不同混合发酵方式对发酵豆乳贮藏品质的影响

Effect of different mixed fermentation methods on storage quality of fermented soymilk

采用牛乳与豆乳混合后再发酵、牛乳发酵后混入豆乳(发酵牛乳无后酸化处理)和单独发酵牛乳,发酵结束4℃后酸化24 h后再混入豆乳3种混合发酵方式制备发酵混合豆乳,探究3种混合发酵方式对发酵混合豆乳贮藏期品质的影响。结果表明,单独发酵牛乳,发酵结束4℃后酸化24 h后再混入豆乳方式可减缓发酵豆乳在贮藏期的后酸化程度,活菌数保持7 log cfu/mL以上,持水力增加,无乳清析出,提高了发酵豆乳的稳定性,贮藏期内发酵豆乳具有良好的感官,颜色微黄,有光泽,口感润滑,有弹性,具有大豆特有的香气,无豆腥味,贮藏期硬度和胶黏性增加,具有良好的咀嚼特性。因此,单独发酵牛乳,发酵结束4℃后酸化24 h后再混入豆乳方式下的产品稳定性更好。

In this study,three mixed fermentation methods were used to prepare fermented mixed soymilk:mixed milk and soymilk after fermentation,mixed soymilk after fermentation(fermented milk without post acidification treatment)and separately fermented milk,acidified at 4℃for 24 h after fermentation,and then mixed soymilk.The effects of the three mixed fermentation methods on the storage quality of fermented mixed soymilk were investigated.The results showed that fermented milk alone,acidified at 4℃for 24 h after fermentation,and then mixed with soymilk could slow down the post acidification degree of fermented soymilk during storage,keep the number of viable bacteria above 7 log cfu/mL,increase the water holding capacity,no whey precipitation,and improve the stability of fermented soymilk.During storage,fermented soymilk has good sensory,yellowish color,luster,smooth taste,elasticity,unique aroma of soybeans,and no beany smell.Therefore,the stability of the product is better when the milk is fermented separately,acidified at 4℃for 24 h and then mixed with soybean milk.