Market diseases of fresh fruits and vegetables

Bruising, crushing, and other mechanical injuries cause very serious losses during the handling, transportation, storage, and marketing of fresh fruits and vegetables. Spoilage caused by molds and bacteria exacts a heavy toll. Freezing, chilling injury, and various physiological disorders add to the consumer cost of living. Careful handling, proper refrigeration, good marketing practices, and the use of safe, approved chemical treatments can reduce marketing losses.     

Pouteria caimito fruit derived nanoparticles inhibited the apple ring rot disease as well as extended the shelf-life of sliced apples

BackgroundApple disease, exaggerated by Botryosphaeria dothidea, is a foremost intimidating problem for extending the apple fruit shelf-life and producing substantial economic losses for cultivators and distributors. Alternate sources are urgently needed to prevent or inhibit the ring rot infection of apple fruit instigated by Botryosphaeria dothideaObjectiveIn this current study, we premeditated to make novel organic nanoparticles as of Pouteria caimito fruit extract and calcium chloride (PCNP), which were used to evaluate the preventive outcome of Botryosphaeria dothidea-caused apple disease on postharvest apple fruits.ResultsOur findings corroborated that the fruit derived nanoparticle had been confirmed for quality and size by altered estimations such as fourier transform infrared (FTIR), UV–vis spectroscopic analysis, scanning electron microscope and energy dispersive X-ray (SEM and EDX) estimation, and dynamic light scattering (DLS) analysis. In addition, we have investigated the excellent inhibitory action of the pathogen infection in apples initiated by Botryosphaeria dothidea. The protective enzymes function was pointedly improved in nanoparticle-treated apple fruits once equated with those of control apple fruits. The catalase (CAT) and superoxide dismutase (SOD) activities were pointedly improved in nanoparticle-treated fruits when compared to those of control fruits. The shelf-life extension studies were conducted for 7 days with a fresh-cut apple. The total soluble solid, pH, weight loss, and sensory studies were analyzed, and they proved the extension of sliced apple shelf life up to 7 days.ConclusionsThe discoveries of this study provided a well-organized, harmless, and environment-friendly substitute to control the apple disease as well as the durability postponement of sliced apples 7 days or may longer.     

植物果实、颜色和形状对橘小实蝇产卵选择的影响

橘小实蝇Bactrocera dorsalis(Hendel)是近几年入侵江苏南部地区,严重危害当地水果、蔬菜的重要害虫。为深入了解其在该地区果树、蔬菜上的产卵特性,进行植物果实、颜色和形状对其产卵选择影响的研究。实验室中"纸杯法"的产卵选择试验结果表明,橘小实蝇对不同水果的产卵偏好性由高到低依次为:柑橘、香蕉、芒果、枣、石榴、苹果、桃子、梨、李、葡萄、柿;对不同蔬菜的产卵偏好性由高到低依次为:丝瓜、豇豆、苦瓜、黄瓜、茄子、南瓜、青椒、番茄。对不同寄主颜色和形状的产卵选择特点为,雌虫常选择桔黄色、绿色,以及圆球形的寄主产卵,而较少选择黑色、方形的寄主产卵。从试验结果可以看出,寄主果实散发出的气味,及其颜色和形状对橘小实蝇的产卵选择有影响。     

The use of 1-methylcyclopropene (1-MCP) on fruits and vegetables

The recent availability of the inhibitor of ethylene perception, 1-methylcyclopropene (1-MCP), has resulted in an explosion of research on its effects on fruits and vegetables, both as a tool to further investigate the role of ethylene in ripening and senescence, and as a commercial technology to improve maintenance of product quality. The commercialization of 1-MCP was followed by rapid adoption by many apple industries around the world, and strengths and weaknesses of the new technology have been identified. However, use of 1-MCP remains limited for other products, and therefore it is still necessary to speculate on its commercial potential for most fruits and vegetables. In this review, the effects of 1-MCP on fruits and vegetables are considered from two aspects. First, a selected number of fruit (apple, avocado, banana, pear, peaches and nectarines, plums and tomato) are used to illustrate the range of responses to 1-MCP, and indicate possible benefits and limitations for commercialization of 1-MCP-based technology. Second, an outline of general physiological and biochemical responses of fruits and vegetables to the chemical is provided to illustrate the potential for use of 1-MCP to better understand the role of ethylene in ripening and senescence processes.     

Preliminary report on a catalyst derived from induced cells of <Emphasis Type="Italic">Rhodococcus rhodochrous</Emphasis> strain DAP 96253 that delays the ripening of selected climacteric fruit: bananas,avocados, and peaches

Despite the use of refrigeration, improved packaging, adsorbents, and ethylene receptor blockers, on average, nearly 40% of all fruits and vegetables harvested in the US are not consumed. Many plant products, especially fruit, continue to ripen after harvesting, and as they do so, become increasingly susceptible to mechanical injury, resulting in increased rot. Other plant products during transportation and storage are susceptible to chill injury (CI). There is a real need for products that can delay ripening or mitigate the effects of CI, yet still permit full ripeness and quality to be achieved. Preliminary results are discussed where catalyst derived from cells of Rhodococcus rhodochrous DAP 96253, grown under conditions that induced high levels of nitrile hydratase, were able to extend the ripening and thus the shelf-life of selected climacteric fruits (banana, avocado, and peach). A catalyst, when placed in proximity to, but not touching, the test fruit delayed the ripening but did not alter the final ripeness of the fruit tested. Organo-leptic evaluations conducted with control peaches and with peaches exposed to, but not in contact with, the catalyst showed that the catalyst-treated peaches achieved full, natural levels of ripeness with respect to aroma, flavor, sweetness, and juice content. Furthermore, the results of delayed ripening were achieved at ambient temperatures (without the need for refrigeration).     

Kinetics of inhibition of polyphenol oxidase mediated browning in apple juice by beta-cyclodextrin and L-ascorbate-2-triphosphate

Polyphenol Oxidase (PPO) mediated browning in raw fruits and vegetables is a major cause of quality deterioration in fruits and vegetables and derived food products. Here the rate of browning reaction in apple juice treated individually and in combination (1:1) of beta-Cyclodextrin (beta-CD) and L-Ascorbate-2-triphosphate (L-AATP) is described. It was observed that the rate of quinone formation can be minimized using a combination of beta-CD and L-AATP as compared to individual treatment with these agents. Kinetic experiments revealed that both compounds are non-competitive inhibitors of PPO.     

Fruit cuticular waxes as a source of biologically active triterpenoids

The health benefits associated with a diet rich in fruit and vegetables include reduction of the risk of chronic diseases such as cardiovascular disease, diabetes and cancer, that are becoming prevalent in the aging human population. Triterpenoids, polycyclic compounds derived from the linear hydrocarbon squalene, are widely distributed in edible and medicinal plants and are an integral part of the human diet. As an important group of phytochemicals that exert numerous biological effects and display various pharmacological activities, triterpenoids are being evaluated for use in new functional foods, drugs, cosmetics and healthcare products. Screening plant material in the search for triterpenoid-rich plant tissues has identified fruit peel and especially fruit cuticular waxes as promising and highly available sources. The chemical composition, abundance and biological activities of triterpenoids occurring in cuticular waxes of some economically important fruits, like apple, grape berry, olive, tomato and others, are described in this review. The need for environmentally valuable and potentially profitable technologies for the recovery, recycling and upgrading of residues from fruit processing is also discussed.     

Genetic engineering of carotenoid formation in tomato

The health promoting and aesthetic qualities of carotenoids have triggered considerable interest in enhancing their levels in crop plants, particularly in fruits and vegetables. One of the main crops of choice is the tomato, since it is readily available in both fresh and processed produce. There are several reports of the use of genetic engineering to increase levels of lycopene and -carotene in ripe fruit. This review will highlight the strategies used to achieve these goals by comparing the use of different genes from plants and microorganisms as well as the choice of promoters.     

Comparative content of total polyphenols and dietary fiber in tropical fruits and persimmon

Recent studies have shown that dietary fiber and polyphenols of vegetables and fruits improve lipid metabolism and prevent the oxidation of low density lipoprotein cholesterol (LDL-C), which hinder the development of atherosclerosis. The goal of this study was to measure the total polyphenol and dietary fiber contents of some tropical fruits (i.e., pineapple, wax apple, rambutan, lichi, guava, and mango) and compare the results to the content of these substances in the better characterized persimmon. It was found that lichi, guava, and ripe mango (cv. Keaw) have 3.35, 4.95, and 6.25 mg of total polyphenols in 100 g fresh fruit, respectively. This is significantly higher than in persimmon, pineapple, wax apple, mature green mango, and rambutan [P < 0.0005 for pineapple (Smooth Cayene variant), wax apple, persimmon, rambutan, mature green mango (cv. Keaw); the value of P < 0.001 is found only for pineapple (Phuket, Queen variant)]. The same relationship was observed for the contents of gallic acid and of dietary fiber. It can be supposed that among the studied fruit, lichi, guava, and ripe mango may be preferable for dietary prevention of atherosclerosis.     

Foliar application of aminoethoxyvinylglycine (AVG) delays fruit ripening and reduces pre-harvest fruit drop and ethylene production of bagged “Kogetsu” apples

Covering apple fruits with double layer waterproof bags to enhance fruit quality and evenness of blush colour is typical on many cultivars in Korea and Japan. Aminoethoxyvinylglycine (AVG) applied to unbagged apple fruits at 3–4 weeks before commercial harvest reduces ethylene production in the fruit, delays fruit ripening and reduces pre-harvest fruit drop. Spray application of AVG to trees of bagged apples should have no effect on apple ripening as there is␣no direct contact with the fruit and the translocation of AVG in apple trees is regarded as negligible. However, preliminary experiments suggested that AVG applied to trees of bagged apples reduced pre-harvest fruit drop in “Kotgetsu” apples. This study investigated the effect of spray treatments of 125 ppm of AVG on fruit drop, fruit ripening (firmness, starch conversion and soluble solids) and ethylene production to whole trees with bagged or unbagged “Kogetsu” fruit, as well as sprays of only the bagged or unbagged fruit on trees on two orchards. AVG applied to whole trees with unbagged apples reduced fruit drop from an average of 58.9% to 10.4%, delayed starch conversion and decreased ethylene production. AVG applied to whole trees with bagged fruit was equally effective in reducing pre-harvest drop, delaying fruit ripening and reducing ethylene production. Application of AVG to unbagged fruit only was nearly as effective as application to whole trees with unbagged fruit but application to bagged fruit only had no effect on fruit ripening or ethylene production. Application of AVG to bagged fruit only did reduce fruit drop to an average of 42.5% but this was not as effective as spraying unbagged fruit only or whole trees with bagged fruit. Possible mechanisms for this effect are discussed.     

Activities of Indoleacetic Acid Oxidase and Peroxidase in Ripening Apple Delicious Fruits

Peroxidase was extracted from the apple (Delicious) fruit and the apple stalk during the various stages of ripening. Activities of peroxidase and IAA oxidase of fruits are different.The activities of peroxidase and IAA oxidase in the apple stalk are much higher than that in the apple fruits. Gel electrophoresis revealed that the number of isozymic bands of peroxidase in the stalk (7–9 bands) were more than that in the fruit (6 bands). It is inferred that peroxidase in apple stalk might play a more important role in IAA and some other inhibitors oxidized before then went into the fruits.     

Expression of MdCAS1 and MdCAS2, encoding apple beta-cyanoalanine synthase homologs, is concomitantly induced during ripening and implicates MdCASs in the possible role of the cyanide detoxification in Fuji apple (Malus domestica Borkh.) fruits

Fruit ripening involves complex biochemical and physiological changes. Ethylene is an essential hormone for the ripening of climacteric fruits. In the process of ethylene biosynthesis, cyanide (HCN), an extremely toxic compound, is produced as a co-product. Thus, most cyanide produced during fruit ripening should be detoxified rapidly by fruit cells. In higher plants, the key enzyme involved in the detoxification of HCN is β-cyanoalanine synthase (β-CAS). As little is known about the molecular function of β-CAS genes in climacteric fruits, we identified two homologous genes, MdCAS1 and MdCAS2, encoding Fuji apple β-CAS homologs. The structural features of the predicted polypeptides as well as an in vitro enzyme activity assay with bacterially expressed recombinant proteins indicated that MdCAS1 and MdCAS2 may indeed function as β-CAS isozymes in apple fruits. RNA gel-blot studies revealed that both MdCAS1 and MdCAS2 mRNAs were coordinately induced during the ripening process of apple fruits in an expression pattern comparable with that of ACC oxidase and ethylene production. The MdCAS genes were also activated effectively by exogenous ethylene treatment and mechanical wounding. Thus, it seems like that, in ripening apple fruits, expression of MdCAS1 and MdCAS2 genes is intimately correlated with a climacteric ethylene production and ACC oxidase activity. In addition, β-CAS enzyme activity was also enhanced as the fruit ripened, although this increase was not as dramatic as the mRNA induction pattern. Overall, these results suggest that MdCAS may play a role in cyanide detoxification in ripening apple fruits.     

Characterization of Protein Kinases in Apple and Grape During Fruit Development

The protein kinases were identified at different developmental stages of apple (Malus domestica L. Borth. cv. Red Starking) and grape (Vitis vinifera L. × V.lubrusca L. cv. Kyoho) fruit, and these protein kinases were found to be greatly activated by Ca2+. This demonstrated that calcium-dependent protein kinase plays an important role in apple and grape fruits. The results also showed that calmodulin (CaM) had no stimulation effect, but the CaM antagonists, such as calmidazolium, W7 and trifluoroacetic acid (TFA), had some inhibitory effects on the activities of this kind of protein kinase in both fruits, indicating that the detected protein kinases may be a kind of calmodulin-like domain protein kinase or calcium-dependent protein kinase (CDPK). There were distinct differences between apple and grape fruits, both in the characteristics and in the activity evolution patterns of the protein kinases during fruit development. The activity of calcium-dependent protein kinase was little changed in the three stages of apple fruit development, while in grape fruit the activity of this protein kinase was much higher in stage Ⅱ than those in stage Ⅰ and stage Ⅲ. The calcium-dependent protein kinase in apple fruits was strongly activated by Mn2+, and it was sensitive to heat treatment, but in grape fruits it was neither stimulated by Mn2+ nor sensitive to high temperature. Besides, phosphatidyl-serine (PS) had little effect on the activities of calcium-dependent protein kinase in grape fruits, but had stimulative effects in apple fruits. It was thus proposed that there might be a kind of calcium- and phosphatide-activated protein kinase, i.e., PKC, in apple fruits. The differences among the kinds, characteristics and the activity evolution patterns of protein kinases during apple and grape fruit development, suggest that the protein kinases may be involved in the process of fruit development.     

Intake of fruits and vegetables,and risk of endometrial cancer in the NIH-AARP Diet and Health Study

Background: Fruits and vegetables contain a wide variety of phytochemicals which may have anti-carcinogenic effects. Although the results of case–control studies have suggested a possible protective effect of fruit and vegetable intake on the risk of endometrial carcinoma, few cohort studies have examined this association. Materials and methods: We used data from the NIH-AARP Diet and Health Study to assess the association of fruit and vegetable consumption, as well as intake of specific botanical groupings of fruits and vegetables, with endometrial cancer risk among 112,088 women who completed a food-frequency questionnaire at baseline, in 1995–1996. During 8 years of follow-up 1142 incident cases of endometrial cancer were ascertained. Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (95% CI). Results: After adjustment for covariates, HRs for the highest compared to the lowest quintile of total fruit and total vegetable intake were 1.30 (95% CI 1.04–1.61, P for trend 0.05) and 1.09 (95% CI 0.90–1.33, P for trend 0.55), respectively. No inverse associations were observed for intake of any of 13 botanical groupings of fruits and vegetables. Conclusions: Results from this large prospective study do not support a protective role of a high intake of fruits or vegetables on the risk of endometrial cancer in older women.     

Paradoxical effects of chemicals in the diet on health

In 1992, Block et al. published a summary of 200 epidemiological investigations which indicated that a diet that was high in fruit and vegetables cut cancer risks approximately in half. These investigations used conventionally farmed produce that contained traces of synthetic pesticides and mycotoxins as well as an estimated 10,000 secondary products (i.e. natural pesticides). Dietary consumption of fruits and vegetables also reduces risks of cardiovascular disease, cataracts and brain dysfunction. Before genetic manipulation is undertaken to elevate or diminish any individual constituent of fruits and vegetables, the contribution of each of these constituents to health must be better understood, as in many cases their effects on health can be paradoxical.     

苹果日烧病程中果皮抗氧化系统与细胞超微结构的变化

以富士品种为试材研究了苹果果实日烧病程中果皮组织细胞膜脂过氧化、抗氧化酶类、酚类物质的变化规律,并用电镜观察细胞超微结构的变化.结果表明膜脂过氧化导致日烧发生并进一步使日烧程度加重.相应地,抗氧化酶类在果皮变白期活性激增,但是,细胞结构仍较完整,只是叶绿体膨胀、类囊体结构部分解体,线粒体周缘模糊,细胞质中含大量的空泡;以后果皮变褐,绿原酸、槲皮素、芦丁、杨梅酮积累,同时靠近上表皮几层细胞解体,由密集的电子致密物充塞,细胞壁加厚.     

A protein inhibitor of polygalacturonase in apple fruits treated with aminoethoxyvinylglycine and cobalt chloride

Ethylene evolution changes were monitored during storage of apple fruits (Malus domestica Borkh., winter variety Mantuanskoe) treated with aminoethoxyvinylglycine and CoCl2. The storage of fruits was shown to be accompanied by changes in the activity of a protein inhibitor of polygalacturonase (PIPG). This inhibitor has been previously isolated from apple fruit tissues. The protein inhibitor of polygalacturonase was also shown to inhibit the activity of an enzyme produced by certain nonpathogenic fungi. The role of PIPG in apple fruit resistance to these fungi is discussed.     

Cyanide-Resistant Respiration in Relation to Fruit Respiratory Climacteric

Changes in respiratory rate and the effects of respiratory inhibitorson respiration were determined in apple (Malus sylvestris cv. Delicious) and red pepper (Capsicum fructescens) fruits dusting different stages of development and ripening.The results showed that there was an abrupt rise in respiration daring ripening inapple fruit, but the respiration of the red pepper declined continuously throughout theripening period. Thus the apple is climacteric and the red pepper is non-climacteric fruit. The respiration of apple fruit was sensitive to KCN (1 mM) during the period ofdevelopment but changed to CLAM-sensitive and CN-resistant during preclimactericand climacteric phases, indicating that a diversion of respiratory pathways from the cy-tochrome path to the alternative path has occurred. The respiration of the red pepperfruit was CN-sensitive thoughout the whole period of fruit ripening, suggesting thatthe operation of the CN-resistant path was insignificant. Slices from climacteric apple fruits developed induced .respiration after aging, bothKCN and CLAM (1 mM) inhibited the induced respiratic considerably. However, slices from red pepper fruits showed no evidence of induced respiration after aging. Slices from climacteric apple fruits infiltrated with 3 mM CLAM before aging, reducedthe peak of the induced respiration by about 30%, indicating that the development ofinduced respiration was suppressed by the presence of CLAM. The above results indicated that the: climacteric fruits were characterized by diversion of traffic from the cytochrome path to the alternative path during ripening andby the development of induced respiration after slicing and aging. While in nonclimacteric fruits no .diversion of electron transport path was observed during ripening andno induced respiration occurred after aging. Although both the eytochrome and alternative pathways were present in the tissue of red pepper fruits, the alternative pathwas not operating except when the cytochrome path was blocked or was saturated by electron flow.