Abstract: Chinese steamed bread(CSB)is a kind of Chinese traditional fermented staple food.It is traditionally fermented by Jiaotou,which is the starter culture of CSB.This study was to determine the microbial characteristics of Jiaotou and its influence on CSB quality.In this paper,lactic acid bacteria (LAB)and yeasts counts in 12 Jiaotou samples were enumerated and seperated by plate method.The isolated strains were identified by BioMerieu Vitek-32 system.The qualities of Jiaotou fermented CSB and that of commercially produced ones were compared by sensory analysis and texture profile analysis(TPA).The average LAB counts of Jiaotou were 8.1 lg CFU/g,while the average yeasts counts were slightly lower(7.7lg CFU/g).The yeasts counts of dry Jiaotou(8.2 lg CFU/g)were significantly higher than wet Jiaotou(7.2 lg CFU/g,p＜0.05).The isolated yeasts were identified as Saccharomyces cerevisiae,and three strains of bacteria were identified as Bacillus cereus,Brevibacillus brevis and Acinetobacter lwoffii,respectively.During dough fermentation,Jiaotou made the dough pH go down with the LAB but the yeasts counts increase. With better interior structure but inferior odor,the general sensory scores of Jiaotou fermented CSB wee not significantly different to those of commercial ones.The TPA results indicated that Jiaotou fermented CSB was significantly superior to some kind of commercial CSB in hardness,gumminess,chewiness,cohesiveness and adhesiveness(p＜0.05).In general,Jiaotou fermented CSB showed better eating quality indicated by parameters of TPA.

Key words: Chinese steamed bread, starter, microflora, sensory analysis, TPA, quality