DEVELOPMENT OF AROMA COMPOUNDS ON FERMENTED SOYBEAN SUBSTRATES WITH Lactobacillus paracasei subsp. paracasei CRL 207

GARRO M S; NACCHIO B; AVILA HAEL GN; MEDINA R

Mar del Plata

Congreso; CYTAL 2017/ XVI Congreso Argentino de Ciencia y Tecnología de Alimentos. 7mo Simposio Internacional de Nuevas Tecnologías; 2017

AATA-Asociación Argentina de Tecnólogos Alimentarios

Argentina is one of the largest producers of soybeans worldwide; however, only a small part of the production is allocated to the domestic market. This may be due to the lack of habit in the consumption of soy foods; as well as to the off-flavors or unpleasant aromas that generate little acceptability of this substrate to include it in the traditional diets. The use of lactic cultures could improve the sensory and nutritional characteristics of the same. In previous studies the behavior of lactic acid strains in soybean substrate was studied, showing good development and ability to use micro and macro-components present. Lactobacillus paracasei subsp. paracasei CRL 207 was able to hydrolyze soy protein and isoflavones using different fermentation strategies, these products presented pleasant aromatic characteristics. The aim of this work was evaluated the production of volatile compounds in liquid and semisolid soy substrates by the action of Lactobacillus paracasei subsp. paracasei CRL 207. A paste and aqueous soy extract were used with and without addition of 2% glucose for fermentation. The 2% microorganism was inoculated into each of the samples and incubated for 16 hours at 37 °C; uninoculated samples were used as controls. It was evaluated: pH, viability, humidity and soluble solids at time 0 and 16 h. The King method was used to qualitatively detect the presence of diacetyl and acetoin (C4 compounds). The production of volatile compounds was evaluated by gas chromatography (GC), using a SPME fiber for the extraction of compounds. The viability in different samples studied ranged from 1 to 2 logarithmic orders, with the highest values showing in samples with added glucose, similarly but inversely proportional to pH. As for the qualitative test of presence of diacetyl/acetoin, a higher production intensity was observed in the samples that had lower humidity and addition of glucose. The GCSPME studies of the fermented products showed chromatograms with different profiles of volatile compounds, relative to the control. In the fermented samples, with the addition of glucose, the presence of two high intensity peaks with retention time of 22 min and 27 min respectively, which could be attributed to volatile compounds C4, diacetyl/acetoin, whose presence was confirmed by the King´s method. Soy products fermented with Lactobacillus paracasei subsp. paracasei CRL 207 (paste and aqueous soy extract), present aroma compounds, which mask the off-flavors of the matrix, which would contribute to a greater acceptability of the product by the consumers.