不同乳酸菌在冬瓜汁中的发酵特性研究

Fermentation Characteristics of Wax Gourd Juice by Various Lactic Acidbacteria

摘要:

向鲜榨并经巴氏灭菌的冬瓜汁中接入不同的乳酸菌（干酪乳杆菌、嗜热链球菌、植物乳杆菌、嗜酸乳杆菌、鼠李糖乳杆菌、双歧杆菌和保加利亚乳杆菌）进行发酵，比较发酵过程中乳酸菌活菌数、pH值、可滴定酸、总糖、还原糖、总多酚和色泽等变化和发酵后挥发性风味物质种类与相对含量。结果表明，冬瓜汁营养丰富，上述各种乳酸菌均能在冬瓜汁中很好地生长，其中干酪乳杆菌的生长速率（对数生长期）略低于其他6种菌；另外，七种乳酸菌发酵后冬瓜汁中主要挥发性风味物质主要有酸类、醇类、酯类、醛类、酮类五类，保加利亚乳杆菌发酵的冬瓜汁中检出的挥发性风味物质最多。除双歧杆菌之外其他六种乳酸菌发酵的冬瓜汁理化性质差别不大，双歧杆菌发酵的冬瓜汁在总色差上明显高于其他乳酸菌，且双歧杆菌的产酸能力最强，在发酵期间其可滴定酸含量最高。

Abstract:

The changes of lactic acid bacterial number, pH, total titratable acidity, total sugar, reducing sugar, total polyphenol, color and volatile components after fermentation in pasteurised wax gourd juices were studied when fermented with various lactic acid bacteria (Lactobacillus casei, Streptococcus thermophilus, Lactobacillus plantarum, Lactobacillus acidophilus, lactobacillus lilactobacillus, Bifidobacteria and Lactobacillus bulgaricus). The results showed that the wax gourd juice was rich in nutrients and all the above lactic acid bacteria could grow well in the wax gourd juice. The growth rate of Lactobacillus casei (logarithmic growth phase) was slightly lower than that of other six kinds of bacteria. In addition, the main volatile flavor substances of melon juice via seven kinds of lactic acid bacteria fermentation are acids, alcohols, esters, aldehydes and ketones, and Lactobacillus bulgaricus fermentation of melon juice resulted in the highest content of volatile flavors. Except Bifidobacteria, other six kinds of lactic acid bacteria gave little difference in physical and chemical properties of the fermented gourd juice. The total color of the Bifidobacteria fermented wax groud juice was significantly higher than those by other lactic acid bacteria. Bifidobacteria showed the strongest acid-producing capacity, with the highest titratable acid content during fermentation.