蒸汽润麦对小麦粉微生物指标和理化特性的影响

Effect of Wheat Tempering with Steam on Microorganisms and Physicochemical Property of Wheat Flour

为缩短小麦的润麦时间,控制小麦粉中的微生物数量,研究了蒸汽润麦处理对小麦粉的降菌作用及对其理化特性的影响。研究表明:蒸汽润麦后,小麦籽粒的温度显著上升(P<0.05),出粉率先下降后上升,小麦粉中的微生物数量显著降低(P<0.05),且随着处理时间的延长,杀菌效果越明显。当蒸汽处理时间为320s时,小麦粉中的微生物数量显著减少(P<0.05),其中菌落总数减少了1.74lgCFU/g、霉菌和酵母总数减少了1.99lgCFU/g、耐热芽孢总数减小了1.01lgCFU/g。蒸汽润麦处理后,小麦粉的酶活显著降低(P<0.05),破损淀粉含量、吸水率和淀粉黏度均呈现先增大后减小的趋势;面团流变学特性的分析结果表明,蒸汽润麦能显著延长(P<0.05)面团形成时间和稳定时间,增加面团强度;同时,蒸汽处理还促进了小麦粉中蛋白质的交联聚合。该研究表明蒸汽润麦在降低小麦粉中微生物数量的同时还能在一定程度上改善小麦粉的理化特性。

In order to shorten the time of wheat tempering and control the number of microorganisms in wheat flour,the disinfection of wheat tempering with steam and its effects on the physicochemical property of wheat flour were studied in this study.Results showed that the temperature of grains was increased significantly ( P < 0.05) after treatment,and the flour yield was decreased at first and then increased.In addition,the number of microorganisms in wheat flour was reduced significantly ( P < 0.05) after tempering with steam,and the disinfection effect became more obvious with the treatment time increasing.When the treatment time was 320 s,the microbial content in flour was decreased significantly ( P < 0.05).The total plate count,yeast and mould count and mesophilic aerobic spore in wheat flour were reduced by 1.74,1.99 and 1.01 lgCFU/g,respectively.After steam treatment,the enzyme activity of wheat flour was reduced significantly ( P < 0.05);the content of damaged starch,water absorption and starch viscosity were increased at first and then decreased.The results on the rheological property of dough showed that the dough development time,along with the stability,was increased significantly ( P < 0.05) and the dough strength was enhanced after steam treatment.At the same time,steam treatment also accelerated the crosslinking polymerization of protein in wheat flour.This research showed that wheat tempering with steam could reduce the number of microbes in wheat flour and improve the physicochemical property of wheat flour to a certain extent.