混菌发酵酸面团对全麦面包风味与烘焙特性的影响

Effects on flavor and baking characteristics of whole wheat bread by fermented sourdough with the mixed culture

将食窦魏斯氏菌和马克斯克鲁维酵母进行混菌发酵,测定菌株生长曲线研究两菌种的共生作用,分析发酵24 h后纤维素酶活力以及胞外多糖(EPS)产量,比较混菌发酵全麦面包与单菌发酵全麦面包烘焙与风味特性的差异。结果表明,相比于单菌发酵酸面团的菌落总数[乳酸菌9.51 lg(CFU/g),酵母菌8.21 lg(CFU/g)],混菌发酵酸面团体系(MBF)中的乳酸菌与酵母菌菌落数分别达到9.61,8.09 lg(CFU/g),说明两株菌具有良好的共生关系。相比于单一乳酸菌发酵,含有马克斯克鲁维酵母的混菌发酵酸面团中纤维素酶活力增加,胞外β-葡萄糖苷酶酶活为13.59 U/g,提高了128.40%。发酵24 h后,体系中水溶性的阿拉伯木聚糖含量从0.77 g/100 g上升至1.89 g/100 g。此外,相比于其他两组单菌发酵的全麦酸面团,混菌发酵全麦酸面团产EPS能力最高,为7.54 g/kg。相比未添加酸面团的全麦面包,含有混菌发酵全麦酸面团的面包(MBB)比容、弹性显著提高(P<0.05),面包芯硬度下降,混菌发酵全麦面包比容显著增加。风味特性结果表明,混菌发酵全麦面包的风味强度明显高于单一乳酸菌发酵,赋予全麦面包更浓郁的酒香和果香,感官评定证实其整体可接受度更高。

In this study,lactic acid bacteria(LAB),Weissella cibaria and Kluyveromyces marxianus were mixed and fermented.The symbiosis of the two strains was studied by measuring strain growth curve.Compared the baking and flavor characteristics between mixed bacteria fermentation(MBF)and single bacteria fermentation of whole wheat bread by analyzing cellulase activity and production of exopolysaccharide(EPS).Results:Compared with the cell counts of single bacteria fermentation[LAB:9.51 lg(CFU/g),yeast:8.21 lg(CFU/g)],the cell counts of LAB and yeast in the MBF reached 9.61 and 8.09 lg(CFU/g),respectively,indicating that the two strains had a good symbiotic relationship.Compared with the single LAB fermentation,cellulase activity in the MBF with K.marxianus increased,and the extracellularβ-glucosidase activity was 13.59 U/g,increased by 128.40%.After 24 h fermentation,water extractable arabinoxylan(WEAX)content in the sample increased from 0.77 g/100 g to 1.89 g/100 g.In addition,the MBF had the highest EPS content produced of 7.54 g/kg.Compared with whole wheat bread without sourdough,the specific volume and elasticity of the bread containing MBF significantly improved(P<0.05),as bread crumb hardness decreased.The results of flavor characteristics showed that the flavor intensity of bread containing MBF was significantly higher than that of bread containing samples from single LAB fermentation.In addition,the whole wheat bread had a richer wine and fruity flavor.Sensory evaluation confirmed that whole wheat bread with MBF had the highest overall acceptance compared to other groups.