Microbiological, technological and therapeutic properties of kefir: a natural probiotic beverage

Abstract

Kefir is a fermented milk beverage produced by the action of bacteria and yeasts that exist in symbiotic association in kefir grains. The artisanal production of the kefir is based on the tradition of the peoples of Caucasus, which has spread to other parts of the world, from the late 19th century, and nowadays integrates its nutritional and therapeutic indications to the everyday food choices of several populations. 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. Several studies have shown that kefir and its constituents have antimicrobial, antitumor, anticarcinogenic and immunomodulatory activity and also improve lactose digestion, among others. This review includes data on the technological aspects, the main beneficial effects on human health of kefir and its microbiological composition. Generally, kefir grains contain a relatively stable and specific microbiota enclosed in a matrix of polysaccharides and proteins. Microbial interactions in kefir are complex due to the composition of kefir grains, which seems to differ among different studies, although some predominant Lactobacillus species are always present. Besides, the specific populations of individual grains seem to contribute to the particular sensory characteristics present in fermented beverages. This review also includes new electron microscopy data on the distribution of microorganisms within different Brazilian kefir grains, which showed a relative change in its distribution according to grain origin.

A review: chemical, microbiological and nutritional characteristics of kefir

“…The term is derived from the word kef, which means 'pleasant taste' in Turkish (De Oliveria Leite et al, 2013;Guzel-Seydim, Seydim, Greene, & Bodine, 2000). Kefir is also known variously as kefyr, kephir, kefer, kiaphur, knapon, kepi or kippi (Sarkar, 2007).…”

Labneh with probiotic properties produced from kefir: development and sensory evaluation

“…Traditionally, kefir is produced by inoculating kefir grains in milk for 18 to 24h at a temperature of 20 to 25 °C (Leite et al, 2013;Sarkar, 2008). At the end of the fermentation process, the kefir grains are recovered and reused, a step which is different from those in the production of other fermented milk products.…”

“…At the end of the fermentation process, the kefir grains are recovered and reused, a step which is different from those in the production of other fermented milk products. Moreover, kefir does not result from the metabolic activity of a single or a few microbial species (Guzel-Seydim et al, 2011;Leite et al, 2013).…”

“…Traditionally consumed in Eastern European countries, Russia, and Southeast Asia, kefir has also become popular in many countries due to its probiotic activity, unique sensory characteristics, and nutritional and therapeutic properties (Leite et al, 2013).…”

“…Among the health benefits associated with kefir are: antimicrobial property and cicatrizing activity (Rodrigues et al, 2005), antimutagenic and antioxidant effect (Liu et al, 2005), hypocholesterolemic properties (Huang et al, 2013), betagalactosidase activity (Leite et al, 2013), anti-allergenic properties, anti-inflammatory activity, and stimulation of the immune system (Lee et al, 2007;Vinderola et al, 2006).…”