益生菌发酵对苹果浆理化性质、抗氧化活性及挥发性风味的影响

Effects of probiotics fermentation on physicochemical properties, antioxidant activity, and volatile flavor of fermented apple pulp

中文关键词:  发酵  苹果浆  理化性质  抗氧化活性  风味

英文关键词:fermentation  probiotics  apple pulp  physicochemical properties  antioxidant activity  volatile flavor

中文摘要:

      目的 探究益生菌发酵对苹果浆理化性质、抗氧化活性及挥发性风味物质的影响。方法 测定苹果浆发酵过程中活菌数、pH、总酸、总糖、还原糖、总酚、黄酮、1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2- picrylhydrazyl, DPPH)自由基清除能力、铁离子还原能力(ferric reducing antioxidant power, FRAP)和2,2’-联氮-二(3-乙基-苯并噻唑啉-6-磺酸)二铵盐[2,2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) ammonium salt, ABTS]阳离子自由基清除能力, 同时比较了发酵前后挥发性风味物质的变化。结果 发酵体系中活菌数、总酚、黄酮在发酵第3 d时达到最大值, 分别较发酵前提高了12.63%、17.63%和22.06%; FRAP与ABTS阳离子自由基清除能力在发酵第4 d达到最大值, 分别较发酵前提高了42.47%和10.45%; 可滴定酸含量与DPPH自由基清除能力随着发酵时间的延长逐渐增加, 发酵第7 d时, 分别升高了126.34%和26.32%; pH、总糖、还原糖含量较发酵前显著下降, 分别降低了57.59%、8.76%和8.03%。苹果浆经益生菌发酵后有41种挥发性风味物质, 新生成了15种, 减少了6种, 有26种与发酵之前相同, 其中酯类、醇类和酸类风味物质相对增加, 醛酮类风味物质降低, 新生成的风味物质多具有愉悦香气。结论 苹果浆可以作为益生菌发酵的良好基质, 发酵改善了苹果浆的抗氧化能力和风味。

英文摘要:

      Objective To explore the effects of probiotic fermentation on the physicochemical properties, antioxidant activity and volatile flavor substances of apple pulp. Methods The number of viable bacteria, pH, total acids, total sugars, reducing sugars, total phenols, total flavonoids, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity, ferric reducing antioxidant power (FRAP), and 2,2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) ammonium salt (ABTS) cation radical scavenging capacities during the fermentation of apple pulp were determined, and the changes of volatile flavor substances before and after fermentation were compared. Results The number of viable bacteria, total phenols and total flavonoids in the fermentation system reached the maximum at the 3th day of fermentation, which were higher than those before fermentation by 12.63%, 17.63% and 22.06%, respectively. The free radical scavenging capacity of FRAP and ABTS reached the maximum on the 4th day of fermentation, which was 42.47% and 10.45% higher than that before fermentation, respectively. The titratable acid content and DPPH radical scavenging ability increased gradually with the fermentation time, and increased by 126.34% and 26.32% on the 7th day of fermentation, respectively. The content of pH, total sugar and reducing sugar decreased significantly, by 57.59%, 8.76% and 8.03%, respectively. There were 41 kinds of volatile flavor compounds in apple pulp fermented by probiotics, 15 kinds of were newly produced, 6 kinds of were reduced, and 26 kinds of were the same as before fermentation, among which, esters, alcohols and acids were relatively increased, aldehydes and ketones were reduced, and most of the newly produced flavor compounds had pleasant aroma. Conclusion Apple pulp can be used as a good substrate for probiotic fermentation, and fermentation improves the antioxidant capacity and flavor of apple pulp.