List of Indian diary products: 1. Kheer 2. Khurchan 3. Rabri 4. Kulfi/Malai-Ka-Baraf 5. Srikhand 6. Lassi 7. Ghee Residue.
1. Kheer:
Kheer, also known as Basundi, is an Indian dessert prepared by the partial dehydration of whole milk in a karahi over a direct fire together with sugar and usually rice or occasionally semolina. It is popular throughout the country.
Chemical Composition:
The average chemical composition of laboratory-made kheer (prepared under standardized conditions in a stainless steel kettle) is given in percentage below:
Moisture – 67.02
Fat – 7.83
Protein – 6.34
Lactose – 8.45
Ash – 1.14
Sugar (added) – 8.95
Food and Nutritive Value:
Containing all the solids of milk in an approximately two-fold concentration plus additional sugar, the food and nutritive value of kheer is fairly high.
Standardized Method of Preparation:
Fresh, sweet, cleaned milk (cow or buffalo) is standardized to 4.0 per cent fat and vigorously boiled in a jacketed stainless steel pan or kettle† for 3 to 5 minutes accompanied by constant stirring-cum-scraping with a khunti‡. High grade (preferably basmati) rice @ 2.5 per cent of milk, pre-cleaned and washed with cold water before use, is now added. The mixture is gently boiled, with periodical stirring- cum-scraping.
When the concentration is about 1.8: 1, clean, good quality sugar (preferably ground) is added @ 5 per cent of milk. Gentle heating is continued for another 3 to 5 minutes till a final concentration of about 2: 1 is obtained. Heating should be stopped somewhat before this stage, depending on the manufacturer’s judgement. The kheer should now be packed and then stored under refrigeration.
Yield:
The yield of kheer is highly variable depending on the percentage total solids in milk, the amount of rice/semolina and sugar added and the ratio of concentration of the mixture required to arrive at the desired consistency (adjudged by experience) in the finished product. If the ratio of concentration is about 2, the yield of the finished kheer should be about 50 per cent of the mi k used.
Keeping Quality:
The average shelf-life of kheer is 2 to 3 days at 37 ± 1°C and 10 to 15 days at 4 ± 1°C. Its storage-life could be increased significantly by the addition of nicin (to the hot product at the end of the manufacturing process and before packaging).
Uses:
For direct consumption as a dessert.
2. Khurchan:
This is a concentrated, sweetened whole-milk product prepared by simmering milk without stirring it in a karahi, so as to allow for the simultaneous formation of a thick creamy layer of skin on the surface of the milk and the slow evaporation of water, after which sugar is added to the concentrated product. This is followed by a thorough mixing of the product. It is quite popular in the northern region of the country.
Composition:
The average chemical composition of laboratory-made samples of khurchan has been given in Table 11.8. The microbial quality of laboratory-made khurchan has also been reported.
Moisture – 27.9
Fat – 23.6
Protein – 15.4
Lactose – 14.9
Sugar – 15.2
Ash – 3.0
Iron (mg %) – 25.3
Food and Nutritive Value:
As khurchan contains all the milk solids in an approximately five-fold concentration, together with an addition of sugar, its food and nutritive value is very high.
Method of Preparation:
Khurchan is normally prepared by heating 3-4 kg. milk in a karahi to simmering temperature (85- 90°C) and then carefully maintaining it at this temperature by controlled heating. In no case is the milk allowed to boil; nor is it stirred (until sugar is admixed). This helps in the formation of a thick creamy layer on the upper surface of the milk.
When the volume of milk gets reduced by the evaporation of water to one-fourth to one- sixth (average one-fifth) of the original, good quality ground sugar is added to the concentrated mass at 5-6 per cent by weight of the original milk and dissolved in it. The finished product has a slightly cooked flavour, which is relished. Buffalo milk is invariably used for the production of khurchan, as it gives a higher yield than cow milk.
Yield:
The yield of khurchan depends on the percentage of total solids in milk, the ratio of concentration of the milk solids and the amount of sugar added.
Uses:
For direct consumption.
3. Rabri:
Definition:
This is an especially prepared concentrated and sweetened whole milk product, containing several layers of clotted cream. While the milk is slowly evaporated (without being stirred) at simmering temperature in a karahi over an open fire, pieces of skin which form on the surface of the milk are continuously broken up and moved to the cooler parts of the karahi.
When the volume of milk has been considerably reduced, sugar is added to it; then layers of clotted cream are immersed in the mixture and the finished product obtained by heating the whole mass for another short period. Rabri is quite popular in the northern and eastern regions of the country.
Composition:
The composition of rabri depends on the initial composition of milk, the degree of concentration of milk solids and the percentage of sugar added. An approximate composition of rabri is given in percentage below. The microbiological and chemical quality of rabri has also been reported.
Moisture – 30
Fat – 20
Protein – 10
Lactose – 17
Ash – 3
Sugar – 20
Food and Nutritive Value:
As rabri contains all the milk solids in an approximately five-fold concentration, plus additional sugar, its food and nutritive value is very high.
Method of Preparation:
Rabri is normally prepared by heating 3-4 kg. of milk in a karahi over an open fire to simmering temperature (85-90°C), and then maintaining the temperature by controlled heating. The milk is neither stirred nor allowed to boil. The surface of the milk may be gently fanned to help the process of skin formation.
A piece of this skin, about 3-4 cm. square, is continuously broken with a thick wooden stick (or bamboo/cane splints) and moved to the cooler parts of the karahi. This operation requires considerable skill and constant attention. Simultaneously, as slow evaporation reduces the milk to about one-fifth of its original volume, good quality ground sugar at 5-6 per cent by weight of the original milk is added to the milk concentrate and dissolved in it.
The layers-of skin collected on the karahi surface are then immersed in the mixture and the finished product obtained by gently heating the whole mass for another brief period. Buffalo milk is invariably used as it produces a more creamy consistency and a higher yield.
Note:
The finished product consists of non-homogeneous flakes covered and floating in a milk-sugar-syrup. By beating the concentrate slightly at the end, a more homogeneous, honeycomb textured mass is obtained.
Yield:
The yield of rabri will depend on the percentage of total solids in milk, the ratio of concentration of the milk solids and the amount of sugar added.
Uses:
For direct consumption.
4. Kulfi/Malai-Ka-Baraf:
Kulfi:
This is an indigenous ice cream frozen in small containers. While the milk is boiling, it is sweetened by an addition of sugar and the product is concentrated to approximately 2: 1. To this concentrate, when it has cooled, are added malai (indigenous cream), crushed nuts and a flavour (commonly rose or vanilla). The mix is placed in triangular, conical or cylindrical moulds of various capacities made of galvanized iron sheets.
The moulds are closed on top by placing a small disc over them and the edges made airtight with wheat-dough. (Modern moulds are made of plastic, generally conical in shape with screw-cap plastic tops.) The mix-in- moulds is frozen in a large earthen vessel containing a mixture of ice and salt in the ratio of 1: 1.
Note:
Malai refers to the creamy layer formed on the surface of milk, which has usually been heated, very slowly, to boiling temperature and then left to cool undisturbed. This creamy layer is then skimmed off and finds various uses, viz. for direct consumption with sugar, as a source of cream in sweets, puddings and fruit, in the preparation of kulfi or malai-ka- baraf, etc.
Owing to its higher fat content and larger fat globules, buffalo milk gives higher yields and is used for the preparation of malai. According to the PFA Rules (1976), malai refers to the product rich in butter fat prepared by boiling and cooling cow or buffalo milk or a combination thereof. It should contain not less than 25.0 per cent milk fat.
Malai-Ka-Baraf:
This term is loosely applied to a variety of frozen products in which sweetened milk or malai may form the chief ingredient. They may also be prepared from diluted milk thickened with some fruit pulp, etc., with a dash of colour and flavour. (The latter kind is usually sold in the market.)
A compact cast-iron freezing-unit, which is generally an imported one and consists of a retort connected to an especially designed condenser, is used for freezing the mix. In rough outline, the method of freezing (in a closed system) consists in first heating the retort containing some crude ammonium salts over an open fire, while the condenser is kept immersed in a tub of cold water.
This heating goes on for nearly 3 hours. Thereafter, the condenser is taken out of the tub and the vessel containing the mix is placed in the annular space in cold water provided in the condenser and the retort.
Some wet cloth or gunny is put on the vessel containing the mix. The freezing takes about 3 hours. The frozen product is then taken out of the vessel, wrapped with an insulating material such as paper-and- felt, and sold by chipping out slices with a sharp knife.
Note:
In the first stage when the retort containing ammonium salts is heated, ammonia gas is liberated. This changes into liquid ammonia as it reaches the cooler parts of the condenser. In the second stage, when the condenser comes in contact with atmospheric air, the liquid ammonia evaporates; while doing so, the latent heat for vaporization is extracted from the mix, which then freezes.
Comparison with Ice Cream:
A comparison of (standard) ice cream with the indigenous product has been made in Table 11.10.
5. Srikhand:
Srikhand is a semi-soft, sweetish-sour, whole milk product prepared from lactic fermented curd. The curd (dahi) is partially strained through a cloth to remove the whey and thus produce a solid mass called chakka (the basic ingredient for srikhand).
This chakka is mixed with the required amount of sugar, etc., to yield srikhand. The srikhand is further desiccated over an open pan to make the srikhand wadi sweet. (All three products are quite popular in the western region of the country.)
Composition:
The composition of chakka will depend on the initial composition of milk, the degree of fermentation (i.e., acidity developed) and the extent of whey removed. These three factors, together with the amount of sugar added, influence the composition of srikhand.
The composition of srikhand wadi depends upon the extent to which srikhand is desiccated. The average composition of chakka (laboratory-made samples from buffalo milk), srikhand and wadi are given in Table 11.15.
Note:
A microbiological study of market samples of shrikhand has been made.
Method of Preparation:
The standardized method of preparation may be described as follows- fresh, sweet buffalo milk, which has been standardized to 6% fat, is pasteurized at 71°C for 10 minutes and then cooled to 28-30°C. It is then inoculated @ 1 per cent with lactic culture (Str. lactis), which is mixed well, and incubated at 28-30°C for 15-16 hours (overnight).
When the curd has set firmly (acidity 0.7-0.8 per cent lactic), it is broken and placed in a muslin cloth bag and hung on a peg for the removal of whey for 8-10 hours. During this period, the position of the curd may be altered, or the curd gently squeezed, to facilitate whey drainage.
The solid mass thus obtained is called chakka, which is the srikhand base. This chakka is then admixed with sugar (crystal or ground) and well kneaded for uniform mixing; colour and flavour may also be added. The product now obtained is known as srikhand. When the srikhand is further desiccated to a hard mass by heating on an open pan over a direct fire, srikhand wadi is obtained.
Uses:
(i) Chakka is used for the preparation of srikhand;
(ii) Srikhand is used either for direct consumption or for the preparation of the srikhand wadi sweet;
(iii) Srikhand wadi is used for direct consumption.
6. Lassi:
Lassi, also called chhas or matha, refers to desi buttermilk, which is the by-product obtained when churning curdled whole milk with crude indigenous devices for the production of desi butter (makkhan).
Statistics of Production:
It appears that 50-60 kg. (ave. 55 kg.) of lassi are produced for every kg. of ghee. Assuming that 90 per cent of India’s total ghee production is obtained by the desi method, the total annual production of lassi may be estimated to be about 27,500 million kg. (1966).
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 below (in percentage).
Water – 96.2
Total Solids – 3.8
Fat – 0.8
Solids-not-fat – 3.0
Protein – 1.3
Lactose – 1.2
Ash – 0.4
Lactic Acid – 0.44
Food and Nutritive Value:
Lassi contains appreciable amounts of milk proteins and phospholipids, and is an excellent beverage for quenching thirst by reason of its lactic acidity.
Yield:
This 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:
(i) As a beverage, usually after the addition of ice (in hot weather), sugar or salt, with or without additional flavours;
(ii) As a starter culture (optional);
(iii) As a coagulant (optional).
Note:
In the northern region of the country, whole milk curd beaten up to be served as a beverage as above, is also called lassi.
7. Ghee Residue:
This refers to the charred (burnt) light to dark brown residue which is obtained on the cloth strainer after the ghee, prepared by any of the methods given above, is filtered. It is a by-product of the ghee industry.
Composition:
This is influenced by the composition of the non-fatty constituents in the raw material (butter or cream), the technique adopted for the production of ghee and that employed for the separation of the ghee-residue (by hand or mechanical pressing).
Essentially it contains heat-denatured milk-proteins, caramelized lactose and varying amounts of entrapped fat, besides some minerals and water. The composition of the ghee-residue together with its yield from the raw material used, is given in Table 11.36.
Food and Nutritive Value:
Ghee-residue is a rich source of milk fat, proteins and minerals. The residue obtained from the desi butter ghee process is appreciably richer in proteins and minerals.
Yield:
This is influenced by the percentage of solids- not-fat in the raw material, the method of ghee making and the technique used for the separation of the residue. The higher the solids-not-fat, the higher the outturn; the lower the final temperature of clarification, the higher the yield (due to the greater residual moisture content in the residue); the lower the pressure used in squeezing out surplus fat from the residue, as in hand pressing when compared to mechanical pressing, the higher the yield, and vice versa. The comparative yields of residue by the different methods of ghee making are given in Table 11.36.
Colour:
This normally varies from light-brown to deep- chocolate. The colour of the residue is chiefly influenced by the temperature-time of heating given; the higher the intensity of heat- treatment, the darker the colour, and vice versa.
Recovery of Ghee from Ghee-Residue:
Two methods have been developed, viz., the centrifugal and pressure techniques. The centrifugal method consists of transferring the occluded ghee to water by heating the ghee-residue in water and centrifuging the water-fat phase; the pressure method (hand-screw or hydraulic) consists of subjecting the heated ghee-residue to a limited pressure in a hand- screw or hydraulic press. The hand-screw method has been recommended for adoption by ghee manufacturers as it is simple, efficient, practical and economical (because it increases the amount of fat recovered).
Note:
In the dairy industry, a common procedure for the recovery of ghee from ghee-residue is to place the residue in milk cans, pour enough water to submerge the entire residue in it and then heat up the mixture with live-steam. Next, the level of water in the can is brought up to the neck (to make it easier to remove the ghee-layer on top at a later stage).
The can with its contents is then moved to the cold store (5-10°C). The ghee-layer, which surfaces at the top, is then added towards the last stages of the next batch of ghee making. The process is continuous.
Uses:
(i) For direct consumption, as such, with rice or chapati in producer’s household (when made in small quantities);
(ii) For the preparation of ghee-toffees;
(iii) For the preparation of pastes to be used as spreads in sandwiches and in dosa and samosa;
(iv) For the preparation of a burfi-type sweet (the method has recently been standardized).