules to very powerful shear forces, which deforms elongate and shatter the spherical globules.

2. The acceleration of the liquid in the gap is accompanied by a pressure drop. This creates cavitations in which the globules are subjected to powerful implosive forces.

3. Further shattering takes places when the fat globules impact at high velocity in the homogenizing head"

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Milking Machines:

Milking machines are used to harvest milk from cows when manual milking becomes inefficient or labour-intensive. One early model was patented in 1907.

The milking unit is the portion of a milking machine for removing milk from an udder. It is made up of a claw, four teatcups, (Shells and rubber liners) long milk tube, long pulsation tube, and a pulsator. The claw is an assembly that connects the short pulse tubes and short milk tubes from the teatcups to the long pulse tube and long milk tube. (Cluster assembly) Claws are commonly made of stainless steel or plastic or both. Teatcups are composed of a rigid outer shell (stainless steel or plastic) that holds a soft inner liner or inflation. Transparent sections in the shell may allow viewing of liner collapse and milk flow. The annular space between the shell and liner is called the pulse chamber.

Milking machines work in a way that is different from hand milking or calf suckling. Continuous vacuum is applied inside the soft liner to massage milk from the teat by creating a pressure difference across the teat canal (or opening at the end of the teat). Vacuum also helps keep the machine attached to the cow. The vacuum applied to the teat causes congestion of teat tissues (accumulation of blood and other fluids). Atmospheric air is admitted into the pulsation chamber about once per second (the pulsation rate) to allow the liner to collapse around the end of teat and relieve congestion in the teat tissue. The ratio of the time that the liner is open (milking phase) and closed (rest phase) is called the pulsation ratio.

The four streams of milk from the teatcups are usually combined in the claw and transported to the milkline, or the collection bucket (usually sized to the output of one cow) in a single milk hose. Milk is then transported (manually in buckets) or with a combination of airflow and mechanical pump to a central storage vat or bulk tank. Milk is refrigerated on the farm in most countries either by passing through a heat-exchanger or in the bulk tank, or both.

The photo to the right shows a bucket milking system with the stainless steel bucket visible on the far side of the cow. The two rigid stainless

29 steel teatcup shells applied to the front two quarters of the udder are visible. The top of the flexible liner is visible at the top of the shells as are the short milk tubes and short pulsation tubes extending from the bottom of the shells to the claw. The bottom of the claw is transparent to allow observation of milk flow. When milking is completed the vacuum to the milking unit is shut off and the teatcups are removed.

Milking machines keep the milk enclosed and safe from external contamination. The interior 'milk contact' surfaces of the machine are kept clean by a manual or automated washing procedures implemented after milking is completed. Milk contact surfaces must comply with regulations requiring food-grade materials (typically stainless steel and special plastics and rubber compounds) and are easily cleaned.

Most milking machines are powered by electricity but, in case of electrical failure, there can be an alternative means of motive power, often an internal combustion engine, for the vacuum and milk pumps. Associated diseases:

• Leptospirosis is one of the most common debilitating diseases of milkers, made somewhat worse since the introduction of herringbone sheds, because of unavoidable direct contact with bovine urine

• Cowpox is one of the helpful diseases; it is barely harmful to humans and tends to inoculate them against smallpox.

• Tuberculosis is able to be transmitted from cattle mainly via milk products that are unpasteurized. The disease has been eradicated from many countries by testing for the disease and culling suspected animals.

• Brucellosis is a bacterial disease transmitted to humans by dairy products and direct animal contact. Brucellosis has been eradicated from certain countries by testing for the disease and culling suspected animals

• Wisteria is a bacterial disease associated with unpasteurized milk, and can affect some cheeses made in traditional ways. Careful observance of the traditional cheese making methods achieves reasonable protection for the consumer.

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• Johne's Disease is a contagious, chronic and sometimes fatal infection in caused by a bacterium named Mycobacterium avium subspecies paratuberculosis (M. partuberculosis). The bacteria are present in retail milk, and are believed by some researchers [who?] to be the primary cause of Crohn's disease in humans. This disease is not known to infect animals in Australia and New Zealand. Organic milk:

Organic milk refers to a number of milk products from livestock raised according to organic farming methods. In most jurisdictions, use of the term "organic" or equivalents like "bio" or "eco", on any product is regulated by food authorities. In general these regulations stipulate that livestock must be: allowed to graze, be fed an organically certified fodder or compound feed, not be treated with most drugs (including growth hormone), and in general must be treated humanely.

There are multiple obstacles to forming firm conclusions regarding possible safety or health benefits from consuming organic milk or conventional milk, including the lack of long term clinical studies.

The studies that are available have come to conflicting conclusions with regards to absolute differences in nutrient content between organic and conventionally produced milk, such as protein or fatty acid content.

The weight of available evidence does not support the position that there are any clinically relevant differences between organic and conventionally produced milk, in terms of nutrition or safety.

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Conclusion:

 Milk is the normal secretion of the mammary gland of mammals.  Also contains vitamins A, B1, B2 and small amount C & D.  Dairy microbiology is to prevent the spread of disease, to prevent the spoilage of milk and to produce desirable products from milk.

Kinds and source s of micro-organism of milk-

Organism Source Biochemical activities

Streptococci Manure, feed Early source of milk

Lactobacilli Manure, feed Produce 2-4% lactic acid

Micrococci Udder, equipment Produce small amount of acid from lactose.

Microbacteria Manure, equipment Heteroferementative.

Coliforms Soil, polluted water, feed Heteroferementative.

T.Lactis Feed, soil Produce gassy fermentation.