‘西拉’葡萄转色期疏除果穗对果实酚类物质的影响

Effect of cluster thinning during veraison on phenolic substances of Vitis vinifera L.cv.Syrah

【目的】探讨山西临汾地区‘西拉’(Syrah)葡萄转色期果穗不同疏除方式对果实酚类物质含量的影响,为酿造优质西拉干红葡萄酒奠定基础。【方法】葡萄转色前保留全部果穗,转色期设置不疏除果穗(C1)、疏除25%果穗(C2)和疏除50%果穗(C3)3种果穗疏除处理,在葡萄成熟过程监控不同处理果实的成熟度,采收后测定果实总酚、单宁、总花色苷、单体花色苷和单体酚类物质含量,分析果穗疏除处理对果实酚类物质的影响。【结果】与C1相比,C2、C3处理提高了葡萄还原糖含量,降低了总酸含量;采收期各处理葡萄果实的总酚含量存在显著差异,总酚含量排序为C1(39.61mg/g)<C2(42.52mg/g)<C3(48.95mg/g);C3处理葡萄果实的单宁含量(21.44mg/g)与C1(21.91mg/g)相比无显著差异,但均显著低于C2(23.46mg/g);各处理果实的总花色苷含量差异显著,含量排序为C1(12.80mg/g)<C2(13.64mg/g)<C3(14.62mg/g);C2、C3处理果实的单体花色苷总量较C1分别提高44.20%和61.94%,其中乙酰化花色苷分别提高42.85%和56.03%;C2、C3处理果实的单体酚类物质总量较C1分别提高7.49%和2.39%,其中黄酮醇类物质分别提高7.03%和4.84%,C2的黄烷醇类物质较C1提高11.55%,而C3的黄烷醇类物质较C1下降了18.83%。【结论】转色期疏除25%的果穗能有效提高‘西拉’葡萄果实的酚类物质含量,疏除50%果穗对单宁含量有降低作用。

[Objective] This study investigated the effect of different cluster thinning levels during veraison on phenolic contents of grape in Linfen, Shanxi to provide basis for high quality dry red winemaking. [Method] All the clusters were reserved until being thinned during veraison at three levels of C1 （0%） ,C2 （25%） and C3 （50%）. Berry maturity was monitored during grape ripening and the contents of total phenol,tannin,total anthocyanin, monomer anthocyanin and monomer phenolic were measured after harvest. [Result] Compared with C1,C2 and C3 treatments improved the reducing sugar while decreased the total acid content. The total phenol contents were significantly different among treatments with the order of C1 （39.61 mg/g）〈C2（42.52 mg/g）〈C3（48.95 rag/g）. There was no significant difference in tannin contents between C3（21.44 mg/g） and C1（21.91 rag/g） ,but both were significantly lower than C2（23.46 mg/g）. The total anthocyanin contents had significant difference in the order of C1 （12. 80 mg/g）〈C2 （13.64 mg/g）〈C3 （14. 62 mg/g）. The total content of monomer anthocyanin of C2 and C3 were increased by 44.20% and 61.94% compared to Cl,among which acylated anthocyanin was improved by 42.85% and 56.03%. The total monomer phenolic contents in C2 and C3 were 7.49% and 2.39G higher than that in Cl,among which flavonoids contents were 7.03% and 4.84% higher. Content of flava＇nols of C2 was in- creased by 11.55% while that of C3 was decreased by 18.83G. [Conclusion] Clusters thinning of 25% during veraison improved phenolic content of Vitis vinifera L. cv. Syrah effectively, while tannin content was decreased by 50 % thinning.