Yogurt Drink: Dairy Products

CHAPTER 1

INTRODUCTION

Yogurt drink is one of the dairy products that were the fastest growing food and beverage sector purchased and commonly consumed around the world. It is defined as a dairy-based yogurt that is drinkable and in a liquid form that may or may not include fruit or fruit flavouring (Matitila-Sandholm and Saarela, 2003). It is a conventional food known for its therapeutic, nutritional and sensory properties (Gonzales et al., 2011).

Popularity of yogurt products continues due to its health benefits. It is rich in calcium, phosphorus, relatively large amount of potassium and can also be considered as a good source of potassium both of which are essential for the development and maintenance of bones. The health benefits of yogurt

Cow milk on the other hand yields a soft coagulum making it suitable for preparing channa and other channa based products like sandesh, rasagolla, chumchum and rasamalai (Dairyforall.com, 2013).

The buffalo milk contains more fat, solids non-fat and total solids and hence yield of products prepared from buffalo milk, be it cream, butter, cheese or condensed milk will be always higher. The higher fat content in buffalo milk helps in increasing the quantity of milk supplied to the cities by toning. Toned milk is milk in which the fat content has been reduced to 3% by adding skim milk or reconstituted skim milk while maintaining the original SNF level at 8.5% (Dairyforall.com, 2013).

Higher total solids in buffalo milk also provide for more calories than cow milk (100 calories are derived from 100 g of buffalo milk while 70 calories from 100 g of cow milk). Higher proportion of beta casein in buffalo milk makes it easier to prepare humanized milk. Large sized fat globules and higher proportion of solid fat in buffalo milk facilitates cream separation and churning of butter. The percentage of fat harvested from buffalo milk is significantly higher when compared to cow milk (Dairyforall.com,

Storage period showed a significant effect (p < 0.05) of yogurt drinks sample on the pH values. Analysis of variance showed that there was a significant difference (p < 0.05) in viscosity during storage for 15 days except at Day 3. All yogurt drinks samples were significantly decreased throughout the period storage. The results of present study in accordance with (Aryana et al., 2006; Gassem and Frank, 1991) they reported a decrease in viscosity of yogurt with increase of storage of time. Table 4.2 Viscosity of buffalo milk yogurt drinks

Viscosity

(mPas) Time Day 0 Day 3 Day 7 Day 11 Day 15

YD1 23.2 ± 0.3 a 13.8 ± 0.8 a 12.4 ± 0.2 c 12.0 ± 0.1 c 11.7 ± 0.1 c

YD2 14.9 ± 0.1 b 14.5 ± 0.1 a 13.8 ± 0.1 a 13.4 ± 0.1 a 13.2 ± 0.1 a

YD3 14.0 ± 0.1 c 13.6 ± 0.1 a 13.0 ± 0.1 b 12.7 ± 0.2 b 12.3 ± 0.1 b

Values are expressed as mean ± standard deviation (n=3). Means with different letters within the same column are significantly different at the level of p < 0.05

Minhas et al. (2002), Gomes et al. (2009), Lee and Lucey (2010) and Rossa et al. (2011) stated that the viscosity of the yogurt drinks decreased due to the pseudoplastic behaviour. The yogurt drinks,