Estudos cinéticos da produção de fermentado simbiótico de soja

Abstract

Healthier eating habits are in evidence. Within this trend there are functional foods, such as products containing probiotic microorganisms and/or prebiotic fibers, for example. In addition, there is a greater demand for food from vegetable sources and soy stands out as an alternative because it is a source of proteins and has bioactive principles. The objective of this work was to analyze the kinetics of soybean extract fermentation by probiotic bacteria, added by the prebiotic fructooligosaccharide (FOS), through the modification of the process variables: soybean extract concentration, FOS concentration, Lactobacillus ratio and agitation. For this purpose, the Central Composite Rotational Design (CCRD) was used and the responses were total growth factor and bifidobactéria growth factor, consumption of reducing sugar (RS) and total sugar (TS), exopolysaccharide (EPS) production and syneresis. The treatment of the center point with soybean concentration of 10g/100mL, FOS of 2g/100mL, proportion of Lactobacillus of 30% and agitation of 50 rpm showed the highest total growth factors (145.86%) and bifidobacteria growth factor (140.88%). On the other hand, treatment 8, with levels close to the central point, presented the highest initial concentration of RS (20.12 g/L) and TS (53.33 g/L), and therefore obtained the highest concentration of lactic acid (9.98%). For EPS, treatment 11, also with levels that are not distant from the central point, presented the best result (4.08 g/L). Regarding syneresis treatments 2, 3, 20, 21 and 23 did not suffer from syneresis (0%), while treatment 6 had the highest syneresis rate (44.63%). The treatments differed in the rheological behavior of the models Newton's Law, Law of the Power and Herschel-Bulkley. CCRD was effective in analyzing the best fermentation conditions for the production of a soy based symbiotic.