Effects of the substitution of cow's milk with soymilk on the micronutrients, microbial, and sensory qualities of yoghurt

The consumption of imported dairy products is high especially in developing countries including Nigeria where little or no milk is produced locally which makes the products expensive, out of reach to common consumers and also inconvenient for lactose intolerance and vegans. Soymilk, as plant-based milk was substituted for cow's milk in parts and in whole for the production of yoghurt and the effect of substitution was evaluated on the minerals, vitamins, microbial, and sensory properties of the products using the established methods. Significant differences (p < 0.05) exits among the yoghurt samples in the micronutrient contents. The soymilk substitution produced yoghurts with trace/macro mineral contents' range of 0.14-28.50 mg/100 g and vitamin contents (ranged 0.02-0.43 mg/100g) that were of comparable range of values with the yoghurt made with 100% cow's milk (0.21-29.60 mg/100g minerals and 0.05-0.58 mg/100g vitamins). Generally, no significant difference (p < 0.05) was observed in most of the sensory attributes evaluated (range 8.00-8.01) in the entire samples (except in the 100% soymilk yoghurt). The microbial analysis proved the safety of the entire products for consumption. These showed the positive effect of substituting soymilk for cow's milk at all the levels used, thus, the lactose intolerance and vegans can find alternative to dairy yoghurt in the 100% soymilk substitution and enjoy the functional health benefits of yoghurt. Also, the total dependence on importation of dairy milk and cost of production of composited milk yoghurt could be reduced to improve the nation's economy and make the product economically accessible to common man.