Flow diagram of YoghurtReceiving whole/defatted milk

|Standardization (0.5-5% fat, 9-15 %SNF)

|Filtration/clarification (35-40°C)

|Pre-heating the mix (60°C)

|Homogenization (2500psi)

|Pasteurization at 85°C/30 min.

|Cooling (43-44°C)

|Inoculation (2%)

|Packaging

|Incubation (41-42°C/3 hrs) (0.75%T.A.)

|Cooling and storage (5-7°C)

R.S.Dabur(APT403)2009Fermented Milk Products

Traditionalo Dahio Lassio Shrikhand

Westerno Cheddar cheeseo Mozzerella cheese

Fermented milk constitutes a vital component of the human diet. Fermented milk products such as dahi (curd) and lassi (stirred yoghurt)/chhach (buttermilk) figure prominently in people’s diet. The Bureau of Indian Standards (BIS) specifications for fermented milk products are based on the type of culture used in their preparations. Conversion of milk into dahi/lassi imparts a thicker consistency, smooth texture and a distinct flavour that provides safety, portability and novelty to milk nutrients. Many refreshing beverages were prepared from fermented milk. Yoghurt, a popular fermented dairy product in Europe, North and South America resembles the Indian dahi. Lassi, a refreshing drink made from, is widely popular in North India. Milk is also fermented to dahi as an intermediate base product in the making of makkhan (cultured butter), ghee, chakka, and shrikhand.Different products made from the fermented milk are as follows: YoghurtYoghurt is a semi-solid fermented product made from a standardized milk mix by the activity of a symbiotic blend of Streptococcus thermophilus and Lactobacillus delbruekki subsp. Bulgaricus cultures. Yoghurt was made from boiled concentrated whole milk, but most modern methods of manufacture use whole or partly defatted milk containing small amounts of skim milk powder or concentrate. The fat content in yoghurt may vary from 0 to 5 % and the solids content from 9 to 20 %. In case of yoghurt thermophilic cultures (Lactobacillus bulgaricus, Streptococcus diacetilactis, and Lactobacillus acidophilus) are used which improves the flavour of the yoghurt. Yoghurt is highly acidic in taste and has a harsh acidic flavour. So, it is rarely consumed plain. Yoghurt is served with various fruits, flavourings and aroma additives Nutritive Value

As it is made up of milk, it is rich in nutrients. It contains protein and a range of vitamins and minerals. Yoghurt is a useful source of Calcium. 150 g contains as much Calcium as 1/3 a pint of milk.

Advantages The cultures found in yoghurt such as Acidophilus are beneficial to

the digestive system. Bifidobacterium is other beneficial bacteria found primarily in the

large intestine and these bacteria produce B-vitamins such as B1, B6 and B12 as well as folic acid and some amino acids.

Eating yoghurt will help maintain healthy levels of beneficial bacteria in your gastrointestinal tract. General Categories of yoghurt

Firm Yoghurt – Firm gel in a pack normally consumed by use of a spoon. Stirred Yoghurt – Gel has been broken, cooled and packed after coagulation. Drinkable Yoghurt - Like stirred but product has been homogenized and brought into a liquid form before filling.

Details of Production: Skim milk powder/concentrate is added to whole or partly defatted milk to increase the solids not fat content by 2-3% to a total of approx. 12% . The mix is preheated to 60°C and homogenized single stage at 2000-2500 psi. Sterilizers are frequently added to the mix but are not essential and excessive amounts are to be avoided. The mix is heated in a vat to 85°C, inoculated with 2% bulk starter and stirred briefly to ensure proper mixing. The mix is then packaged, care being taken that the temperature does not fall below 41°C during the filling operation. The time interval between inoculation and filling should not exceed 45 min. Yoghurt is incubated in the package without further agitation at 41-42°C for about 3 hours, till a titratable acidity of

1

R.S.Dabur(APT403)20090.75% is reached. It is then placed under refrigeration to cool to 5-7°C; approx. 8 hours are required, at which time the product is ready for distribution. A final acidity of 0.9% is desired in the product. SHRIKHANDShrikhand is semi solid soft, sweetish sour fermented dairy product. It is prepared from cow, buffalo or mixed milk. Lactic fermented curd is obtained by the associative action of microorganisms on the milk constituents. The curd is cut or stirred to expel whey through a muslin cloth. This results in a solid mass known as chakka.

The next step in the preparation of shrikhand is mixing chakka with the required amounts of sugar, colour, flavour etc. to get the end product. The composition of the shrikhand depends on the initial composition of the milk, the degree of fermentation, the extent of whey removal and the quality of sugar added. The standards outlined by BIS are given below.

Recipe for Shrikhand / Method of ManufactureTraditional Method

Good quality milk is standardized to 5.0 per cent fat This milk is transferred a kettle / vat / container through a muslin cloth. The milk is heated to boiling and cooled to 30°C. Lactic culture is added at the rate of 0.5 percent of milk and mixed well with the help of a stirrer. The starter culture should preferably be

curd from the previous batch. The milk is incubated at 30°C till the desired acidity is attained. The duration of incubation is usually 10-12 hours. After the curd has been properly set and the desired acidity developed, the contents are transferred to another vessel through a clean,

wet muslin cloth. The muslin cloth containing the curd is formed in to a bag and hung on a stand to facilitate draining of whey. To achieve the faster

expulsion of whey, gentle pressure may be applied. The whey is collected separately in another container. A semi solid mass is obtained after the complete expulsion of whey. This is called as chakka and this is used as an ingredient in the

production of shrikhand. The weight of the chakka is measured and is transferred to mixer or blender. Good quality sugar at the rate of 80% of the weight of chakka is added to chakka and it is thoroughly kneaded or mixed either manually

or mechanically to a homogeneous consistency. Flavour, colour and other additives such as fruits, nuts etc. may be added to enrich the shrikhand depending on the consumers taste. The weight of the product is recorded and it is usually packaged in polystyrene cups and stored under refrigerated condition.

Industrial Method Milk of good quality is selected and then it is separated in a cream separator into skim milk and cream. The skim milk should be devoid of

fat as for as possible and the fat percentage in cream should be high (preferably 70% and above). The skim milk is heated to 90°C for 10 min followed by cooling to 30°C or the milk can be pasteurized in a batch pasteurizer. The cream

can also simultaneously be pasteurized at 85°C for 15 sec for later use. The heated skim milk is taken in a pre sterilized storage vat and 0.5 percent lactic starter culture is added and mixed well with a

mechanical agitator. The temperature of vat is maintained at 30°C by circulating warm water and incubated for 8 h. When the curd is properly set and the acidity level reaches 0.8 – 1.0 percent, the incubation is stopped. The whey is separated by centrifuging the curd for 5 min using a basket centrifuge (working at 1100 rpm). After centrifugation, chakka is obtained. It is then transferred to a planetary mixer. The required quantum of pasteurized cream and sugar is added to the chakka (the fat in the final product should be about 6 percent and

sugar 42%). The contents are mixed by running the mixer at variable speeds. Flavour, colour and the required additives may also be added during the mixing process with sugar and cream. The final product is cooled and filled in the wax coated paper cups or polystyrene cups and the quantity packed varies between 100 and

500 g. The shrikhand is stored under refrigerated temperature till consumed.

2

Characteristics Skim Milk Chakka Whole Milk Chakka ShrikhandTotal solids % min 20 30 58

Milk fat (%) DM 5 (Max) 33 (Min) 8.5

Milk Protein (%) min on DM 60 37 10.5

Titratable acidity % LA 2.5 2.5 1.4

Total ash (%) Max on DM 5 3.5 0.9

Sugar (%) Max on DM -- -- 72.5

Coliform (per g) Max 10 10 10

Yeast and Mould (per g) Max 20 20 50

Flow diagram of LassiMilk

|Standardization (1.5-3.8%fat, 9%SNF)

|Pasteurization at 90°C/15 min.

|

Homogenization at 150 kg/cm²(First stage) and 50 kg/cm² (second stage).

at 60°C.|

Cool to 31°C|

Inoculation (1.0-1.5%)|

Setting overnight for 16 hrs to pH 4.1Breaking the firm curd by agitation for a

Minute|

Addition of water (20litre/100 litres lassi)|

Mix well and let it stand for 1 hour|

Packaging

R.S.Dabur(APT403)2009LASSI

Lassi is a refreshing summer beverage, popular in North India. Lassi is a white to creamy-white, viscous liquid, rich aroma and mild to high acidic taste. It is obtained from pasteurized milk or part skim milk, cultured with Lactic and aroma/flavour producing organisms. The term Lassi is also used for a phospholipids-rich fluid fraction obtained as a by-product during the churning of dahi and cold water mixture while making makkhan. Lassi, also called chhach or matha, refer to desi buttermilk. It is also called Moru in Kerala and is consumed as an accompaniment to rice and pickle. Moru diluted with water to reduce its acidity and flavoured with salt, crushed ginger, curry leaves and green chillies is called sambhaaram, which is popular in the southern states of India. It appears that 50-60 kg. (ave. 55 kg) of lassi are produced for every kg. of ghee. Composition

The composition of lassi varies considerably, depending upon the composition of dahi, the extent to which the curd is diluted when churning and the efficiency of fat removal. An average composition of lassi is given in table.Composition of lassi (percentage)Water Total

solidsFat Solids-

not-fatProtein Lactose Ash Lactic

acid93.2 6.8 0.8 6.0 2.5 2.2 0.6 0.44Food and nutritive value

Lassi contains appreciable amounts of milk proteins and phospho-lipids, and is an excellent beverage for quenching thirst by reason of its lactic acidity.

YieldThis will depend mainly on the extent to which the curd is diluted when churning –

the greater the dilution, the greater the yield, and vice versa.

Uses:As a beverage, usually after the addition of ice (in hot weather) sugar or salt, with or without additional flavours; As a starter culture (optional); As a coagulant (optional).Matha, chhach or chhas are synonyms for a product – buttermilk, which is commonly consumed in all parts of India. It is a popular refreshing summer beverage. It is also known by at least five synonyms in southern states.Technology: Boiled/pasteurized milk is cultured with dahi used as inoculum @ 1.0-1.5 per cent. Milk is allowed to set overnight at 220C. Fresh cold water is added to the set dahi, and it is stirred using a “mathani” (wooden stirrer with blade impellers) driven by a small rope in to and fro circular motion. Grains of makkhan which form as a result of beating the dahi water mixture float up on top and are scooped out from time to time using a wooden ladle. When all the makkhan is recovered, the residual watery fluid is consumed as chhach/lassi.

Physiochemical aspects: Lassi is highly flavourful and mildly to highly acidic. The composition of lassi varies considerably, depending upon the composition of dahi, the extent to which the curd is diluted when churning or efficiency of fat is removed. It contains 6-7% milk solids and 1-2%fat. The fat retained in lassi is comparatively high in low-melting constituents of milk fat. The product is also rich in protein and lactose. The quality defects commonly encountered in lassi similar to those of dahi. Uses

As a beverage, usually after the addition of ice (in hot weather) sugar or salt, with or without additional flavour.As a starter culture (optional).As a coagulant (optional).

DahiIndian curd, known as dahi is a well known fermented milk product consumed by large section of the population. According to PFA rules, dahi or curd is the product from pasteurized or boiled milk by natural or using bacterial culture. Dahi may contain additional cane sugar. It should have the same percentage of fat and solids-not-fat as milk from which it is prepared. Dahi is consumed as a part of daily diet or a refreshing beverage. It can be categorized as follows: North Zone Dahi, Lassi South Zone Dahi, Buttermilk (matha) East Zone Payodhi or misti dahi West Zone Shrikhand, Chakka

3

Flow diagram of DahiReceiving Milk

|Pre-heating (35-40°C)

|Filtration/Clarification

|Standardization

|Pre-heating (60°C)

|Pasteurization (80-90°C/15-30 min.) and

homogenization|

Cooling (22-25°C)|

Inoculation (1-3%)|

Packaging|

Incubation (22-25°C/16-18 hrs)|

Cooling and Storage

R.S.Dabur(APT403)2009The Indian Standard (1978) specification for fermented milk products, dahi should have a pleasing flavour and a clean acidic taste, devoid of undesirable flavour, should have firm body and texture and be uniform with negligible whey separation. Other characteristics should be as follows:

Nutritive Value Dahi has more nutritive value as compared to original milk. Dahi is more palatable, and those who usually do not like drinking milk would

consume it readily. Dahi is more easily digested and assimilated than milk. Dahi seems to exert possible therapeutic value in the stomach and during intestinal

disorders, due to its content of antibiotics.Starter cultures used in manufacture of fermented milk products:Product Microorganisms Incubation temp. &

timeDahi, Shrikhand, Misthi doi, Lassi, Buttermilk

Lactococcus lactis subsp. lactis Lactococcus lactis subsp cremoris Lactococcus lactis subsp. Lactis var. Diacetyllactis

22°C for 12-14 hours or37°C for 5-8 hours

Yoghurt Lactobacillus delbrueckii subsp.bulgaricus Streptococcus thermophilus

43-45°C for 3-4 hours

Uses of Dahi Whole milk dahio For direct consumption: either as such or with salt/sugar.o For the preparation of Chakka and Shrikhand.o For the preparation of makkhan. Skim milk dahi o For direct consumption.o Especially by heart patients since it is low in fat.

Details of production: Fresh, sweet, good quantity milk (cow, buffalo or mixed) is received, pre-heated to 35-40°C and subject to filtration/clarification. It is then standardized to desired level of fat and SNF may be increased at 10%, pre-heated to 60°C and homogenized single stage at a pressure of 176kg/sq.cm. The milk is pasteurized at 80-90°C for 15-30 min. ., cooled to 22-25°C and inoculated with 1-3% of specific starter culture. It is then filled in suitable containers (glass, bottles or plastic cups etc.)of the required capacity and incubated at 22-25°C for 16-18 hrs, during which period the acidity reaches 0.6-0.7% and a firm curd is formed. The curd is cooled to less than 10°C and then stored at about 5°C in a cold room.

MISTI DAHI

Misti dahi or sweet curd is an indigenous sweetened fermented milk product popular in the eastern parts of the India, particularly, in the district of West Bengal. Because of its brown colour as a result of caramelization of sugar during heating, it is also called Lal Doi. The misti dahi is mainly produced on a domestic scale. But the potential for its adoption on an industrial scale is very bright. At present no legal standards are available for

the product. The recipe for misti dahi is as follows. Method of manufacture Good quality cow milk or buffalo milk selected on the basis of organoleptic properties and acidity is standardized to 3.5% fat and 9.0% SNF.

The standardized milk is filtered through a muslin cloth and then heated to a temperature of 70°C in a multipurpose vat. The milk is homogenized in a single stage homogenizer with the pressure at 800 PSI. The milk is then added with 12% sugar and heated to 85°C accompanied by continuous stirring. The heating is continued till it attains 1.5

times concentration. A caramelized flavour develops in the product during concentration. Then the milk is cooled to 30°C and lactic culture is added at the rate of 1% and mixed thoroughly. The cultured milk is filled in polystyrene cups under aseptic condition. The cups are incubated at 30°C till the curd (dahi) is properly set

and desired acidity develops. This usually takes around 8 h.

4

Characteristics Requirements Sweet dahi Sour dahi

Acidity lactic (%wt.)Max. 0.70 1.0Yeast and mould count per g. Max. 100 100Coliform Count per g. Max. 10 10Phophatase test -ve -ve

The designation of dahi based on the types of culture used.Designation culture used Sweet dahi Streptococcus lactis single or

in combination with S.diacetilactis, S. cremoris & Leuconostoc species

Sour dahi Same as above, along with Lactobacillus bulgaricus or Streptococcus thermophilus or both

R.S.Dabur(APT403)2009 The cups containing misti dahi are stored in refrigerated temperature (5°C) till use.

Cheese Cheese has been defined by’Davis as a product made from the curd obtained from milk by coagulating the casein with the help of rennet or similar enzymes in the presence of lactic acid produced by added or adventitious micro-organisms, from which part of the moisture has been removed by cutting, cooking and/or pressing, which has been shaped in a mould, and then ripened by holding it for some time at suitable temperatures and humidity Frequently, cheeses are classified on the basis of moisture content and mode of ripening. One such classification system as follows:

1. Very hard (moisture <25%) a. Ripened by bacteria: - Parmesan, Romano.

2. Hard (moisture 25% to 35%)a. Ripened by bacteria, without eyes: Cheddar, Colby.b. Ripened by bacteria, with eyes: Swiss (Emmental).

3. Semi soft (moisture35-40%)a. Ripened principally by bacteria internally: Edam and goudab. Ripened by bacteria and surface microorganisms: Limburger, Brick.c. Ripened principally by blue mold internally: -Roquefort, Blue, and Stilton.

4. Soft (moisture >40%) a. Surface Ripened: Camembert, Brie.b. Unripened: Cottage: Baker’s Cream, Ricotta, Mozzarella.

MANUFACTURING OF CHEDDAR CHEESEStandardization: refers to adjustment of the casein/fat ration in cheese milk to 0.68-0.70.Objective: I) To regulate the fat of cheese on dry mater basis.

ii) To produce the maxi. Yield of cheese/kg of fat in cheese milk.Culturing:Role of LAB

i) Helps in curdling milk with rennet.ii) Helps in expulsion of wheyiii) Helps in the fusion of curd particlesiv) Exerts protective action against putrefactive bacteriav) Favors proteolytic action of rennet extract during curing.

Renneting: 1 part can clot about 5 million parts of milk.Activity: Temp. 30-480C opt. 400CRennet is added when the acidity has increased from initial level by 0.02%Amount of rennet should be added depends on:

1. Temperature of milk2. Acidity of milk3. Strength of rennet4. Composition of milk

Liquid rennet - @ 15-25 ml/100 litre of milkCoagulation / setting: Refers to liquid milk changes to semi solid curd.Cutting: refers to the cutting of firm coagulum into cubes of a specific sizeCooking: heating of curd cubes within 15 minutes of cutting.Drainage of whey / dipping: refers to the removal of whey from the curd.Cheddaring: This refers to the combined operation of packing, turning, piling and repeling the curd cubes.(a) Packing: After the bulk drainage of whey, the Curd cubes are kept closely together in two heaps with a channel in between (for continuing the whey removal process). This is known as Packing, and takes 5 to 15 minutes after dipping. It results in the formation of two long slabs of curd. These are cut with a cheese knife into blocks or strips 15 to 20 cm wide.(b) Turning: As soon as the blocks (strips) of curd can be handled without breaking, they are rolled bottom-side up in the vat. This is called turning and is carried out every 15 minutes till curd is ready for milling and salting.Note: The vat is kept covered and the temperature of the curd maintained at about 32oC.(c) Piling and repiling: Within 30 to 45 minutes of packing blocks of curd are turned and laid one over another in twos and threes. This is called piling. Then the position of the curd block altered and this is known as repiling.(d) The Cheddaring operation usually lasts two hours or more and is very important not only for moisture control but also improving body and texture. After Cheddaring, the curd becomes drier, more mellow and silky and changes from a sorbo rubber like material to one resembling chicken

5

CHEDDAR CHEESE CHEDDAR CHEESE Receiving milkReceiving milk

Pre-heating (35—4OoC)Pre-heating (35—4OoC)

Filtration/ClarificationFiltration/Clarification

StandardizationStandardization

Pasteurization (63°C; 30 min.)Pasteurization (63°C; 30 min.)

Adding Starter (@ 0.5-1.0% ofAdding Starter (@ 0.5-1.0% of

milk (Ripening) 30oCmilk (Ripening) 30oC

Adding colour (@ 50-200Adding colour (@ 50-200 ml/1000 kg)ml/1000 kg)

Adding Rennet (Renneting) 30Adding Rennet (Renneting) 30

oCoC

Coagulation / SettingCoagulation / Setting

CuttingCutting

Cooking (Up to 37—39oC)Cooking (Up to 37—39oC)

Drainage of wheyDrainage of whey

CheddaringCheddaring

MillingMilling

SaltingSalting

HoopingHooping

DressingDressing

PressingPressing

DryingDrying

ParaffiningParaffining

(Curing & Maturing)(Curing & Maturing)

R.S.Dabur(APT403)2009breast-meat. In the later stages, it tends to tear apart in fibrous shreds and develops a Characteristic nutty and buttery aroma. The end of the Cheddaring operation is indicated by:(i) Titratable acidity: 0.30-0.35 percent more than at cutting.(ii) Hot iron test: long threads, 12 mm or slightly more:(m) pH: About 5.4. Milling. This refers to the mechanical operation of cutting the blocks of cheddared curd into small pieces with the help cheese mill.

Objects: These are: To promote the further removal of whey; To enable quick distribution of salt in the curd; To prepare curd for pressing into final form; Other benefits include: de-odourization; cooling of curd, through more rinsing if needed; and making cheese more uniform in

composition.The curd pieces are stirred gently to prevent matting.(i) Milling normally releases a small amount of whey from (ii) After milling; the curd pieces may be rinsed with water to improve their physical

condition for salting and pressing. Salting: This refers to the addition of common salt to the curd pieces. Salt in cheese affects flavour, body and texture, and keeping quality. Cheeses without salt are soft, ripen quickly and rapidly develop unpleasant flavours.(a) Objects. These are:

The farther removal of whey; Hardening and shrinking of curd Retarding further formation of lactic acid; Checking undesirable fermentation; It producing desirable quality characteristics.Cheese curd is normally salted: About 15 minutes after milling; when a hot iron test shows

threads 1 to 2 cm. long; When acidity is 0.4 to 0.5 per cent; and When pH is 5.4 to 5.0.

Arnount of salt added. This depends on the amount of curd in vat and salt content desired, and generally varies from 1 to 2 per cent.Both under-salting and over-salting of cheese are undesirable; while under-salting produces a weak and pasty body, open texture and abnormal ripening, over salting produces a harsh body, slow ripening, close texture and cracked rinds.

Hooping: refers to the curd being placed in hoops or moulds in which cheese curd is pressed into its final shape. Temp. of hoping should be 30-320C.

Dressing: refers to the arrangement of the cheese cloth before and after pressing.

Pressing: refers to the operation of forcing the particles of milled and salted curd in the hoops into the smallest possible space.

Drying: Keeping cheese block at 12-160C and relative humidity at 50% for a few days. The cheese is turned at 24 hr intervals so that both the sides can dry and form the desired rind.

Paraffing: refers to the operation of dipping the cheese for a few seconds in a bats of melted paraffin, to make a thin coating of paraffin is applied to the surface of the cheese.

Curing maturing: Curing/ripening/maturing of cheese refers to the storage of cheese for at least 2 to 3 months at a given temperature (0-160C).

Yield: Cheese yield is mainly depends upon casein and fat content of milk 1 kg extra casein increases 2.5-2.75 kg cheese since each 1 kg of casein comes 1.5-1.75 kg of moisture. On the other hand, an extra 1 kg fat increased the yield by only 1 kg. Y = (F+) NY = Kg cheese/100 mg milkF = fat /100 kg milkC = Casein /100 kg milk

6

MANUFACTURING OF PROCESS CHEESEMANUFACTURING OF PROCESS CHEESEReceiving of raw cheeseReceiving of raw cheese

AnalyzingAnalyzing acidity, fat, moisture and salt etc.

Selecting for blending Selecting for blending

Blending: Preferred 75% 2-3 month Old 25% 6-12 old month High acid cheese should not be more than 5% of total

Tempering and cleaning Tempering and cleaning

Tempering refers to luring it proper consistency or hardness by attaining its temp. 16-200C 48 hrs

Cleaning means removal of inedible portions of cheese before processing.

Quartering and grindingQuartering and grinding

Refers to cut cheese block into four pieces. Shredding of cheese block by forcing it pass through heavy

metal perforated screen

ProcessingProcessing Shredded is dropped into cheese kettle cooker and then

added calculated amount of water, colour, emulsifier (0.5-3.0% - disod. Phosphate or trisod. Citrate) and salt.

The optimum time – temp combination for processing 650C-2.5 minutes

PackagingPackaging

Semi fluid condition it is packed in plastic containers/cups

Cooling and storageCooling and storage

Packed cheese is slowly cooled down to 10-210C and then only after ward kept at under refrigeration 2-40C

R.S.Dabur(APT403)2009N = 1.63 for green cheese

= 1.555 for curd cheese

7