高效氯氟氰菊酯在香蕉中的残留及其消解动态

采用气相色谱—质谱联用仪建立了香蕉全果中高效氯氟氰菊酯的测定方法,香蕉样品经乙腈提取,氯化钠盐析分层后,N-丙基乙二胺(PSA)净化去除杂质后,以多反应监测模式(MRM)测定,内标法定量,研究了高效氯氟氰菊酯在云南和福建香蕉中的残留消解动态规律和最终残留量.结果 表明,在0.002～0.500 mg/kg范围内,高效氯...     

香蕉和大蕉果实在不同温度下催熟后的色泽变化

 香蕉和大蕉在20℃和30℃条件下果实催熟期间果皮色泽及几种色素含量的变化结果表明: 在20℃下香蕉、大蕉具有正常的呼吸和乙烯释放高峰, 果皮色泽由绿转黄, 叶绿素含量逐渐降低, 类胡萝卜素含量逐渐上升; 但在30℃下, 香蕉果实虽然出现了正常的呼吸和乙烯释放的高峰, 但叶绿素的降解受到了一定的抑制, 果皮不能正常褪绿, 出现了青皮熟现象, 而大蕉却能正常褪绿转黄。     

苯醚甲环唑在香蕉中的残留及消解动态

采用田间试验和气相色谱ECD检测方法,研究了苯醚甲环唑在香蕉中的残留降解动态和最终残留量。结果表明,苯醚甲环唑在云南、海南和广东香蕉中的半衰期为17.2～22.4 d。最终残留量与苯醚甲环唑施药剂量、施药次数和采收至最后一次施药间隔时间有关。苯醚甲环唑25%乳油按推荐剂量施药3次,距最后一次施药间隔42 d,收获的香蕉全果中苯醚甲环唑留量小于0.33 mg·kg-1,蕉肉中残留量小于0.046 mg·kg-1,低于我国规定的最大残留限量标准(MRL值)1.0 mg·kg-1。栽培措施香蕉断蕾后套袋能显著减少苯醚甲环唑在香蕉中的残留量。     

烯酰吗啉在黄瓜中的残留消解动态

烯酰吗啉（dimethomorph）化学名称为4-[3-（4-氯苯基）-3-（3，4-二甲氧基苯基）丙烯酰]吗啉（Z与E的比一般为4：1），对霜霉属、疫霉属病菌有特效，可用于防治黄瓜霜霉病、番茄晚疫病、马铃薯晚疫病、甜椒疫病等。为明确烯酰吗啉在黄瓜中的残留消解规律及最终残留状况，并为制定其在黄瓜上的合理使用准则提供科学依据，笔者于2003～2004年进行了烯酰吗啉在黄瓜中的残留试验。     

5种农药在温室和露地番茄中消解动态及安全使用研究

为了研究北方设施与露地条件下啶虫脒、甲氰菊酯、三唑酮、乙酰甲胺磷、丙溴磷在番茄上的消解动态差异和安全性,采用气相色谱技术,在北方露地和冬春温室条件下分别测定了它们在番茄上的残留消解动态和最终残留量。结果表明:在温室条件下啶虫脒、甲氰菊酯、三唑酮、乙酰甲胺磷、丙溴磷在番茄上的原始沉积量为1.78、1.34、0.30、1.25和4.38 mg/kg,分别比露地条件下高36.9%、83.6%、66.7%、6.8%和162.3%;施药后1 d番茄上的残留量为2.67、1.62、0.42、2.05和5.18 mg/kg,分别较原始沉积量高50%、20.9%、40%、64%和18.3%。北方冬春设施番茄结果期按照推荐剂量使用三唑酮、乙酰甲胺磷、丙溴磷是安全的,使用啶虫脒、甲氰菊酯是不安全的。     

6种农药在温室和露地辣椒上消解动态及安全使用

采用气相色谱和高效液相色谱技术,在北方露地和冬春温室条件下分别测定了丙溴磷、甲氰菊酯、吡虫啉、乙酰甲胺磷、啶虫脒、三唑酮在辣椒上的残留消解动态和最终残留量。结果表明,温室条件下丙溴磷、甲氰菊酯、吡虫啉、乙酰甲胺磷、啶虫脒、三唑酮在辣椒上的原始沉积量分别为3.13、1.11、1.23、1.29、1.67、0.38mg·kg-1,分别比露地条件下高74.9%、3.7%、17.1%、27.7%、39.2%、111.1%;施药后1d温室辣椒上的残留量分别为3.78、1.27、1.88、1.36、2.85、0.58mg·kg-1,分别较原始沉积量高20.8%、14.4%、52.8%、5.4%、70.7%、52.6%。丙溴磷、甲氰菊酯、吡虫啉、乙酰甲胺磷、啶虫脒、三唑酮在北方冬春设施辣椒上的原始沉积量明显高于露地条件下的相应值,施药后1d的残留量比原始沉积量明显增加。北方冬春设施辣椒按照推荐剂量使用啶虫脒、三唑酮是安全的,使用甲氰菊酯是不安全的;丙溴磷、乙酰甲胺磷、吡虫啉应严格按照推荐剂量使用。     

蔗糖磷酸合成酶与香蕉果实成熟、衰老的关系

 研究了正常成熟、成熟抑制和促进成熟处理的香蕉果实蔗糖磷酸合成酶( SPS) 与呼吸速率、硬度及蔗糖形成的关系。结果表明: (1) 使用乙烯吸收剂不仅极显著抑制了呼吸速率、果实软化和蔗糖的积累(P < 0.01) , 同时抑制了SPS的活性, 与正常成熟果实相比, 其SPS活性高峰延迟3 d出现, 酶活性明显降低。(2) 丙烯处理不仅使SPS活性高峰比对照提前9 d出现, 而且促进了呼吸速率的提高, 加速了硬度的下降和蔗糖的积累。表明SPS与香蕉果实的成熟、衰老和糖的积累及果实软化等有密切的关系。     

基因型和果实成熟阶段影响香蕉果实中柠檬酸和苹果酸积累

据《Scientia Horticulturae》的一篇研究报道（http：／／dx．doi．org／10．1016／j．scienta．2014．02．013），来自法国国际农业研究中心的A．Etienne等人研究了香蕉果实（Mzsasp．AA）中柠檬酸和苹果酸积累的影响因素。香蕉时考虑的主要因素，主要与柠檬酸和苹果酸含量相关。本项研究的目的是调查农业环境和基因型对香焦生长阶段和采后成熟阶段果肉中柠檬酸和棼果酸含量的影响。     

16%多抗霉素B在西瓜和土壤中的残留及消解动态

【目的】评价16%多抗霉素B可溶粒剂在西瓜上使用的安全性。【方法】利用超高效液相色谱-光电二极管阵列检测器(UPLC-PDA)对2 a(年)两地的西瓜和土壤中的多抗霉素B残留消解动态及最终残留进行测定和研究。【结果】多抗霉素B在西瓜和土壤中的降解动态曲线均符合一级动力学方程,半衰期分别为1.9～3.4 d和1.6～2.2 d,最终残留试验结果表明,当施药量为每666.7 m~285 g和127.5 g时,施药次数为3次和4次时,多抗霉素B在西瓜全瓜、瓜肉和土壤的残留量均0.100 mg·kg~(-1)。【结论】16%多抗霉素B可溶粒剂属于易降解农药,在西瓜上的安全间隔期为5 d。     

醚菌酯在平菇和榆黄蘑及培养料中的残留动态研究

采用子实体喷药、培养料拌药的方法对醚菌酯在平菇和榆黄蘑残留量进行了分析。结果表明:醚菌酯在平菇和榆黄蘑及培养料中的降解过程均符合一级动力学方程,醚菌酯在平菇、榆黄蘑和培养料的半衰期分别为2.6~2.7 d和14.6 d。平菇、榆黄蘑及其培养料在收获时期的醚菌酯残留量均小于0.01 mg/kg。试验建立的方法准确可靠,为在平菇和榆黄蘑上制定的MRL(农药最高残留限量)值提供了科学依据。     

香蕉皮脂肪酸的提取及GC-MS分析

为了给香蕉皮变废为宝加以更广泛利用提供科学依据,以提取过挥发油后的香蕉皮为材料,利用索氏提取法提取脂肪酸。并利用气相色谱质谱联用法鉴定出了21种成分及各种成分的相对含量。结果表明,香蕉皮脂肪酸中十六碳酸(Hexadecanoic acid)的含量最高,为45.90%,2种必需脂肪酸a-亚麻酸((Z,Z,Z)-9,12,15-octadecatrienoic acid)和亚油酸((Z,Z)-9,12-octadecadienoic acid)的含量分别为20.75%和19.56%。     

A novel postharvest UV-C treatment to reduce chilling injury (membrane damage,browning and chlorophyll degradation) in banana peel

To investigate the mode of action of UV-C to alleviate CI in banana. Banana [Musa (AAA group), Cavendish subgroup cv. Cavendish] fruits were treated with UV-C at dosages of 0.03 kJ m⁻² prior to storage at 8 or 25 °C. UV-C treatment reduced both the incidence and severity of banana fruits stored under low temperature. UV-C treatment reduced membrane damage indicated by lower activity of lipoxygenase (LOX) and malondialdehyde (MDA) content. In additions, the in vitro polyphenol oxidase (PPO) activity was activated when fruits were stored at CI temperature and UV-C treatment could inhibit the PPO activity. UV-C treatment also delayed yellowing and chlorophyll (Chl) degradation due to the inhibition of chlorophyllase and chl-degrading peroxidase activities. Furthermore, the reduction of ethylene production and respiration rate by UV-C treatment results in extended postharvest shelf life of banana. These finding suggest that the loss of cellular compartments in consequence of membrane degradation, combined with the increase of PPO activity, might contribute to the development of CI in banana peel. UV-C treatment may play an important role in maintained membrane integrity and inhibited PPO activity, reducing the severity of CI symptom and delayed ripening in banana. This novel technique may offer an advance in postharvest handling of bananas and other chilling-sensitive commodities in order to reduce postharvest losses resulting from CI.     

山楂果实中可溶性糖与果皮色素的关系

大黄面楂、上口、左伏3号、星石榴、甜水5个山楂品种在果实发育过程中,叶绿素含量先上升后下降,类胡萝卜素含量持续下降。花青素含量除大黄面楂外,在果实着色期迅速上升。葡萄糖、果糖、蔗糖含量在采收时逐渐上升,果皮花青素含量与不同种类糖含量之间呈显著正相关或极显著正相关。左伏3号果糖含量与花青素含量呈极显著正相关,大黄面楂和星石榴呈显著正相关;甜水、上口、星石榴蔗糖含量与花青素含量呈显著正相关;甜水和星石榴葡萄糖含量与花青素含量呈极显著正相关。     

Cultivar variation in apple peel and whole fruit phenolic composition

The quali-quantitative distribution of phenolic compounds varies considerably between apple flesh and peel, but the concentration of phenolics is substantially higher in the peel than flesh. Because the peel comprises only a small percentage of the entire fruit weight, its significance as a donor of phenolics is disputable. We assessed the contribution of the peel to the total phenolic yield of 19 apple cultivars. Calculations were based on the weight of the whole fruit and the peel (which is frequently discarded) and the concentration of individual phenolic compounds. On average, 8, 24, 32, 50 and 66% of chlorogenic acid, (+)-catechin, (−)-epicatechin, phloridzin, and rutin, respectively, were present in the peel, which constitutes about 6–8% of the whole apple weight. With the exception of chlorogenic acid, 50% or more, on average, of the above phenolics were present in the peel of ‘Granny Smith’, ‘Idared’, ‘Red Rome’, ‘Jonamac’ and ‘Gloster’ apples; the highest percentage was found in ‘Starking Delicious’ apple peel (82%). The lowest peel contribution to total phenolic content per whole apple ranged between 26 and 29% and was observed in ‘Pilot’, ‘McIntosh’ and ‘Prima’ apples. Presented results may be useful for further investigations of the relationship between phenolics and agronomical parameters or future selection of apple genotypes having improved nutritional quality when consumed as fresh or as processed apple products.     

石榴果实成熟期不同品种果皮蛋白质表达的双向电泳分析

【目的】石榴果实色泽是影响果品商品价值的重要因素之一,但石榴果皮颜色形成的分子机制还不清楚。应用差异蛋白组学技术,从蛋白水平上探究石榴果实发育成熟期果皮的代谢进程。【方法】运用双向电泳和MALDI-TOFTOF MS质谱鉴定技术研究‘三白’石榴和‘中农红’石榴果实成熟时果皮蛋白质组学差异。【结果】分别对‘三白’、‘中农红’石榴进行2-DE和质谱鉴定,在‘三白’和‘中农红’石榴果皮的电泳图谱中发现每一张重复胶上分别可以检测到892个蛋白点和890个蛋白点,与‘中农红’相比,在‘三白’果皮图谱中共检测到36个表达量相差2倍以上的蛋白质点,相对于‘中农红’,‘三白’有13个蛋白质点上调表达,19个蛋白质点下调表达。通过质谱鉴定和数据库检索注释了4个蛋白质点。分别为半胱氨酸合酶1(sport 1402)、细胞色素b6-f复合体(sport 0013)、叶绿素a/b结合蛋白(sport 5108)及果糖激酶2-like(sport 0503)。【结论】细胞色素b6-f复合体(sport 0013)、叶绿素a/b结合蛋白(sport 5108)和果糖激酶2-like(sport 0503)可能与果皮颜色变化相关;半胱氨酸合酶1(sport 1402)可能对提高石榴的抗氧化胁迫能力起到了重要作用。为研究石榴果实发育蛋白质组学及改善石榴果实品质提供一定的理论依据。     

Changes in antioxidants and fruit quality in hot water-treated ‘Hom Thong’ banana fruit during storage

The effects of hot water treatment on antioxidants and fruit quality were investigated in banana fruit of cv. Gros Michel (Musa acuminata, AAA Group, locally called cv. Hom Thong) by immersing fruits in hot water (50 °C) for 10 min, before storage at 25 °C for 10 days or 14 °C for the first 8 days followed by storage at 25 °C for the second 8 days until ripening. Quality parameters including peel color and pulp firmness indicated that hot water treatment helped to delay banana fruit ripening at both storage conditions. Hot water treatment decreased the levels of hydrogen peroxide (H₂O₂) and malonydialdehyde (MDA) during storage at 25 °C. Glutathione (GSH and GSSG) contents and the ratio of GSH/GSSG during fruit approaching ripening were significantly induced in hot water-treated fruits while ascorbic acid (AA) contents were slightly increased. In addition, the combined treatment increased free phenolics and flavonoids during storage. Results suggest that hot water treatment has led to an induction of antioxidants in banana fruits as indicated by an increase of antioxidants and a decrease of H₂O₂ during ripening, and all of which result in a delayed ripening of banana fruit.     

苹果果实不同部位裂纹的研究

对红富士苹果果实不同部位裂纹的发生情况及生理指标和矿质元素含量的研究结果表明:红富士苹果果实裂纹率,梗洼部高于中部和萼洼部;原果胶含量和抗坏血酸含量,萼洼部均高于梗洼部和中部;可溶性糖含量和含水量,梗洼部、中部、萼洼部差异均不显著;磷元素和锌元素含量,梗洼部高于中部和萼洼部;钾元素含量,梗洼部高于中部与萼洼部;钙元素含...     

Effects of short-term N2 treatments on ripening of banana fruit

Summary

Experiments were conducted to evaluate the effects of anoxia treatments on banana fruit ripening. Pre-climacteric banana fruit were exposed to pure N₂ for 0, 6, 9, 12 or 24 h, then stored for up to 3 weeks at 20°C and approx. 90% relative humidity. Changes in peel colour, fruit firmness and post-harvest life were evaluated. Ripening was inhibited most effectively in fruit exposed to N₂ for 9 h. Furthermore, exposure of banana fruit to pure N₂ gas for 9 h reduced the rates of ethylene production and respiration, as well as the activities of polygalacturonase and pectin methyl esterase. These results suggest that anoxia treatment is a feasible technology to inhibit ripening and extend the shelf-life of banana fruit.     

Relation of peel damage in citrus fruit to wind climate in orchard and its control

Peel damage originated by wind is the main abiotic cause of citrus fruit discards for export in Uruguay. Natural windbreaks such as Eucalyptus and Casuarinas have not been effective in reducing it. This research was carried out during three years in a citrus orchard situated in the coastal plain of Uruguay (35° SL). The purpose of this work was to study wind climate inside the orchard, fruit seasonal sensitivity, basal leaf effect on the onset and evolution of peel damage, and the efficiency of artificial windbreaks to reduce fruit discard of ‘Ellendale’ tangor. Average wind velocity in the orchard did not exceed 5 m s⁻¹. First peel scars were evident two weeks after petal fall and damaged fruit percentage importantly increased during the first stage of fruit growth. Low energy vortexes caused almost permanent friction between basal leaves and the developing fruitlets growing in their axil. Removal of the basal leaf decreased significantly wind damaged fruit. Natural wind flow modification through the use of semi-porous artificial windbreak nets (5 cm by 10 cm mesh) modified low energy vortexes and increased significantly the percentage of export quality fruit. We conclude that this type of net is more efficient than natural windbreaks or classical nets to reduce wind damage in citrus fruit.     

香蕉果实果胶裂解酶基因cDNA克隆及序列分析

利用已报道果胶裂解酶基因的保守序列设计简并引物,进行RT-PCR,得到1个大约1300bp的香蕉果胶裂解酶基因cDNA片段,命名为MA-pl。DNA序列分析表明:MA-pl片段全长1277bp,包含1个882bp的开放读码框(ORF),编码294个氨基酸;其具有所有果胶裂解酶共有的保守区域:钙协调部位(Asp72,Asp74,Asp96,andAsp100)、酶活性位点(Arg152,Pro154,Arg157)及3个重要的结构域(motifI:WVDH,motifII:DGLVDAVMGSTAITVSNNYF,motifIII:LYQRMPRCRHGYFHVVWNDY);MA-pl氨基酸序列与草莓-1、葡萄、草莓-2、拟南芥、苹果、香蕉(banana-1)的相似性分别为85.8%、74.2%、79.7%、78.6%、72.4%和71.4%。