1-methylcyclopropene (1-MCP) and sulfur dioxide (SO2), two chemical preservatives for table grapes, can delay senescence and prevent gray mold infection via different mechanisms. This research utilized a combination of metabolome and transcriptome analyses to investigate the impact of two preservatives on the metabolic and regulatory effects of various compounds, particularly phenols, throughout the storage period of ‘Shine Muscat’ grapes. In comparison to the control, the syntheses of phenolic acids, stilbenes, and certain flavonoids were hindered by 1-MCP and SO2 through the downregulation of structural genes in the phenylpropane pathway. Compared with SO2 treatment, 1-MCP treatment significantly reduced the contents of stilbenes, quercetins and kaempferols at the later stage of storage. Furthermore,1-MCP reduced flavan-3-ol accumulation during each stage of storage, owing to its inhibition of leucoanthocyanidin reductase expression. In addition, 1-MCP was more effective than SO2 in inhibiting berry drop, decay, some genes of ethylene/abscisic acid synthesis and signal transduction pathway. This study offers new perspectives on the impact of two chemical preservatives on phenol metabolism in grapes throughout the storage period.

采用红肉火龙果为原料制备火龙果酒,使用罗汉果甜苷和蔗糖调配得到2种甜味发酵型火龙果酒,利用顶空固相微萃取-气相色谱-质谱联用(HS-SPME-GC-MS)和电子鼻分析其挥发性成分,应用香气活性值(OAV)法、香气轮廓法对其关键香气成分及特征香气成分鉴定.结果表明,2种火龙果酒共鉴定出50种挥发性成分,其中10种物质OAV≥1,其中乙酸乙酯、己酸乙酯被鉴定为特征香气成分.2种火龙果酒香气轮廓相近,主要香气特征为果香、脂肪味、香料味及焦糖味,罗汉果甜苷火龙果酒在果香和香料味香气特征上更突出.电子鼻检测2种火龙果酒香气特征与GC-MS分析结果一致.在甜味火龙果酒生产中使用天然代糖罗汉果甜苷替代蔗糖,可达到增香效果.

该研究以桂葡6号葡萄为原料制备葡萄酒,在发酵前分别添加辅色素槲皮素与芦丁,以不添加辅色素为对照,对不同葡萄酒基酒理化指标进行测定,并研究其在瓶储期内(1、3、6、9个月)颜色参数及花色苷含量的变化.结果表明,槲皮素组基酒酒样的总酚含量最高(0.857 g/L),pH值及总糖含量最低,其他指标无显著差异(P＞0.05);瓶储结束时,该组别葡萄酒酒样的a*、b*、C*值最佳,分别为21.11、3.16、21.38;各组酒样中均含有15种不同类型的花色苷,槲皮素组酒样花色苷总量及各类花色苷(除花色素单糖苷和酰化类花色苷外)含量在瓶储6个月时达最大值;瓶储3、6、9个月时,槲皮素组酒样花色素双糖苷、未酰化与未甲基化类花色苷占比高于对照组和芦丁组.综上所述,槲皮素在瓶储期内对酒样的辅色效果明显.

在冬种马铃薯种植中安装薄膜滴灌设施，采用薄膜滴灌水肥一体化栽培管理技术进行肥水管理，制定合理水肥计划，本文通过实验，证明薄膜滴灌水肥一体化栽培管理技术操作简单，节水效果显著，有效提高冬种马铃薯产量。

In order to study the effect of storage temperature on the aroma characteristics of Shine Muscat grape during storage,headspace-solid phase microextraction（HS-SPME） and gas chromatography-mass spectrometry（GC-MS） were used to qualitatively and quantitatively analyze the volatile components of grape fruits at four storage temperatures（0 ℃, 4 ℃, 10 ℃ and 15 ℃）. The characteristic substances and aroma characteristics were identified and analyzed by odor activity value（OAV） aroma profiles and aroma notes. The results showed that 55 volatile components were identified by GC-MS, including 20 aldehydes, 6 alcohols, 6 esters, 16 terpenes and 7 others.Specifically, 16 of them were identified as active aroma components（OAV ＞1）. The characteristic aroma components of Shine Muscat grape were terpenes and aldehydes. The analysis results of aroma profiles and aroma notes showed that the characteristic aroma changes of Shine Muscat grape under ice temperature（0 ℃, 4 ℃） and low temperature（10 ℃, 15 ℃） tend to be consistent respectively. The characteristic aroma changes during storage were mainly floral characteristics, especially the aroma notes of bell, jasmine, orchid, rose and mandarin duck. 0 ℃could keep the fresh fruit flavor of grapes, while the floral characteristics was obviously lost. The characteristic aroma deteriorated after 8 weeks of storage at 4 ℃ and 10 ℃, and after 6 weeks of storage at 15 ℃. Conclusion: storage at ice temperature caused a sharp decrease in the aroma of flowers at the early stage of storage, and storage at low temperature was difficult to maintain the aroma quality of the fruit during the long storage period.

以广西地区9个酿酒葡萄品种为试材,利用高效液相色谱(HPLC)技术对果实样品中糖和有机酸组分进行测定.结果表明,9个酿酒葡萄品种成熟果实中的糖分以葡萄糖和果糖为主,含量最高的有机酸是酒石酸和苹果酸;葡萄果实总糖含量在不同品种间表现出欧亚种>欧山杂种>东亚种的总体规律;东亚种葡萄中柠檬酸含量及其占比较高.判别分析结果表明,葡萄发育期造成的差异大于品种差异,且糖酸含量较其比例的影响更显著;糖组分对多品种判别的影响力大于有机酸;较高的柠檬酸含量和比例可以作为毛葡萄和腺枝葡萄的重要特征.葡萄果实中的糖酸组分特征可以作为区分种/品种的重要指标,这对于完善广西地方特色葡萄种质资源品质评价体系具有重要意义.

以阳光玫瑰葡萄为试材,采用1-甲基环丙烯(1-MCP)与二氧化硫(SO2)保鲜剂分别结合冰温贮藏,不使用保鲜剂的葡萄果实为对照,分析葡萄贮藏期的主要品质指标变化.结果表明,贮藏60 d内,各处理间无差异,冰温贮藏可保持葡萄果实贮藏品质.贮藏90 d后,保鲜剂处理较对照更能保持葡萄贮藏好果率,降低脱粒率及果梗褐变指数,保持甜酸风味,SO2保鲜剂作用效果更好.1-MCP保鲜剂可以用于中短期的阳光玫瑰葡萄贮藏保鲜,SO2保鲜剂有利于延长阳光玫瑰葡萄贮藏期,保持贮藏品质.

高效液相色谱(HPLC)分析0℃和10℃保鲜的阳光玫瑰冬葡萄贮藏期糖酸组分含量,探究葡萄贮藏过程甜酸风味的变化规律.结果表明,不同贮藏温度阳光玫瑰冬葡萄糖酸组分含量变化规律不同,糖酸含量的变化直接引起风味品质改变.贮藏期4周内,10℃保鲜的葡萄果实甜酸风味保持较好;4～8周,0℃贮藏的葡萄果实风味保持较好;12周后,阳光玫瑰葡萄甜酸风味品质开始发生劣变.甜酸风味变化可作为判定贮藏期葡萄品质劣变程度的因素之一.