title: Optimization of fermentation parameters to study the behavior of selected lactic cultures on soy solid state fermentation.
abstract: The use of solid fermentation substrate (SSF) has been appreciated by the demand for natural and healthy products. Lactic acid bacteria and bifidobacteria play a leading role in the production of novel functional foods and their behavior is practically unknown in these systems. Soy is an excellent substrate for the production of functional foods for their low cost and nutritional value. The aim of this work was to optimize different parameters involved in solid state fermentation (SSF) using selected lactic cultures to improve soybean substrate as a possible strategy for the elaboration of new soy food with enhanced functional and nutritional properties. Soy flour and selected lactic cultures were used under different conditions to optimize the soy SSF. The measured responses were bacterial growth, free amino acids and β-glucosidase activity, which were analyzed by applying response surface methodology. Based on the proposed statistical model, different fermentation conditions were raised by varying the moisture content (50-80%) of the soy substrate and temperature of incubation (31-43°C). The effect of inoculum amount was also investigated. These studies demonstrated the ability of selected strains (Lactobacillus paracasei subsp. paracasei and Bifidobacterium longum) to grow with strain-dependent behavior on the SSF system. β-Glucosidase activity was evident in both strains and L. paracasei subsp. paracasei was able to increase the free amino acids at the end of fermentation under assayed conditions. The used statistical model has allowed the optimization of fermentation parameters on soy SSF by selected lactic strains. Besides, the possibility to work with lower initial bacterial amounts to obtain results with significant technological impact was demonstrated.
authors.affiliation: Centro de Referencia para Lactobacilos (CERELA-CONICET), Chacabuco 145, San Miguel de Tucumán, T4000ILC Tucumán, Argentina.
authors.forename: A
authors.initials: A
authors.lastname: Rodríguez de Olmos
authors.affiliation: Centro de Referencia para Lactobacilos (CERELA-CONICET), Chacabuco 145, San Miguel de Tucumán, T4000ILC Tucumán, Argentina.
authors.forename: E
authors.initials: E
authors.lastname: Bru
authors.affiliation: Centro de Referencia para Lactobacilos (CERELA-CONICET), Chacabuco 145, San Miguel de Tucumán, T4000ILC Tucumán, Argentina. Electronic address: mgarro@cerela.org.ar.
authors.forename: M S
authors.initials: MS
authors.lastname: Garro
mesh_terms: D001644:Bifidobacterium / Q000378:metabolism*; D005285:Fermentation; D005516:Food Microbiology; D055951:Functional Food / Q000382:microbiology; D007777:Lactobacillaceae / Q000378:metabolism; D007778:Lactobacillus / Q000378:metabolism*; D030262:Soybean Proteins / Q000378:metabolism; D013025:Glycine max / Q000382:microbiology*
chemical_list: D030262:Soybean Proteins
keywords: Lactic cultures; Response surface methodology; Solid state fermentation; Soy flour