Kefir - grains and beverages: a review

Abstract

Kefir is a fermented milk beverage produced by the action of bacteria and yeasts that exist in symbiotic association in kefir grains. The large number of microorganisms present in kefir and their microbial interactions, the possible bioactive compounds resulting of microbial metabolism, and the benefits associated with the use this beverage confers kefir the status of a natural probiotic, designated as the 21th century yoghurt. The importance of probiotics in food industry is growing nowadays and further research should be performed on the symbiotic relations between different microorganisms and how these interactions can result in nutritional and therapeutic benefits as curing and preventing human diseases and other disorders. This review includes a thorough and detailed discussion on the structure, microbiological and chemical composition, and the production and utilization of kefir will be presented covering different aspects.