Fermented milk: history, composition, physical and chemical properties, processing technology and defects

Abstract

Fermented milk is the generic name given to products such as yogurt, cultured milk, acidophilus milk, kefir, curd and kumys. This name is due to the fact that the milk is inoculated with starter cultures of lactic acid microorganisms, which convert part of the lactose from milk to lactic acid by fermentation. The lactic acid fermentation increases the shelf life of milk, inhibiting the growth of pathogenic bacteria and / or deteriorating. Other substances are also formed in the fermentation process, giving the products desirable sensory characteristics. Originally popular in the Middle East, fermented milks have a global spread of its consumption, mainly from the development of products containing added ingredients such as fruits and flavorings. The ratio of these products as functional foods aimed at health benefits, simplicity of manufacturing technology, the affordable and high relative expiration date for milk are some of the factors responsible for the success of these products in the world. In this paper we present a literature on the history, importance, composition, physico-chemical characteristics, manufacturing and defects that can occur in fermented milk products, with emphasis on yogurt and kefir.