Search

With the aim of improving the processing added value of soybean isolate protein, the single factor and response surface testing method were used to optimize the enzymatic conditions of soybean isolate protein using hydrolysis degree and protein recovery as evaluation indexes. The enzymatic digest of soybean isolate protein fermented by Corynebacterium glutamicum was used to prepare the seasoning, which was evaluated by glutamic acid content and sensory evaluation. The results showed that the optimal enzyme digestion conditions were 2.0 g/100 g of enzyme, pH7.0, 15 g/100 mL of substrate, 54.0 ℃, and 13.0 h. The hydrolysis degree (37.1%) and protein recovery (70.3%) of the optimized enzyme solution were 1.7 times and 0.8 times higher, respectively, than those before the optimization. In the shake flask fermentation conditions, the glutamic acid content of the enzymatic digest fermentation (32.1 g/L) was increased by 32.1% compared to that before optimization. Under the batch replenishment condition of 20 L tank, the glutamic acid yield was (83.6 g/L) 10.0% higher than before optimization. The results of sensory evaluation of the seasonings prepared by fermentation with batch replenishment showed that the freshness of the fermented seasonings was significantly improved (P

In this study, corn meal was fermented by Corynebacterium glutamicum to produce a new natural flavoring materia. Firstly, the enzymatic hydrolysis process of corn meal was optimized by single factor experiment and orthogonal experiment. Then, the fermentation conditions of C. glutamicum GL-6 were optimized at shaking flask level to determine the best nitrogen source and content and the best addition amount of corn meal enzymolysis solution. Then verification was carried out at the level of 20 L fermenter. 5% Maltodextrin was added into the supernatant of fermentation broth and spray dried to obtain the umami sample. Finally, the composition of the sample was detected and evaluated. The results showed that the optimal enzymatic hydrolysis conditions were solid-liquid ratio 1:4, enzyme dosage 1%, temperature 90 ℃, time 3 h, under which the enzymatic hydrolysis degree DE value reached 60.84%. The optimal nitrogen source for glutamate production by C. glutamicum GL-6 fermentation was yeast extract FIG12LS 30 g/L, and the optimal addition amount of corn meal hydrolysate was 50%（v/v）. The content of MJ glutamate was 43.9 g/100 g, and the total content of amino acid was 44.8 g/100 g, which increased by 24.0% and 23.4%, respectively, compared with that of CK without corn meal enzymolysis fermentation. In addition, sample MJ was rich in nutty and coffee-flavored pyrazines. Compared with sample CK, its umami content and nutritional value were improved, and its flavor was richer. This study provides a new idea for the production of umami flavoring by fermentation of natural plant materials and improves the market competitiveness of the product.