果蔬运输振动损伤及其减振包装设计

水果和蔬菜容易在运输的过程中承受静载、振动、挤压和冲击而造成损伤和品质下降.振动是引起果蔬运输损伤的主要原因.将缓冲材料应用于果蔬包装,可以减轻果蔬采后运输过程的振动,大大降低损耗.本文综述了国内外果蔬采后减振的研究进展,主要论述了振动损伤、缓冲材料的类型及减振作用、模拟振动实验和减振包装设计.     

果蔬采后机械损伤特性研究进展

论述了果蔬采后机械损伤的主要类型及其相关特性,着重分析了静压、振动、碰撞损伤的研究方法和进展,并对影响机械损伤的其他因素进行了分析,提出了果蔬机械损伤研究存在的问题.     

果蔬机械损伤的生理及分子机制研究进展

机械损伤是造成果蔬腐烂变质的重要原因,解决果蔬机械损伤问题能有效延长果蔬的储藏货架期,提高果蔬的商品价值。该文综述果蔬在采摘、运输、贮藏和销售过程中产生机械损伤的类型、机械损伤对果蔬生理特性和品质的影响,以及机械损伤激活信号分子进行防御反应和基因表达调控的分子机制,为减少果蔬机械损伤提出有效的防控措施奠定理论基础。     

果蔬采后内部损伤无损检测研究进展

果蔬产品含人体所必需的一些维生素、无机盐及植物纤维等营养元素,是人们日常膳食的重要组成部分。果蔬在采后处理过程中容易遭受机械损伤,不仅会降低果蔬自身外观品质,而且使果蔬容易受到真菌或细菌侵染,造成腐烂(如晚疫病、干腐病、软腐病等),影响其食用安全性。受侵染果蔬在运输、贮存等过程中会感染正常果蔬,进一步扩大经济损失。由碰压引起的内部损伤因损伤果蔬和正常果蔬外部特征差别不明显,容易相互混杂,对果蔬外观及食用品质造成潜在危害。因此,识别并剔除有内部损伤的果蔬日益引起国内外学者的注意。本文从果蔬损伤后发生的生理和物理变化角度入手,阐述了无损检测技术应用于内部损伤检测的机理,并综述了利用光、热、声和电磁学特性检测果蔬采后内部损伤的研究进展,最后指出了研究难点和今后研究方向。     

物理技术在果蔬保鲜中的应用研究进展

我国果蔬产量高、品种丰富、果蔬产业持续发展,但果蔬采后存在自身品质下降、病原菌侵袭以及采摘和运输过程中易引起机械损伤等问题。该文简述果蔬采后的生理变化,综述物理技术在果蔬保鲜中的应用并进行探讨,旨在为果蔬的保鲜提供参考。     

机械损伤对橄榄采后品质及其生理的影响

通过人工上树采摘、拦网采摘和自然掉果三种采收方式,探讨不同程度的机械损伤对橄榄采后商业品质及其生理的影响,结果表明:橄榄果实受到机械损伤后,在贮藏期间,果实的失重率和可溶性固形物呈线性增加,细胞膜透性增大,有机酸和VC的含量减少,含水量快速下降,呼吸速率迅速提高,PPO、POD、CAT活性上升,加速了果实的衰老进程.轻采轻放,减少机械损伤,对延长橄榄果实贮藏寿命,提高果品商业品质具有积极意义.     

植物精油在果蔬采后病害控制中的研究进展

采后病害是导致果蔬贮运过程中损失的主要原因,并且影响果蔬的品质及货架期。植物精油具有显著的抑菌效果,且安全无毒。综述了植物精油对常见果蔬病原真菌的抑菌作用、果蔬采后病害的控制效果、抗真菌的机制及发展前景。     

果蔬机械损伤特性研究进展

运输是果蔬流通过程中必经的一个环节,并且容易对果蔬造成损伤。果蔬在流通过程中承受着静载、挤压、振动、跌落和冲击等多种载荷形式的作用,产生了机械损伤。在归纳和分析国内外果蔬机械损伤相关研究成果的基础上,分析果蔬振动损伤机理,从静压损伤、振动损伤、冲击损伤3个类型研究果蔬机械损伤,综述研究机械损伤方面建立的模型及减缓果蔬损伤的对策,并对未来的研究方向进行展望,旨在为今后更深入的研究提供借鉴和参考。     

鲜切果蔬机械伤害刺激信号分子转导及 防御反应的研究进展

鲜切果蔬在加工过程中会使果蔬受到机械损伤,组织结构遭到破坏,极易发生褐变与受到微生物侵染,从而加速果蔬组织的衰老和腐败。机械伤害刺激信号分子的产生、运转、感知、接受和转导,以激活受伤害诱导的防卫基因表达,进而诱发鲜切果蔬整体协调产生防御反应。茉莉酸类、水杨酸、乙烯、脱落酸和系统素信号分子诱导果蔬防御反应可减轻机械损伤对鲜切果蔬品质的影响,能够有效抑制微生物对受伤部位的侵染以及果蔬组织内部的酶促褐变,改善果蔬贮藏品质。本文从机械伤害刺激信号分子茉莉酸类、水杨酸、乙烯、脱落酸和系统素的产生及转导方面综述了鲜切果蔬对机械伤害防御反应机制,并从伤害防御方面介绍了外源施用茉莉酸类、水杨酸和乙烯的作用机制与保鲜效果。     

低温维持果蔬采后活性氧代谢平衡的抗氧化转录调控机制研究进展

果蔬采后活性氧（reactive oxygen species,ROS）代谢失衡造成氧化胁迫,加速品质劣变,破坏其商业价值。文章以ROS代谢与果蔬贮藏品质的关系为切入点,探讨低温诱导抗氧化酶活性延缓果蔬采后品质劣变的作用;同时,从转录调控角度综述bHLH、WRKY及NAC等低温响应转录因子参与果蔬采后抗氧化作用,进而揭示低温延缓果蔬品质劣变的抗氧化转录调控作用的可能机制,旨在为开展果蔬采后品质生理生化及分子生物学等基础研究及进一步阐明果蔬采后成熟衰老和品质劣变机制提供新的理论依据。     

钙在果蔬生产加工应用中的研究进展

钙是构成植物细胞壁的重要元素,也是构成质膜的重要成分,它不仅影响果实品质,而且在延缓果蔬的衰老方面有较好抑制的效果。在生产加工中可以通过采前喷施钙肥或采后浸钙来提高果蔬品质,增加产量,另外在延长果蔬贮藏期的同时,还可保持好的品质,减少果蔬采后的损耗量。文章综述果实细胞中的钙的存在形式及钙在果蔬加工中的应用进展,以期为钙在果蔬加工中的合理利用提供理论参考。     

褪黑素在果蔬采后品质劣变中的调控作用

褪黑素是广泛存在于生物体内的一种吲哚类色胺, 具有调控果蔬衰老、清除活性氧自由基、防止抗氧化酶钝化等作用。最新研究发现褪黑素可以显著延缓果蔬采后由呼吸作用、乙烯释放、蒸腾作用、自由基代谢等代谢活动导致的品质劣变。本文从果蔬采后品质劣变角度综述了褪黑素对果蔬采后生理的调节作用, 从导致品质劣变的关键生理活动包括呼吸作用、乙烯合成、蒸腾作用、酶促褐变、膜脂氧化、抗性激活等方面阐述了外源褪黑素的调控机制, 系统阐述了外源褪黑素对果蔬品质的影响, 包括感官品质、糖酸代谢、风味变化等, 以期为褪黑素在保持果蔬采后品质及相关贮藏保鲜新技术的应用奠定一定的理论基础和技术支持。     

采后苯丙噻重氮处理促进梨果实的愈伤

研究采后苯丙噻重氮（benzothiadiazole,BTH）处理对梨果实愈伤的促进作用,探讨苯丙烷代谢及抗氧化 酶在愈伤中的作用。以‘玉露香’梨果实为试材,人工模拟损伤后,用100 g/L BTH处理,在常温（20～25 ℃）、 相对湿度80%～85%的黑暗条件下进行愈伤,通过测定质量损失率和损伤接种梨果实的发病率来评价愈伤效果,比 较BTH处理组和对照组梨果实愈伤期间苯丙氨酸解氨酶、超氧化物歧化酶、过氧化物酶和多酚氧化酶的活力,以及 总酚、类黄酮和木质素含量的差异。结果表明：BTH处理对梨果实愈伤期间的质量损失率没有显著影响;愈伤期 间,BTH处理组和对照组梨果实的发病率均降低,处理组和对照组之间存在显著性差异（P＜0.05）,由此表明, BTH处理降低了梨果实的采后发病率;BTH处理明显提高了苯丙烷代谢途径关键酶苯丙氨酸解氨酶、抗氧化酶多酚 氧化酶、过氧化物酶和超氧化物歧化酶的活力;此外,BTH处理还有效促进了梨果实总酚、类黄酮和木质素的积 累。相关性分析结果表明,处理组梨果实的发病率和苯丙氨酸解氨酶活力、总酚含量和类黄酮含量之间呈显著负相 关,和过氧化物酶及多酚氧化酶活力之间呈极显著负相关。采后BTH处理可促进梨果实的愈伤,苯丙烷代谢以及过 氧化物酶和多酚氧化酶在愈伤组织形成中发挥了重要作用。     

Postharvest Heat Treatment for Mitigation of Chilling Injury in Fruits and Vegetables

Low-temperature storage is widely used as a postharvest treatment applied for delaying senescence in vegetables and ornamentals and ripening in fruits, upholding their postharvest quality. But the refrigerated storage of tropical and subtropical crop plant species provokes a set of physiological alterations known as chilling injury (CI) that negatively affect their quality and frequently renders the product not saleable. The increasing demand for consumption of fresh fruits and vegetables, along with restriction on the use of synthetic chemicals to reduce CI, has encouraged scientific research on the use of heat treatments as an environment-friendly technology for CI mitigation. Membrane damage and reactive oxygen species production are multifarious adverse effects of chilling as oxidative stress in sensitive fruits and vegetables. Chilling mitigation in heat-treated fruits and vegetables could be attributed to (1) enhancement of membrane integrity by the increase of unsaturated fatty acids/saturated fatty acids (unSFA/SFA) ratio; (2) enhancement of heat shock protein gene expression and accumulation; (3) enhancement of the antioxidant system activity; (4) enhancement of the arginine pathways which lead to the accumulation of signaling molecules with pivotal roles in improving chilling tolerance such as polyamines, nitric oxide, and proline; (5) alteration in phenylalanine ammonia-lyase and polyphenol oxidase enzyme activities; and (6) enhancement of sugar metabolism. In the present review, we have focused on the impacts of heat treatments on postharvest chilling tolerance and the mechanisms activated by this environment-friendly technology in fruits and vegetables.     

组学技术与果蔬采后质量和安全控制

果蔬可以提供营养, 有利于人类健康, 而果蔬的后熟及其与环境的相互作用会影响果蔬采后的质量和安全。对果蔬生物学过程的了解和掌握是减少果蔬采后损失和保障果蔬采后质量和安全的关键。在过去的10多年, 基于组学技术的系统生物学在了解果蔬后熟及其与环境相互作用的分子机制方面得到了越来越多的应用。本文对此做了细致的总结, 指出了存在的不足, 并提出了未来的发展方向。     

Maintaining overall quality of fresh traditional leafy vegetables of Southern Africa during the postharvest chain

Traditional leafy vegetables are rich in bioactive macronutrients and micronutrients, including antioxidants. The increased consumption of traditional vegetables has been proposed as part of the solution to micronutrient malnutrition among the rural populations. Traditional vegetables are not grown commercially on a large scale or sold widely but are cultivated, traded, and consumed locally. These vegetables are easy to cultivate with minimal management and grow quickly under adverse soil and weather conditions. Their availability throughout the year and their affordability can also contribute to health and nutritional security rather than costly off-seasonal vegetables. After harvest, the leafy vegetables are prone to severe moisture loss due to their high surface-area-to-volume ratio. This results in a series of physical and biochemical changes that cause loss of weight, nutritional value, and texture, with the loss of overall quality eventually making the vegetable unattractive and unsalable. Reducing these losses during harvest and postharvest chain is an important part of sustainable agricultural development efforts to increase food availability. The review summarizes the research findings on nutritional quality, influence of preharvest factors on growth, challenges encountered during marketing, postharvest quality changes and novel methods to reduce postharvest quality losses, and bioactive compounds of selected traditional leafy vegetables.     

Reduction of the incidence of postharvest quality losses,and future prospects

Both quantitative and qualitative food losses of extremely variable magnitude occur during all harvest and postharvest stages, from harvesting, through handling, storage, processing and marketing, to final delivery to the consumer. The latest values published indicated that industrialized and developing countries dispose of roughly similar quantities of food. Whereas in developed countries the losses occur at the retailer and consumer stages, in the developing countries the losses occur during the production, harvest, postharvest and processing phases, because of poor infrastructure, low levels of technology, and low investment in food production systems. Quality cannot be improved after harvest, only maintained; therefore it is important to harvest fruits, vegetables and flowers at the proper stage and size and at peak quality. Preharvest production practices and factors such as cultivation practices, water supply, type of soil, environmental temperature and mechanical damage may seriously affect postharvest quality and result in the rejection or downgrading of produce at the point of sale. In addition, after harvest, improper temperature and humidity management as well as packaging and handling may have adverse effects on storage life and quality. Thus, integration of treatment methods calls for specific differential combinations of treatments for each product in each country.     

Flavor quality of fruits and vegetables

Fruits and vegetables are important sources of vitamins, minerals, dietary fiber, and antioxidants. The relative contribution of each commodity to human health and wellness depends upon its nutritive value and per capita consumption; the latter is greatly influenced by consumer preferences and degree of satisfaction from eating the fruit or vegetable. Flavor quality of fruits and vegetables is influenced by genetic, preharvest, harvesting, and postharvest factors. The longer the time between harvest and eating, the greater the losses of characteristic flavor (taste and aroma) and the development of off‐flavors in most fruits and vegetables. Postharvest life based on flavor and nutritional quality is shorter than that based on appearance and textural quality. Thus, it is essential that good flavor quality be emphasized in the future by selecting the best‐tasting genotypes to produce, by using an integrated crop management system and harvesting at the maturity or ripeness stage that will optimize eating quality at the time of consumption, and by using the postharvest handling procedures that will maintain optimal flavor and nutritional quality of fruits and vegetables between harvest and consumption. Copyright © 2008 Society of Chemical Industry     

柑橘果实采后热处理研究进展

采后热处理作为一种无污染、无残留的新型贮藏保鲜技术,近年来发展快速,已经应用于多种果蔬的采后品控及病虫害防治。本文综述了柑橘类果实采后热处理的主要方法,综合分析了不同处理方法对柑橘类果实理化特征的影响及对冷害和病虫害的控制作用,并展望柑橘果实采后热处理技术的发展趋势及其商业化前景。