PRECONDITION OF 'D' ANJOU' PEARS FOR EARLY MARKETING BY ETHYLENE TREATMENT

'D' Anjou' pears (Pyrus communis, L.) harvested at an optimum maturity with the flesh firmness (FF) of 66.7N required 8 weeks of chilling at- 1C in order to initiate normal ripening in an ethylene-free environment at room temperature. If harvested fruit were not exposed to chilling or chilled at- 1C for less than 8 weeks, they could be preconditioned with 100 ppm ethylene for 3 days at 20C to initiate normal ripening. Fruit preconditioned with ethylene were capable of softening normally, reducing extractable juice, decreasing titratable acidity, and showing the climacteric rise of ethylene production during ripening at 20C when treated fruit had been further held at -1C in air for 14 days. The properly ripened fruit developed an acceptable dessert quality. When ‘d'Anjou’fruits had been stored at -1C in air for 8 weeks or longer, they could also be preconditioned without ethylene for 3 days at 20C to enhance ripening capacity. The nonethylene preconditioned fruit were capable of ripening normally following 14 days in simulated transit at -1C and upon arrival in retail markets at room temperature.     

The effects of fruit maturation,delayed storage and ethylene treatment on the incidence of low‐temperature breakdown of ‘Hayward’ kiwifruit

BACKGROUND: Low‐temperature breakdown (LTB), a disorder inducing quality loss, during and after cold storage of ‘Hayward’ kiwifruit was investigated. Harvested kiwifruits during fruit maturation or after delayed storage (DS) at 20 °C for 0, 1, 2, 3 and 4 weeks and 1 µL L^?1 ethylene treatment for 24 h were stored at ? 0.5 °C for 24 weeks and additional ripening at 20 °C for 5 days. Fruit quality indices and LTB incidence and severity were determined before and after treatments. RESULTS: Harvested fruits ripened during maturation, DS and after ethylene treatment. After storage and shelf life, fruits of all treatments were at complete ripening stage. LTB incidence of early harvested fruits was high, while that of fruits of the mid (third) and late harvests was low. Fruits of the third harvest date showed progressively increased LTB incidence with increasing duration of DS to as high as 95–100% after 4 weeks. Ethylene‐treated fruits showed a comparable increase in LTB to that corresponding to 2–3 weeks of DS. CONCLUSION: In contrast to fruit maturation, postharvest (after harvest and before storage) DS at non‐chilling temperature and ethylene treatment advanced the ripening of ‘Hayward’ kiwifruit and resulted in increased LTB incidence. Copyright © 2012 Society of Chemical Industry     

Control of Superficial Scald on 'ďAnjou' Pears by Ethoxyquin: Effect of Ethoxyquin Concentration, Time and Method of Application, and a Combined Effect with Controlled Atmosphere Storage

‘d'Anjou’ pears (Pyrus communis, L.) without ethoxyquin developed superficial scald upon ripening after 3 months of storage. Ethoxyquin at 1,000 ppm controlled scald for 4 months and did not cause phy-totoxicity to the fruit. Ethoxyquin at 2,700 ppm controlled scald for 5 months but caused phytotoxicity to the fruit. Fruit drenched with 1,000 ppm ethoxyquin within 2 days after harvest plus an additional line spray of 1,700 ppm ethoxyquin after 1 to 3 months of storage developed minimal scald incidence and did not suffer phytotoxicity after 5 months. Pre-storage drench of ethoxyquin at 500 ppm to ‘d'Anjou’ fruit was sufficient to control the scald disorder for up to 7 months in a controlled atmosphere (2% O₂+ 1% CO₂) storage.     

EFFECTS OF THE RATE OF HEATING ON APPLE AND PEAR FRUIT QUALITY

There is evidence that the rate of heating to meet quarantine security impacts fruit quality as well as insect mortality. Linear heating rates, of 4, 6, 8, 10, and 12C/h to treatment temperatures of 44 and 46C were used to treat 8 cultivars of apples (‘Delicious’, ‘Golden Delicious’, ‘Granny Smith’, ‘Fuji’, ‘Gala’, ‘Jonagold’, ‘Braeburn’, and ‘Cameo’) and two cultivars of winter pear (‘d'Anjou’ and ‘Bosc’). Fruit were stored, ripened, and tested for various quality parameters. Scald was controlled, firmness was higher in heat treated fruit, ripening was delayed but uniform in pears, decay organisms were suppressed, red fruit became redder and green fruit remained green, the Brix‐acid ratio (SS/TA) was either unchanged (‘Granny Smith’) or increased. Physiological disorders such as bitter pit were exacerbated by the heat treatment, requiring culling after treatment to avoid storage of fruit so affected.     

Effect of delayed storage and continuous ethylene exposure on flesh reddening of ‘Royal Diamond’ plums

BACKGROUND: Flesh reddening has been described as one of the manifestations of plum fruits to low‐temperature storage for prolonged periods. The influence of factors such as ethylene and delayed storage has not been studied to date. In order to assess that, plum cv. ‘Royal Diamond’ fruits were (a) stored at 5 °C (control), (b) held at 20 °C for 2 days before storage at 5 °C (delayed storage) or (c) maintained at 5 °C under 15 µL L^?1 ethylene. Fruits were then transferred to 20 °C and ethylene, respiration, weight loss, firmness, soluble solids content, acidity, flesh reddening, anthocyanin accumulation and phenylalanine ammonia‐lyase (PAL) activity were determined. RESULTS: Delayed storage fruits showed more extensive flesh reddening than control fruits, with increased PAL activity and higher anthocyanin accumulation. Symptoms were expressed more markedly when fruits were stored at 5 °C in ethylene. CONCLUSION: Results indicated that the fruit ripening stage is a critical factor determining the susceptibility of ‘Royal Diamond’ plums to flesh reddening. Fruits continuously exposed to ethylene showed a dramatic increase in reddening, suggesting that ethylene contributes to the development of the disorder. Copyright © 2008 Society of Chemical Industry     

Browning Potential,PPO, Catalase and Acid Phosphatase Activities during Ripening of Non-chilled and Chilled Avocado

During storage at 17°C, an increase in respiration and ethylene production and a decrease in firmness occurred sooner in avocados chilled previously than in non-chilled ones. The browning potential of avocado mesocarp changes markedly during ripening of both non-chilled and chilled fruits, reaching the same maximal level in both groups. However, non-chilled ripened avocados are characterised by a much lower browning potential than ripened chilled fruits. The changes in browning potential during ripening are associated with larger changes in polyphenol oxidase (PPO) and catalase than in acid phosphatase activities. The levels of PPO and of catalase detected during ripening are about the same in non-chilled and chilled avocado, yet the former produced much more ethylene than the latter, implying that the level of these enzymes per se does not determine the level of ethylene produced by the fruit.     

Controlled Atmosphere and Ethylene Effects on Quality of California Canning Apricots and Clingstone Peaches

Storage at 2% O₂ plus 5% CO₂ at 1.1°C maintained higher flesh firmness and lower pH and retarded decay more effectively than air storage of immature (M1) and over-mature (M3) Patterson and Tilton apricot fruits. CA storage of fruits picked at the optimum maturity stage (M2) produced little benefit over air storage, however. -Treatment with 100 ppm ethylene for 48 hours accelerated softening and color change at 20°C compared to ripening in air and may potentially be used to prepare immature apricot fruits for canning in the shortest possible time. Large differences in storageability and canned quality following storage were found among the five clingstone peach cultivars tested. Loadel and Carolyn: peaches, if in sound condition at harvest, can be stored for up to 4 wk under 2% O₂+ 5% CO₂ at 1.1°C. Andross, Klamt and Halford peaches should be stored for shorter storage periods only. Fruits ripened at 20°C with ethylene (100 ppm for 48 hr) were similar to those ripened without it in appearance, texture, and flavor.     

Methyl jasmonate reduces chilling injury symptoms and enhances colour development of ‘Kent’ mangoes

Treatment of mango (Mangifera indica cv ‘Kent’) fruits with methyl jasmonate (MJ) vapour for 20 h at 20 °C reduced chilling injury (CI) symptoms and enhanced skin colour development. MJ at 10^?4 M was the most effective concentration for reducing CI and decay in fruits stored at 5 °C followed by 7 days at 20 °C (shelf‐life period). The use of 10^?5 M MJ enhanced yellow and red colour development of mangoes stored at 20 °C. These fruits possessed higher L*, a* and b* values than untreated fruits and those treated with 10^?4 M MJ. Ripening processes were inhibited by cold storage (5 °C) in control fruits. After cold storage and shelf‐life period, fruits treated with 10^?5 M MJ ripened normally and contained the highest total soluble solids (TSS). These fruits also maintained higher sugar and organic acid levels than fruits subjected to other treatments. We concluded that MJ treatment could be used to reduce decay and CI symptoms and also to improve colour development of mango fruits without adversely affecting quality. © 2001 Society of Chemical Industry     

Effects of ascorbic acid and pre-packaging on shelf-life and quality of raw and cooked okra (Hibiscus esculentus)

Fresh okra fruits were dipped in aqueous solutions containing 250 and 500 ppm ascorbic acid (AA) or 1000 ppm Tween-20 for 5 min, air-dried, packaged and stored at 2°C. Blackening of the fruits dipped in the Tween-20 solution occurred within 2–4 days of storage while the AA-treated samples showed signs of deterioration after 20 days. Weight loss was greatly reduced in the AA-treated okra samples.The total chlorophyll, oxalate, fibre (hot-water-insoluble materials), ash and moisture contents of all the treated samples remained fairly constant. The maintenance of good quality by AA-treated samples packed in ‘cellophane’ bags was reflected in all aspects of sensory evaluation for cooked okra, even after 29 days of storage. It is concluded that a postharvest dip in 500 ppm ascorbic acid can be beneficial in maintaining texture and greenness of okra.     

Physicochemical changes during strawberry development in the field compared with those that occur in harvested fruit during storage

‘Chandler’, ‘Oso Grande’ and ‘Sweet Charlie’ strawberry cultivars were harvested at four stages of color development ranging from color break to full red and stored in the dark for 8 days at 1 °C. Changes in the physical and chemical characteristics of fruit during storage were compared with those occurring during development in the field. Strawberry fruit harvested at the three‐quarters colored and full red stages continued their development and ripening during storage. However, fruit harvested at the color break and half‐colored stages did not develop like those ripened in the field. Strawberries harvested at the three‐quarters colored stage developed the same pH, acidity, soluble solids, ascorbic acid and total phenolics content during storage as the at‐harvest levels present in strawberries harvested at the full red stage. In addition, three‐quarters colored strawberries were as firm and red after storage as the full red stage fruit were at the time of harvest. Thus, strawberries harvested at the three‐quarters colored stage can be stored for a longer period than strawberries harvested full red while retaining better color and firmness. Copyright © 2005 Society of Chemical Industry     

Effect of heat treatment and individual shrink packaging on quality and nutritional value of bell pepper stored at suboptimal temperature

The goal of this study was to develop a technology for prolonged storage of pepper fruit at low temperature, based on physical treatments and packaging materials. Physical and compositional changes of red bell pepper fruit (Capsicum annuum L. cv.’Selika’) were monitored during 21 days of cold storage (at 2 °C) plus 3 days at 20 °C (market simulation). Fruits were treated with tap and hot water and stored without packaging or sealing each fruit in individual shrink packaging (Cryovac®). This research revealed that individual shrink packaging following prestorage with hot water rinse (55 °C for 15 s) over brushes, significantly reduced weight loss, softening, decay incidence and chilling injury, while maintaining a quality. The wrapped fruit ripened normally (carotenoid content increased) during shelf‐life period, when shifted to 20 °C after unwrapping. This study showed that antioxidant levels of pepper fruit may be preserved during storage.     

Pre‐harvest calcium treatments in relation to the respiration rate and ethylene production of ‘Golden Smoothee’ apples

Multivariate procedures were used to evaluate the effect of different pre‐harvest calcium treatments on the changes of respiratory rate and ethylene production in apples both at harvest and after extended cold storage. The study was carried out over two years on ‘Golden Smoothee’ apple trees from Lleida (Spain). Trees were sprayed with a calcium chloride based formulation (STOPIT) at a concentration of 1% (v/v). The first (6 applications) and second (12 applications) treatments began 60 days after full bloom (DAFB) and were repeated at intervals of 15 and 7 days respectively. After harvesting, the fruit was stored for 4 and 6 months under controlled ultra‐low oxygen atmosphere conditions (CA‐ULO). Each time fruit was withdrawn from storage, carbon dioxide and ethylene production were measured for 14 days at 20 °C. Independently of the calcium treatments, respiration rates fell from harvesting until 6 months of storage, while ethylene production was greater on withdrawal from storage than at harvest. Respiratory rate and ethylene production correlated negatively with calcium content. However, calcium apparently had a greater effect on the respiratory capacity (CO₂) of fruit than on ethylene production. Copyright © 2004 Society of Chemical Industry     

Improving storability,physiological disorders,and antioxidant properties of ‘Bartlett’ and ‘d’Anjou’ pears (Pyrus communis L.) by pre-harvest 1-methylcyclopropene spraying

Ethylene continues to be a major factor influencing quality of European pears during storage. Although research has been done on the effect of pre-harvest 1-methylcyclopropene (1-MCP) on physiological characteristics in pears, a full understanding of cultivar response and antioxidant metabolism remains elusive. Spraying 1-MCP on ‘Bartlett’ and ‘d’Anjou’ pears was studied with respect to physiology, storage and eating quality, disorders, and antioxidant properties at two harvest date (H1 and H2) during storage and ripening. Treatment with 1-MCP extended the harvest window of ‘Bartlett’ and ‘d’Anjou’ pears 3 and 4 days, respectively, without reducing storage or eating quality. Treatment with 1-MCP reduced ethylene production (EPR) and respiration rates (RR), maintained fruit firmness and green colour during storage and retarded development of desirable melting texture in both cultivars. Additionally, 1-MCP lowered the incidence of disorders by alleviating membrane lipid peroxidation, retaining high total flavonoids (TF) and antioxidant capacity, and enhancing superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) activity in both cultivars. Overall, pre-harvest 1-MCP applications could extend storage time of ‘Bartlett’ and ‘d’Anjou’ pears to 5 and 6 months, respectively, at −1.1 ± 0.5 °C, by reducing ethylene synthesis and enhancing antioxidant metabolism.     

1-MCP缓释处理对气调贮藏后的‘安久’梨货架期品质的影响

以‘安久’梨为试材,利用3% 1-甲基环丙烯（1-MCP）缓释剂处理在2.2% O₂下贮藏6个月后的两个果园梨果实,研究1-MCP缓释处理对梨果实出库后在冷藏（模拟运输过程）和货架期中果实生理病害发生、乙烯释放率、硬度、果皮叶绿素、可溶性固形物和可滴定酸的影响,为今后其商业标准化应用提供理论依据。结果表明:与对照组果实相比,1-MCP缓释处理能降低货架期果实腐烂率和虎皮病发病率,降低α-法尼烯含量和共轭三烯积累。此外,1-MCP缓释处理能抑制果实乙烯释放,延缓果实硬度下降,果皮叶绿素和可滴定酸降解,但对可溶性固形物含量无影响。1-MCP处理的Lot 375果园（海拔为114.30 m）梨果实在经冷藏10 d后第21 d货架期时果实硬度降至24.76 N并伴随乙烯逐渐上升,而1-MCP处理的Lot 39果园（海拔为10.06 m）梨果实果实硬度为39.14 N,此时乙烯仍维持在较低的水平。因此,在人工短缺时,晚采收的高海拔地区果园‘安久’梨可先进行气调贮藏,待出库、清洗、分拣、包装处理后加入缓释型1-MCP,可降低货架期果实生理病害发生,保持较高的果实品质,但不影响果实软化。     

FRUIT QUALITY OF "D'ANJOU" PEARS AFTER BIN STORAGE AND LATE-SEASON PACKING

Scald and decay control are problems associated with the long‐term storage of “D’Anjou” pears. In this 3‐year study, D’Anjou pears were treated with combinations of fungicides (Scholar [fludioxinil], Penbotec [pyrimethanil] and Mertect [thiabendazole]), and antiscald agents (ethoxyquin [ETH] and diphenylamine [DPA]). Little decay was evident with or without the use of fungicides, but scald was a major problem after long‐term bin storage. ETH reduced scald incidence, but stimulated the severity of phytotoxicity. However, when fruits were evaluated by quality control personnel, phytotoxicity did not represent a major issue. ETH treatment enhanced sensory scores for finish and pedicel condition, improving fruit grade. In this study, scald control was better with ETH than DPH. However, DPH did produce acceptable scald control even though it aggravated phytotoxicity. D’Anjou pears packed in boxes with ETH and Cu paper wraps developed less decay and scald than pears in polyethylene bags.     

Use of the APIZYM Testing System to Assess the State of Ripeness of Banana Fruit

The APIZYM activity profiles of untreated fruit ripening at 20°C and 85% RH were compared with those from fruits treated with Pro-long, a fruit coating material, and fruit stored under controlled atmosphere conditions (5% O₂, 95% N₂) at the same temperature and RH. Banana fruits coated with Pro-long or stored under CA conditions ripened more slowly than untreated fruits, and this was reflected in lower activity of some enzymes during the storage period in coated and CA-stored fruit. Reduced activity in these treatments was more noticeable at day 4 of storage than day 7; however, even at day 7, the activity of certain enzymes was still lower than in controls.     

POSTHARVEST QUALITY AND SENSORY ATTRIBUTES OF ‘BYRONGOLD’ AND ‘RUBYSWEET’ PLUMS1

Fruit from two new cultivars of plums, ‘Byrongold’ and ‘Rubysweet’ were harvested at three maturities. Maturity one and two were ripened for three and six days at 20C and 85% relative humidity to determine fruit quality characteristics during storage. Plums were separated into three maturity categories by delayed light emission. Fruit size, weight, hue angle, flesh firmness, soluble solids and concentration of sugars, organic acids and sensory attributes were determined to evaluate stroage quality of the fruit. Significant differences were found between cultivars for sucrose, glucose, fructose and sorbitol. Sugar concentrations varied within the same cultivar by maturity and storage times. In general, acid levels decreased as plums ripened. Panelists preferred “Byrongold” ripened for three days for tartness and juiciness and “Byrongold” ripened for six days for sweetness. “Rubysweet” ripened for three days was preferred for sweetness, tartness and juiciness. Significant differences were found in peel bitterness between cultivars and days ripened. Unripened maturity 2 ‘Byrongold’ and unripenedd maturity 3 ‘Rubysweet’ had the highest peel bitterness. Hedonic scores showed ‘Rubysweet’.     

EFFECT OF COLD STORAGE ON THE QUALITY CHARACTERISTICS OF ‘AU-RUBRUM’ PLUMS1

The effect of cold storage (0°C) and maturity on the physical, chemical and sensory characteristics of plums (cv. ‘AU-Rubrum’) was determined. The size, weight, soluble solids and total sugar contents of the more mature fruit were significantly higher (P<0.05) and the “L” and hue angle were significantly lower (P<0.05) than plums in the less mature class. ‘AU-Rubrum’ fruit contained glucose, fructose and sorbitol but had no sucrose. Artificially ripening fruit at 20°C had a significant effect (P<0.01) on all color values for both maturity 1 and 2 fruit. The titratable acidity and sugar contents of the fruit ripened at 20°C were lower for ripened than for unripened fruit. Storage of the plums at 0°C for 5 weeks followed by subsequent ripening at 20°C had no significant effect on physical, chemical or sensory characteristics. Data indicate that ‘A U-Rubrum’ plums which have one-half red ground color (maturity 1) will develop full color and complete the normal ripening process. Data also indicate that the plums can be stored for at least 5 weeks at O°C without loss of quality and that the cultivar has potential for shipping to distant markets.     

采后1-MCP和MAP处理对‘红富士’苹果冷藏和货架期品质的影响

对‘红富士’苹果进行1.0 μL/L 1-甲基环丙烯（1-methylcyclopropene,1-MCP）和自发气调包装（modified atmosphere package,MAP）处理,继而进行0 ℃冷藏和20 ℃货架贮藏。结果表明：贮藏期间,‘红富士’苹果果实硬度和可滴定酸含量下降,可溶性固形物含量升高,虎皮病和果心褐变增多。1-MCP处理能较好维持冷藏期间‘红富士’苹果果实硬度和可溶性固形物含量,降低了包装内CO2和乙烯含量。同时,1-MCP明显降低了冷藏期间虎皮病发病指数、果心褐变指数以及果柄端果肉褐变率,显著抑制果皮α-法尼烯及共轭三烯的生成。1-MCP＋MAP结合使用可较好维持果实可滴定酸含量和果皮色泽、抑制果柄端果肉褐变。综合分析认为,1-MCP＋MAP处理能较好维持‘红富士’果实冷藏和货架期间的品质,并显著抑制果实虎皮病的发生。     

水杨酸结合微孔保鲜袋对‘京沧1号’枣贮藏品质的影响

为提高‘京沧1号’枣果实贮藏品质和商品性,以‘京沧1号’枣为试材,考察不同浓度水杨酸（10、30、50 mmol/L SA）结合微孔保鲜袋处理对‘京沧1号’枣保鲜效果的影响。结果表明,未使用微孔保鲜袋包装处理的‘京沧1号’枣在贮藏14 d后即出现明显的失水皱缩,品质劣变严重;仅使用微孔保鲜袋包装处理的‘京沧1号’枣保鲜效果不理想,微孔保鲜袋包装结合30 mmol/L SA处理效果最好,可使其贮藏期较未使用微孔保鲜袋处理组延长40 d左右。该处理能够有效延缓‘京沧1号’果实中可溶性固形物、可滴定酸等营养物质的消耗,延缓果实贮藏过程中失水皱缩和亮度、硬度的下降,维持相对较高的贮后可溶性糖、维生素C、总酚、可溶性蛋白等营养物质含量和抗氧化活性（P<0.05）。因此,微孔保鲜袋包装结合30 mmol/L SA处理是一种应用于‘京沧1号’枣的有效贮藏保鲜方法。