| Wheat flour is one of the main raw material of food in China. With the development of social economy,the rhythm of people’s lives have accelerated in recent years.Small package wheat flour with its compact, easy to carry, as well as for home use, but also as a gift, can make delicious flour products at home, has won the favour of many consumers.It has become a development trend of wheat flour market in the future.However, due to small particles of wheat flour, nutrients and easy exposure to moisture and other characteristics. So Microbes breed, resulting in moldy during storage, can not completely kill during baking, to store wheat flour and processed food security risk.At present,the microbial contamination condition, microbiological control in the process of storage and processing big package of wheat flour in national reserve research more deeply.However,the microbial contamination and control research of small packages of wheat flour has not been reported.Therefore,this study provides a theoretical basis for ensuring storage security small packages of wheat flour and food safety of other processed products.The results as follows:1.Typical level of microbial contamination of small package wheat flourThrough the analysis of microbial contamination situation of 56 copies small package wheat flour purchased in the supermarket or enterprise.Positive detection rate of aerobic bacteria,Escherichia coli and aerobic bacterial spores is 100%.Positive detection rate of Bacillus cereus and moulds is 93% and 82% respectively. All kinds of microbial numbers is lower than big package wheat flour of the literature.Its typical level:aerobic bacteria is 102-103CFU/g;moulds is 102-103CFU/g;we did not check out the mold in the self-raising flour. White aspergillus is superiority strains in all samples.Escherichia coli is 101-102CFU/g;aerobic bacterial spores is 102CFU/g;Bacillus cereus is 101-102CFU/g.2.Microbial control indicators of enterprise producting small package wheat flourBased on the results of microbial analysis of small package wheat flour,we can according to it in the actual machining process:aerobic bacteria<103CFU/g;moulds < 10 CFU/g,Escherichia coli< 10 CFU/g,aerobic bacterial spores< 102CFU/g,Bacillus cereus<102CFU/g.So we can obtain a good practice.Microbial detection of 90～95% samples is under this provision.3.the microorganism and quality change about the small package wheat flour and its control during storage timeAs the extension of storage time,the microbial indicators and moisture about the small package of wheat keep basically unchanged, the fatty acid value Increases less When the temperature is 15℃.Unless the total aerobic spore-bearing bacilli increase, the total plate count, the Mold, the total bacillus cereus, the total Escherichia Coli decrease as the extension of storage time When the temperature is 25℃ or 35℃. It is concerned with the desorption of water at the temperature. Compare to the initial storage,the moisture about the small package of wheat falls, by 15.1% and 20.6%,the temperature is 25℃ and 35℃ respectively. Thus the microorganism decrease due to lack of enough water. But the extent of fatty acid value increases a considerably higher than the same time of 15℃. Further study showed, fatty acid value about the small package of wheat is significantly positively related with the storage temperature during storage time. The fatty acid value is the most important indicators on evaluating flour quality. Considering the microorganism and quality change about the small package of wheat during storage time, to ensure its safe storage, we should choose low temperature 15℃.The microbial biomass was basically stable, The extent of fatty acid value increases less, The water content remains the same When the temperature is 15℃. It is in favor of delaying decline in quality and net content of wheat.4.1n the process of baking biscuit,small packaging wheat flour as raw material,th e microorganism and quality change about the small package of wheat and its co ntrol.Apart from mold levels drop, the microbial biomass were showing increased in the process of small package wheat flour to make dough.It states it is polluted second in the process of wheat flour into the dough.With the increase of temperature and time,the amounts of aerobic bacteria,moulds,Escherichia coli,aerobic bacterial spores and Bacillus cereus reduced continuously in the process of baking.And the amounts have a extremely significant linear relationship with baking temperature or time.But the temperature is too high, time is too long,biscuit burnt paste seriously,sensory quality is hard to accepted.Considering quantity of pathogen of biscuits and sensory evaluation of biscuits, it is advisable to choose 185℃ and 15 min.At this point,biscuits meets the requirements of microbial content.Cookies form complete, uniform thickness, tan and uniform color, crispy taste not sticky. |
