Preservation of Yoghurt and Soymilk Using Organic Substances

Yoghurt is a fermented dairy product obtained from the lactic acid fermentation of milk. It is one of the most popular fermented milk products in the world. Yoghurt is a food staple that can be enjoyed in many ways. The product is always at risk of proteolytic degradation through proteolysis of milk which may occur during cold storage due to the growth of psychotropic bacteria hence the need for preservation. It was reported that yoghurt from whole cow milk powdered milk and soy milk should be kept under refrigeration for no more than 7 days to maintain its freshness. But refrigeration is not quite practicable in Nigeria due to the epileptic nature of power supply and the inability of some consumers to purchase these refrigerators due to poverty. Therefore there is a need to use preservatives that will be within the reach of local producers. The most available preservatives in dairy (yoghurt and soymilk) industry are the chemical preservatives such as potassium sorbate and sodium metabisulphite which are chemical preservatives. In addition to these chemical preservatives there are natural preservatives that extend the shelf life of dairy products.