乳酸菌发酵前后山药汁营养功能成分及风味物质的变化

Changes in Nutritional Functional Components and Flavor Substances of Yam Juice Before and After Lactic Acid Bacteria Fermentation

研究了乳酸菌发酵对山药汁营养功能成分及感官特性的影响。结果显示,经L.plantarum 101和L.paracasei HGD组合发酵后的山药汁在总体感官上更容易被接受。与未发酵山药汁相比,乳酸菌发酵可将pH值由6.12降至3.88,总糖含量降低69.35%,总酚、可溶性膳食纤维、总酸和游离氨基酸的含量分别提高98.00%、53.15%、493.51%和64.30%。同时气相色谱-质谱分析结果表明,乳酸菌发酵可使山药汁中风味物质的种类及含量显著变化,其中酸类提高195.02%,酯类提高172.73%,酯类物质种类及含量的增加赋予了发酵山药汁丰富的香味;酮类和醇类分别提高88.27%和7.46%,醛类下降了85.82%,使得最终山药汁发酵液的可接受度提高。综上所述,山药汁经乳酸菌发酵后不仅能够提高其营养成分,还可以改善风味,该研究结果表明乳酸菌发酵山药汁可作为一种待开发的新型功能性饮品。

By evaluating the effects of lactic acid bacteria fermentation on the nutritional components and sensory properties of yam juice,a combination of L.plantarum 101 and L.paracasei HGD fermented yam juice was found to be the most acceptable to the overall senses.Compared with unfermented yam juice,the pH value of the fermented decreased from 6.12 to 3.88,whereas the total sugar content decreased by 69.35%.The content of total phenols,soluble dietary fiber,total acids,and free amino acids increased by 98.00%,53.15%,493.51%,and 64.30%,respectively.At the same time,the results of gas chromatography-mass spectrometry analysis showed that lactic acid bacteria fermentation could significantly change the types and contents of flavor substances in yam juice,among which acids increased by 195.02%and esters increased by 172.73%.The increase in ester species and content gave rise to a rich flavor in the fermented yam juice,in which ketones and alcohols increased by 88.27%and 7.46%,respectively,while aldehydes decreased by 85.82%.As a result,this improved the acceptability of the final yam juice fermentation broth.In summary,the fermentation of yam juice by lactic acid bacteria not only improve its nutritional composition but also its flavor.These findings indicate that fermented yam juice shows promise as a new type of functional beverage.