Lactic Acid Bacteria from Argentinean Fermented Foods: Isolation and Characterization for their Potential Use as Vegetable Starters

GABRIEL D. SÁEZ; LEANDRO FLOMENBAUM; GABRIELA ZÁRATE

FOOD TECHNOLOGY AND BIOTECHNOLOGY

FACULTY FOOD TECHNOLOGY BIOTECHNOLOGY

Lugar: Zagreb; Año: 2018

1330-9862

Lactic acid bacteria (LAB) improve the organoleptic, nutritional and physicochemical properties of artisanal foods. In this study, 31 dairy and vegetable fermented foods marketed in Tucumán city, Argentina, were selected as sources of LAB for the production of pickles. Sixty-four isolates presumptively identified as Lactobacillus strains were screened for relevant technological properties for fermented foods. Most strains showed moderate-good acidification (> 0.04 pH units/h) and proteolytic capabilities (> 1 mmol FAA/L), produced diacetyl-acetoin and were resistant to 4 % NaCl. Based on acid production and osmotolerance, six LAB strains were selected and identified by 16S rDNA sequencing (97-100 % identity) as: Lactobacillus rhamnosus CRL2159 and CRL2164, L. plantarum CRL2161 and CRL2162, Weissella viridescens CRL2160 and W. paramesenteroides CRL2163. Relevant properties for pickle manufacturing were further assessed. At an initial pH of 4.5 and 7 % NaCl, L. plantarum CRL2162 and L. rhamnosus CRL2164 showed the best performance with high growth and inhibitory activity against Escherichia coli and Listeria innocua. No direct antagonism was observed between selected strains that could dismiss their use in mixed cultures. Properties exhibited by the selected LAB suggest their potential as starter cultures for obtaining standardized, fermented vegetable products of high quality. The development of these new industrial starters would increase the competitiveness of production which would lead to the opening of the country´s frontiers in the canned vegetables market.