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

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.(AU)

Análise microscópica e microbiológica de diferentes marcas de "ração humana"

A Ração Humana é considerada um complemento alimentar e uma das novas tendências de dietas da moda. O objetivo do presente estudo foi avaliar a qualidade microbiológica e microscópica de diferentes marcas de "ração humana". Foram avaliadas dez diferentes marcas do produto e realizadas análises microscópica e microbiológica. Os resultados mostraram que todas as marcas apresentam qualidade comprometida, segundo aspectos físicos e microscópicos. Com relação à análise microbiológica apenas uma marca apresentou resultado fora das especificações da legislação para Coliformes a 45°C, e outras duas apresentaram maior contagem de bolores e leveduras, o que caracteriza a deterioração do produto. Concluiu-se que todas as amostras estavam impróprias para o consumo. Enfatiza-se, portanto, a necessidade de fiscalização pelos órgãos competentes a fim de garantir ao consumidor clareza e idoneidade das informações descritas nos rótulos e produtos de boa qualidade.(AU)

The "human ration" is considered a food complement and a new trend of diet. The aim of this study was to analyze the microbiological and microscopic quality of different types of "human ration". It was analyzed ten different human ration's types. The results showed that all types presented bad quality in accord of microscopic aspect. The microbiologic analysis showed that only one type presented result out of the legislation specific for fecais coliforms at 45°C/g. Other two, presented higher count for molds and yeast; it characterize the deterioration of the product. These results suggest that all types of "human ration" were inadequate for human consumption.(AU)