茭白接种-真空浸渍快速发酵新工艺

Rapid fermentation of wild rice stem by inoculated fermentation combined with vacuum impregnation

研究了一种接种与真空浸渍相结合的茭白发酵新工艺。由单因素试验初步确定温度、盐水浓度和接种量3个因素的水平范围,通过Box-Behnken设计及响应面法优化茭白发酵条件,同时测定菌落总数、乳酸菌总数和脆度值,结合感官评定方法,比较该工艺与传统工艺产品品质的差异。结果表明:在25.3℃、NaCl质量分数为4.9%的盐水中和接种量6.0%的条件下,经真空厌氧发酵而成的产品效果最好,生产周期为3 d,菌落总数为7.1×107CFU/mL,乳酸菌总数为5.8×107CFU/mL,脆度值为0.861 9 kg,感官评分为91;以传统工艺发酵生产茭白,生产周期为7 d,发酵成熟时产品菌落总数为19.2×107CFU/mL,乳酸菌总数为3.1×107CFU/mL,脆度值为0.560 8 kg,感官评分为83。接种结合真空浸渍发酵缩短了发酵茭白的生产周期,改善了发酵过程中乳酸菌总数和菌落总数的比例,同时无汁液浸泡的发酵过程也缓解了发酵蔬菜组织软化,使产品保持更好的脆度。

A novel inoculated fermentation of wild rice stem combined with vacuum impregnation method was studied. The optimal fermentation parameters were established through Box-Behnken central composite designs experiment under the response surface methodology. The total count of lactic acid bacteria,colony-forming unit,crispness value and sensory evaluation were analyzed to investigate the effects of fermentation conditions on the quality of resulted products,and to compare the fermented rice stems prepared by the novel method and prepared by the traditional one. The results showed that an incubation temperature of 25. 3 ℃,an initial salt content of 4. 9% and an inoculum volume of 6. 0%( v /v) were the optimal conditions to obtain the fermented wild stem with the best quality. Under the optimal conditions,the fermentation period was shorten from 7 days to 3 days,and the indices were measured as the total number of colonies 7. 1 × 107CFU /mL,the total number of lactic acid bacteria 5. 8 × 107CFU /mL,the crispness value 0. 8619 kg and the sensory evaluation scores 91. While the indices from the traditional fermentation were measured as the total number of colonies 19. 2 × 107CFU /mL,the total number of lactic acid bacteria 3. 1 × 107CFU /mL,the crispness value 0. 5608 kg and the sensory evaluation scores 83. Inoculated fermentation combined with vacuum impregnation method could shorten the fermentation period and meanwhile ensure high quality of the final products.