Abscisic Acid in the Response of ‘Fortune’ Mandarins to Chilling. Effect of Maturity and High-Temperature Conditioning

The possible role of abscisic acid (ABA) and peel colour in chilling tolerance of ‘Fortune’ mandarins has been examined. Fruit stored at 2·5°C, but not at 12°C, showed pitting damage. The degree of damage changed considerably during development and maturity from November until May. Green fruit were more tolerant to chilling injury (CI). After colour break, chilling susceptibility increased from the beginning of December until January and February (the coolest season during the growing period) and declined towards May. This trend did not parallel changes in fruit colour index or free and bound ABA levels, which increased from November until May. At the time of chloroplast transformation to chromoplast a noticeable shift in free but not in bound ABA occurred. During storage, free ABA levels increased in fruits stored at 12°C, but not at 2·5°C. Changes in ABA with storage temperature depended on the stage of maturity of the fruits, but not on their susceptibility to CI. It has also been shown that there was no relationship between ABA content following exposure to 37°C and chilling tolerance. At all stages of maturity, the susceptibility of the fruits to CI and the free ABA levels of the flavedo decreased after conditioning the fruits for 3 days at 37°C. After storage at 2·5°C, the ABA levels of the conditioned fruit were similar or even lower than those of non-conditioned fruit. Treatment of fruit for 3 days with 10 μl litre^-1 ethylene increased free ABA about four times, whereas bound ABA remained nearly constant. This treatment enhanced cold-induced peel damage after prolonged storage. Thus, the ethylene-induced changes in free ABA appear not to be related to the induced changes in chilling susceptibility. The results obtained indicated, therefore, that free and bound ABA appear not to be involved on the adaptative mechanism developed in ‘Fortune’ mandarins to cope with chilling stress. © 1997 SCI.     

Effects of tal pro-long,a surface coating agent,on the shelf life and quality attributes of plantain

The effects of Tal Pro-long, a commercial fruit coating, on the shelf life and selected quality attributes of plantain were investigated. Relative to untreated fruits, yellow colour development was retarded by 4 to 8 days, and changes in pH and total acidity were delayed in plantain dipped in 1.5% or 2.5% Pro-long solution when stored at 30°C or at 20–24°C. Pro-long treatment had less effect on the pulp: peel ratio of plantain and on changes in moisture contents of pulp and peel during storage. After ripening, fruits dipped in 1.5% Pro-long solution produced an acceptable, though slightly inferior, fried plantain product relative to untreated fruits.     

Proton spin–spin relaxation time of peel and flesh of navel orange varieties exposed to freezing temperature

Proton spin–spin relaxation times (T₂) of peel (albedo and flavedo) and juice sacs (flesh segments) of navel oranges were measured at 10 MHz using a Bruker Minispec PC 110 NMR spectrometer. The oranges were subjected to chilling (5 °C) and freezing (−7 °C) temperatures for 20 h and warmed to room temperature before peeling for T₂ measurements. The exposure to chilling or freezing temperature did not affect the T₂ values of peel, but freezing caused an appreciable decrease (∼15%) in the T₂ values of flesh segments of the varieties of navel oranges studied. When the peel was exposed to −20 °C, the T₂ showed a drastic reduction suggesting that the peel did not freeze at −7 °C. The possible cause of reduction in the T₂ values when exposed to freezing temperature may be damage to the juice sac membrane and leakage of juice out of the sac. The difference in the T₂ values between juice sacs of freeze-affected and normal oranges can potentially be used for detection of freeze-damaged fruits. Copyright © 2005 Society of Chemical Industry     

Alleviation of chilling injury in postharvest tomato fruit by preconditioning with ultraviolet irradiation

BACKGROUND: Tomato fruit is usually stored at low temperatures for delayed ripening and extended shelf life. However, tomato fruit is susceptible to chilling injury when exposed to low temperatures. In this study, the potential effects of preconditioning with UV‐C or UV‐B irradiation on chilling injury of postharvest tomato fruit were investigated. RESULTS: Mature–green tomato fruit were exposed to 4 kJ m^?2 UV‐C or 20 kJ m^?2 UV‐B irradiation and stored for 20 days at 2 °C and subsequently 10 days at 20 °C. UV irradiation was effective in reducing chilling injury index and delaying ethylene peak. Furthermore, UV irradiation preserved storage quality as manifested by reduced weight loss, better retention of firmness, and higher contents of total soluble solids, soluble protein and soluble sugar during subsequent storage at 20 °C. UV‐C irradiation significantly delayed the development of the red colour after 10 days of storage at 20 °C. On the other hand, UV irradiation decreased total phenolics content and antioxidant capacity, suggesting possibly reduced stress response to low temperature resulted from enhanced physiological adaptation by UV preconditioning. CONCLUSION: Our results suggest that preconditioning with UV‐C or UV‐B irradiation in appropriate doses had a positive effect on alleviating chilling injury in postharvest tomato fruit. Copyright © 2012 Society of Chemical Industry     

Hot water and curing treatments reduce chilling injury and maintain post-harvest quality of 'Valencia' oranges

‘Valencia’ oranges [Citrus sinensis (L.) Osbeck] were harvested at optimal maturity and either dipped in hot water at 53 °C for 3 or 6 min or at 48 °C for 12 min or cured at 53 °C for 1 or 6 h or at 48 °C for 12 h. The fruits were not degreened, waxed or treated with any post‐harvest fungicides. All fruit samples were stored at 4 °C for 6 months following the treatments. Both hot water dip and curing treatments reduced chilling injury and decay when compared with the untreated control. The most effective treatments were curing of fruit at 53 °C for 6 h and at 48 °C for 12 h. Weight loss and juice yield were higher in cured fruits than those from other treatments, but the heat treatments had no consistent effects on titratable acid, soluble solids, ascorbic acid and peel colour. It was concluded that a pre‐storage hot water dip and curing at high temperatures might be beneficial in preventing chilling injury and decay of ‘Valencia’ oranges for 6 months of storage at 4 °C.     

Nondestructive Measurement of Peel Gloss and Roughness to Determine Tomato Fruit Ripening and Chilling Injury

Mature-green tomatoes showed a gradual decrease in peel gloss during ripening at 20°C. Gloss correlated well with parameters such as a* values and °Brix and could possibly serve as criteria for ripeness. When stored at 2°C for 7, 14 or 21 days and then allowed to ripen at 20°C, fluctuations in gloss during ripening were observed. Peel roughness increased as a result of chilling, but did not appear to be related to time elapsed at the chilling temperature and no changes were observed on subsequent ripening. Pink tomatoes showed fluctuations in gloss similar to mature-green fruit. Chilling had no influence on roughness of pink tomatoes.     

A simple pretreatment with low O2 to alleviate superficial scald in Granny Smith apples

Sealing Granny Smith apples in a low‐O₂ atmosphere for 7 days at 20 °C (LO₂‐20C) prior to cold storage reduced superficial scald development after 6 and 8 months at 0 °C plus 10 days at 20 °C. This LO₂‐20C treatment reduced the O₂ levels that induce endogenous production of significant amounts of CO₂, acetaldehyde and ethanol, and thereby reduced ethylene production in cold storage, which in turn reduced scald development. Treatment with ethanol vapour (20 mL L^?1) for 1 day at 20 °C plus 6 days at 1 °C or with low O₂ for 1 day at 20 °C plus 6 days at 1 °C (LO₂‐1C) did not reduce scald effectively. 1‐Methylcyclopropene (1‐MCP) treatment at 0.5 µL L^?1 was the most efficient at reducing scald development. In all treatments, superficial scald development proceeded from the distal blossom end towards the proximal stem end of fruits. After 6 months of cold storage at 0 °C, peel browning and membrane leakage, measured as electrical conductivity in situ, were greater at the blossom end than at the stem end of control, ethanol‐ and LO₂‐1C‐pretreated fruits. In LO₂‐20C‐ and 1‐MCP‐pretreated fruits, colour indices (hue angle, lightness and chroma) and electrolyte leakage were similar at both the stem and blossom ends and were associated with less scald development after 6 months at 0 °C. The reduction in scald development was also associated with lower peroxidase and polyphenol oxidase activities in the peel of LO₂‐20C‐ and 1‐MCP‐pretreated fruits. A simple treatment at 20 °C (LO₂‐20C) prior to regular cold storage could also be suitable for organically grown apples that cannot be treated with diphenylamine or 1‐MCP. Copyright © 2007 Society of Chemical Industry     

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     

Effect of chemical treatment on the fatty acid composition of european cucumber fruit during cold storage

Mature green European cucumber fruits (Cucumis sativus L. cv. ‘V-5’), grown in the greenhouse, were treated with butylatedhydroxytoluene (BHT) and calcium chloride, stored at 4°C for 7 days and transferred to 20°C for another 7 days. There were no visible symptoms of chilling injury on cucumbers during cold storage, but surface pitting and shrinking started 2 days after fruits had been transferred to 20°C. Total lipid content was not affected by chilling or chemical treatment, but changes in the lipid classes were observed. Neutral lipids were increased and phospholipids decreased. Laurie and myristic acids were decreased by chilling and chemical treatment, and palmitic acid increased in each lipid class with BHT treatment. Linoleic acid was increased by CaCl₂ treatment in each fraction. Linolenic acid response varied with chilling and chemical treatment. The unsaturation ratio of 18-carbon acids was increased for total lipids and phospholipids.     

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.     

Effect of Chilling Exposure of Tomatoes During Subsequent Ripening

Mature green tomatoes were stored at 4°C, ≥ 90% RH, for up to 39 days and transferred to 21°C, ≥ 90% RH, for further ripening. After 15 days of chilling exposure, stimulation of C₂H₂ production and increased susceptibility to decay were observed when the fruit was ripened at ambient temperatures. As chilling exposure increased, C₂H₄, production upon removal to 21°C returned to the level of the control. Irreversible inhibition of color development was observed in fruit exposed to 4°C for 34 days and an increase in CO₂ production was noted upon warming of tomatoes chilled for 39 days.     

EFFECT OF WAX APPLICATION ON THE QUALITY,LYCOPENE CONTENT AND CHILLING INJURY OF TOMATO FRUIT

ABSTRACT

Waxed and nonwaxed mature green tomato fruits were stored at 12C (nonchilled) or 5C (chilled) for 5, 10, 15 and 20 days before being transferred to 22C for 3, 6, 9 and 12 days, were evaluated for weight loss, chemical composition, skin color, chilling injury (CI) index and pigment content. Waxed fruits showed a delay in weight loss, color development and ripening. The sensitivity of tomato fruit to CI was reduced in waxed fruits, which showed a delay in the appearance of symptoms. A delay in chlorophyll degradation and lycopene synthesis was observed as a result of the use of wax and low temperature. Waxing of tomato fruits allowed their storage at temperatures below critical reducing CI sensitivity and maintaining quality giving more time for marketing.

PRACTICAL APPLICATIONS

Nowadays, local tomato producers use wax on fruits as an everyday practice to carry postharvest fungicides and to improve brightness. They store tomato fruits at nonchilling temperature (12C) because lower temperatures would cause chilling injury and irregular ripening. In this way, it is interesting that waxing tomato fruits allow reducing their storage temperature, protecting them from chilling injury and maintaining their quality and correct color change and ripening; thereby producers and sellers have more days to position their fruits with no extra cost.     

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.     

Effects of temperature on the ripening of mango fruit (mangifera indica L. var. tommy atkins)

The effects of temperature on the ripening of Tommy Atkins mango were studied. Ripening temperature can affect fruit colour, flavour and texture development differently. Fruits at 12°C did not ripen to full eating quality during the 16 days of the experiment. Sugar levels were comparable with those at other temperatures, but acid levels were higher; they retained some green coloration, had lower pulp carotenoids and showed incomplete softening. After 15 days at 17°C, fruits had softened and degreened to an acceptable level but had a poor pulp colour. They were comparatively high in sugars but were also high in acids, resulting in a low sugar:acid ratio. Fruits kept at 22, 27 and 32°C all showed the development of good quality characteristics of high chlorophyll breakdown, high pulp carotenoids, a good texture and a balanced sugar: acid ratio. Similar characteristics were shown at 37°C, although the peel generally appeared mottled and the pulp had slightly lower sugar:acid ratios.     

Quality improvement and extension of shelf life by 1-methylcyclopropene in plum as affected by ripening stage at harvest

Plum (Prunus domestica L. cv. ‘President’) fruits were harvested at two pre-climacteric stages of ripeness (stage 1 and stage 2), and then treated with 1-methylcyclopropene (1-MCP) at two doses (0.3 and 0.5 μl l⁻¹) followed by 1, 2, 3, 4 and 5 weeks of cold storage and their respective 7 days of shelf life at 20 °C. Both 1-MCP doses were effective in terms of ethylene inhibition during shelf life after cold storage, for both ripening stages. Similarly, lower weight losses, delayed colour changes, reduced softening rate and diminished ripening index were found in 1-MCP treated plums than in controls at both stages of ripeness. Hence, during cold storage and shelf life, the efficacy of 1-MCP on ethylene production, weight loss, pulp firmness and ripening index was dose-dependent, while for colour and respiration rate the dose-dependence was only found during shelf life. The storability of 1-MCP treated plums could be extended up to 4 weeks of cold storage plus 7 days at 20 °C, and only up to 1 week of cold storage plus 7 days at 20 °C for controls. Then, 1-MCP is an effective tool for quality improvement and extension of shelf life in plums, and fruit might be harvested in stage 2 of ripening, at which the most desirable organoleptic attributes had been developed on tree.     

Effects of high oxygen concentration on pro- and anti-oxidant enzymes in peach fruits during postharvest periods

Peach fruits (Amygdalus persica cv. Okubao) were stored in air, controlled atmospheres (CA) of 5% O₂ plus 5% CO₂, or CA with high O₂ concentration (70% O₂ plus 0% CO₂ for 15 days, then in CA with 5% O₂ plus 5% CO₂) at 0 °C, to determine the effects of different O₂ and CO₂ atmospheres on the activities of lipoxygenase (LOX), peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT), as well as malondialdehyde (MDA) content and membrane integrity during storage periods with or without 3 days of post-storage ripening at 20 °C. SOD, CAT and POD activities of the fruits stored in air markedly decreased during the first 30 days of storage, while LOX activity increased after 15 days. CA (5% O₂ plus 5% CO₂) reduced chilling injury, and delayed the reduction of SOD, CAT and POD activities compared to the control. CA with high O₂ treatment induced SOD and CAT activities and maintained membrane integrity, but no significant effect on alleviating chilling injury was found compared to CA storage. The results indicated that the decrease of SOD and CAT might contribute to the development of chilling injury in peach fruits.     

Effect of aminoethoxyvinylglycine and low-pressure storage on the post-storage production of aroma volatiles by Golden Delicious apples

Golden Delicious apple fruits untreated (control) or treated pre-harvest with the ethylene biosynthesis inhibitor aminoethoxyvinylglycine (AVG) were stored at 2°C under either ambient pressure or low pressure (6.7 kPa; LPS). The production of aroma volatiles during post-storage periods at 20°C was measured on fruits stored for 3, 5, 7 and 9 months. Aroma production of AVG- or LPS-treated fruits immediately after storage was considerably lower. However, after 14 days at 20°C, aroma production almost reached values for control fruits (AVG fruits had to be treated with 50 μl C₂H₄ litre^?1). After the longer storage this effect of a post-storage period at 20°C declined gradually and finally was almost absent. Only a post-storage period at 2°C in a normal atmosphere followed by a period at 20°C was now able to partially revive long-stored fruits from this ‘residual’ effect of AVG or LPS. It is suggested that changes in the sensitivity of fruits to C₂H₄ are responsible for the observed decline in aroma production.     

Effect of preharvest sprays containing calcium,magnesium and titanium on the quality of peaches and nectarines at harvest and during postharvest storage

Peach and nectarine trees were foliar sprayed with a formulation containing Ca²⁺, Mg²⁺ and Ti⁴⁺. Parameters related to fruit quality were evaluated at harvest, after 7–28 days of cold storage and after subsequent ripening for 4 days at 20 °C (shelf life). At harvest, treated fruits from both cultivars had higher weight and pulp firmness than control fruits, while no effect was observed for either colour, total soluble solid content (TSS) and titratable acidity (TA) or the time required to ripen on the tree. During cold storage, lower levels of weight loss, colour evolution, TSS/TA ratio and ethylene production and higher pulp firmness were found in treated peaches and nectarines compared with control fruits. Also, the storability of treated fruits was extended for up to 14 days more than that of control fruits. During ripening at 20 °C after different periods of cold storage, parameters related to ripening evolved faster in control than in treated fruits. Also, the occurrence of the climacteric peak of ethylene production was delayed and its intensity was lower in treated peaches and nectarines than in controls. Copyright © 2004 Society of Chemical Industry     

Effect of 1-methylcyclopropene on tomato flavour components, shelf life and decay as influenced by harvest maturity and storage temperature

BACKGROUND: In Florida, tomatoes are harvested green (GR), which includes mature green (MG) and immature green (IG) fruits, and stored at low temperature (13 °C), resulting in poor flavour. Flavour improvement might be achieved if fruits were harvested with some colour (to eliminate IG fruits) and/or stored at higher temperature with the ripening inhibitor 1‐methylcyclopropene (1‐MCP). RESULTS: ‘Florida 47’ tomatoes were harvested at GR (MG + IG), breaker (BR), turning (TR) and pink (PK) stages, treated (+) or not (?) with 1‐MCP and stored at 13 and/or 18 °C. 1‐MCP treatment resulted in a gain of up to 6 days of shelf life depending on harvest maturity and storage temperature. Storage at 18 °C rather than 13 °C resulted in an increase in internal red colour, soluble solids (SS)/titratable acidity (TA) ratio and levels of many volatiles studied. The shelf life of BR (+) MCP fruits stored at 13 °C was similar to that of MG fruits. IG fruits exhibited lowest levels of SS, TA and ten volatiles compared with BR fruits. CONCLUSION: Harvesting tomatoes with colour (BR), thereby eliminating IG fruits, and treating with 1‐MCP resulted in better quality with adequate shelf life. Published 2011 by John Wiley & Sons, Ltd.     

The effects of ethanol treatment on the metabolism,shelf life and quality of stored tomatoes at different maturities and temperatures

Two maturity stages of commercially grown tomatoes (breaker and mature green) were exposed to ethanol vapour (2 ml ethanol kg⁻¹ fruit) for 6 h at 20 °C prior to storage at 5 °C and 20 °C. During storage the colour, firmness and composition changes were examined every 3 and 7 days. The results showed that ethanol vapour treatment could significantly slow down the colour changes and softening of both mature green and breaker tomatoes with greater effects when stored at 5 °C. There was no difference between the two maturity stages in retardation of softening during storage; in contrast the maturity stage had a highly significant effect in the colour development of stored tomatoes. When the fruit stored at 5 °C was then held at 20 °C for 7 days the ripening process was accelerated but the fruit did not reach the same level of colour development as the fruit stored at 20 °C continuously. The results suggest that ethanol vapour pretreatment could be used as a cheap and easy method to extend the storage life of tomatoes. © 1999 Society of Chemical Industry