Fermentation Of Bran With Lactic Acid Bacteria And Its Application In Steamed Bread

In this paper,we studied the fermentation of bran by lactic acid bacteria,determined the optimum fermentation temperature and time,and the changes of biochemical indexes,properties and composition of bran during fermentation;The effects of the addition of fermented bran on flour pasting properties,the rheological properties and fermentation characteristics of dough,as well as on the quality and flavor of steamed bread.The conclusions are as follows:1.During the fermentation process of wheat bran,the growth of lactic acid bacteria was good and the total number of mold colonies decreased first and then increased.The pH value decreased with the fermentation time prolonged,and then decreased to about 4,and TTA increased.The content of SAX and total phenol in wheat bran increased significantly,the content of phytic acid and the content of total dietary fiber decreased,the proportion of soluble dietary fiber increased.The water holding capacity,water solubility index and water absorption index increased after bran fermentation.The fermentation temperature was 35 ?C and the fermentation time was 24 h.If the enzyme was selected,the enzyme addtion was 30 mg / kg,the fermentation temperature was 35 ?C,and the fermentation time was 16 h.2.With the increase of the amount of fermented bran,the peak viscosity,minimum viscosity,final viscosity and backwash value of fermented bran powder were significantly decreased,and the gelatinization temperature of fermented bran mixed powder was higher than that of white flour.When the bran was added into the flour,the water absorption increased significantly,the formation time increases,shorten the stability time.The water absorption rate of fermented bran powder was significantly decreased,the stabilization time was shortened and the degree of softening was significantly increased.After adding alkali,the formation time and the stability time of fermented bran dough was increased slightly,and the degree of softening was significantly reduced.Under the same conditions,the tensile area and the tensile resistance of fermented bran dough was increased significantly,and the elongation decreased significantly.After adding bran,the maximum fermentation height of the dough was significantly reduced,the gas production was reduced,but the stability was better.Compared with ordinary bran dough,the fermentation speed of fermented wheat bran dough was faster,gas production lower,gas holding capacity was significantly increased.The addition of bran made produced transformation among protein secondary structure,the fermented bran dough changed more.The addition of enzyme-assisted fermented bran can enhance the fermentation effect,and exacerbate the secondary structure of the protein changes.3.The addition of bran reduced the specific volume of the bread and deepened the color.The addition of fermented bran can improve the specific volume and internal structure of the steamed bread with bran,but cannot eliminate the weakening of bran.The bran fermentation can improve the taste of bran bread.The addition of fermented bran resulted in a significant reduction in phytic acid content in the steamed bread and a significant increase in the content of polyphenols,which was significantly higher than that of steamed bread with bran.The addition of fermented bran reduced the digestibility of starch and the releasion of reducing sugar was lower than that of common bran bread.The protein digestibility was significantly increased.4.After the fermentation of bran,the contents and types of hydrocarbon species were significantly decreased.The contents of organic acids,esters,alcohols,benzene rings and ketones were significantly increased after 24 h fermentation.The main volatile substances of the stream bread and stream bread with bran are alcohols,esters,aldehydes and heterocycles.The main volatile substances in the streamed bread with fermented bran are alcohols,esters,aldehydes,benzene rings and heterocycles.The content and species of volatile matter in the steamed bread were significantly increased after adding bran,and the content of the alcohol in the fermented bran bread was decreased,while the volatile compounds of the benzene ring were significantly improved.