Characterisation of Lactobacilli from eweʼs and goatʼs milk for their further processing re-utilisation

Abstract

Raw ewe's and goat's milk is a good source for isolation of wild lactobacilli which are able to bring unique processing properties in development of dairy products - cheeses or fermented dairy products. 34 strains of lactobacilli were isolated, purified and identified from fermented ewe's and goat's dairy products. These products were processed without thermal treatment and without using of any commercial starters. After preliminary selection, the final collection of 5 strains was established. The strains were identified as: Lbc. plantarum (2), Lbc. paraplantarum (1), Lbc. paracasei (1) and Lbc. johnsonii (1). Except two strains, all were able to coagulate milk. After hydrolysis of lactose in milk, two strains were able to form sensorial attractive coagulate too. All of the strains were homofermentative, they produced lactic acid but they did not produce CO2. Their ability to produce diacetyl was low. They did not show strong proteolytic activity. All strains grew at 30 °C and 37 °C, however Lbc. johnsonii much slower at 30 °C than the others. Except Lbc. johnsonii, all strains tolerated 2% concentration of NaCl and even in presence of 5% concentration of NaCl their growth was inhibited only moderately. All of characterized strains can be provisionally used as starter or starter adjuncts in dairy technology, during production of cheeses or fermented milk products from pasteurised milk. These results will be used in further processing studies of isolated strains and will be supplemented with other properties e.g. safety, probiotic and antimicrobial properties.

Keywords

• ewe’s milk
• goat’s milk
• lactobacilli
• isolation
• technological properties