水杨酸提高香蕉采后果实抗氧化能力和保鲜效果研究

为了探讨水杨酸(SA)对香蕉采后抗氧化能力和保鲜效果的影响,用0.8mmol/L的SA溶液浸泡香蕉果实4h后,以蒸馏水处理为对照,每个处理取90个蕉指,设3个重复.贮藏于25℃、相对湿度85%的人工气候箱内,处理后于第0、3、6、9d进行相关生理指标测定.结果表明:贮藏期间香蕉果皮的SOD、CAT活性大于果肉的活性,果肉的POD活性远大于果皮的活性;水杨酸处理提高香蕉果实SOD、CAT和POD活性:降低果实H2O2含量,使果实MDA含量减少;水杨酸降低淀粉向可溶性糖转化速率,提高果实的硬度和降低果实腐烂指数,从而提高香蕉的保鲜效果.     

中草药提取液对砂糖橘保鲜效果的研究

用具有良好防腐抑菌作用的中草药高良姜、大黄、丁香、桂皮、大蒜的提取液浸果,研究中草药提取液对无核砂糖橘果实的保鲜效果.结果表明:在常温贮藏条件下,与对照相比,中草药提取液处理提高了砂糖橘的好果率,减少了水分损失,延缓了果肉可溶性固形物(TSS)、可滴定酸(TA)及VC含量的下降.其中稀释50倍的中草药提取液处理的果实贮藏40 d时,好果率达98%,比对照提高了10%,失重率仅为1.9%,果实品质最好.中草药提取液处理还提高了贮藏前期果皮过氧化物酶(POD)和过氧化氢酶(CAT)活性,增强了贮藏后期超氧化物歧化酶(SOD)活性,有利于延缓果皮的衰老和病变.     

外源乙烯和1-甲基环丙烯对'圣心'芒果采后物性和香气特征的影响

色泽、质地及香气特性是评价果实感官品质的主要参考指标,为了探明芒果果实采后物性和香气特征规律,本研究采用外源乙烯和1-甲基环丙烯(1-methylcyclopropene,1-MCP)对采后'圣心'芒果果实进行保鲜处理,并分析其果皮色泽、果肉硬度、果肉总可溶性固形物质量分数及果皮、果肉中香气特征物质3-蒈烯含量的变化情况。结果表明:外源乙烯和1-MCP分别诱导和延缓了果实采后成熟衰老进程,其成熟衰老具体表现为果皮色泽由绿变黄、果肉硬度降低、总可溶性固形物质量分数增加;3-蒈烯是芒果香气物质的主要成分,其在果皮中含量高于果肉,且在果皮所有香气物质中的相对含量均在80%以上;乙烯处理在贮藏前期诱导了果皮中3-蒈烯的合成,在贮藏第3天,其含量即达到了极大值0.161μg/g;1-MCP处理在贮藏期间总体抑制了果皮中3-蒈烯的合成,而对果肉中3-蒈烯的合成则总体上起到促进作用。研究结果为芒果果实采后贮藏保鲜及品质调控技术提供实验依据。     

1-OCP处理对芒果常温贮藏采后生理的影响

研究了3种含量(1,5,50μL/L)的环丙烯类乙烯效应抑制剂1-OCP在常温(20±2)℃条件下熏蒸处理20h对青熟期芒果贮藏保鲜效果的影响。试验结果表明:3种含量的1-OCP处理均能延缓果实的后熟,其中50μL/L 1-OCP处理的芒果保鲜效果最好。贮藏第13天时,50μL/L 1-OCP处理的果实SSC含量和失重率分别比对照低4.4%和0.79%,果实硬度高于对照51%,MDA含量仅为对照的43.1%;POD,PPO活性高峰和呼吸高峰较对照均有所减弱,峰值分别仅为对照峰值的89%,67%,75.1%,呼吸高峰的出现也延迟了3 d。由此说明1-OCP能够有效地抑制芒果果实贮藏期间品质的下降,可作为乙烯效应抑制剂,应用于呼吸跃变型果蔬的贮藏保鲜。     

中药提取物对‘红地球’葡萄保鲜效果的影响

以黄连、黄芩、大黄、大青叶、艾叶五种中药材的乙醇提取物浸渍处理‘红地球’葡萄,以无菌水为CK1、2 g·L^-1的亚硫酸钠溶液为CK2,在4℃下贮藏65 d,比较不同中药提取物处理的‘红地球’葡萄果实腐烂率、总酚和抗坏血酸含量、可溶性固形物及相关抗氧化酶活性的差异,旨在明确中药提取物在葡萄贮藏保鲜方面的应用潜力。结果显示,大青叶处理组的葡萄果实多酚、抗坏血酸、可溶性固形物含量下降速度均较慢,烂果率较低,抑菌效果较优,多酚氧化酶(PPO)活性较低;艾叶处理组烂果率较低,抑菌效果最优,超氧化物歧化酶(SOD)、过氧化物酶(POD)活性较高,多酚氧化酶(PPO)活性较低;黄芩处理组SOD、POD酶活性显著高于CK1、CK2,抗坏血酸、可溶性固形物含量下降速度较慢。大青叶、艾叶和黄芩提取物对‘红地球’果实的贮藏保鲜具有一定效果,其中黄芩处理能使葡萄果实维持较高的抗氧化保护酶活性,以保持果实的品质;而大青叶和艾叶处理能较好地抑制葡萄表面杂菌生长,延缓葡萄果实的腐烂来保持果实品质。综合比较,大青叶对葡萄贮藏品质的综合保鲜效果较佳。     

蜂胶提取物处理对柑橘诱导抗病性的影响

以柑橘为材料,对蜂胶提取物诱导柑橘抗青霉病的表达时间以及蜂胶提取物处理对柑橘果实抗病性相关物质及酶的影响进行研究。结果显示,蜂胶提取物处理后48h 人工接种意大利青霉,柑橘所表现出的抗病性最强。蜂胶提取物处理增加了柑橘果皮中酚类物质的含量,提高了柑橘果皮中苯丙氨酸解氨酶(PAL)、过氧化物酶(POD)、多酚氧化酶(PPO)、几丁质酶(CHT)与诱导抗病性密切相关的酶的活性。这表明蜂胶提取物可增强柑橘果实的防御系统,降低果实贮藏期间的发病率,对柑橘表现出良好的保鲜效果。     

中草药提取液与淀粉复合膜在晚大新高梨的应用研究

为探讨中草药提取物与淀粉复合膜对晚大新高梨贮藏效果的影响,采用菌丝生长速率法探讨中草药提取物对引起梨轮纹病和梨黑星病两种贮藏病害病原菌的抑制作用,并探讨中草药提取液与淀粉复合膜对晚大新高梨贮藏效果的影响。结果表明:中草药以虎杖、黄苓和苦参等3种抑菌材料为原料的提取混合液对引起采后梨常见的贮藏病害梨轮纹病和梨黑星病害有一定抑制作用,而且随着提取液浓度的增加,抑制作用越强。中草药提取液和淀粉复合膜涂膜处理能延长晚大新高梨的贮藏寿命,使果实内呼吸强度、硬度和Vc含量变化明显低于对照组,延缓果实的物质消耗,减少果实与贮藏环境的物质交换,由于中草药中活性成分的作用抑制病原菌生长,减少果实腐烂;膜的特性及其对果实酶的诱导作用,有效抑制果实的呼吸强度,提高SOD活性,从而达到保鲜目的。     

赤霉素处理对南果梨贮藏品质的影响

以南果梨为试材,研究了10 mg/L和50 mg/L赤霉素(GA_3)处理对其常温贮藏品质的影响。结果表明:与对照相比,不同浓度GA_3处理均能降低果实的软化速度和果皮的转黄速度,保持果梗保鲜指数,抑制果实可溶性固形物(TSS)含量和丙二醛(MDA)含量的上升以及可滴定酸(TA)含量的下降,同时抑制多酚氧化酶(PPO)的活性和第一次呼吸高峰的出现,延缓了维生素C(V_C)含量和总酚含量的降低。结论:GA_3处理延缓了采后南果梨果实的成熟衰老进程,保持了其贮藏品质,其中50 mg/L的GA_3处理效果较好。     

外源柠檬酸处理对杨桃采后后熟及衰老的影响

为探索杨桃采后果实保鲜新方法,研究外源柠檬酸对采后杨桃后熟衰老及保鲜效果的影响。以广东湛江红杨桃为试材,采用5、10 mmol/L的柠檬酸溶液浸泡果实20 min并在15℃下贮藏,研究柠檬酸处理对果实的后熟软化及相关生理指标的影响。结果表明:柠檬酸处理有效延缓了杨桃果实硬度的下降、可溶性固形物含量的上升、可滴定酸含量的降低、细胞膜透性的上升以及果实VC含量的下降;柠檬酸处理还能提高果实贮藏后期POD的活性;同时,柠檬酸处理也抑制了果实中PPO活性的升高和MDA含量的积累。相关性分析表明,柠檬酸处理果实的硬度与POD活性、PPO活性及可滴定酸含量密切相关。外源柠檬酸能有效地抑制采后杨桃的后熟衰老进程,有较好的保鲜效果。     

壳聚糖处理对采后红地球葡萄低温贮藏保鲜效果的影响

以采后红地球葡萄果实为材料,用不同浓度的壳聚糖涂膜处理后低温贮藏,研究壳聚糖处理对低温贮藏下红地球葡萄果实保鲜效果的影响.结果表明,用壳聚糖涂膜处理能够降低红地球葡萄果实的失重率,延缓葡萄果实中的Vc含量、还原糖含量、可滴定酸含量及POD活性和SOD活性的降低速度,其中以1.5％的壳聚糖保鲜效果最好.     

核桃青皮乙醇提取物对采后无花果的保鲜效果

为解决无花果采后贮藏保鲜和核桃采收后核桃青皮资源浪费的问题,本文探究核桃青皮提取物对无花果的保鲜作用。以硬度、可滴定酸含量、维生素C含量、呼吸速率为指标,在常温环境和低温(0±2) ℃条件下,测定浓度为3%、5%的核桃青皮乙醇提取物和0.3 mol/L CaCl₂处理后无花果的生理生化变化情况。结果表明:在常温环境保存5 d后,5%的核桃青皮乙醇提取物处理无花果的硬度、可滴定酸含量、维生素C含量、呼吸速率分别为4.52 N、0.19%、25.83 mg/100 g、25.99 mg CO₂/(kg·h),在低温环境冷藏30 d后,5%的核桃青皮乙醇提取物处理无花果的硬度、可滴定酸含量、维生素C含量、呼吸速率分别为5.42 N、0.14%、35.83 mg/100 g、15.64 mg CO₂/(kg·h)。在常温和低温环境下5%的核桃青皮乙醇提取物对无花果果实的保鲜效果仅次于0.3 mol/L CaCl₂化学处理组,且无花果果实的品质和风味均能得到较好的保持,故选择5%核桃青皮乙醇提取物作为植物源保鲜剂。     

代表性热带水果及其废弃物提取液的抑菌效果研究

目的研究热带水果(火龙果、杨桃、菠萝、芒果、荔枝、龙眼、绿橙和莲雾)以及水果废弃物(龙眼壳、荔枝壳、龙眼核、香蕉皮、火龙果皮、菠萝蜜芯和菠萝蜜仁)的乙醇、丙酮、乙酸乙酯和正己烷溶剂提取液对沙门氏菌、单增李斯特菌、金黄色葡萄球菌和大肠杆菌O157:H7的抑菌活性。方法采用平板打孔法测量抑菌圈的大小,以表示提取液的抑菌活性。通过测量菌株生长曲线,确定提取液对细菌的生长抑制率。结果乙醇、丙酮提取液的抑菌效果均较好。提取液对单增李斯特菌、金黄色葡萄球菌和大肠杆菌O157:H7抑菌效果最好。火龙果、芒果和菠萝提取液的抑菌效果最好。菠萝提取液的最小抑菌稀释比例为1/10,其他提取液为1/100。碱性条件下,龙眼壳提取液抑菌活性增强,其他提取液在酸性条件下抑菌活性较强。各类提取液具有较好的耐热性。火龙果、芒果、菠萝的乙醇提取液中金黄色葡萄球菌的生长明显受到抑制,提取液可改变该菌的细胞膜渗透性。结论芒果、菠萝、龙眼壳、火龙果、火龙果皮、莲雾、荔枝壳、龙眼核、菠萝蜜芯和菠萝蜜仁的提取液具有一定抑菌活性。火龙果、芒果、菠萝的乙醇提取液对金黄色葡萄球菌有明显抑制作用并可破坏细胞膜渗透性,为有效防控食源性致病菌提供了基础数据。     

Mango peel powder: A potential source of antioxidant and dietary fiber in macaroni preparations

Antioxidants like phenolics and carotenoids both as additives in foods or pharmaceutical supplements can scavenge reactive oxygen species and protect against degenerative diseases like cancer, cardiovascular diseases. Mango peel, which is a by-product obtained during processing of mango products such as mango pulp and amchur, is currently discarded and thus, causing environmental pollution. In the present study, mango peel was incorporated into macaroni at three different levels (2.5, 5.0, 7.5%) and studied its effect on the cooking properties, firmness, nutraceutical and sensory characteristics of macaroni. The total dietary fiber content in macaroni increased from 8.6 to 17.8%. The content of polyphenols increased from 0.46 to 1.80 mg/g and carotenoid content increased from 5 to 84 μg/g of macaroni with 7.5% incorporation of mango peel powder. The macaroni products incorporated with mango peel exhibited improved antioxidant properties. The cooking loss of macaroni increased from 5.84 to 8.71%, and the firmness increased from 44 to 73.45 gf upon incorporation of mango peel powder. Incorporation of 5% mango peel powder into semolina yielded macaroni with acceptable quality. Thus, the results suggest that by incorporating mango peel powder, it is possible to enhance the nutritional quality of macaroni without affecting its cooking, textural and sensory properties.Industrial relevanceMango is one of the important tropical fruits. As mango is a seasonal fruit, it is processed into various products and during its processing, huge amount of peel is generated as a by-product and its disposal is a major problem. The peel constitutes about 15–20% of the fresh fruit. The peel contains various bioactive compounds and the peel extract exhibited potential antioxidant properties. In the present study, mango peel was incorporated into macaroni at three different levels and found that incorporation up to a 5% level into the formulation of macaroni yielded an acceptable product with improved nutraceutical properties. Thus, mango peel, a waste from mango industry can be utilized for the preparation of macaroni with improved nutritional properties.     

黄芩多糖大孔树脂纯化工艺优化及其抑菌活性

为优化大孔树脂纯化黄芩粗多糖的工艺,比较不同类型树脂的静态吸附与解吸性能,确定适宜树脂型号,研究其吸附机理。通过动态吸附与洗脱试验确定最佳纯化工艺,同时利用滤纸片法考察黄芩多糖对大肠杆菌、枯草杆菌和金黄色葡萄球菌的抑菌效果。结果表明,AB-8型大孔树脂对黄芩多糖的吸附过程符合Langmuir模型特征,最佳纯化工艺条件为:3 mg/mL的黄芩粗多糖溶液(pH 5.0) 60 mL,以2.0 mL/min流速上样至AB-8型树脂饱和吸附后,采用75%乙醇溶液,以1.0 mL/min流速洗脱,纯化后的多糖含量从26.25%提高至77.12%。黄芩多糖对三种供试菌具有不同程度的抑制作用,其中对大肠杆菌的抑制活性最强,对大肠杆菌、金黄色葡萄球菌及枯草杆菌的最小抑菌浓度分别为0.625、0.625、1.25 mg/mL。因此该纯化工艺效率较高,纯化后的黄芩多糖具有较好的抑菌活性,可为相关资源的开发提供参考。     

Limiting the deterioration of mango fruit during storage at room temperature by oxalate treatment

Effects of oxalate on the incidence of decay and ripening in mango fruit, and its physiological effects on the peel and flesh of mango were investigated after mango fruit (Mangifera indica L.) were dipped in different oxalate solutions for 10 min and then stored at 25 °C. Oxalate application decreased the incidence of decay and delayed the ripening process in mango fruit during storage. Potassium oxalate treatment resulted in increased activities of peroxidase (POD) in both the peel and the flesh and polyphenol oxidase (PPO) in the peel, without activation of phenylalanine ammonia-lyase activity, and elevated total phenolic content in the peel. The physiological effects of oxalate in increasing activities of POD and PPO and elevating total phenolic level could be involved in induced resistance of mango fruit against postharvest disease. Oxalate application could be a promising method to suppress postharvest deterioration and extend the useful shelf-life of mangoes.     

Antioxidant and antiproliferative activities of mango (Mangifera indica L.) flesh and peel

The antioxidant and antiproliferative properties of flesh and peel of mango (Mangifera indica L.) were investigated. The cytoprotective effect of mango flesh and peel extracts on oxidative damage induced by H₂O₂ in a human hepatoma cell line, HepG2, were determined, and the underlying mechanism was examined by a single-cell electrophoresis assay (comet assay). Treatment of HepG2 cell with mango peel extract prior to oxidative stress was found to inhibit DNA damage. The free radical scavenging activities of mango flesh and peel extracts were evaluated by electron spin resonance (ESR). The mango peel extract exhibited stronger free radical scavenging ability on 1,1-diphenyl-2-picrylhydrazyl (DPPH) and alkyl radicals than mango flesh extract, regardless of ripeness. Similarly, peel extract exhibited significant antiproliferative effect against all tested cancer cell lines, compared to that of flesh extract, in a dose-dependent manner. The result also showed that the antiproliferative activity of mango flesh and peel extracts correlated with their phenolic and flavonoid contents. Thus, mango peel, a major by-product obtained during the processing of mango product, exhibited good antioxidant activity and may serve as a potential source of phenolics with anticancer activity.     

无花果叶提取物对不同品种青皮核桃保鲜效果的影响

以温185、新丰和新2青皮核桃为实验材料,探究无花果叶提取物对青皮核桃的保鲜效果,将不同品种青皮核桃在4℃下贮藏60 d,探究无花果叶提取物对贮藏期青皮核桃的颜色、失重率、硬度以及核桃仁的酸价、可溶性蛋白等评价指标的影响。结果表明：无花果叶提取物显著提高了青皮核桃的保鲜效果,以青皮核桃果皮颜色和形状可知,新丰核桃贮藏到60 d时果皮绿色保留较好,新2核桃仅贮藏到15 d和温185核桃可贮藏到45 d的果皮颜色保留较好;贮藏到60 d时,新丰核桃青皮的a*值为-1.21,而新丰-CK的a*值为23.87,青皮核桃新丰、温185和新2相比对照组的失重率依次降低了85.28%、80.39%和79.41%,可见无花果叶提取物处理延缓了青皮核桃水分蒸发的速度,保持了青皮核桃的水分含量,其中,新丰核桃仁丙二醛含量最低,其含量为5.84μmoL/g,比新丰-CK降低了53.91%,无花果叶提取物处理显著延缓了核桃仁丙二醛的积累,新丰核桃仁可溶性蛋白含量最高为11.38 mg/g,且比新丰-CK高了55.01%,可见无花果叶取液处理保留了青皮核桃鲜食品质,延缓核桃仁脂类的过氧化,提高了青皮核桃的保鲜效...     

Valuable components of raw and ripe peels from two Indian mango varieties

Mango is one of the most important tropical fruits and India ranks first in its world production. During the processing of mango, mainly for mango pulp and preparation of amchur powder, peel is a by-product. Peel forms about 20% of the whole fruit and at present it is a waste product and its disposal has become a great problem. With a view to exploit mango peel as a source of valuable components, in the present study, proximate composition, polyphenols, carotenoids, dietary fibre contents and activities of few enzymes in raw and ripe peels of two Indian mango varieties, namely, Raspuri and Badami were determined. The polyphenol contents in these peels ranged from 55 to 110 mg/g dry peel. Dietary fibre content ranged from 45% to 78% of peel and was found at a higher level in ripe peels. Similarly, carotenoid content was higher in ripe fruit peels. Vitamins C and E contents ranged from 188 to 392 and 205 to 509 μg/g dry peel, respectively; and these were found at a higher level in ripe peels. Both raw and ripe mango peels exhibited significant amount of protease, peroxidase, polyphenol oxidase, xylanase and amylase activities.     

Carbendazim and metalaxyl residues in post-harvest treated apples

Bramley apples were treated with Ridomil mbc 60 WP, containing carbendazim and metalaxyl, at half and full rate application at 10 and 20°C, and with diphenylamine to control disease during storage. Carbendazim and metalaxyl residues were determined by HPLC and GC/MS, respectively, in apple core, flesh and peel at the initial time, 3 and 6 months after storage under controlled atmosphere conditions of 4.5°C, 5% CO₂ and 1% O₂. The concentration of carbendazim residues in apple flesh was ≤ 0.43 mg kg^-1 in all treatments; the mean concentrations in apple core and peel were 2.2 ±1.1 and 5.2 ±2.2 mg kg^-1, respectively. The MRL for carbendazim in apple was 2.0 mg kg^-1. The concentration of metalaxyl residues in apple flesh was ≤ 0.22 mg kg^-1; the mean concentrations in apple core and peel were 0.41 ±0.18 and 0.79 ±0.94 mg kg^-1, respectively. The MRL for metalaxyl in apple was 1.0 mg kg^-1. The temperature of the fungicide solution had little effect on the carbendazim residues but did have some effect on metalaxyl residues. Carbendazim residue content per apple was decreased when diphenylamine was included. A change in the ratio of carbendazim to metalaxyl was noted in the flesh, core and peel of the stored apple. The ratio of carbendazim to metalaxyl was 5:1 in the fungicide mix as applied. The ratio remained fairly constant in the core during storage. However, the ratio changed significantly in the peel and, to a lesser extent, and in a different direction, in the flesh. In the peel, the ratio was around 15:1 at 3 months of storage and 12:1 after 6 months of storage, whereas for flesh the ratios were 2:1 and 4:1, respectively.     

套袋对芒果果实采后品质和后熟的影响

在芒果(Mangifera indica L.cv.Zihua)的生长期内,分别用纸袋和无纺布袋进行套袋处理,以不套袋果实作为对照。果实采收后于20℃,85%～95%RH的环境下进行贮藏,并定期取样进行观察测定。结果表明,生长期套袋的"紫花"芒果果实果面的锈斑发生率和锈斑指数都比对照果实低,套袋对芒果果实的可溶性固形物和可滴定酸含量、硬度、呼吸强度几乎没有影响,但套袋处理更容易使果实着色。布袋的效果优于纸袋。