Papaya Fruit Quality Management during the Postharvest Supply Chain

Papayas are popular in tropical and subtropical regions and are being exported in large volumes to Europe, the United States, and Japan. The fruit has a sweet, exotic flavor and is rich in vitamins A and C and antioxidants. However, due to its highly perishable nature, it has not emerged as a major traded fruit. Papayas are highly susceptible to qualitative and quantitative postharvest losses. Maintenance of papaya fruit quality during the supply chain depends on orchard management, harvesting practices, packing operations, postharvest treatments, temperature management, and transportation and storage conditions. Postharvest losses are attributed to mechanical damage, rapid flesh softening, decay, physiological disorders, pest infestation, and improper temperature management. The aim of postharvest technology and management in the supply chain is to provide favorable conditions to extend storage life and retain quality and nutritional attributes. This review focuses on the available research findings to retain overall papaya fruit quality and to reduce postharvest losses during the supply chain via adopting appropriate or novel postharvest technologies.     

Maintaining mango (Mangifera indica L.) fruit quality during the export chain

Mangoes are tropical/sub tropical fruit with a highly significant economic importance. Preferable quality attributes include freedom from external damages such as bruises, latex or sap injury and decay, uniform weight, colour, aroma, firmness (with little give away, not soft), shape and size. The fruit is rich in antioxidants and recommended to be included in the daily diet due to its health benefits such as reduced risk of cardiac disease, anti cancer, and anti viral activities. Maintenance of mango fruit quality during the supply chain depends on many aspects including adequate orchard management practices, harvesting practices, packing operation, postharvest treatments, temperature management, transportation and storage conditions, and ripening at destination. Postharvest losses are high during the supply chain due to harvesting fruit at improper maturity, mechanical damage during the whole chain, sap burn, spongy tissue, lenticels discolouration, fruit softening, decay, chilling injury, and disease and pest damage. The aim of postharvest treatments and management practices in the supply chain is to create suitable conditions or environments to extend the storage life and retain the quality attributes, nutritional and functional compositions. This review summarises the available research findings to retain the overall mango fruit quality and to reduce postharvest losses during supply chain by adopting suitable postharvest novel technologies.     

Avocado Fruit Quality Management during the Postharvest Supply Chain

Avocados are a popular subtropical fruit of high economic importance, and the European Union is the biggest importer of the bulk of the fruit coming from countries such as South Africa, Chile, and Israel. The fruit is highly nutritious, being rich in vitamins A, B, C, minerals, potassium, phosphorus, magnesium, iron, and antioxidants. The biggest challenge is that the fruit is highly susceptible to qualitative and quantitative postharvest losses. Successful maintenance of avocado fruit quality during the supply chain depends on many aspects, including adequate orchard management practices, harvesting practices, packing operations, postharvest treatments, temperature management, transportation and storage conditions, and ripening at destination. Postharvest losses are mostly attributed to flesh softening, decay, physiological disorders, and improper temperature management. Management of the supply chain is solely done to provide the fruit with the most favorable conditions to extend storage life, and retain quality and nutritional attributes of the fruit. The focus of this review is therefore to study the findings that have emanated from research done to retain overall avocado fruit quality and to reduce postharvest losses during the supply chain through the adoption of appropriate and novel postharvest technologies.     

Aqueous chlorine dioxide treatment of horticultural produce: Effects on microbial safety and produce quality–A review

Microbial load on fresh fruit and vegetables causes decay and losses after harvest and may lead to foodborne illness in case of contamination with human pathogens on raw consumed produces. Washing with tap water only marginally reduces microorganisms attached to produce surfaces. Chlorine is widely used for decontamination on fresh horticultural produces. However, due to harmful by-products and the questionable efficacy it has become increasingly challenged. During the last 20 years, the interest to study ClO₂ treatments as an alternative sanitation agent for industrially prepared fresh produce has largely increased. For a wide range of commodities, the application of gaseous ClO₂ has meanwhile been investigated. In addition, since several years, the interest in aqueous ClO₂ treatments has further risen because of the better manageability in postharvest processing lines compared to gaseous application. This article critically evaluated the effects of postharvest application of aqueous ClO₂, either alone or in combination with other treatments, on microbial loads for various horticultural produces. In laboratory investigations, application of aqueous ClO₂ at concentrations between 3 and 100 ppm effectively reduced counts of natural or inoculated microorganisms (bacteria, yeasts, and mold) in the range of 1 and 5 log. However, various effects of ClO₂ treatments on produce quality have been described. These mainly comprise implication on sensory and visual attributes. In this context, there is increasing focus on the potential impacts of aqueous ClO₂ on relevant nutritional components of produces such as organic acids or phenolic substances.     

The impact of the postharvest environment on the viability and virulence of decay fungi

Postharvest decay of fruits, vegetables, and grains by fungal pathogens causes significant economic losses. Infected produce presents a potential health risk since some decay fungi produce mycotoxins that are hazardous to human health. Infections are the result of the interplay between host resistance and pathogen virulence. Both of these processes, however, are significantly impacted by environmental factors, such as temperature, UV, oxidative stress, and water activity. In the present review, the impact of various physical postharvest treatments (e.g., heat and UV) on the viability and virulence of postharvest pathogens is reviewed and discussed. Oxidative injury, protein impairment, and cell wall degradation have all been proposed as the mechanisms by which these abiotic stresses reduce fungal viability and pathogenicity. The response of decay fungi to pH and the ability of pathogens to modulate the pH of the host environment also affect pathogenicity. The effects of the manipulation of the postharvest environment by ethylene, natural edible coatings, and controlled atmosphere storage on fungal viability are also discussed. Lastly, avenues of future research are proposed.     

Postharvest biology and technology of pomegranate

Pomegranate is a subtropical and tropical fruit of great importance from a health point of view. Despite increasing consumer awareness of the health benefits of pomegranate, consumption of the fruit is still limited owing to poor postharvest handling, storage recommendations, short shelf life and quality deterioration during transportation, storage and marketing. The occurrence of physiological disorders such as husk scald, splitting and chilling injury is another challenge reducing marketability and consumer acceptance. Recently, notable work on postharvest biology and technology has been done. Pomegranate is highly sensitive to low‐oxygen (<5 kPa) atmospheres, chilling injury and decay. One of the major problems associated with pomegranate fruit is excessive weight loss, which may result in hardening of the husk and browning of the rind and arils. To reduce chilling injury incidence and to extend storability and marketing of pomegranates, good results were obtained with polyamine, heat, salicylic acid, methyl jasmonate or methyl salicylate treatments prior to cold storage. This article reviews the maturity indices, changes during maturation and ripening, postharvest physiology and technology of pomegranate fruit as well as the various postharvest treatments for maintaining fruit quality. © 2015 Society of Chemical Industry     

Effect of yeast antagonist in combination with heat treatment on postharvest blue mold decay and Rhizopus decay of peaches

The potential of using heat treatment alone or in combination with an antagonistic yeast for the control of blue mold decay and Rhizopus decay of peaches caused by Penicillium expansum and Rhizopus stolonifer respectively, and in reducing natural decay development of peach fruits, as well as its effects on postharvest quality of fruit was investigated. In vitro tests, spore germination of pathogens in PDB was greatly controlled by the heat treatment of 37 degrees C for 2 d. In vivo test to control blue mold decay of peaches, heat treatment and antagonist yeast, as stand-alone treatments, were capable of reducing the percentage of infected wounds from 92.5% to 52.5% and 62.5%, respectively, when peach fruits stored at 25 degrees C for 6 d. However, in fruit treated with combination of heat treatment and Cryptococcus laurentii, the percentage of infected wounds of blue mold decay was only 22.5%. The test of using heat treatment alone or in combination with C. laurentii to control Rhizopus decay of peaches gave a similar result. The application of heat treatment and C. laurentii resulted in low average natural decay incidences on peaches after storage at 4 degrees C for 30 days and 20 degrees C for 7 days ranging from 40% to 30%, compared with 20% in the control fruit. The combination of heat treatment and C. laurentii was the most effective treatment, and the percentage of decayed fruits was 20%. Heat treatment in combination with C. laurentii had no significant effect on firmness, TSS, ascorbic acid or titratable acidity compared to control fruit. Thus, the combination of heat treatment and C. laurentii could be an alternative to chemicals for the control of postharvest decay on peach fruits.     

Modified Atmosphere Packaging of Pomegranate Fruit and Arils: A Review

Ongoing global drive for a healthier diet has led to a rise in demand for convenient and fresh food produce, with high nutritional value and free of additives. Minimally fresh processed fruits and vegetables, satisfies the consumers’ perception of a high nutritional quality and convenience produce. Minimally processed fruit and vegetables are susceptible to increased deterioration in quality and microbial infestation due to increase in endogenous enzymatic processes and respiration rate. Modified atmosphere packaging (MAP) technology offers the possibility to retard produce respiration rate and extend the shelf life of fresh produce. However, it is important to correlate the permeability properties of the packing films with the respiration rate of the produce, in order to avoid anaerobic conditions which could lead into fermentation of produce and accumulation of ethanol. Hence, mathematical prediction modelling is now widely applied in the design and development of effective MAP technology in both whole and minimally processed fresh produce. With increasing global interest in postharvest handling and nutrition value of pomegranate, MAP of minimally processed pomegranate arils offers additional innovative tool for optimal use and value addition, including the utilization of lower-grade fruit with superficial peel defects such as; cracks, splits, and sunburnt. This review paper highlights the current status and applications of modified atmosphere packaging in whole fruit and minimally processed pomegranate arils and identifies future prospects.     

The use of ozone to extend the shelf‐life and maintain quality of fresh produce

Fresh produce has been recognised as a healthy food, thus there is increasing consumer demand for fresh fruit and vegetables. The shelf‐life of fresh produce, however, is relatively short and is limited by microbial contamination or visual, textural and nutritional quality loss. There are many methods to reduce/eliminate microorganisms present in food and ozone treatment is one of them. The use of ozone by the fresh produce industry is a good alternative to chemical treatments, e.g. the use of chlorine. The effectiveness of ozone as an antimicrobial agent has previously been reviewed and has been updated here, with the latest findings. The main focus of this review is on the effects of ozone on the fresh produce quality, defined by maintenance of texture, visual quality, taste and aroma, and nutritional content. Furthermore, ozone has been found to be efficient in reducing pesticide residues from the produce. The treatments that have the ability to reduce microbial contamination of the product without having an adverse effect on its visual, textural and nutritional quality can be recommended and subsequently incorporated into the supply chain. A good understanding of all the benefits and limitations related to the use of ozone is needed, and relevant information has been reviewed in this paper. © 2014 Society of Chemical Industry     

3种鲜枣贮藏期致病真菌的检测及定性研究

鲜枣采后贮藏期间易发生病害而腐烂。为深入研究危害采后鲜枣的主要病原菌和发病原因,以天津静海所产梨枣、圆铃枣、冬枣3个品种鲜枣为试材,对采后低温贮藏后期的病原菌进行了分离和鉴定,并对其生物学性质进行了初步研究。结果表明,侵染梨枣的病原菌主要有根霉和交链孢。侵染圆铃枣的病原菌是交链孢,但主要表现为生理性病害酒化。侵染冬枣的病原菌主要是交链孢和裸孢壳菌。     

An Analysis of the Published Literature on the Effects of Edible Coatings Formed by Polysaccharides and Essential Oils on Postharvest Microbial Control and Overall Quality of Fruit

Consumers have shown increased concern about the importance of adopting regular fresh fruit consumption. Because fresh fruit are highly susceptible to postharvest decay, several studies have focused on the development of alternative technologies to extend their market period. The application of polysaccharides in combination with essential oils (EOs) to formulate edible coatings has been considered an innovative strategy to reduce postharvest losses in fruit. However, available studies have used different methodological procedures related to the production and application of these coatings on fruit, which could be potential influential factors on the achievement of the desired effects in coated fruit. This review summarized the studies focusing on the application of edible coatings formed by polysaccharides and EOs to preserve fruit, in addition to examine and discuss possible factors affecting their functionalities. The approach given in this review envisages to contribute to research in edible coatings formed by polysaccharides and EOs and help to their optimized application as a postharvest treatment of fruit. Despite of the different methods selected for use in experimental assays, data of available literature demonstrate that coatings formed by polysaccharides (that is, chitosan—the only polysaccharide used as an antimicrobial, cassava starch, flaxseed gum, gum arabic, hydroxypropylmethylcellulose, locust bean gum, mesquite gum, pectin, pullulan, and sodium alginate) and different EOs (or their individual constituents) are effective to reduce postharvest losses in fruit and generally do not adversely affected their physicochemical and sensory characteristics during storage.     

Gaseous ozone to preserve quality and enhance microbial safety of fresh produce: Recent developments and research needs

Fresh fruits and vegetables are highly perishable and are subject to large postharvest losses due to physiological (senescence), pathologic (decay), and physical (mechanical damage) factors. In addition, contamination of fresh produce with foodborne human pathogens has become a concern. Gaseous ozone has multiple benefits including destruction of ethylene, inactivation of foodborne and spoilage microorganisms, and degradation of chemical residues. This article reviews the beneficial effects of gaseous ozone, its influence on quality and biochemical changes, foodborne human pathogens, and spoilage microorganisms, and discusses research needs with an emphasis on fruits. Ozone may induce synthesis of a number of antioxidants and bioactive compounds by activating secondary metabolisms involving a wide range of enzymes. Disparities exist in the literature regarding the impact of gaseous ozone on quality and physiological processes of fresh produce, such as weight loss, ascorbic acid, and fruit ripening. The disparities are complicated by incomplete reporting of the necessary information, such as relative humidity and temperatures at which ozone measurement and treatment were performed, which is needed for accurate comparison of results among studies. In order to fully realize the benefits of gaseous ozone, research is needed to evaluate the molecular mechanisms of gaseous ozone in inhibiting ripening, influence of relative humidity on the antimicrobial efficacy, interaction between ozone and the cuticle of fresh produce, ozone signaling pathways in the cells and tissues, and so forth. Possible adverse effects of gaseous ozone on quality of fresh produce also need to be carefully evaluated for the purpose of enhancing microbial and chemical safety of fresh produce.     

水杨酸用于水果采后贮藏保鲜的研究进展

综述近年来使用水杨酸减少水果腐烂、延缓采后果实成熟衰老、保持果实品质、增强果实抗冷害性能和诱导采后果实对病原菌的抗性等方面的研究进展,并展望水杨酸用于水果采后贮藏保鲜的趋势和研究方向.     

Factors affecting quality and safety of fresh-cut produce

The quality of fresh-cut fruit and vegetable products includes a combination of attributes, such as appearance, texture, and flavor, as well as nutritional and safety aspects that determine their value to the consumer. Nutritionally, fruit and vegetables represent a good source of vitamins, minerals, and dietary fiber, and fresh-cut produce satisfies consumer demand for freshly prepared, convenient, healthy food. However, fresh-cut produce deteriorates faster than corresponding intact produce, as a result of damage caused by minimal processing, which accelerates many physiological changes that lead to a reduction in produce quality and shelf-life. The symptoms of produce deterioration include discoloration, increased oxidative browning at cut surfaces, flaccidity as a result of loss of water, and decreased nutritional value. Damaged plant tissues also represent a better substrate for growth of microorganisms, including spoilage microorganisms and foodborne pathogens. The risk of pathogen contamination and growth is one of the main safety concerns associated with fresh-cut produce, as highlighted by the increasing number of produce-linked foodborne outbreaks in recent years. The pathogens of major concern in fresh-cut produce are Listeria monocytogenes, pathogenic Escherichia coli mainly O157:H7, and Salmonella spp. This article describes the quality of fresh-cut produce, factors affecting quality, and various techniques for evaluating quality. In addition, the microbiological safety of fresh-cut produce and factors affecting pathogen survival and growth on fresh-cut produce are discussed in detail.     

Quality of fresh‐cut products as affected by harvest and postharvest operations

There is a rising demand for fresh‐cut convenience products with high quality and nutritional standards that needs to be met by the fresh‐cut industry. It is well known that harvest and postharvest handling of fresh produce has a paramount impact on its quality and storage, although most of the existing literature has focused on these impacts related only to fresh produce that is destined for the final consumers. Indeed, current harvest methods and postharvest technologies have improved fruit and vegetable handling and distribution processes by slowing down physiological processes and senescence. Nonetheless, these technologies and methods may influence the quality of fresh produce as raw material for fresh‐cut processing as a result of the dynamic responses of fresh produce to handling procedures and treatments. Here, we review the existing literature on the challenges facing the fresh‐cut industry, focusing on the impact of harvest, maturity, and handling of fruit and vegetables on the quality of raw materials, as well as the implications for fresh‐cut products. The review also highlights areas for further research with the aim of enhancing the sensorial, nutritional and biochemical quality of such products. © 2018 Society of Chemical Industry     

Photocatalytic and Photochemical Oxidation of Ethylene: Potential for Storage of Fresh Produce—a Review

The phytohormone ethylene exerts numerous beneficial and detrimental effects on postharvest quality and storage life of fruit and vegetables. In view of the current global challenge of reducing postharvest losses and waste of fruit and vegetables, the importance of ethylene management in the supply chain is paramount. For this purpose, various methods have been applied along the supply chain over the years; however, effective management of ethylene under real-time storage and transport conditions still remains a challenging task. This review explores the potential of photocatalytic and photochemical oxidation of ethylene for effective removal of this gas along the value chain of fruit and vegetables. These techniques involve the use of ultraviolet (UV) radiation with or without a catalyst. In photocatalytic oxidation, a semiconductor such as titanium dioxide is essential which acts as a photocatalyst on irradiation with UV light and thus facilitates the oxidation of ethylene at its surface, whereas in photochemical oxidation, extreme short wave (i.e. below 200 nm) vacuum ultraviolet radiation (VUV) consisting of high-energy photons eliminates ethylene in the gaseous state. This review gives a brief overview of current commercial techniques used in ethylene removal and then focuses on the photocatalytic and the photochemical oxidation of ethylene and the combination of both methods. The various factors affecting these processes are also discussed including the advantages and the drawbacks associated with them, and current applications of these methods in fruit and vegetable storage systems are highlighted. In addition, a future outlook on the application of these methods in postharvest storage of fresh produce is given.     

灰霉病菌拮抗放线菌的筛选鉴定及对草莓的防腐保鲜效果

为丰富草莓采后病害拮抗菌资源,以草莓灰霉病菌（Botrytis cinerea）为指示菌,采用琼脂块法对草莓根际土壤分离的78 株放线菌进行筛选,并测定拮抗效果最强的菌株T3-5的拮抗谱。根据形态学特征、生理生化特性及16S rDNA序列进行鉴定,并初步研究其无菌发酵液对贮藏草莓腐烂发生及果实品质的影响。结果表明：草莓根际土壤分离的菌株T3-5对草莓灰霉病菌具有较强拮抗作用,拮抗圈直径为22.5 mm;对3 株常见细菌和6 株果蔬采后病原真菌均具有不同程度的抑制效果。该菌株经鉴定为黄暗色链霉菌（Streptomyces xanthophaeus）。菌株无菌发酵液能够显著降低贮藏草莓腐烂率（P＜0.05）,延缓果实硬度、可溶性固形物、可滴定酸及VC的降低。研究表明拮抗链霉菌T3-5对贮藏草莓具有良好的防腐保鲜作用,在草莓采后贮藏和生物保鲜中具有潜在的应用价值。     

宁夏枸杞鲜果采后病原菌的分离、鉴定及水杨酸的抑病效果研究

目的 分离、鉴定宁夏中宁地区引起枸杞鲜果采后病害的主要病原菌, 并研究水杨酸(salicylic acid, SA)的抑病效果。方法 采用常规方法从自然发病果实中分离病原真菌, 通过形态学和ITS(internal transcribed spacer)序列信息进行鉴定。使用不同浓度的水杨酸处理病原菌和果实, 观察SA对病原菌体外和体内的抑制效果。结果 共分离到4株病原真菌菌株, 它们均能引起枸杞鲜果的采后腐烂。其中, WB-1鉴定为梨黑斑链格孢(Alternariagaisen), WB-2鉴定为互隔链格孢(Alternariaalternata); WB-3和WB-4分别鉴定为镰刀霉属(Fusarium)和枝孢属(Cladosporium)真菌。SA对3种供试病原真菌的生长均有明显抑制作用, 且SA浓度越高抑制效果越明显。SA浸泡处理对常温和低温贮藏的枸杞鲜果病害有显著的控制效果, 并且SA处理对枸杞果实固形物含量(soluble solids content, SSC)无显著影响。结论 枸杞鲜果采后腐烂由多种病原真菌引起, SA处理对枸杞采后病害具有较好的控制效果, 具有潜在的应用前景。     

Quality Measurement of Intact and Fresh-cut Slices of Fuji, Granny Smith, Pink Lady, and GoldRush Apples

ABSTRACT: Development of fresh-cut apple products requires consideration of cultivars that store well as both intact and fresh-cut fruit. We compared the instrumental and sensory quality of 2 apple cultivars, Granny Smith and Fuji, that are used for fresh cutting with 2 new cultivars, Pink Lady and GoldRush, which were considered to have quality characteristics suitable for fresh cutting. Firmness, titratable acidity (TA), soluble solids content (SSC), and aromatic volatile concentration were measured in intact fruit of the 4 cultivars during 12 mo storage in air at 0 °C and during 3 wk storage at 5 °C as fresh-cut slices. After 1 wk storage as fresh-cut slices, sensory evaluations for acceptability of flesh and peel appearance, flavor, texture, and overall eating quality were performed. During storage, GoldRush apples maintained > 80 N firmness, approximately 17% SSC, > 0.5% TA, and had high aromatic volatile production, that is, maintained quality better than the other cultivars. The quality and shelf stability of GoldRush slices were also as good as or better than slices from the other cultivars, whereas Granny Smith slices generally rated lower than the other cultivars. The acceptability of flavor, texture, and overall eating quality of GoldRush slices was as good as that for Pink Lady and Fuji. The quality of GoldRush apples can be maintained throughout the year in refrigerated air storage and still remain suitable for fresh-cut processing. The results indicate that GoldRush and Pink Lady are 2 promising new, high-quality apple cultivars for fresh cutting. Keywords: fresh-cut fruit, Malus × domestica , postharvest quality, respiration rate, shelf life     

Chitosan and postharvest decay of fresh fruit: Meta-analysis of disease control and antimicrobial and eliciting activities

Consumers are increasingly aware of the importance of regular consumption of fresh fruit in their diet. Since fresh fruit are highly sensitive to postharvest decay, several investigations focused on the study natural compounds alternative to synthetic fungicides, to extend their shelf life. A long list of studies reported the effectiveness of the natural biopolymer chitosan in control of postharvest diseases of fresh fruit. However, these findings remain controversial, with many mixed claims in the literature. In this work, we used random-effects meta-analysis to investigate the effects of 1% chitosan on (a) postharvest decay incidence; (b) mycelium growth of fungal pathogens Botrytis cinerea, Penicillium spp., Colletotrichum spp. and Alternaria spp.; and (c) phenylalanine ammonia-lyase, chitinase and β-1,3-glucanase activities. Chitosan significantly reduced postharvest disease incidence (mean difference [MD], −30.22; p < 0.00001) and in vitro mycelium growth (MD, −54.32; p  < 0.00001). For host defense responses, there were significantly increased activities of β-1,3-glucanase (MD, 115.06; p = 0.003) and chitinase (MD, 75.95; p < 0.0002). This systematic review contributes to confirm the multiple mechanisms of mechanisms of action of chitosan, which has unique properties in the natural compound panorama. Chitosan thus represents a model plant protection biopolymer for sustainable control of postharvest decay of fresh fruit.