Production of fermented cheese whey-based beverage using kefir grains as starter culture : evaluation of morphological and microbial variations

摘要

Whey valorization concerns have led to recent interest on the production of whey beverage simulatingkefir. In this study, the structure and microbiota of Brazilian kefir grains and beverages obtained frommilk and whole/deproteinised whey was characterized using microscopy and molecular techniques.The aim was to evaluate its stability and possible shift of probiotic bacteria to the beverages. Fluorescencestaining in combination with Confocal Laser Scanning Microscopy showed distribution of yeasts inmacro-clusters among the grain’s matrix essentially composed of polysaccharides (kefiran) and bacteria.Denaturing gradient gel electrophoresis displayed communities included yeast affiliated to Kluyveromycesmarxianus, Saccharomyces cerevisiae, Kazachatania unispora, bacteria affiliated to Lactobacillus kefiranofacienssubsp. Kefirgranum, Lactobacillus kefiranofaciens subsp. Kefiranofaciens and an unculturedbacterium also related to the genus Lactobacillus. A steady structure and dominant microbiota, includingprobiotic bacteria, was detected in the analyzed kefir beverages and grains. This robustness is determinantfor future implementation of whey-based kefir beverages.