Obtención de pastas de soja bio-enriquecidas en isoflavonas utilizando cultivos lácticos seleccionados

RODRIGUEZ DE OLMOS A; GARRO M S

Cordoba

Congreso; V Congreso Internacional de Ciencia y Tecnología de los Alimentos (CICyTAC); 2014

Cordoba Ciencia

At present, the consumer demand for foods with nutritional value and a beneficial effect on human health by reducing the risk of disease is growing. In this sense, the interest of fortified products with soy isoflavones (IS) has increased due to the beneficial attributed properties such as antioxidants, hypoglycemic, prevention of some cancers, cholesterol lowering, among others. In soybeans, the IS predominate as β-glucosides (GE: genistin and DA: daidzin). The IS deglycosylation to the corresponding aglycones (GEi: genistein and DAi: daidzein) which are easily absorbed in the intestine and responsible for the beneficial effect, is mediated by the action of the enzyme β-glucosidase of intestinal microbiota. Incorporation of microorganisms like lactic bacteria and bifidobacteria with β-glucosidase activity on soy substrates is a promising solution to enhance bioavailability of the IS. The aim of this study was analyze the β-glucosidase activity and content of IS aglycones in fermented soybean pastes by selected lactic cultures under different conditions of moisture and temperature. The pastes were prepared from commercial soy flour and distilled water to achieve different moisture contents (50, 55, 65, 75, 80%) and they were inoculated at 4% with cultures of Lactobacillus (L.) paracasei subsp paracasei CRL 207 and Bifidobacterium longum CRL 849, belonging to the culture collection of CERELA (CRL). After that, the pastes were incubated at different temperatures: 31, 33, 37, 41, 43 ° C for 24h. β -glucosidase activity and IS content at the final of fermentation were assayed. Enzyme activity of each strain in all fermented pastes was evidenced. L. paracasei subsp paracasei CRL 207 was able to increase both types of IS aglycones in all tested conditions, in contrast with the control (unfermented paste).The greater proportion in the pastes was GEi. A linear effect of moisture content on IS was observed, showing maximum concentration for 50% moisture. For the strain B. longum CRL 849 a lower amount of IS at 24 h was observed. The final content of IS was higher than the unfermented paste. This strain hydrolyzed partially or completely the IS depending on the humidity and temperature of the pastes. This work allowed us to evaluate the ability of lactic cultures to increase the content of IS aglycones in soybean pastes under different process conditions. Obtaining soybean pastes with higher levels of aglycones IS using potentially probiotic microorganisms is interest for the development of differentiated products with higher added value.