关键词: 白酒糟, 复合菌发酵, 真蛋白, 条件优化

Abstract:

With the aim of achieving increased true protein content of distilled spirit lees, this study investigated the effects
of different mixed cultures and solid-state fermentation conditions on protein content of distilled spirit lees. Comparison was
carried out with the unfermented control group. Fermentation experiments were conducted with pure and mixed cultures of
Bacillus subtilis, Geotrichum candidum and Candida utilis, and the best results were obtained when all the three strains were
used together. By the combined use of one-factor-at-a-time and orthogonal array design methods, the optimal fermentation
conditions were determined as follows: addition of wheat bran and urea to distilled spirit lees in proportions of 15% and 2%,
respectively, and sequential culture at 30 ℃ for 24 h with 5% Bacillus subtilis and 10% Geotrichum candidum followed
by 5% Candida utilis for 72 h. The fermented lees under these conditions contained 24.85% true protein and 32.09% crude
protein, and the crude fiber content was reduced to 17.66%.

Key words: distilled spirit lees, mixed-culture fermentation, true protein, optimization of fermentation conditions