Physicochemical and functional properties of roasted soybean flour, barley, and carrot juice mixture fermented by solid-state fermentation using Bacillus subtilis HA

Abstract

Roasted soybean flour (RSF) was fermented by solid-state fermentation using Bacillus subtilis HA to produce wholesome food ingredients containing biologically active compounds. To enhance the fibrinolytic activity of fermented RSF, RSF was fortified with barley powder and carrot juice (CJ). The RSF and barley mixture fermented with 40% CJ showed the highest tyrosine content (818 mg%), protease activity (97.8 unit/g), fluid consistency (22.5 Pa·sn), and crude mucilage content (27.1%). In particular, the RSF and barley mixture fermented with 40% CJ showed higher fibrinolytic activity of 31.5 unit/g. The fibrinolytic activity was partially reduced to 18.9 unit/g by heating at 60°C for 10 min and inactivated completely by 60°C for 40 min. The RSF and barley mixture fermented with 40% CJ showed reduced off-flavor compared to that of fermented textured vegetable protein. In GC analysis, the contents of trimethyl and tetramethyl pyrazine, which are responsible for typical off-flavors, were greatly reduced.