BY-PRODUCTS TECHNOLOGY

Module 6. Buttermilk

Lesson 44
UTILIZATION OF BUTTERMILK

44.1 Introduction

The uses of sweet cream buttermilk are somewhat similar to those of skim milk. It is valued in the food industry because of its emulsifying capacity and its positive impact on flavor. Commercially produced buttermilk is mostly sweet cream buttermilk. It is a desirable component of bakery products to improve their flavor and texture, the condensed and dried forms being the most convenient ones. High phospholipids content in dried buttermilk makes it a good functional ingredient in food formulations. Casein made from buttermilk is different in many respects from skim-milk casein. For most purposes, it is less desirable than casein from skim milk. But for casein paints, it is especially suitable if used in paste form without being dried. Buttermilk as such and in condensed form is also used as animal feed and dried buttermilk is added in the formulation of their mixed feeds.

44.2 Utilization of Sweet Cream Buttermilk

Sweet cream buttermilk, because of its resemblance in gross chemical composition with skim milk, is usually admixed with bulk of skim milk for further spray drying or even products manufacture in dairy plants. Sweet cream buttermilk can be used in beverage form and in the fluid milk industry as a milk extender with specific benefits over skim milk. The other potential uses of buttermilk solids are in manufacture of soft varieties of cheese, paneer, fermented milks and traditional milk products. Judicious use of buttermilk solids in the development of functional foods is another promising area.

44.2.1 Market milk

The undiluted sweet cream buttermilk can be admixed with the whole milk for fluid milk supply. The use of sweet cream buttermilk in the market milk for toning of buffalo milk, improves its palatability, viscosity and heat-stability and reduces the curd tension without adversely affecting the keeping quality. In addition to plain fluid milk, it can also be used for the preparation of flavoured milks and milk beverages. The powder made from the mixture of skim milk and sweet cream buttermilk is treated as a skim milk powder and used for reconstitution purposes.

44.2.2 Fermented dairy products

44.2.2.1 Dahi

Curd prepared by incorporating sweet cream buttermilk into whole milk has soft-body, which is probably due to i) the change in the electric charge on the casein during churning, ii) the presence of phospholipids and other MFGM materials, and iii) the free fat in the buttermilk. Addition of 1-2% skim milk powder is recommended for improving the body of dahi made from buttermilk. As an alternative to curd making, sweet cream buttermilk can be successfully utilized in the manufacture of cultured buttermilk and lassi, in which the firmness is not of much consideration.

44.2.2.2 Yoghurt

Increasing the total solids in yoghurt milk to around 14-16% is one of the essential steps in the process of yoghurt making. Traditionally, the fortification of the total solids in the yoghurt mix is achieved by boiling to reduce the volume of the milk to two-thirds of its original or by the addition of skimmed milk powder (SMP). Replacement of SMP with buttermilk powder up to 50% in the manufacture of low-fat yoghurt was found to be acceptable and similar to the control product. Buttermilk powder when added to low-fat yoghurts up to 4.8%, yielded a soft and smooth product. Among the various dairy ingredients used in the manufacture of yoghurt, dried buttermilk was found to reduce its susceptibility to syneresis.

44.2.2.3 Cheeses

Mixture of buttermilk and skim milk can be utilized for the production of low fat cheeses. Addition of buttermilk in the manufacture of low-fat Cheddar cheese can improve the texture of the cheese because of the high water-holding capacity of phospholipids. The preparation of hard varieties of cheese like Cheddar and Gouda involves the adjustment of casein and fat ratio with the help of skim milk. The replacement of skim milk with sweet cream buttermilk results into softer body due to the presence of higher amount of fat globule membrane materials in buttermilk. Joshi and Thakar (1996a) however, were successful in improving the firmness and producing acceptable quality of Cheddar cheese from blends of buffalo milk and sweet cream buttermilk. They maintained the setting temperature at 33°C, added starter @ 2% and rennet @ 4.5 g/100 kg milk. The cheddar cheese so prepared was also used for making processed cheese of satisfactory quality. Several benefits of utilizing buttermilk solids in the manufacture of soft varieties of cheeses are: decreased waste disposal problems, reduction in cost, increased cheese yield and improved flavour, texture, biological value and hypocholesterolaemic effects of cheese.

44.2.3 Indian traditional dairy products

44.2.3.1 Channa

Channa produced from buffalo milk is reported to be hard and greasy because of inherent differences in qualitative and quantitative aspects of buffalo milk than cow milk. Recently, it has been reported that good quality channa can be produced by admixing SCBM to buffalo milk. Good quality rasogolla and sandesh could also be prepared from this channa.

44.2.3.2 Paneer

Buffalo milk has to be standardized to a fat and SNF ratio of about 1:1.65 to meet the FSSAI requirements for the manufacture of paneer. The replacement of skim milk with sweet cream buttermilk for the standardization of buffalo milk has been found to increase the yield of paneer by about one per cent without altering the organoleptic and textural properties. It is also possible to prepare good quality paneer from low fat milk by incorporating buttermilk solids to buffalo milk.

44.2.3.3 Basundi

Basundi, a partially desiccated sweetened milk product, is prepared traditionally from buffalo milk. Attempts were made by Patel and Upadhyay (2004) to replace buffalo milk solids by SCBM solids in basundi making and reported that 100% replacement of buffalo milk solids resulted in a significant decrease in the lactose and ash contents and adversely affected the physico-chemical properties such as free fatty acids (FFA) and hydroxyl methyl furfural (HMF) contents. However, it was recommended by the workers that replacement up to 25% would check such adverse effects on the product.

44.2.3.4 Chakka and shrikhand

Chakka, a semi-solid mass obtained after draining whey from dahi, is an intermediate product for shrikhand manufacture. Karthikeyan et al, (2000) studied the effect of replacement of buffalo skim milk by SCBM on various technological parameters and reported that chakka made from 50% replacement of skim milk by SCBM had improved flavour and with smoother body and texture, and no adverse effect on chemical composition. Karthikeyan et al, (1999) attempted to prepare shrikhand from SCBM with varying total solids content and reported that shrikhand prepared from SCBM with 15% total solids was similar to that of control product prepared from buffalo skim milk.

44.2.4 Frozen dairy products

The buttermilk powder has been extensively used in preparation of ice cream and other frozen desserts. The 100% replacement of skim milk solids in the form of a blend of spray dried whey protein concentrate (WPC) and dried SCBM (50:50) in ice cream resulted in better quality product than the control.

44.2.5 Beverages

The most economical use of buttermilk is in the manufacture of beverages that is highly used as a refreshing drink in summer season. Besides providing valuable nutrients and freshness to consumers at cheaper cost, it offers variety to the consumers. As beverage, buttermilk is consumed in plain and spiced forms throughout the year. Salted spiced buttermilk (SSBM) is prepared by addition of common salts, sugar, roasted jeera, chilli powder in plain buttermilk. After preparation of SSBM, the fruit flavours in form of syrup viz. Cashew and Kokum are added and mixed properly to obtain uniform consistency. The prepared buttermilk is cooled to 7-10^oC for 3 to 5 h.

Fresh buttermilk beverages prepared by the addition of flavor concentrates and sugar results in a product having smooth texture and rich tangy fruity flavor. Addition of fruit juices or fruit pulps is an attractive avenue for the utilization of buttermilk. With the availability of a variety of region-specific and season/climate-specific fruits country wide, a large variety of beverages can be formulated and marketed as ready-to-serve drinks. Fruits like pineapple, cherry or raspberry and orange or strawberry have been tried for fortification and enhancement of flavor of buttermilk. Addition of fruit pulp/syrup to buttermilk not only enriches its taste, but also enhances its quality. Shukla et al. (2004) studied the suitability of blending apple, banana, guava, litchi and mango juice/pulp with buttermilk at different levels and reported that apple juice, litchi juice, banana pulp, guava pulp and mango pulp could be added up to 30%, 30%, 20%, 10% and 20% levels, respectively in buttermilk to make refreshing drinks.

Shrivasta et al. (1985) reported the utilization of buttermilk in the preparation of drink using culture of Streptococcus thermophilus or mixed culture of S. thermophilus and Lactobacillus acidophilus and added sugar and pineapple flavorings. Buttermilk acidified by starter culture containing lactic streptococci, is widely used as a beverage in Europe.

44.2.6 Probiotic drinks

The growing interest worldwide in probiotic foods led the researchers to find all possible ways of developing health foods and buttermilk is no exception. Various workers have developed buttermilk-based probiotic drinks with different probiotic bacteria. Rodas et al, (2002) developed probiotic buttermilk by adding the probiotic strain of Lactobacillus reuteri at a rate of 1%.

44.3 Utilization of Sour Buttermilk

During the manufacture of butter, a considerable amount of sour buttermilk is obtained either from natural souring of milk/cream or by controlled fermentation. Sour buttermilk obtained from first category is not preferred for human consumption. This may, however, be converted into casein by adopting modified processing conditions for other uses. A process has been standardized for the manufacture of paneer from the mixture of buffalo milk and sour buttermilk. The paneer prepared by this method gave higher yield by retaining more moisture in comparison with control paneer. The organoleptic quality and shelf life of the buttermilk extended paneer were comparable to control paneer.

44.4 Utilization of Desi Buttermilk

Desi buttermilk also known as chhach makes an excellent drink, especially in warm weather. Chhach is an important domestic beverage in India. It can be flavored in various ways with salt, mint, cumin, and even spicy additions such as ground chilies, fresh ginger or garlic. It is considered to be an excellent thirst quenching and nourishing beverage, particularly during summer months. It is also used for making some popular traditional preparations e.g. karhi, rabri (fermented) etc. The industrial utilization of chhach cannot be exploited due to lack of proper collection system and day-to-day variations in the composition and quality of desi buttermilk.

44.5 Utilization of Buttermilk Powder

Buttermilk powder can replace partly skim milk powder for incorporation into baked goods, ice cream, Pudding, sauces, beverages and chocolates. In baked goods it provides desirable flavor, help to incorporate air into product, aid in the development of browning as the product is baked and preserve freshness by binding water. In pudding, sauces and beverages, buttermilk powder is used to absorb water and increase their viscosity. In chocolate it provides the beneficial emulsifying ability.

Great scope lies in the effective use of buttermilk or buttermilk solids in the manufacture of some of our popular indigenous Indian dairy products, e.g., khoa, kheer, rabri and gulabjamun. The dried buttermilk can replace the SMP in the manufacture of gulabjamun mix powder. Because of high lecithin content in buttermilk, it may improve the textural properties of rasogolla.

Selected references

Rodas, B.A., Angulo, J.O., Cruz, J.De-La. And Garcia, H.S. 2002. Preparation of probiotic buttermilk with Lactobacillus reuteri. Milchwissen. 57 (1): 26-28.
Shukla, F.C., Sharma, A. and Singh, B. 2004. Studies on the preparation of fruit beverages using whey and buttermilk. J. Food. Sci. Technol. 41 (1): 102-105.
Srivastava, M.K., Trimutrulu, N. and Lohani, P.P. 1985. Utilization of by-products of dairy industries-whey and buttermilk. Indian Dairyman, 37: 507-509.