Aglycone production by Lactobacillus rhamnosus CRL981 during soymilk fermentation |
| |
Authors: | Jose A. Marazza Marisa S. Garro Graciela Savoy de Giori |
| |
Affiliation: | 1. Centro de Referencia para Lactobacilos (CERELA-CONICET), Chacabuco 145, (T4000ILC) San Miguel de Tucumán, Tucumán, Argentina;2. Cátedra de Microbiología Superior, Facultad de Bioquímica, Química y Farmacia, UNT, Tucumán, Argentina |
| |
Abstract: | Lactobacillus rhamnosus CRL981 showed the highest levels of β-glucosidase and was selected to characterize this enzyme system, among 63 strains of different Lactobacillus species. The maximum activity was obtained at pH 6.4 and 42 °C. The enzyme showed weak resistance to thermal inactivation maintaining only 20% of the initial activity when it was exposed at 50 °C for 5 min. It also, showed stability when stored at 4 °C for 60 days. Afterwards, L. rhamnosus was evaluated for hydrolysis of isoflavones to aglycones, cell population, residual sugars and organic acid produced during fermentation on soymilk (37 °C for 24 h). Higher viable counts were obtained after 12 h of fermentation (8.85 log CFU ml−1) followed by a drop of pH and an increase of acidity during fermentation due the production of organic acids. L. rhamnosus CRL981 was able to proliferate in soymilk and produce a high β-glucosidase activity achieving a complete hydrolysis of glucoside isoflavones after 12 h of fermentation. The present study indicates that L. rhamnosus CRL981 could be used in the development of different aglycone-rich functional soy beverages. |
| |
Keywords: | Soymilk fermentation Lactic acid bacteria β-Glucosidase enzyme Sugars and isoflavones |
本文献已被 ScienceDirect 等数据库收录! |
|