However, the general composition of yogurt is more or less similar to that of milk. Therefore, yogurt is a rich source of milk proteins, carbohydrate, minerals such as calcium and phosphorous, and vitamins such as riboflavin (B2), thiamin (B1), cobalamin (B12), folate (B9), niacin (B3) and vitamin A. Milk proteins available in yogurt is in high quality due to its high biological value and provide almost all essential amino acids necessary to maintain good health [9]. In addition, milk proteins available in yogurt contain higher content of proline- and glycine-contain amino acids than that in whole milk while performing additional body functions such as enhancing calcium
absorption and boosting the immune system [9]. Lactose is the main carbohydrate found in yogurt as in other dairy products. Lactose content in raw milk is about 4.6%. However, the original lactose content in milk is lowered by 20-30% during the fermentation process as the lactose coverts into its simple forms of glucose and galactose due to the metabolic activity of lactic acid bacteria. Fat content of yogurt is highly dependable on the fat content of the original yogurt mixture. According to the USDA specifications for yogurt, low-fat yogurt and non-fat yogurt, fat content varies from 0.5-3.25% [4]. However, the fat content of yogurt is highly subjective as some products; for instance Greek style yogurt contains a high fat content as high as 10%. Unlike milk,processes that are employed in yogurt manufacturing such as homogenization and fermentation result in breakdown of some amount of fat into easily digestible and absorbable fatty acids [9]. Vitamins and minerals found in milk and dairy products are in bio-available form where they are available for absorption and use by body. Yogurt as of other dairy products is an exceptional source of several B vitamins in particular, riboflavin and thiamin. It is reported that a 150g serving of whole milk plain yogurt and low-fat plain yogurt will provide 31% and 30% of an adult’s daily riboflavin requirement respectively whereas the same amount of serving of each type of yogurts will provide 23% and 45% of an adult’s daily thiamin requirement [9]. However, vitamin B12 and B6 are found in significantly lower concentrations than that in milk as Streptococcus thermophilus uses these B vitamins for its metabolism. Folic acid/folate content of yogurt can be varied depending on the composition of lactic acid bacteria used as some of the LAB species such as S. thermophilus and Bifidobacteria synthesize certain vitamins including folate by their own [9].