The Effects of Blending Cow Milk with Soy Milk on Yoghurt Quality

ABSTRACT

A quantity of 1 litre each of cow milk and blended (cow/soy) milk was pasteurized and each was inoculated with 5g of a mixed starter culture comprising streptococcus thermophilus, Lactobacillus acidophilus and Lactobacillus bulgaricus and incubated at 500C for 5 hours to ferment to yoghurt. Proximate analysis on both yoghurts showed that there was no significant difference (P>0.05) between the moisture content, protein content and fat content of the two yoghurts samples. The ash content and carbohydrate content of the blended (cow, soy) milk yoghurt were significantly (p<0.05) than that of cow milk yoghurt. Also, significant difference (p, 0.05) was observed in terms of colour between the two yoghurt samples. However, no significant difference (p>0.05) was observed in terms of taste, aroma, consistency and general acceptability of the two yoghurts. Physicochemical analysis showed that the specific gravity of blended (cow/soy) milk was significantly higher (p<0.05) than that of cow milk yoghurt but there was no significant difference (p>0.05) observed in pH and T.T.A of both yoghurts. However, the two yoghurt were generally accepted.