嘉峪关地区不同成熟度‘佳美’葡萄理化成分的研究

【目的】研究‘佳美’葡萄果实成熟期间葡萄皮和葡萄籽中理化成分及其相关性,为该地区‘佳美’葡萄成熟度的监控提供参考。【方法】以‘佳美’葡萄为试材,于不同的成熟度(采收日期08-19,08-26,09-02,09-09)采收取样,用模拟葡萄酒溶液分别提取葡萄皮和葡萄籽中的多酚,研究不同成熟度下葡萄皮和葡萄籽中的总酚、黄酮、总黄烷醇和单宁含量的差异,并对不同成熟度葡萄理化指标之间的相关性进行分析。同时利用主成分分析,对不同成熟度葡萄品质进行研究,确定嘉峪关地区‘佳美’葡萄的最佳采收期。【结果】随着成熟度的增加,‘佳美’葡萄的还原糖、糖酸比逐渐升高,总酸质量浓度逐渐降低。葡萄皮中的总酚、黄酮和总黄烷醇含量先上升后下降,单宁含量先下降后上升。葡萄籽中的总酚、黄酮、总黄烷醇和单宁含量均呈先下降后上升趋势。不同成熟度葡萄理化指标的相关性分析表明,葡萄皮中的总酚与总黄烷醇呈显著正相关,与葡萄籽总酚之间呈显著负相关,并且葡萄皮中的黄酮与葡萄籽中的黄酮、总黄烷醇和单宁之间均呈显著负相关,葡萄皮总黄烷醇与葡萄籽单宁含量之间呈显著负相关,葡萄籽黄酮、单宁和总黄烷醇含量之间呈极显著正相关。不同采收期葡萄果实品质排序为09-0909-0208-2608-19。【结论】葡萄果皮多酚含量显著升高,而葡萄籽中多酚含量显著降低,且不同采收期葡萄籽中的多酚均高于葡萄皮。嘉峪关地区‘佳美’葡萄的最佳采收日期在09-09前后。     

蓝靛果忍冬(Lonicer acaerulea L.)果实中内源酚类物质抗氧化性能检测方法的研究进展

蓝靛果忍冬(Lonicer acaerulea L.)是一种优质的药食同源类浆果,因其果实中富含酚类物质而具有明显的抗氧化功能并具有抗病、杀菌等功效。介绍了蓝靛果忍冬果实提取物中内源酚类物质的组成,并从直接检测和间接检测两方面综述了其抗氧化性能检测方法的研究进展,同时对未来内源酚类物质抗氧化性能的检测方法进行展望,以期为我国蓝靛果忍冬果实产品的开发和利用提供参考。     

森林土壤酚类物质的消解规律

采用室内模拟培养的研究方法,对4种森林生态系统(天然更新常绿阔叶林、一代杉木老龄林、二代杉木萌芽天然更新林、二代杉木人工林)土壤酚类物质含量的动态变化规律进行研究.结果表明,在常温或冷藏状态下,各系统土壤总酚、复合态酚和水溶性酚含量基本上呈现明显降低的趋势,各系统土壤总酚、复合态酚和水溶性酚的总消解率分别为64.91%-91.21%、58.13%-83.24%和65.27%-83.78%.在冷藏状态下,土壤总酚的消解率比在常温状态的土壤低,说明低温抑制了土壤总酚的消解作用,而对土壤复合态酚和水溶性酚的消解率影响不明显.不同森林生态系统的土壤总酚和复合态酚的消解率均存在显著差异,不同森林生态系统土壤水溶性酚的消解率差异不显著.初始酚类物质含量高的土壤系统,其消解率也较高,表明如果没有外来的酚类物质继续加入,土壤中各种酚类物质的消解率较高.由此推测,在野外自然条件下,酚类物质在土壤中发生严重积累并造成林木中毒的可能性较小.     

K营养对烤烟叶片中几种抗性物质及野火病发生的影响

 通过对云南中部地区不同生长状况、不同发病程度的34个烤烟样品的钾、总酚、类黄酮含量分析和田间病害调查，结果表明：烟叶一般K含量为1%～4%，K含量高于4%的较少，无低于1%的样品；在K含量为2%～4%的范围内，随钾含量的增加，总酚、类黄酮含量提高，过氧化物酶活性增强，烤烟野火病病情逐渐减轻； K含量＞4%及<2%时，总酚、类黄酮含量降低，过氧化物酶活性减弱，野火病发病严重。     

胡卢巴抗氧化成分提取方法研究

本研究探讨提取胡卢巴抗氧化成分的方法,旨在为胡卢巴的保健效用及其开发利用提供基本资料。采用乙酸乙酯、丙酮、水、乙醇、乙醚等溶剂,结合超声波处理从胡卢巴中提取抗氧化成分,对各种提取物设置不同的浓度梯度,分别测定清除超氧阴离子自由基的能力、对羟自由基的清除作用、抗膜质过氧化能力、DPPH自由基清除能力,以及测定总黄铜和总酚的含量。结果表明:5种溶剂提取的成分中,乙酸乙酯提取物的超氧阴离子自由基的清除率最高;乙醚提取物的羟自由基清除率最高;丙酮提取物的抗膜质过氧化能力最强;水提取物的DPPH自由基清除率最高;乙酸乙酯提取物的总黄酮测定结果最高;乙醚提取物的总酚浓度最高。     

热激处理对甜柿外植体总酚含量和PAL、PPO、POD活性的影响

甜柿在组织培养过程中极易褐化,为了防止褐变,在培养之前应对外植体进行热激处理。文中研究了热激处理后的宝华甜柿叶片在培养过程中其酚类物质含量和苯丙氨酸解氨酶(PAL)、多酚氧化酶(PPO)、过氧化物酶(POD)活性的变化情况,并对热激处理抑制组培褐变的生理机制进行了初步探讨。结果表明:热激处理后,宝华甜柿叶片的褐变程度比没有处理的明显减轻,其总酚含量与苯丙氨酸解氨酶(PAL)及多酚氧化酶(PPO)活性均有所降低,但热激处理对其过氧化物酶(POD)活性的抑制效果并不明显,说明热激处理通过降低外植体的PAL及PPO活性,抑制酚类物质的合成及氧化,减少了褐变产物——醌类物质的形成,从而有效抑制了褐变现象的发生。     

削砧、削穗后放置时间对油茶嫁接成活率及苗木生长的影响

以油茶新品种"朝霞"为试验材料,对芽苗砧嫁接过程中削砧、削穗后放置不同时间包扎对嫁接成活率、苗木生长及切口处酚类物质与单宁含量的影响开展了研究。结果表明:削砧、削穗后放置时间对嫁接成活率及地径均有极显著影响。削砧、削穗后放置10 min的处理,其成活率及地径均为最大,分别为97.65%和3.39 mm;削砧、削穗后放置时间对抽梢率、苗高没有显著影响。以削砧、削穗后清水中泡30 min的处理酚类物质含量最高,达306.43μg。单宁含量以削砧、削穗后放置20 min的处理最高,达0.266 mg/L;其次是削砧、削穗后水泡30 min的处理,为0.241 mg/L。     

Biochemical defense responses of black pepper (Piper nigrum L.) lines to Phytophthora capsici

A study on biochemical factors involved in black pepper defense response against Phytophthora capsici, was carried out in P. capsici susceptible (Sreekara) and resistant (04-P24, shows root resistance to the pathogen) black pepper lines. Seven important factors – change in membrane conductance, total phenols, orthodihydroxy (OD) phenols, lignin and defense related enzymes (peroxidase, β-1,3 glucanase and β-1,4 glucanase) – were studied under uninoculated and pathogen (P. capsici, isolate 06-04) inoculated condition to know the preformed and induced responses. The pathogen was inoculated (soil inoculation) and plants were observed for changes, at 24 h intervals for 10 days. On 8th day after inoculation symptoms started appearing on Sreekara and increased the severity till 10th day. Both root and stem samples were subjected for biochemical analysis. Of the factors analyzed, it was found that membrane conductance, OD phenol, lignin and peroxidase activity play significant role in root resistance to P. capsici in 04-P24. Light microscopy of the portion of root – where pathogen found attached – was also done.     

Impact of environmental factors on infestation of tea leaves byHelopeltis theivora, and associated changes in flavonoid flavor components and enzyme activities

Attack of tea plant (Camellia sinensis (L.) O. Kuntze) leaves by the tea mosquito bugHelopeltis theivora (Hemiptera: Miridae) was positively correlated to temperature and rainfall, and partially to humidity, as determined in 12 varieties during the period 2000–2002. The insect attack was severe during the months of May–September, which had high temperature and rainfall, and led to severe loss of biomass due to curling and drying up of the leaves. The biochemical response of these 12 varieties of tea to attack by the insect was determined with special reference to oxidative enzymes and flavonoid flavor components. Insect attack led to an increase in the activities of the oxidative enzymes peroxidase, ascorbate peroxidase and polyphenol oxidase. Activities of phenyl alanine ammonia lyase generally decreased as a result of insect attack, which was significant in the United Planters Association of South India (UPASI) varieties. A significant decrease in polyphenols was also obtained in UPASI varieties. HPLC analysis of catechins revealed a decrease in some of the catechins in the infected leaves. Analysis of theaflavins from infusion of healthy andHelopeltis-infested tea leaves revealed no changes. http://www.phytoparasitica.org posting Dec. 19, 2004.