Biotechnological innovations in kefir production: a review

Abstract

PurposeThe purpose of the paper is to show that traditionally, kefir was obtained by fermenting milk with kefir grains. Wide variation in microflora of kefir grains makes it difficult to obtain an optimal and uniform starter culture necessary for obtaining a quality kefir. Reviewed literature on microbiological and technological innovations in kefir production would enrich the scientific knowledge resulting in production of kefir with superior physical, chemical, nutritional, therapeutic and sanitary qualities.Design/methodology/approachAn attempt is made to highlight the microbiological and technological aspects of kefir production with regard to the microflora of kefir grains, suitability of different types of milk, treatment of milk, starter inoculation and incubation, packaging, storage and post‐production treatment of kefir as well as methods of preservation of kefir grains.FindingsDiverse microflora of kefir grains is the prime cause for the wide variation in kefir quality. Production of kefir is based on symbiotic relation between lactic acid bacteria and yeasts and the type of milk, their heat‐treatment, size of inoculating starters and temperature of incubation influence their metabolic activities. Application of a suitable combination of lactic acid bacteria and yeasts would enable production of kefir with more uniform product with specific properties Packaging of kefir in a suitable container and storage at low temperature are suggested to retain its qualities.Originality/valueFermentation of milk with a suitable starter combination consisting of lactic acid bacteria and yeasts rather than application of kefir grains during the production of kefir would be more scientific to yield a product with enhanced nutritional and therapeutic qualities.

A review: chemical, microbiological and nutritional characteristics of kefir

“…Traditional kefir made from caprine milk was found to have a low viscosity and sensory properties unlike those of bovine kefir and contained 0.04-0.3% ethanol (Sarkar, 2008). Tratnik et al (2006) found that the ethanol content in bovine and caprine kefir enriched with whey protein concentrate was 0.32 and 0.35%, respectively.…”

“…Kefir microfloral composition varies according to culture medium and production method (Sarkar, 2008).…”

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

“…The fermentation agent of kefir known as the "kefir grain" is a gelatinous mass of protein and polysaccharide structure containing a variety of species of lactic acid bacteria, acetic acid bacteria, and yeasts, which make up a natural microbial ecosystem (Farnworth, 2005;Guzel-Seydim et al, 2011;Montanuci et al, 2012;Sarkar, 2008). Due to the large quantity and complex nature of the associations between the species involved, the microflora of kefir grains has not been fully elucidated yet (Pogačić et al, 2013).…”

“…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.…”

“…The total amount of 5% of grains were used for fermentation, a percentage considered ideal for adequate production of ethanol and volatile acids (Sarkar, 2008). The inoculate was maintained at 28 °C ± 2 °C, room temperature, for 24 hours without agitation (Santos et al, 2013).…”