外源脱落酸处理对葡萄果实及葡萄酒中抗氧化成分的影响

以天津蓟州区栽培的“美乐”和“赤霞珠”葡萄为试验品种,分别在其始熟期的初、中和末期3个阶段利用外源脱落酸(200mg/L)处理果实,采用分光光度法测定葡萄和葡萄酒中酚类总含量和抗氧化活性,利用液质联用技术分析花色苷的含量和组成。研究结果表明:始熟期的外源脱落酸处理对成熟果实的质量、可溶性固形物、可滴定酸和pH值,以及葡萄籽的酚类含量和抗氧化活性没有显著影响,但对葡萄皮和葡萄酒的酚类物质含量和活性具有显著影响。在始熟期中期(30%~50%果实转色)以前,对果实喷施外源脱落酸可以显著提高葡萄皮和葡萄酒的酚类总含量、花色苷总含量和抗氧化活性。始熟期外源脱落酸处理使“美乐”和“赤霞珠”果实的酚类总含量分别提高了14%~39%和73%~172%,花色苷总含量和抗氧化活性分别提高了18%~143%和88%~178%；外源脱落酸处理使葡萄酒的3个指标(酚类总含量、花色苷总含量和抗氧化活性)分别提高了17%~69%、18%~36%和21%~46%,而这些影响可以有效改善葡萄酒的感官品质和营养价值。外源脱落酸处理时期的精准控制可以提高酿酒葡萄及葡萄酒中酚类物质含量及抗氧化作用,进而提高葡萄酒品质和营养价值。

Effects of Exogenous Abscisic Acid Treatment on Antioxidants in Grapes and Wines

In this study, Vitis vinifera cvs. Merlot and Cabernet Sauvignon in Jixian of Tianjin were used as research grape cultivars, the effects of exogenous abscisic acid (ABA) on phenolic characteristics of grapes and wines were systematically investigated. Grape clusters were treated with exogenous ABA (200mg/L) at early, middle and late of veraison, respectively. The total contents and antioxidant capacities of phenolic compounds were determined with spectrophotometry. The contents and compositions of anthocyanins were analyzed by high performance liquid chromatography-tandem mass spectrometry technology. The results indicated that exogenous ABA treatment at veraison had no significant effects on berry weights, soluble solids, titratable acids, pH, and the total contents and antioxidant activities of phenolic in grape seeds, but had a significant effect on phenolic characteristics of grape skins and wines. Exogenous ABA treatment before the middle veraison (30%-50% berries turned color) significantly improved the total contents of phenolics, anthocyanins and antioxidant activities of grape skins and wines. Exogenous ABA treatment increased the total contents of phenolics in grape berries of Merlot and Cabernet Sauvignon by 14%-39% and 73%-172%, respectively, and contents and antioxidant activities of anthocyanins increased by 18%-143% and 88%-178%, respectively. And the three indexes (total phenolic contents, anthocyanin contents, and antioxidant activity) of wines increased by 17%-69%, 18%-36% and 21%-46%, respectively, which could offer opportunities to effectively improve the organoleptic properties and nutritional value of wines. The precise control during the treatment period of exogenous ABA can increase the phenolic contents and antioxidant activity in wine grapes and wines, thereby improving wine quality and nutritional value.