1‐MCP does not improve the shelf‐life of Chinese cabbage

Chinese cabbages cv ‘Yuki’ (Brassica campestris L ssp pekinensis (Lour) Olsson) were treated with air containing 1‐methylcyclopropene (1‐MCP) at concentrations ranging from 0 to 1 µl l^?1 for 12 h at 22°C before storage for 9 weeks at 3°C. Quality, weight loss and trimming loss were measured before treatment, and before and after storage, but were not influenced by 1‐MCP. 1‐MCP at 0.1 and 1.0 µl l^?1 elicited increased levels of respiration and ethylene production which subsided when the cabbages were placed in cold storage. Copyright © 2004 Society of Chemical Industry     

Use of 1‐methylcyclopropene to extend the postharvest life of lettuce

This study examined the effect of fumigation of iceberg lettuce with 1‐methylcyclopropene (1‐MCP) at 0.1–1 µl l^?1 for 1–5 h on the storage life at 5 °C in air containing 0.1 µl l^?1 ethylene. 1‐MCP extended the storage life of shredded lettuce at all concentrations, with the optimal treatment being fumigation with 0.1 µl l^?1 1‐MCP for 1 h at 5 °C, which resulted in an extension in storage life of about 50% over untreated lettuce. Application of this treatment to whole lettuce heads resulted in a 100% increase in storage life. 1‐MCP thus appears to be of considerable commercial potential for the lettuce industry. © 2002 Society of Chemical Industry     

Effect of pre‐ripening chilling temperatures on ripening,shelf life and quality of bananas treated with 1‐methylcyclopropene

Ethylene production, shelf life and fruit quality of Cavendish bananas (cv. Williams), held at different pre‐ripening storage temperatures (5 °C, 10 °C or 15 °C) prior to ethylene and/or 1‐methylcyclopropene (1‐MCP) application, were determined and compared. Levels of ethylene production during ripening were highest for control fruit that had been stored at 5 °C followed by 10 °C and then 15 °C. 1‐MCP treatment (at 300 nL L^?1) had no effect on ethylene production of fruit that had been stored at 10 °C by day 10 of storage, but ethylene production was significantly higher for fruit that had been stored at 15 °C and lower for those stored at 5 °C before 1‐MCP treatment. 1‐MCP also increased shelf life to a greater extent when applied to fruit that had been stored at 10 °C or 15 °C. Even though 1‐MCP had no significant effect on under peel chilling injury, it increased discolouration significantly, regardless of storage temperature. Firmness of 1‐MCP‐treated fruit decreased significantly compared to the control when fruit were held at 5 °C or 15 °C prior to ripening (and 1‐MCP application) but had no effect on fruit stored at 10 °C before ripening. These results indicate that pre‐ripening storage temperature affects ripening, shelf life and quality in both ethylene and 1‐MCP‐treated bananas.     

The effects of 1-methylcyclopropene on peach fruit (Prunus persica L. cv. Jiubao) ripening and disease resistance

In order to learn how 1‐methylcyclopropene (1‐MCP) affects ripening and disease‐resistance of peach fruit (Prunus persica L. cv. Jiubao) after harvest, they were treated with 1‐MCP and some were inoculated with Penicillium expansum. Treating peach fruit with 0.2 μL L^?1 of 1‐MCP at 22 °C for 24 h effectively slowed the decline in fruit firmness. The minimal concentration of 1‐MCP able to inhibit fruit softening was 0.6 μL L^?1. Changes in other parameters related to peach ripening, such as content of soluble solids, total soluble sugar, titratable acidity, soluble pectin and ethylene production were also significantly reduced or delayed by 1‐MCP. Repeated treatment of peach with 1‐MCP resulted in more effective inhibition of ripening. Post‐harvest decay of peach fruit was reduced by treatment with 1‐MCP and disease progress in fruit inoculated with P. expansum was reduced. The activities of phenylalanine ammonialyase, polyphenoloxidase and peroxidase in the inoculated fruit were also enhanced by 1‐MCP.     

1‐METHYLCYCLOPROPENE DELAYS POSTHARVEST RIPENING AND REDUCES DECAY IN HAMI MELON

ABSTRACT

The effects of 1‐methylcyclopropene (1‐MCP) on postharvest ripening and fruit decay in Hami melon were investigated. Melons were treated with 0, 0.1, 1, or 5 µL/L 1‐MCP at 25C for 24 h and then stored at 25C for 16 days. 1‐MCP treatment significantly inhibited respiration rate and ethylene production and delayed their climacteric rise. The treatment also significantly inhibited the decrease of firmness and the increase of electrolyte leakage. Moreover, treatment with 1 or 5 µL/L 1‐MCP maintained significantly higher total soluble solids, vitamin C and chlorophyll contents. In addition, 1‐MCP treatment significantly delayed the incidence of fruit decay and inhibited the increase of decay index. The efficacy of 1‐MCP on delaying postharvest ripening and controlling fruit decay increased with increasing concentration. These results indicate 1‐MCP treatment has great potential to extend shelf‐life and maintain quality in Hami melon during distribution at ambient temperature.

PRACTICAL APPLICATIONS

1‐Methylcyclopropene (1‐MCP) has been commercially used to delay postharvest ripening and extend the storage life on some climacteric fruits. Hami melon has a very short shelf‐life mainly due to fruit ripening and decay, which causes significant economic losses. In this study, a postharvest application of 1‐MCP significantly delayed ripening and reduced fruit decay while maintaining overall quality during storage at 25C. The results will allow long‐distance transportation and marketing of Hami melon and benefit growers, shippers and distributors of this melon fruit.     

Responsiveness of ‘Conference’ pears to 1‐methylcyclopropene: the role of harvest date,orchard location and year

BACKGROUND: In some pear varieties like ‘Conference’, 1‐methylcyclopropene (1‐MCP) treatment often impairs the ripening process indefinitely and the pears remain ‘evergreen’. To better understand this behaviour, the influence of the harvest date, orchard location and year on the effectiveness of 1‐MCP treatment was investigated. RESULTS: Pear softening was inhibited by 1‐MCP treatment and the effectiveness of the treatment depended on harvest date, orchard location and year. Differences in the rate of softening in 1‐MCP‐treated pears depended mainly on the fruit physiological maturity at the moment of 1‐MCP treatment. Accordingly, the combination of the Streif index and ethylene production at harvest appeared to be able to predict the evergreen behaviour. Treated pears with a low Streif index (<0.8) and high ethylene production at harvest (≥0.23 µL kg^?1 h^?1) maintain significantly high firmness but did soften during shelf life, reaching acceptable eating quality. CONCLUSION: Evergreen behaviour was mainly influenced by the initial fruit maturity and especially by the ability of the fruit to produce ethylene at the moment of treatment. More mature fruit were able to overcome the inhibition by 1‐MCP, and the solution to prevent evergreen behaviour therefore lies in the adequate determination of harvest maturity. © 2012 Society of Chemical Industry     

How to prevent ripening blockage in 1-MCP-treated 'Conference' pears

BACKGROUND: Some European pear varieties treated with 1‐methylcyclopropene (1‐MCP) often remain ‘evergreen’, meaning that their ripening process is blocked and does not resume after removal from cold storage. In this work this was confirmed also to be the case in ‘Conference’ pears. To reverse the blockage of ripening 1‐MCP treatments combined with external exogenous ethylene were tested. RESULTS: 1‐MCP treatment of ‘Conference’ pears is very effective in delaying ripening and, more specifically, softening. The same 1‐MCP concentration in different experimental years caused a different response. The higher dose of 1‐MCP (600 nL L^?1) always resulted in irreversible blockage of ripening, whereas the behaviour of fruit receiving a lower dose (300 nL L^?1) depended on the year, and this did not depend on maturity at harvest or on storage conditions. Simultaneous exposure to 1‐MCP and exogenous ethylene significantly affected fruit ripening, allowing significant softening to occur but at a lower rate compared with control fruit. CONCLUSION: The application of exogenous ethylene and 1‐MCP simultaneously after harvest permitted restoration of the ripening process after storage in ‘Conference’ pears, extending the possibility of marketing and consumption. Copyright © 2011 Society of Chemical Industry     

EFFECT OF 1-METHYLCYCLOPROPENE ON AROMA COMPOUNDS IN "BIG TOP" NECTARINES AFTER SHELF LIFE

“Big Top” nectarines picked at two dates (Pick 1 and Pick 2) and treated at harvest with 0 (control), 0.25, 0.5 and 1.0 µL/L 1‐methylcyclopropene (1‐MCP) when fruit ripening had already started were kept at 20 C until control fruit softened. Ethylene production was lowered by 0.25 and 1.0 µL/L doses in Pick 1 fruits and by all the doses in Pick 2 fruits. Fruit softening was delayed, but at the end of shelf life, treated fruits were as soft as the controls. Total volatile production was lowered by 0.25 and 1.0 µL/L doses in Pick 2 fruits. 1‐MCP influenced the aroma composition at the end of shelf life, yet it was not always dose dependent. Consequently, 1‐MCP changed fruit odor pattern by influencing the distribution of lactone odor units, the major odor contributors, reducing the “overmature” note and enhancing the “fresh” note.     

Effects of 1‐methylcyclopropene and gibberellic acid on ripening of Chinese jujube (Zizyphus jujuba M) in relation to quality

Overripening of Chinese jujube (Zizyphus jujuba M) fruit at the postharvest stage usually results in a dramatic decline in quality. The role of 1‐methylcyclopropene (1‐MCP) and gibberellic acid (GA) in fruit ripening of Chinese jujube during storage in relation to quality was investigated. Fruit ripening of jujube was significantly enhanced by ethylene, whereas rates of respiration and ethylene production of the fruit were reduced by 1‐MCP. Treatment with 1‐MCP or GA delayed the decreases in firmness and vitamin C and reduced the level of ethanol. Furthermore, the effectiveness of 1‐MCP was improved by replicate treatments during storage at 20 or 2 °C. In addition, treatment with GA + 1‐MCP resulted in additive beneficial effects on ripening inhibition of the fruit. Copyright © 2003 Society of Chemical Industry     

Pre‐ or post‐harvest applications of putrescine and low temperature storage affect fruit ripening and quality of ‘Angelino’ plum

BACKGROUND: Plum has a very short storage life. The role of pre‐ or post‐harvest applications of putrescine (PUT) and low temperature storage on fruit ripening and quality was investigated in plum fruit (Prunus salicina Lindl. cv. Angelino). RESULTS: Pre‐ or post‐harvest PUT treatments [(0.1, 1.0 or 2.0 mmol L^?1) + 0.01% Tween‐20 as a surfactant] delayed and suppressed the climacteric ethylene production and respiration rate irrespective of the method used to apply PUT. PUT‐treated fruit following low temperature storage (0 ± 1 °C; 90 ± 5% RH), at the ripe stage exhibited higher fruit firmness and titratable acidity (TA), while soluble solids content (SSC), levels of ascorbic acid, total carotenoids and total antioxidants were lower than in untreated fruit. Fruit both sprayed with PUT and stored in low temperature for 6 weeks, at the ripe stage showed reduced respiration rate, delayed changes in the SSC:TA ratio and levels of total carotenoids compared to post‐harvest PUT application. CONCLUSION: Pre‐harvest application of 2.0 mmol L^?1 PUT 1 week before the anticipated commercial harvest was more effective in delaying plum fruit ripening and can be used to extend the storage (0 ± 1 °C) life of plums for up to 6 weeks with minimum losses in fruit quality. Copyright © 2008 Society of Chemical Industry     

Effects of 1‐Methylcyclopropene and Hot Water Quarantine Treatment on Quality of “Keitt” Mangos

The optimal 1‐methylcyclopropene (1‐MCP) treatment to slow ripening of whole “Keitt” mangos, either alone or in combination with hot water treatment (HWT) (prior to or post 1‐MCP) was identified. USDA‐APHIS mandates that HWT can be used for control of fruit flies, but this may affect fruit response to 1‐MCP. Mangos were evaluated by repeated measurement of nondestructive firmness, peel color, and ethylene production on the same mango fruits during 2 wk of ripening at 20 °C after treatment. The magnitude of ethylene production increased as a result of both 1‐MCP and HWT. With softer mangos (65 N), treatment with 1‐MCP alone delayed fruit softening and extended the number of days to full‐ripeness (25 N) from 5 d in untreated fruit to 11 d. For these riper fruit, application of 1‐MCP prior to HWT extended the days to full‐ripeness to 9 d compared with 7 d when 1‐MCP was applied after HWT. With firmer mangos (80 N), 1‐MCP treatments alone prolonged the days to full‐ripeness to 13 d as compared to 11 d for the untreated fruit. There was no significant concentration effect on firmness retention among 1‐MCP treatments (0.5, 1.0, or 10.0 μL/L). HWT resulted in a faster rate of fruit softening, taking only 7 d to reach full‐ripeness. Combining 1‐MCP with HWT reduced the rate of softening compared to HWT alone, resulting in 9 to 11 d to full‐ripeness. Application of 1‐MCP before HWT showed a greater ability to reduce the rate of fruit softening compared with 1‐MCP treatment after HWT.     

Increased ethylene biosynthesis elevates incidence of chilling injury in cold‐stored ‘Amber Jewel’ Japanese plum (Prunus salicina Lindl.) during fruit ripening

Mature ‘Amber Jewel’ Japanese plum fruit were stored at 0 or 5 °C for 3 and 6 weeks to investigate their effects on ethylene (C₂H₄) biosynthesis during ripening at ambient temperature in the development of chilling injury (CI) and fruit quality. CI (internal breakdown and browning) and fruit softening were higher during ripening, in the fruit stored at 5 °C than 0 °C, irrespective of storage period (SP). C₂H₄ production and activities of 1‐aminocyclopropane‐1‐carboxylic acid synthase (ACS) and 1‐aminocyclopropane‐1‐carboxylic acid oxidase (ACO) enzymes, and 1‐aminocyclopropane‐1‐carboxylic acid (ACC) content were higher during ripening in fruit stored at 5 °C than 0 °C. The fruit stored at 5 °C also exhibited higher respiration rate and higher soluble solids concentration/titratable acidity ratio. In conclusion, increase in storage temperature and SP elevates the activities of ACS and ACO enzymes and consequently C₂H₄ production which leads to the development of CI in plum fruit with advancement of ripening.     

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.     

1-MCP suppresses ethylene biosynthesis and delays softening of 'Hami' melon during storage at ambient temperature

BACKGROUND: ‘Hami’ melon is susceptible to softening during postharvest storage at ambient temperature, which enhances postharvest deterioration and limits transportation and storage. To look for a method of softening control, the effect of 1‐methylcyclopropene (1‐MCP) on regulating postharvest softening of ‘Hami’ melon fruit was investigated. RESULTS: 1‐MCP treatment at 1 µL L^?1 significantly reduced ethylene production and maintained higher levels of fruit firmness. It also markedly inhibited the accumulation of 1‐aminocyclopropane‐1‐carboxylic acid (ACC) and maintained lower activities of ACC synthase and ACC oxidase. In addition, 1‐MCP treatment reduced the activities of fruit‐softening enzymes such as pectin methyl esterase, polygalacturonase, endo‐1,4‐β‐glucanase and β‐galactosidase. CONCLUSION: 1‐MCP was effective in suppressing ethylene production and delaying fruit softening in ‘Hami’ melon by decreasing the activities of ethylene biosynthesis enzymes and inhibiting fruit‐softening enzymes. Copyright © 2011 Society of Chemical Industry     

Effects of 1‐MCP applied postharvest on epicuticular wax of apples (Malus domestica Borkh.) during storage

BACKGROUND: Certain apple cultivars develop a greasy feel when overripe. Treating fruits with the ripening inhibitor 1‐methylcyclopropene (1‐MCP, SmartFresh^™) reduces fruit greasiness. This study examines the nature of this phenomenon. ‘Royal Gala’ apples were treated with 1‐MCP at 1.0 µl L⁻¹ following harvest. Periodically, during storage at − 1 °C for up to 6 months, fruits were evaluated for internal ethylene concentration, fruit epicuticular wax morphology (using scanning electron microscopy) and non‐polar organic solvent‐extractable (NPOSE) wax constituents of the cuticle (using gas chromatography/mass spectrometry). RESULTS: In 2004, 1‐MCP strongly inhibited internal ethylene production; however, total weight of NPOSE wax during storage was unaffected by treatment. In 2005, several wax constituents present in both ‘Autumn Gold’ and ‘Royal Gala’ showed differences during storage. In 2006, cuticular wax constituents comprising 80% of the total from ‘Royal Gala’ showed no treatment differences. Although several minor constituents did exhibit differences within treatment and sampling date, these did not appear sufficient to cause the subtle differences in surface wax morphology. CONCLUSION: 1‐MCP strongly inhibited ethylene production and delayed development of certain wax constituents thought responsible for fruit greasiness during cold storage. Subtle differences in surface wax morphology appeared unrelated to wax production. Published in 2008 by John Wiley & Sons, Ltd.     

The role of 1‐methylcyclopropene in lignification and expansin gene expression in peeled water bamboo shoot (Zizania caduciflora L.)

BACKGROUND: Water bamboo shoot (WBS) (Zizania caduciflora L.) is a fleshy aquatic vegetable susceptible to lignification. In this study, effects of 1‐methylcyclopropene (1‐MCP) anti‐ethylene treatment on lignification of harvested peeled WBS were investigated. RESULTS: Peeled shoots were treated with 0.5 µL L^?1 1‐MCP for 20 h at 20 °C and then stored at 20 °C for up to 9 days. Sensory quality, lignin content and activities of the lignification‐associated enzymes peroxidase (POD) and phenylalanine ammonia lyase (PAL) were evaluated. Expression of expansin (ZcExp) was also assessed. 1‐MCP application maintained better sensory quality and inhibited the increase in lignin content. Lessened lignification was associated with reduced activities of POD and PAL. Moreover, 1‐MCP‐treated shoots showed lower expression of the ZcExp gene. CONCLUSION: 1‐MCP pretreatment suppressed the synthesis of lignin and thereby delayed lignification in peeled WBS. Copyright © 2011 Society of Chemical Industry     

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     

Use of very low ethylene levels to extend the postharvest life of Hass avocado fruit

Abstract

Unripe Hass avocados were stored at 0, 10 and 20°C in air containing ethylene at concentrations ranging from 1.0 μl l^‐1 down to 0.005 μl l^‐1. The time to ripen of fruit held continuously at 10 and 20°C increased linearly with a logarithmic decrease in ethylene concentration. Fruit held at 0°C were transferred to 20°C after 2, 4 and 6 weeks and allowed to ripen. While there was no effect of ethylene concentration on ripening time, the severity of chilling injury on fruit held at 0°C for 4 and 6 weeks was reduced with decreasing log ethylene concentration. Analysis of avocados in the wholesale markets at ambient temperature showed an average presence of ethylene at 0.16 μl l^‐1. An increase in storage life would be achieved if levels of ethylene currently present during marketing were reduced.     

Multiple forms of β‐galactosidase from mango (Mangifera indica L Alphonso) fruit pulp

Mango (Mangifera indica L cv Alphonso) was found to contain three isoforms (I, II and III) of β‐galactosidase which, upon purification on Sephadex G‐200, had relative abundances of 44, 38 and 18%, respectively. The total specific activity increased from 20 to 727 µmol l^?1 upon purification, representing a ～36‐fold increase with a recovery of 0.28 U U^?1. The optimal pH for activity and stability were in the ranges 3.6–4.3 and 4–6.2, respectively. The optimal temperature for β‐galactosidase activity was between 42 and 47 °C with T_m in the range 45–51 °C. The K_m for pNP‐β‐galactopyranoside was 0.98, 1.11 and 0.95 mM , and V_max was 0.56, 0.53 and 0.35 µmol pNP min^?1, respectively for isoforms I, II and III. Hg²⁺ caused strong inhibition, whereas galacturonic acid, galactose, xylose, fucose and mannose slightly inhibited the activity of β‐galactosidase isoforms. The apparent molecular weights by GPC were 78, 58 and 91 kDa for isoforms I, II and III, respectively. The ability of these isoforms to degrade the endogenous substrate (arabinogalactan) possibly suggests a role in pectin dissolution during tissue softening/fruit ripening. Copyright © 2004 Society of Chemical Industry