BY-PRODUCTS TECHNOLOGY

Module 3. Processing and utilization of whey

Lesson 25
FERMENTED WHEY BEVERAGES

25.1 Introduction

Fermentation is one of the oldest forms of food preservation and biological upgrading of dairy by-products into value added foods, which possesses nutritional properties in addition to their palatability. For whey fermentations, mainly starter and probiotic cultures of lactic acid bacteria are used, while in case of alcoholic fermentations mostly yeast species Kluyveromyces is used. In this category of products big attention has been paid to development of probiotic whey beverages. The preparation of wide varieties of palatable beverages through microbial fermentation of whey by using selected strains of lactic acid bacteria, yeast, probiotic and prebiotic microorganisms has been reported. Whey is an excellent growth medium for lactic acid bacteria as it contains lactose in abundant amount, which is the basic medium for fermentation. On fermentation with lactic acid bacteria, it becomes a suitable drink for lactose-intolerant people. The lactic acid imparts fresh flavor, masks the effect of curdy flavour of whey and is known to suppress the growth of pathogenic spoilage organisms.

Broadly fermented whey beverages have been classified into two categories depending upon the starter culture used to carry out the fermentation process in whey. These are a) Lactic fermentation or non-alcoholic fermentation and b) Alcoholic fermentation. Different types of fermented whey beverages developed under these categories, have been described and some of the processes have been patented.

25.2 Preparation of Fermented Whey Beverages

A number of non alcoholic and alcoholic beverages have been prepared from the whey and market value of these beverages is increasing day by day. Some globally famous whey based fermented beverages are given in Table 25.1.

25.2.1 Non-alcoholic whey beverages

These beverages are obtained by fermenting lactose in whey to lactic acid by lactic acid bacteria (LAB) and can be mainly categorized into whey based fermented drink, whey based fermented carbonated drink and whey based cultured dairy products.

Table 25.1 Some famous whey based fermented beverage in the world

25.2.1.1 Whey based fermented & carbonated drinks

There are many fermented and carbonated whey beverages produced in different parts of the world and can be grouped accordingly to basal substrate and types of cultures used. A flow diagram for the preparation of fermented whey beverage by using lactic acid bacteria is given in ).

25.2.1.2 Preparation of fermented whey drink ‘Acidowhey’

A palatable soft drink “Acidowhey” from whey was developed at National Dairy Research Institute, Karnal. “Acidowhey” is a non-carbonated drink, fermented with selected strain of lactic acid bacteria and retaining all the nutrients of whey intact. For its preparation , whey from paneer, cheese, chhana or casein manufacturing is first separated to remove fat and traces curd particles. Clarified whey is heat treated to 85-90°C for 10 min. or its equivalent combination. Clarified whey after cooling to 40°C is inoculated with an active culture of L. acidophilus and incubated at 40°C temperature. After incubation, fermented whey is clarified to remove precipitated cellular mass, whey protein and minerals formed during the process. Sugar is then added to the product at the rate of 10-12% in the form of 50% sugar syrup, which had been earlier pasteurized. Then desirable amount of pineapple flavor or any compatible citrus flavor is added and the beverage is chilled to 4°C and packaged. Beverage should be pasteurized before packing or alternatively pasteurized in the container. Additional studies demonstrated antibacterial properties of ‘Acidowhey’ against certain gram positive and gram negative organisms such as Micrococcus flavus, Staphylococcus aureus, Escherichia coli and Bacillus subtilis.

25.2.1.3 Whey-based cultured dairy products

Current world-wide popularity of fruit-flavoured drinkable yoghurt offers an excellent opportunity for the incorporation of whey into these products. The compatibility of whey - especially of acid whey and/ or further fermented sweet whey-with the character of cultured dairy beverages makes such an approach particularly attractive for traditional dairy processors. In addition to whey based yoghurt drink for example yor and interlac ‘thin buttermilk’ products, prepared by culturing a mixture of regular milk and an ultrafiltration whey protein retentate containing the same protein content as milk are another example of whey-containing cultured dairy beverages.

25.2.2 Alcoholic whey beverage

Alcoholic whey beverages include drinks with small amount of alcohol (to 1.5%), whey beer, whey wine and whey champagne. Some of these beverages have been well accepted by the consumers and are being produced commercially. Patents have been granted on the processes of production of alcoholic beverages.

25.2.2.1 Whey wine

Whey is used for production of various types of whey based wines that contains relatively low alcohol amount (10-11%) and mostly flavored with fruit aromas. These have been made from demineralised UF permeate or reconstituted acid whey powder. In reconstituted acid whey powder, protein is removed by UF and permeate had a total solids concentration of 26-28% before demineralizing to a mineral level of 1% or less. Any residual whey taints after fermentation are removed with bentonite and charcoal. In one process for the preparation of sweet whey wine, whey is deproteinized, heated at 82°C for 5 min and approximately 22% dextrose added depending upon the amount of alcohol desired in the wine. Fermentation is completed in seven days at room temperature using the yeast Saccharomyces cerevisiae spp. ellipsoids. As the whey itself contains sufficient nutrients for yeast growth, no additional nutrients are added. Similarly different type of whey based wines like pop wine, whey champagne, sweet wine etc can be prepared by using different strains of yeast and processing conditions.

25.2.2.2 Beer like whey beverage

Like wine, whey is also used for preparation of different types of whey based beer type beverages. Whole whey or whey concentrate can be used as suitable substitute ingredient of cereals in the manufacturing of beer and beer like products. Whey has been reported to have certain materials similar to the colloids of beer wort and has great capacity for binding carbonic acid. On prolong heating under pressure, it develops caramel like flavor, which is similar to the taste and odour of the cured malt. Dietrich (1988) developed a beer substitute by making 5.4% malt wort with 2.5% deproteinzed whey. The malt whey mixture was fermented by Saccharomyces lactis. After 5-7 days, the product had developed a true beer flavor and characteristics.

25.2.2.3 Whevit- A nourishing soft drink

National Dairy Research Institute, Karnal, have developed a soft drink out of whey known as “Whevit”. The manufacturing process of whevit is: fresh whey obtained from chhana (or paneer) making is passed through a cream separator, and the separated whey is steamed for 30 min in a double jacketed vat. It is cooled to room temperature and kept overnight to allow the precipitated proteins to settle down, and then filtered through a muslin cloth. Now 50% sugar syrup @ 22-23% of whey, 10% citric acid @ 2-2.1% of whey and sugar mixture, selected colour and flavours in requisite amounts are added . This mixture is inoculated with a culture of Saccharomyces cerevisiae @ 1% of yeast whey broth (whey broth is prepared by adding 1% sugar in filtered whey and sterilizing it at 15 lb pressure for 15 min; the inoculums is prepared by inoculating it with the yeast culture and incubating it for 48 h at 25°C). After mixing the inoculums in the whey, it is incubated at 22°C for 14-16 h. The product is then filled in bottles leaving about 5% air space. The bottles are then crown corked to retain CO₂ and pasteurized at 75°C for 30 min in hot water, cooled and stored at low temperature (5-10°C).

In the above process of manufacture, the carbonation is achieved by the fermentation of sugar by the yeast culture. With a view to meet situation where cultivation of the yeast and fermentation of whey is not practicable, the process has been modified to incorporate CO₂ through a carbonated plant.

Selected references

Parekh, J.V. 2007. Small-scale utilization of whey. In: Dairy India-sixth edition, ed. P.R. Gupta and Sharad Gupta. Dairy India Yearbook, New Delhi: 245-246.
Dietrich, K.R. 1988. Whey containing malt wort as a raw material for preparation of malt whey beer. Brauwissenschaft: 26.
Gandhi, D.N. 1996. Fermented whey beverages, NDRI Bulletin, No. 278: 1-7.