Dairy products are various products derived from cow’s milk or that of other female mammals such as goat, sheep, yaks, horses, camel. Dairy products include yoghurt, nono (fermented cow’s milk, madara (unfermented cow’s milk, cheese, whey, condensed and evaporated milk.) (cultureforhealth, 2015).
Yoghurt, nono, Madara has become so highly valued in humans diet because of their nutritional values and their culinary possibilities (George and pamplon, 2006) Yoghurt is made by controlled thermoduric fermentation of pasteurized non-fat or low fat milk carried out around 45% (Prescott et al., 2005) . It is probably the most popular fermented milk in Nigeria. Yoghurt is a foods produced by bacterial fermentation of milk and these bacteria are known as “yoghurt cultures. Fermentation of lactose by these bacteria produces lactic acid which acts on milk and protein to give yoghurt its texture and characteristic tang. Also yoghurt is made by inoculating certain bacteria (starter culture) usually Streptococcus thermopiles and Lactobacillus bulgaricus into milk, after inoculation, the milk is incubated at 40 to 46% (105 to 115%) until fermentation, the milk is coagulated by bacteria to produce lactic acid (serre et al., 2009)