不同酿酒酵母PDEs缺失突变株对磨盘柿果酒抗氧化及挥发性物质的影响

以磨盘柿子为原料，考察野生型及基因型为PDE1/Dpde1、Dpde1/Dpde1、PDE2/Dpde2和Dpde2/Dpde2的环核苷酸磷酸二酯酶基因缺失的酿酒酵母（Saccharomyces cerevisiae）发酵过程中可溶性固形物、总糖、乙醇体积分数和pH值等基本理化指标，总酚和总黄酮等活性物质以及2’-联氨-双-（3-乙基苯并噻唑啉-6-磺酸）二铵盐自由基、1,1-二苯基-2-三硝基苯肼自由基清除能力和总还原力等抗氧化能力的变化；并采用顶空固相微萃取技术与气相色谱-质谱联用相结合的方法，对不同菌株发酵的磨盘柿果酒挥发性物质成分进行比较分析。结果表明，在12?d达到发酵终点，4?株突变体发酵速率均比野生型快，其中Dpde2/Dpde2菌株的发酵速率最快；4?株突变体菌株酿造的磨盘柿果酒中总黄酮含量和抗氧化能力均高于野生型菌株，Dpde2/Dpde2菌株酿造的磨盘柿果酒抗氧化功效最强。PDEs基因缺失菌株与野生型酿酒酵母酿造的磨盘柿果酒中的风味物质种类差异不大，PDE2/Dpde2菌株酿造的磨盘柿果酒中酯类相对含量较高。

Effects of PDEs Gene Deletion in Saccharomyces cerevisiae on Antioxidant and Volatile Substances in Mopan Persimmon Wine

In this study, persimmon wine was produced with the wild type Saccharomyces cerevisiae and four mutant strains (PDE1/Dpde1, Dpde1/Dpde1, PDE2/Dpde2 and Dpde2/Dpde2). Changes in the physicochemical properties including soluble solids content (SSC), total sugar, alcohol content and pH, the contents of total phenols and flavonoids, and antioxidant properties including scavenging capacities against 2,2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals and total reducing power were detected during the fermentation process. The volatile components of five persimmon wines were analyzed and compared by headspace solid phase microextraction (SPME) coupled to gas chromatography-mass spectrometry (GC-MS). The results showed that the fermentation end point was reached at day 12, and the fermentation rates of the four mutants were faster than that of the wild-type strain, of which the Dpde2/Dpde2 strain had the fastest fermentation rate. The total flavonoids content and antioxidant ability of persimmon wines fermented with the four mutants were higher than those of the wine fermented with the wild-type strain. The wine produced with Dpde2/Dpde2 had the strongest antioxidant ability. No significant difference in volatile substances profiles was observed between the mutants and the wild-type strain, except that the relative content of esters in the persimmon wine fermented by PDE2/Dpde2 was higher than that of other persimmon wines.