Module 7. Chhana
Lesson 16
PREPARATION OF CHHANA FROM BUFFALO MILK
16.1 Introduction
In India about 53% of the total milk produced is from buffaloes. Dairy plants prefer to buy buffalo milk as it contains higher proportion of fat and total solids, approximately 1.5 to 2.0 times more fat than cow milk. Because of many inherent differences in physico-chemical makeup of cow and buffalo milk, several problems are encountered during processing of buffalo milk. Calcium content has direct correlation with hardness of chhana. The high calcium and casein (cow milk contains 110mg calcium and 2.42 - 2.7% casein and buffalo milk contains 170mg calcium and 2.6 - 3.38% casein per 100g milk) contents in buffalo milk render it unfit for preparation of most chhana based sweets. Few attempts have been made to produce chhana from buffalo milk.
A mixture of buffalo milk and cow milk in the ratio of 1:3 yields chhana with soft body and smooth texture which is desired feature of chhana for rasogolla and sandesh preparation.
Addition of mixture of sodium diphosphate (75g per 100lit.) and disodium phosphate (58g per 100lit.) followed by storing the hot milk for some time before precipitation produces a soft chhana. Sodium citrate converts some of the insoluble calcium into soluble salts in buffalo milk and this helps in production of softer chhana.
Dilution of buffalo milk (standardized to 4% fat) with potable water @ 30% of milk after boiling and coagulating at 70°C using 0.5% citric solution produces chhana good for sandesh making.
16.2 Factors influencing quality of chhana
16.2.1 Type of milk
Cow milk produces chhana with moist surface, light yellow colour, soft body, smooth texture and mildly acidic flavour which is more suitable for sweet preparation than buffalo milk chhana. Buffalo milk produces chhana with hard body and coarse texture, with white colour and greasy surface. Sweets prepared from buffalo milk chhana are hard, coarse and less spongy. Colostrum milk produces pasty Chhana with deeper yellow colour and unsuitable for rasogolla production.
16.2.2 Quality of milk
16.2.2.1 Fat level
Minimum 3.5 to 4% fat in cow milk and 5% fat in buffalo milk gives a satisfactory body and texture in chhana. Lower than 3.5% fat leads to hard body and coarse texture while higher fat level results in greasy surface.
16.2.2.2 Acidity
Acidic milk produces chhana with sour smell and bitter taste hence unfit for sweet making. Addition of neutralizer to slightly acidic milk helps in getting chhana suitable for sandesh and not for rasogolla. Milk with 0.25-0.28% LA can be used by adding 0.2% Sodium Citrate followed by thorough washing of the coagulum.
16.2.3 Type, strength and quantity of coagulant
16.2.3.1 Type
Organic acids, like citric acid, lactic acid or sour whey are normally used. Lactic acid produces granular chhana suitable for rasogolla making. Citric acid gives pasty texture suitable for sandesh making. However, dilute solution of citric acid can also be used for making chhana suitable for rasogolla. Sour whey with (0.9% LA) can also be used for producing good quality chhana. Calcium lactate produces chhana with bright white colour, soft body and smooth texture and pleasant flavour and most suitable for sandesh making.
16.2.3.2 Strength
Low acid strength (0.5%) results in very soft body and smooth texture suitable for rasogolla but unsuitable for sandesh making. The optimum strength of coagulant should be between 0.5 to 0.8% citric or lactic acid to produce good quality chhana suitable for making both rasogolla and sandesh. However, calcium lactate of 4% solution produces most satisfactory quality chhana.
16.2.3.3 Quantity
The quantity of coagulant required is dependent on the type of milk. Generally, 2 to 2.5 g of citric acid per kg of fresh milk and 2.5 to 3.9 gm of lactic acid and 6 to 12 gm of calcium lactate per kg are required individually for complete coagulation.
16.2.4 Temperature and pH of coagulation
As the coagulation temperature decreases, the moisture content of chhana increases resulting in softer body and smooth texture. Higher coagulation temperature imparts graininess and hardness to chhana. Optimum coagulation temperature of cow milk is 80 to 85°C and pH is 5.4 and that of buffalo milk is 70 to 75°C and pH is 5.7.
16.2.5 Speed of stirring during coagulation
Higher speed of stirring during coagulation reduces the moisture content of chhana and increases its hardness, optimum speed is 40-50 rpm.
16.2.6 Method of Straining
Delayed straining produces a soft and smooth texture chhana than immediate straining. Delayed straining gives a higher proportion of moisture, yield, recovery of milk solids and lower hardness. Delayed straining is recommended for buffalo milk.
16.2.7 Effect of heat treatment given to milk
The recovery of milk solids and yield of chhana is influenced by the heat treatment given to milk prior to acidification. The heat treatment prior to acidification involves temperature to which milk is heated, the rate of heating, temperature to which milk is cooled and the rate of cooling. Several heat induced changes occur during heating; denaturation of whey proteins and their subsequent association with casein micelles, precipitation of calcium phosphate onto the casein micelles and dissociation of κ-casein from the micelle. The degree of denaturation of whey proteins depends on time temperature combination during heating and is mainly determined by maximum temperature to which milk is heated. Whey protein denaturation at above 70°C is two step process, first an infolding of whey proteins takes pace followed aggregation. α-lactalbumin shown the higher resistance to denudation and it reported that 95°C temperature denaturates all the whey proteins.