蘑菇醇的抑菌活性及其在馒头保鲜中的应用

Inhibition of Bacterial Activity by Mushroom Alcohol and Its Application in Steamed Breads Preservation

为降低由微生物作用对馒头造成的损失,文章研究了蘑菇醇对金黄色葡萄球菌和蜡样芽孢杆菌2种馒头常见相关细菌的抑制活性,将蘑菇醇以最低抑菌浓度(Minimum inhibitory concentration,MIC)、1/2MIC、1/4MIC值分别添加到馒头中,测定了不同添加量下馒头的质构特性和保藏期间的微生物变化情况。结果表明:蘑菇醇对2种细菌均有抑制作用,对2株细菌的MIC为1 mg/m L,最低杀菌浓度(Minimum bactericidal concentration, MBC)为2 mg/mL,这与牛津杯法测量的抑菌圈结果一致。流式细胞仪显示,经过1 mg/mL蘑菇醇处理,金黄色葡萄球菌死亡细胞增加了4.61%,损伤细胞增加了58.85%;蜡样芽孢杆菌死亡细胞增加了0.59%,受损细胞增加了66.58%。倒置荧光显微镜观察发现,处理后的细菌荧光强度增强,细菌细胞壁和细胞膜受损,细胞膜通透性增加。MIC浓度的馒头相比对照比容增加了28%,馒头硬度降低了46%,馒头评价得分最高为91分。在储藏期间,相比对照最多降低了2.65 lg CFU/g菌落总数,1.80 lg CFU/g的霉菌/酵母菌数量。加入1 mg/mL的蘑菇醇能够显著降低馒头中的细菌总数和霉菌/酵母的数量(P<0.05),并赋予其蘑菇香气,提升商业酵母馒头品质和风味。

In order to reduce the loss of steamed bread caused by microorganisms,this study investigated the inhibitory activity of mushroom alcohol against Staphylococcus aureus and Bacillus cereus,two common bacteria associated with steamed bread.MIC,1/2 MIC,and 1/4 MIC values of mushroom alcohol were added to the steamed bread.The structural characteristics and microbial changes of mushroom alcohol steamed breads with different dosages were determined.The results revealed that mushroom alcohol exhibited inhibitory effects on both bacteria,with MIC and MBC values of 1 mg/mL and 2 mg/mL,respectively.These findings were consistent with the results obtained using the Oxford Cup method.Flow cytometry analysis demonstrated that treatment with 1 mg/mL of mushroom alcohol led to a 4.61%increase in dead cells and a 58.85%increase in damaged cells of Staphylococcus aureus.For Bacillus cereus,the percentage of dead cells increased by 0.59%and the percentage of damaged cells increased by 66.58%.Observation under an inverted fluorescence microscope revealed enhanced fluorescence intensity in the treated bacteria,along with damage to the cell wall and membrane,and increased membrane permeability.Compared to the control,the specific volume of steamed breads with the 1 MIC concentration increased by 28%,while the hardness of the steamed breads decreased by 46%.The steamed bread scored the highest with 91 points.During storage,the total number of colonies and the number of molds/yeasts decreased by up to 2.65 lg CFU/g and 1.80 lg CFU/g,respectively,compared to the control.Addition of 1 mg/mL of mushroom alcohol significantly reduced the total number of bacteria and the number of mold/yeast in the steamed bread(P<0.05),imparted a mushroom aroma,and improved the quality and flavor of the commercial yeast steamed bread.