一氧化二氮处理提高香蕉保鲜效果

以“巴西”香蕉(Musa nan acv，Baxi)为材料，研究了短期和连续一氧化二氮(N2O)处理对香蕉保鲜效果的影响。结果表明：20％、400％，利60％N2O(均含20％O2)预处理24h或连续处理均延缓了香蕉的后熟软化进程，推迟了香蕉果皮褪绿。对于短期预处理，以40％N2O效果最好；而连续N2O处理虽能显著推迟果实褪绿，但果皮不能正常转黄。此外，连续N2O处理还可明显减少香蕉贮藏过程中果实腐烂发生。     

冷激处理对香蕉保鲜效果的影响

本试验以“巴西”香港（Musa nana cv.Baxi）为材料，研究了冷激处理对香蕉保鲜效果的影响。结果表明：0－2℃冷空气处理2．5h显著延缓了香蕉的后熟软化过程，推迟了香蕉果皮褪绿，抑制了乙烯的形成和释放。冷激处理还显著抑制了果实淀粉酶活性和淀粉的降解，从而延缓了果实的软件。     

BTH浸泡处理对厚皮甜瓜采后病害的控制及贮藏品质的影响

为了探讨BTH浸泡处理对厚皮甜瓜采后病害的控制及贮藏品质的影响,以‘玉金香’厚皮甜瓜为试材,用0.1g/L BTH常温浸泡处理10min,研究处理对粉红单端孢(Trichothecium roseum)损伤接种果实病斑面积和自然发病率的抑制以及对果实主要贮藏品质的影响。结果表明:BTH处理显著降低了(P<0.05)果实损伤接种T.roseum的病斑面积和常温贮藏期间的自然发病率;BTH处理明显诱导了果实体内苯丙氨酸解氨酶(PAL)、过氧化物酶(POD)、多酚氧化酶(PPO)等防御酶活性的增强。此外,BTH处理还有效减缓了果实质量损失率和可溶性果胶含量的上升,明显延缓了果实硬度、VC和可溶性固形物含量(SSC)的下降,推迟了果皮颜色的转黄,从而延缓了甜瓜果实采后衰老进程,提高了果实的采后抗病性和贮藏品质。     

电生功能水冷激处理对香蕉保鲜效果的影响

为探讨电生功能水冷激处理对香蕉保鲜效果的影响,以"巴西"香蕉为试材,发现经0℃、氧化还原电位(1128±20)m V、p H2.4的酸性功能水冷激处理0.5 h的香蕉,贮藏于20℃、85%湿度的恒温恒湿箱中,与对照组相比,明显降低了呼吸强度和失重率,延缓了果实后熟软化、推迟了果皮的褪绿;同时显著抑制了丙二醛(MDA)积累量、果胶酶活性及可溶性固形物的上升,进而对香蕉硬度的维持起到重要作用,明显提高香蕉的保鲜效果。     

短波紫外线照射对苹果采后灰霉病抗性诱导作用

为探究短波紫外线（ultraviolet C,UV-C）照射对苹果采后灰霉病的防治效果与抗性诱导机理,以红富士苹果为材料,采用剂量分别为3.5、7.0、10.5 kJ/m2 的UV-C（280 nm）进行照射,常温条件下放置2 d 后接种灰葡萄孢菌,以不经UV-C照射直接接种灰葡萄孢菌的果实作为对照。结果表明：照射剂量为3.5 kJ/m2 和7.0 kJ/m2的UV-C照射可显著降低果实灰霉病的发生率,抑制病斑直径的扩展（P＜0.01）,其中照射剂量为7.0 kJ/m2 UV-C处理的效果更好;而照射剂量为10.5 kJ/m2 的UV-C照射处理在接种后贮藏前期对病害有抑制作用,后期却加快病害发展。3.5 kJ/m2 和7.0 kJ/m2 UV-C处理能诱导苹果果实几丁质酶、β-1,3-葡聚糖酶、过氧化物酶（POD）、多酚氧化酶（PPO）和苯丙氨酸解氨酶（PAL）等抵御酶活性的提高,诱导酚类物质的合成,进而增强果实的抗病性,其中7.0 kJ/m2 UV-C处理诱导效果更明显,与对照差异显著（P＜0.01）。10.5 kJ/m2 UV-C照射仅在接种后前期诱导POD、PPO、PAL和几丁质酶的活性迅速上升,提高总酚和类黄酮含量,但对β-1,3-葡聚糖酶活性没有诱导作用。     

炭疽病菌侵染对香蕉采后品质变化及抗病相关酶活性的影响

研究人工接种炭疽病菌对采后香蕉果实贮藏品质的影响。分析测定了接种炭疽病菌后"宝岛蕉"和"东莞大蕉"两个品种香蕉果实的硬度、叶绿素含量、可溶性固形物含量、还原糖含量、可滴定酸含量、呼吸强度、病情指数及抗病相关酶POD、PPO活性等指标的变化。结果显示,接种炭疽病菌的香蕉果实的硬度迅速下降,贮藏4 d后显著低于未接种炭疽病菌组,香蕉果皮叶绿素含量的分解速率显著增加,加速了香蕉褪青和转黄;接种炭疽病菌促进了果实中淀粉等多糖物质不断地向可溶性糖的转化,可溶性固形物、还原糖含量明显增加,对"宝岛蕉"的影响更为明显。炭疽病菌侵染促进了香蕉果实中可滴定酸含量的升高,同时加快果实的呼吸和感病速率;接种炭疽病菌后,抗病相关酶POD、PPO活性显著升高。结果表明炭疽病菌的侵染加速了两种香蕉的成熟、软化、衰老及腐烂。     

不同条件对‘巴西蕉’和‘南天黄’香蕉后熟的影响

‘南天黄’为性状优良且抗枯萎病的香蕉新品种,其后熟条件与传统栽培品种‘巴西蕉’不同,然而生产中常以统一做法对‘南天黄’进行催熟,易造成生产误判。为提高香蕉品质,延长货架期,本研究以500 mg/L乙烯利喷雾处理后的‘南天黄’与‘巴西蕉’果实为材料,实验分为（22±2）℃处理组（T2）、（22±2）℃＋双向拉伸聚丙烯（biaxially oriented polypropylene,BOPP）薄膜包装处理组（T-2）、17 ℃处理组（T1）、17 ℃＋BOPP薄膜包装处理组（T-1）,观察果皮色差、果肉硬度、果实质量损失率、可溶性固形物质量分数的变化和货架期的特点,以此制定‘南天黄’合理催熟方案。T1、T-1处理组‘南天黄’褪绿转黄（催熟时间）比‘巴西蕉’早1 d,T1处理组‘南天黄’比‘巴西蕉’货架期长2 d;T2处理组‘南天黄’褪绿转黄比‘巴西蕉’迟1 d,货架期长2 d;与T2处理组相比,T1处理组香蕉后熟末期硬度、色差L*值、C*值、a*值更大,货架期长2 d,但后熟后颜色不如T2处理组的鲜黄;BOPP包装延缓了褪绿转黄,使催熟时间延长4 d,货架期缩短。因此前期高温（21 ℃）后期低温（17 ℃）是‘南天黄’获得较好的货架品质和货架期的后熟条件。     

外源茉莉酸甲酯处理对采后绿熟番茄果实根霉果腐病抗病性的影响

以"中蔬4号"绿熟期番茄果实为材料,通过真空渗透的方法,筛选能够有效控制采后绿熟期番茄果实抵抗根霉果腐病的茉莉酸甲酯处理浓度,研究外源茉莉酸甲酯处理后的接种果实抗性相关酶活性的变化.结果表明,10 mmol/L茉莉酸甲酯处理有效地减弱采后绿熟期番茄果实病害症状的发展,抑制果实发病率,控制病斑的扩增,同时也提高接种番茄果实中苯丙氨酸解胺酶、几丁质酶、β-1,3葡聚糖酶的活性.     

壳寡糖诱导采后番茄储藏品质的研究

研究了壳寡糖处理对番茄采后品质的影响。用浓度为50μg/mL的壳寡糖处理采后番茄,检测果实发病率与病斑严重度,确定壳寡糖对番茄抗灰霉病的效果,并对番茄果实在壳寡糖处理前后的储藏品质变化进行了深入研究。结果表明,壳寡糖诱导番茄抗灰霉病菌,挑战接种灰霉与只接种灰霉病原菌的果实的发病率在发病初期存在明显变化。在接种病原菌第12天时,发病率为对照未诱导接种的56.73%,诱导组果实病斑扩展速率下降,果实软化速度降低,推迟了可溶性固形物的变化周期。通过DPS软件分析,果实颜色变化无显著差异。第6天时,壳寡糖处理组的抗坏血酸含量比水处理组含量高13.1%,处理组可溶性酚含量大概维持在14.60 mg/g范围内,高于对照。因此,结果说明壳寡糖处理有利于延缓番茄果实的后熟衰老,减少病害的发生,保持良好的风味和营养价值。     

BABA处理提高采后砂糖桔对青霉菌的抗病性

诱导抗病性是水果采后病害生物防治的重要内容之一。对非呼吸跃变型的砂糖桔(Citrus Reticulata Blancdo Cv.Shiyueju)果实进行BABA渗透处理后接种绿霉病菌孢子,结果表明:不同浓度BABA处理果实的发病率和病斑面积均比对照果实的低,其中0.5g/L BABA处理效果最好,BABA处理提高了沙糖桔果实CHT、GUN、PAL、PPO、POD活性,提高了果皮H2O2含量。     

UV radiation-induced changes of antioxidant capacity of fresh-cut tropical fruits

The effect of ultraviolet (UV-C) treatment on total phenol, flavonoid, and vitamin C content of fresh-cut honey pineapple, banana “pisang mas”, and guava was investigated. The antioxidant capacity of the fruit also was evaluated by measuring its ferric reducing/antioxidant power (FRAP) and DPPH free radical-scavenging activity. The fresh-cut fruits were exposed to UV-C for 0, 10, 20, and 30 min. Total phenol and flavonoid contents of guava and banana increased significantly with the increase in treatment time. In pineapple, the increase in total phenol content was insignificant, but the flavonoid content increased significantly after 10 min of treatment. UV-C treatment decreased the vitamin C content of all three fruits. In fresh-cut banana, longer treatment time resulted in higher FRAP and DPPH values; these values remained stable throughout the experiment for fresh-cut pineapple. For fresh-cut guava, FRAP and DPPH values were stable until 30 min, after which a significant increase in FRAP values occurred.

Industrial relevance

UV irradiation processing of fresh-cut fruits leads to increase in antioxidants, polyphenols, and flavonoids. Hence, apart from the application of UV for microbial safety at industrial levels, this novel technology can also be exploited for enhancement of health promoting compounds for benefit of consumers.     

水杨酸处理对采后台农芒果品质和活性氧代谢的影响

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采前套袋结合低浓度乙烯利替代蜜橘果实乙烯褪绿处理的可行性研究

本文探讨采前套袋结合低浓度乙烯处理对蜜橘果实采后乙烯褪绿行为的影响。用黄色单层果袋对重庆北碚早熟蜜橘果实进行采前套袋处理,采收后分别设置对照组（CK）、1000 mg/kg乙烯利处理组（ETH）、仅套袋处理组（套袋+0 mg/kg ETH）、套袋+250 mg/kg乙烯利处理组（套袋+250 mg/kg ETH）、套袋+500 mg/kg乙烯利处理组（套袋+500 mg/kg ETH）和套袋+1000 mg/kg乙烯利处理组（套袋+1000 mg/kg ETH）,并将所有果实置于20℃的环境中贮藏。结果表明：随着贮藏期的延长,套袋结合乙烯利处理能更好改善早熟蜜橘果实的呈色问题,贮藏第6 d后,套袋+250 mg/kg ETH处理、套袋+500 mg/kg ETH处理和套袋+1000 mg/kg ETH处理均能显著提高果实的色差参数（a^*和a^*/b^*）（P<0.05）。在整个贮藏期,套袋+250 mg/kg ETH处理能够延缓蜜橘果实腐烂率和褐变指数的上升,并能维持果实硬度,对果实可溶性固形物和V_C含量无不良影响。此外,采收时,采前套袋处理的蜜橘果实的游离氨基酸总含量与对照组相比未发生显著性变化（P>0.05）,采前套袋处理对蜜橘果实风味无不良影响,但能提高蜜橘果实中与衰老抗病有关的精氨酸的含量。综合分析,采前套袋结合低浓度乙烯利（套袋+250 mg/kg ETH）在改善果实褪绿效果的同时,能降低常规乙烯褪绿引起的腐烂、果蒂褐变等问题,且该处理操作简单,在柑橘产业中具有一定的应用前景。     

短波紫外线处理对木薯保鲜效果及生理指标的影响

探讨短波紫外线对木薯果实感官品质、营养品质和生理指标的影响,为木薯的贮运保鲜提供技术指导。以‘华南5号’木薯果实为试材,以波长254 nm紫外线杀菌灯为辐射源,比较研究不同时间的紫外线处理对木薯品质的影响。结果表明：与对照相比,紫外线处理能够显著推迟果实硬度的下降和色泽的转变,延缓总可溶性固形物（TSS）含量的增加和淀粉的降解,并且能够抑制丙二醛（MDA）的积累,维持超氧化物歧化酶（SOD）和过氧化物酶（POD）活性在较高的水平,保持果实的贮藏品质,推迟果实的成熟软化过程。综合来看,30 min紫外线处理时间对木薯品质的保持最好,20 min处理次之,10 min效果最差。     

Degreening and postharvest storage influences 'Star Ruby' grapefruit (Citrus paradisi Macf.) bioactive compounds

Ethylene is commercially used for artificial degreening of early season grapefruits. The present study investigated the effect of degreening and storage period on Star Ruby grapefruit (Citrus paradisi Macf.) bioactive compounds. Freshly harvested grapefruits were degreened in commercial packing shed for 60h using 2ppm of ethylene at a constant temperature of 20°C. Both degreened and non-degreened (control) fruits were stored at 10°C for 21days and later transferred to 20°C for a period of 14days to simulate shipment and retail store market conditions. Bioactive compounds including carotenoids, limonoids, flavonoids and furocoumarins were analyzed using high performance liquid chromatography. Nomilin was significantly higher (P<0.05) in degreened fruits at 35days after storage. In contrast, flavonoids such as narirutin, naringin and poncirin were significantly (P<0.05) lower in degreened fruits at 35days after storage. Degreening treatment reduced the levels of deacetyl nomilinic acid glucoside and bergamottin after 35days of storage; however, it had no significant effect on total soluble solids, decay, fruit softening, taste, odour, ascorbic acid, β-carotene, lycopene, limonin, neohesperidin, didymin, 6,7-dihydroxybergamottin, 5-geranyloxy-7-methoxycoumarin and radical scavenging activity. Therefore, degreening could be utilized to enhance the grapefruit aesthetic quality, with minimal effect on nutritional quality.     

Reduction of Postharvest Decay of Peach and Nectarine Caused by Monilinia laxa Using Hot Water Dipping

The effect of hot water dipping (HWD) at 40, 44 and 48 °C for 6 and 12 min on germination of conidia of brown rot fungus (Monilinia laxa) in vitro and the effect of HWD at 48 °C for 6 and 12 min on the fruit quality and development of M. laxa on peach cv. “Roig” and nectarine cv. “Venus” after artificial inoculation in cold storage were studied. Temperature and duration of treatment significantly affected germination of conidia. After HWD at 48 °C for 12 min, the lowest germination of conidia (9%) was recorded, which was more than 10 times lower than control (93%). After 3 days from inoculation, there were 80% of inoculated spots with visual symptoms of decay caused by M. laxa on control peaches and 40% of such spots on control nectarines. Successful infections were recorded on only 5% of inoculated spots of nectarine and 10% of inoculated spots of peach after HWD at 48 °C for 12 min. HWD at 48 °C for 12 min significantly decreased titratable acidity and increased soluble solids concentration/titratable acidity ratio in nectarines. No visual symptoms of heat damage were found on fruits as a consequence of any of the studied treatments. The results show that it is possible to control postharvest brown rot (M. laxa) on peach using HWD at 48 °C for 12 min and on nectarine using HWD at 48 °C for 6 min without a significant loss of fruit quality.     

Study on the efficiency of ethylene scavengers on the maintenance of postharvest quality of tomato fruit

The objectives of this study were to achieve the best level of each ethylene scavenger and evaluate the effect of selected levels of treatments on some quality traits of tomato during storage. Tomato fruits were subjected to four levels of treatments: palladium-promoted nano zeolite, KMnO₄-promoted nano zeolite, 1-MCP, CaCl₂, salicylic acid (SA) and UV-C. The sampling was done at 0, 7th, 14th, 21st, 28th and 35th days of cold storage. The results showed that palladium-promoted nano zeolite 5%, KMnO₄-promoted nano zeolite 20%, 1-MCP 30 ppm, CaCl₂ 2%, SA 1% and UV-C 15 min levels had the most ethylene scavenging function. Effectiveness of the treatments in ethylene scavenging was in the order: palladium?>?KMnO₄?>?1-MCP?>?SA?=?CaCl₂?>?UV-C. The palladium-promoted nano zeolite 5% had more positive effects on phenol content, polygalacturonase activity, lycopene content, fruit firmness and weight loss, and UV-C 15 min had effect on decay severity as compared to the other treatments. Overall, palladium-promoted nano zeolite 5% could be considered not only as favorable tool in tomato shelf life extension but also in preservation of quality characteristics of tomato fruits during storage. Moreover, the UV-C 15 min treatment could be an effective method for reducing decay severity and maintaining postharvest quality of tomato fruits.     

采后UV-C处理对延缓香梨软化及相关酶活性的影响

研究采后UV-C照射处理对延缓香梨软化及相关酶活性的影响。照射剂量分别为3kJ·m-2、6kJ·m-2,以未经照射处理香梨为对照,避光储藏于20℃、相对湿度90%～95%的人工气候箱,定期取样测定各指标。结果表明,短波紫外线处理增加果实硬度,显著降低细胞膜透性和MDA含量,促进还原性糖和酚类物质的合成,降低纤维素酶和β-葡萄糖苷酶活性。这些结果显示短波紫外线能延缓香梨软化,延长香梨的贮藏保鲜期。     

低浓度乙烯利结合1-甲基环丙烯处理对香蕉果实香气合成的影响

为研究香蕉采后低浓度乙烯利结合1-甲基环丙烯（1-methylcyclopropene,1-MCP）处理对香蕉贮藏过程中香气合成途径的影响,通过气相色谱-质谱（gas chromatography-mass spectrometer,GC-MS）技术、酶活力测定以及实时荧光定量基因表达分析,测定了‘巴西’香蕉（Musa spp. cv. ‘Brazil’）果实不同成熟阶段特征香气物质含量、关键合成酶活力和相关基因表达量。结果表明：单独1-MCP处理和乙烯利（50 μL/L）结合1-MCP（400 nL/L）处理均能明显延缓和抑制香蕉黄熟期特征香气物质（包括乙酸异丁酯、乙酸异戊酯、丁酸丁酯、丁酸异戊酯）和过熟期特征香气物质乙醇和乙酸乙酯、绿硬期特征香气物质己醛和反-2-己烯醛的形成,但乙烯利结合1-MCP处理组与对照组相比各物质含量更接近。单独1-MCP处理和乙烯利结合1-MCP处理都显著抑制了果实香气代谢途径中醇酰基转移酶（alcohol acyltransferase,AAT）、醇脱氢酶（alcohol dehydrogenase,ADH）活力,但乙烯利结合1-MCP处理组AAT和ADH活力与对照组更接近,均显著高于单独1-MCP处理组。两个处理都在贮藏前期提高了酶脂氧合酶（lipoxygenase,LOX）活力,贮藏后期抑制了其活力;抑制ADH1、丙酮酸脱羧酶（pyruvate decarboxylase,PDC）基因的表达,并延缓高峰的出现;延缓支链氨基酸转移酶（branched-chain amino acid transaminase,BCAT）、LOX和AAT基因高峰的出现,但不降低峰值。单独1-MCP处理显著抑制ADH2表达,但乙烯利结合1-MCP处理对ADH2表达影响很小。结论：乙烯利结合1-MCP处理能够有效缓解不适当1-MCP处理引起的香蕉后熟障碍,保持香蕉果实的重要香气品质。本研究结果为1-MCP在香蕉采后品质保持的应用提供了理论依据。     

海藻酸钠/纳米TiO2复合涂膜对采后番木瓜果实软化及细胞壁降解影响

为探究海藻酸钠/纳米TiO2(sodium alginate/nano-TiO2,SA/TiO2)复合涂膜处理抑制采后番木瓜果实软化的作用机理,以"日升10号"番木瓜为试材,采用SA/TiO2复合涂膜处理,研究采后番木瓜果实硬度、细胞壁组分含量和细胞壁水解酶活性的变化规律.结果表明,SA/TiO2复合涂膜处理能有效地抑...