Radiation preservation of foods of plant origin. Part IV. Subtropical fruits: citrus, grapes, and avocados

Current information on the use of ionizing radiation for improving the storage of subtropical fruits like citrus, grapes, and avocados is reviewed. The feasibility of applying radiation either alone or in combination with other physical or chemical treatments for the control of postharvest fungal diseases is considered. Irradiation effects on the physiology of the fruits as related to respiration, ethylene evolution, changes in major chemical constituents, and quality are discussed. The recent trends in the possible use of irradiation as an alternative treatment to chemical fumigants for disinfestation of citrus and avocados and the prospects for the future application of irradiation for preservation of some of these fruits are outlined.     

Radiation preservation of foods of plant origin. Part VI. Mushrooms, tomatoes, minor fruits and vegetables, dried fruits, and nuts

In this concluding article in the series on the technological feasibility of ionizing radiation treatment for shelf life improvement of fruits and vegetables, the present status of research on several commodities that have not been dealt with earlier is discussed. The commodities include mushrooms, tomatoes, pineapples, lychees, longans, rambutans, mangostenes, guavas, sapotas, loquats, ber, soursops, passion fruits, persimmons, figs, melons, cucumbers, aubergines, globe artichokes, endives, lettuce, ginger, carrots, beet roots, turnips, olives, dates, chestnuts, almonds, pistachios, and other dried fruits and nuts. Changes induced by irradiation on metabolism, chemical constituents, and organoleptic qualities are considered while evaluating the shelf life. The commodities have been grouped into those showing potential benefits and those not showing any clear advantages from radiation treatment. Shelf life improvement of mushrooms and insect disinfestation in dried fruits, nuts, and certain fresh fruits appears to have immediate potential for commercial application.     

Radiation preservation of foods of plant origin. III. Tropical fruits: bananas, mangoes, and papayas

The current status of research on the use of ionizing radiation for shelf life improvement and disinfestation of fresh tropical fruits like bananas, mangoes, and papayas are reviewed. The aspects covered are influence of maturity and physiological state of the fruits on delayed ripening and tolerance to radiation; varietal responses; changes in chemical constituents, volatiles, respiration, and ethylene evolution; biochemical mechanisms of delayed ripening and browning of irradiated fruits; and organoleptic quality. The efficacy of the combination of hot water dip and radiation treatments for control of postharvest fungal diseases are considered. The immediate potential of radiation as a quarantine treatment, in place of the currently used chemical fumigants, for disinfestation of fruit flies and mango seed weevil are discussed. Future prospects for irradiation of tropical fruits are discussed in the light of experience gained from studies conducted in different countries.     

电离辐射对食品品质的影响

电离辐射处理食品可以减少食品贮藏期间的损失、延长货架期、提高食品卫生质量,采用合理的辐照工艺还可以提高谷物、豆类、酒类、果蔬茶和肉类的食用及工艺品质。指出应重视电离辐射影响食品品质的机理、辐射降解食品中的药物残留、提高不同种类食品的食用及工艺品质的辐照工艺及辐射技术与其它的食品加工工艺相结合提高食品品质的研究。随着研究工作的不断深入,辐射技术将进一步拓宽应用领域,加速向食品工业的渗透,在提高食品品质中发挥更重要的作用。     

短波紫外线法处理对鲜切果蔬抗氧化系统影响的研究进展

短波紫外线（ultraviolet-C,UV-C）作为一种绿色无污染的非热处理技术,近年来在鲜切果蔬保鲜中的研究越来越多,主要研究热点在UV-C对鲜切果蔬抗氧化系统的影响。鲜切加工、贮藏、运输、销售等过程会引发一系列的不利于果蔬贮藏的生理生化和品质特性改变,导致其食用品质和商用价值下降,带来重大的经济损失。鲜切果蔬抗氧化系统主要由酚类物质、黄酮类物质、维生素类等物质组成非酶抗氧化系统,超氧化物歧化酶、过氧化氢酶、过氧化物酶、抗坏血酸氧化酶等组成酶促抗氧化系统,共同发挥对鲜切果蔬贮藏品质的调节作用。本文介绍了UV-C和鲜切果蔬的特点,综述了UV-C对不同鲜切果蔬中非酶抗氧化系统和酶促抗氧化系统的影响,并对未来研究前景进行了展望,旨在为探究果蔬鲜切伤害条件下,UV-C处理对果蔬抗氧化系统响应机制的影响和鲜切果蔬贮藏品质特性影响的机理,并为UV-C在鲜切果蔬上的进一步推广、应用提供参考。     

采后果实减压贮藏技术的研究进展

减压贮藏技术作为果蔬贮藏保鲜史上的第三次技术革命,可有效提高采后果实的贮藏品质,尤其是对易腐园艺水果产品。该文结合当前减压贮藏技术的研究进展,介绍了减压贮藏的基本原理和方式、减压对采后果实的贮藏保鲜效果,并针对减压贮藏研究和应用过程中的问题提出了未来的研究方向。     

Pre-processed fruits as raw materials: part II—process conditions,demand and safety aspects

The demand for pre-processed fruits has grown rapidly in recent years as a result of consumer attention towards fresh, healthy and convenient foods. Most of the fruits are available seasonally and they are perishable, so it is necessary to have a continuous supply of the fruits to avoid the blockages in the fruit processing industry. The review is written in the purview of this issue, and it presents pre-processed fruits as a sustainable solution. The present review is part II of the series of articles on pre-processed fruits as the raw material for various food industries. The fruits covered here are mango, pineapple, pear, olive and papaya. The article continues to emphasise the critical processing and storage condition for these fruits ranked higher in terms of their production quantity and economic value. The fruits are critically reviewed for their processing, storage and safety aspects along with key research findings of different processing techniques. The important safety aspects associated with such processed commodities are also discussed.     

Microbial safety of tropical fruits

There are approximately 140 million tons of over 3,000 types of tropical fruits produced annually worldwide. Tropical fruits, once unfamiliar and rare to the temperate market, are now gaining widespread acceptance. Tropical fruits are found in a variety of forms, including whole, fresh cut, dried, juice blends, frozen, pulp, and nectars in markets around the world. Documented outbreaks of foodborne disease associated with tropical fruits have occurred. Norovirus and Salmonella are the leading viral and bacterial pathogens, respectively, documented to have caused outbreaks of infections associated with consumption of tropical fruits. Sources of contamination of tropical fruit have been identified in the production environment and postharvest handling, primarily related to sanitation issues. Limited data exist on the specific route of transmission from these sources. Research on the microbial safety of tropical fruits is minimal; with the growing market for tropical fruit expected to increase by 33% in 2010 this research area needs to be addressed. The aim of this review is to discuss the foodborne pathogen outbreaks associated tropical fruit consumption, research previously completed on pathogen behavior on tropical fruits, preventive strategies for pathogen contamination, and research needs.     

Ultrasonic washing as an abiotic elicitor to increase the phenolic content in fruits and vegetables: A review

Ultrasonic washing has been widely applied to the postharvest storage of fruits and vegetables as a residue-free physical washing technology, which plays an important role in improving shelf-life, safety, and nutritional value. Phenolics are a large group of phytochemicals widespread in fruits and vegetables, and they have been considered potential protective factors against some diseases because of potent antioxidative properties. Previous studies have shown that ultrasonic washing can increase the phenolic content of fruits and vegetables immediately or during storage through the induction of plant stress responses, which is of great significance for improving the functional and nutritional value of fruits and vegetables. However, the mechanisms of ultrasound as an elicitor to improve the phenolic content remain controversial. Therefore, this review summarizes the applications of ultrasonic washing to increase the phenolic content in fruits and vegetables. Meanwhile, the corresponding physiological stress response mechanisms of the phenolic accumulation in terms of immediate stress responses (i.e., higher extractability of phenolics) and late stress responses (i.e., metabolism of phenolics) are expounded. Moreover, a hypothetical model is proposed to explain phenolic biosynthesis triggered by signaling molecules produced under ultrasound stress, including primary signal (i.e., extracellular adenosine triphosphate) and secondary signals (e.g., reactive oxygen species, Ca²⁺, NO, jasmonates, and ethylene). Additionally, the techno-economic feasibility of ultrasonic washing technology is also discussed. Further, challenges and trends for further development of ultrasonic washing as an abiotic elicitor applied to the postharvest storage of fruits and vegetables are presented.     

非热加工在鲜切果蔬安全品质控制中的应用进展

鲜切果蔬由于其食用方便、营养丰富、清洁卫生等特点,近年来倍受人们关注。但由于鲜切果蔬在实际生产中极易发生微生物污染、营养成分和食用品质降低等不良变化,严重阻碍了鲜切果蔬加工业的进一步发展。非热加工技术是目前鲜切果蔬加工研究的热点,基于此探讨臭氧、电解水、辐照、紫外、脉冲物理场、超声波、高静压及高压二氧化碳等非热加工技术,在鲜切果蔬安全性与品质控制中的应用研究进展。     

茉莉酸甲酯调控果蔬采后品质的机制及应用研究进展

茉莉酸甲酯（methyl jasmonate,MeJA）是一种广泛存在于植物中的生长调节因子,具有广谱的生理效应,其作用于果蔬能够显著诱导果蔬产生抗病性、提高果蔬的耐冷能力、改善果蔬采后的感官品质和耐贮性。MeJA改善果蔬采后品质的机制主要包括诱导基因的表达、提高抗氧化及抗病相关酶的活性、促进抗性物质的积累、改善果蔬体内能量的代谢等方面。本文就MeJA的结构及理化性质、在果蔬采后方面的应用现状、作用机制及其在果蔬生产中的作用方式进行了综述,并讨论了其研究和应用前景,以期为MeJA在果蔬采后中的深入研究及推广应用提供参考。     

Citrus fruits. Part II. Chemistry,technology, and quality evaluation. C. quality evaluation

In Part II of this review on citrus fruits, the literature on chemistry, technology, and quality evaluation are critically considered. Sweet oranges, mandarin, grapefruit, lemon and lime are generally used for processing. The literature on chemical components of citrus fruits reviewed and discussed in Section A includes the following: sugars, polysaccharides, organic acids, nitrogenous constituents, and lipids; carotenoids which contribute to color; vitamins and minerals, and flavonoids; limonoids, some of which impart bitterness to the juice, and the volatile components which contribute to aroma. Chilled and pasteurized juices, juice concentrates, and beverages are the important products manufactured commercially, and to a limited extent powdered citrus juices, canned segments, and marmalades. The literature on the manufacture of these products as well as new types of juice and oil extractors, TASTE, and other types of evaporators, tank farms to store juice and concentrate in bulk, aseptic filling in bulk containers and retail packs, alternate flexible and rigid containers other than glass and tin and recovery of volatile flavoring constituents during juice processing are some of the important technological developments in the recent past which were discussed in Section B. Bitterness in citrus juices and its control, composition of cloud and its stability, and changes during storage have been reviewed. Essential oils, pectin, frozen and dried juice sacs, dried pulp and molasses, flavonoids, seed oil, and meal are the important by‐products, the manufacture of which is given in essential details. Generally, consumers judge the product on the basis of its sensory attributes. The quality of the finished products is dependent upon the raw materials used and control of processes. In this section, the USDA standards for different products, physico‐chemical and microbiological parameters prescribed as indices of quality of fruit, juice, concentrate, and other products, composition of essential oils, and aroma concentrates are discussed in relation to sensory quality. Analytical methods for compounds affecting quality and methods for detection of adulteration in different citrus products are briefly reviewed. The importance of sensorily evaluating quality of citrus products to select and develop quality control indices is emphasized. Areas where further research is required are indicated. A comprehensive bibliography is provided to aid further study and research.     

Mycotoxins in fruits,fruit juices,and dried fruits

This review gives an overview of the presence of mycotoxins in fruits. Although several mycotoxins occur in nature, very few (aflatoxins, ochratoxin A, patulin, Alternaria toxins) are regularly found in fruits. It has been shown that the presence of fungi on fruits is not necessarily associated with mycotoxin contamination. The formation of mycotoxins depends more on endogenous and environmental factors than fungal growth does. Mycotoxins may remain in fruits even when the fungal mycelium has been removed. Depending on the fruit and the mycotoxin, the diffusion of mycotoxins into the sound tissues of fruits may occur. The influence of the selection and storage of fruits and the influence of different processing steps involved in the production of fruit juices and dried fruits on possible mycotoxin contamination is described. It is shown that the careful selection, washing, and sorting of fruits is the most important factor in the reduction of mycotoxin contamination during the production of fruit juices. The processing of fruits does not result in the complete removal of mycotoxins.     

鲜切果蔬微冻技术的研究进展

鲜切果蔬具有天然、便利、营养、保健以及口感清脆爽口等优点,深受国内外快餐业、旅游业、零售业等行业青睐。但鲜切果蔬贮藏品质损耗严重,保鲜期限短,一直是困扰其工业化发展的瓶颈因素之一。目前,国内外研究者试图采用各种物理、化学方法改善果蔬的贮藏品质问题。虽然这些方法在杀菌或在改善质量方面取得一定成效,但在满足人们对果蔬天然、高营养、安全、较长的保鲜期限等综合品质的需求方面存在局限。微冻技术以其突出的保鲜效果,成为低温保鲜领域的研究热点。而关于微冻技术在果蔬保鲜上应用效果的报道还很少。基于此现状,本文从果蔬保鲜技术的研究现状、微冻保鲜作用效果及组织损伤机制3方面,探究了微冻技术在鲜切果蔬上的应用前景。     

Radiation preservation of foods of plant origin. Part 2. Onions and other bulb crops

The various factors contributing to post harvest losses in onions and other bulb crops are briefly outlined in terms of the current storage methods. The present status of research on sprout inhibition by irradiation is reviewed in detail with respect to dose requirements, effect of time interval between harvest and irradiation, and the influence of environment on sprouting during storage. Biochemical mechanisms of sprout inhibition, metabolic and compositional changes (particularly sugars, anthocyanins, flavor and lachrymatory principles), and the culinary and processing qualities of irradiated onions are discussed. The future prospects for the commercial irradiation for sprout inhibition of bulb crops are considered.     

壳聚糖对果蔬的抗菌保鲜效果及其应用研究进展

由于采后旺盛的生理代谢, 新鲜水果和蔬菜会出现品质劣变, 采取有效的抗菌保鲜策略是果蔬采后贮藏过程亟待解决的问题。天然大分子壳聚糖作为果蔬的活性包装材料具有来源广泛、安全和可生物降解等优点。本文综述了近年来壳聚糖基涂层/膜用于果蔬保鲜包装的抗菌保鲜效果及其对果蔬品质的影响, 首先介绍了壳聚糖的来源及应用特点以及制备壳聚糖薄膜材料的常用方法, 然后综述了壳聚糖及其与其他生物活性材料复合使用在果蔬保鲜中的应用, 并总结了使用壳聚糖基涂层/膜保鲜对果蔬外观品质、营养品质、挥发性香气物质等方面的影响; 最后, 对壳聚糖在果蔬抑菌保鲜机制方面的研究进行归纳介绍, 以期为其未来发展和应用提供新的思路。     

香辛料在果蔬保鲜中的应用及研究进展

香辛料通常是指生长在热带地区的芳香植物的种子或者果实、根、树皮,常作为调料使用。香辛料在我国的使用已有悠久的历史。我国土地辽阔,植物资源种类繁多,香辛料植物作为植物的一部分,来源也十分丰富。香辛料不仅具有强烈的呈味、呈香作用,还有较强的抑菌防腐作用。从香辛料中提取的物质能够有效地抑制微生物的生长繁殖,延长果蔬的贮藏时间,保持果蔬原有的品质。果蔬采后保鲜与农业的发展有着密切关系,采用安全高效的天然植物源防腐剂运用于果蔬贮藏保鲜是将是今后研究的重点内容。本文介绍了香辛料的抑菌活性成分和保鲜机制,以及香辛料在水果和蔬菜贮藏保鲜中的应用及其研究进展。最后,对香辛料在果蔬保鲜中的应用提出了展望,为天然食品防腐剂的研究提供参考。     

1-MCP在果品贮藏上的研究进展

1-MCP是一种新型乙烯作用抑制剂,可以延缓采后果实的衰老,延长果实的贮藏保鲜期。对1-MCP的作用机理及其对采后果品保鲜效果的影响进行了初步探讨,并综述了近年来1-MCP在果品贮藏保鲜上的应用研究进展。     

Comparative studies between fumigation and irradiation of semi-dry date fruits

This experiment was carried out on Egyptian semi-dried date fruits “El-Seidi CV.” which are used to process paste of dates. It is aimed to compare the effect of irradiation (1.5, 3.0 kGy) and fumigation with methyl bromide (MB) on physical, chemical and mycological characters, especially production of aflatoxins during storage of the dates for long time (8 months). Irradiation was more effective in de-infestation of dates than MB, but caused significant loss in weight of dates. No significant changes were observed in irradiated samples as well as in MB samples for moisture content, pH-values and titratable acidity, but significant changes were observed in browning and sugars, either total, reducing, non reducing or sugar/acid ratio. Irradiation (3.0 kGy) was more effective than other treatments for inhibition of the growth of fungi and prevention of aflatoxin production in synthetic broth media or date fruits. Therefore, irradiation dose (3.0 kGy) can be recomended to use than fumigation (MB) to keep date fruits with good quality, free from infestation, contamination and more safe for human consumption during long storage period.     

电离辐射对果蔬采后病害的控制

电离辐射技术因其效果好、简便、实用、卫生安全等特点而被作为代替化学合成防腐剂的物理方法应用于果蔬防腐保鲜中。综述了电离辐射在采后果蔬病害控制上的应用,包括电离辐射的直接抑菌作用、电离辐射对采后果蔬病害控制的效果及提高电离辐射对果蔬采后病害防治能力的方法等。