发酵方式对馒头在冷藏过程中品质及其货架期的影响

将一次发酵、快速二次发酵和老面发酵的馒头进行冷藏贮存,测定冷藏过程中馒头的pH、水分含量、比容、菌落总数、霉菌的变化趋势,以及将馒头复蒸之后的感官评分变化。结果表明:馒头的水分含量、pH、感官评价均呈现总体下降趋势;馒头的比容在冷藏过程中略有波动比较稳定;三种馒头的菌落总数14 d时未达到10⁶CFU/g,低温有效地抑制了微生物的生长;0~2 d未检测到霉菌,随着贮存时间延长霉菌超出标准范围。老面发酵馒头在0~4 d时稳定性最好,各项指标变化幅度最小,8~14 d时霉菌生长迅速,加快了变质,一次发酵馒头微生物生长最快,水分含量下降最快,二次发酵馒头水分含量变化最为稳定。综合霉菌和感官评分,将冷藏馒头分别划分成三个食用阶段。一次发酵馒头最佳食用阶段为0~4 d,可食用阶段为5~11 d,不可食用阶段为12 d以上;快速二次发酵馒头最佳食用阶段为0~2 d,可食用阶段为3~11 d,不可食用阶段为12 d以上;老面发酵最佳食用阶段为0~4 d,可食用阶段为5~9 d,不可食用阶段为10 d以上。

Effect of Fermentation Method on the Quality and Shelf Life of Steamed Bread during Cold Storage

The steamed bread of one-time fermentation,rapid secondary fermentation and old-fashioned fermentation was refrigerated and stored. The change trend of pH,moisture content,specific volume,total number of colonies,mold and sensory score of steamed bread after resteaming were measured.The results showed that the moisture content,pH and sensory evaluation of steamed bread showed an overall downward trend;the specific volume of steamed bread was slightly stable during the cold storage process;the total number of colonies of three steamed breads did not reach 106 CFU/g at 14 d,and low temperature effectively inhibited the growth of microorganisms. No mold was detected at 0~2 d,and with the increase of storage time,mold was out of the standard range.The old-fashioned fermentation steamed bread had the best stability at 0~4 d,and the change of each index was the smallest. The mold grew rapidly at 8~14 d,which accelerated the deterioration. The microbial growth of one-time fermentation steamed bread was the fastest and the moisture content decreased the fastest. The moisture content of rapid secondary fermentation steamed bread was the most stable.The cold steamed bread was divided into three stages according to the mould and sensory scores.The best edible stage of one-time fermentation steamed bread was 0~4 days,the edible stage was 5~11 days,the inedible stage was 12 days or more;the best edible stage of the rapid secondary fermentation steamed bread was 0~2 days,and the edible stage was 3~11 days,the inedible stage was more than 12 days;the best edible stage of old-fashioned fermentation steamed bread,0~4 days,the edible stage was 5~9 days,and the inedible stage was more than 10 days.