ESTERASE ACTIVITIES AND BIOCHEMICAL PROPERTIES OF LACTIC ACID BACTERIA ISOLATED FROM GOATS MILK CHEESE IN ARGENTINA

N.TABOADA; M.C. ABEIJÓN MUKDSI; S. LÓPEZ ALZOGARAY; R.B. MEDINA

Journal of Agricultural Science and Technology B

David Publishing Company

Lugar: Dakota; Año: 2014 vol. 4 p. 752 - 760

1939-1250

Twenty two lactic acid bacteria (LAB) strains isolated from goat dairy products from northwest Argentina were screened for biotechnological properties relevant in flavor development in order to select the strains to be used as starter or adjunct cultures for the manufacture of Argentinean goatʼs milk cheese. Streptococcus thermophilus (UNSE314), Lactobacillus (L.) delbrueckii subsp. bulgaricus (UNSE309), L. rhamnosus (UNSE308), L. plantarum (UNSE287, UNSE316, UNSE317) and Pediococcus pentosaceus (UNSE315) presented high acidifying activity. All strains tested metabolized citrate, produced diacetyl- acetoin in goat milk and 77.3% of them showed proteolytic activity. Based on these results ten strains with the best performance in diverse technological properties were screened to determine the esterolytic activity. In all selected strains, esterase specific activity (ESA) was detected on a- and b- naphthyl (NA) acetate, propionate, caprylate and a-NA butyrate. No activity was detected on b-NA laurate. The highest values were detected when using a-NA instead of b-NA derivatives as substrate. The preference for short-chain fatty acids for esterases from lactobacilli strains was observed. In pediococci strains wide variability in ESA were observed, which were species-and strain-specific. The present work represents a first contribution to knowledge of the biotechnological properties of autochthonous LAB strains from Santiago del Estero, Argentina. These results allow us to choose strains which could be considered in the design of selected cultures for their potential contribution to   flavor development during cheese ripening, preserving the typical organoleptic characteristics of artisanal goat milk cheese.