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1.
The regulatory effects of 5 kPa CO2 and of the ethylene action inhibitor, 1-methylcyclopropene (1-MCP) at 0.5 μmol/l on the senescence of harvested mint, Mentha longifolia L. were assessed. Visual parameters of senescence including yellowing, browning, decay and leaf abscission were recorded and scored on scales linking the onset and progression of senescence to marketability. The effects of plant age on the rate of postharvest senescence and on the efficacy of the CO2 and 1-MCP treatments were also investigated. All experiments were repeated with and without the presence of exogenous ethylene. Two experimental formats were used, with 6 days storage at room temperature representing local market conditions, and 6 days cold storage at 1.5 °C followed by 4 days at room temperature representing export market conditions. Sprigs from old plants were no longer of marketable quality after 6 days storage at room temperature. Exogenous ethylene accelerated the onset of senescence causing unacceptably high rates of leaf abscission. Raised levels of CO2 in a controlled atmosphere system were found to be more effective in inhibiting senescence without the presence of exogenous ethylene than pre-treatment with 1-MCP, and no additive effect was found. However in the presence of exogenous ethylene, a combined treatment with 1-MCP together with raised CO2 levels resulted in a significant additive effect in nullifying the ethylene-induced leaf abscission. Respiration rates as measured by CO2 production, and ethylene production, were recorded throughout all experiments. While CO2 levels were not affected by any experimental treatment, ethylene production was elevated in mint sprigs exposed to an initial dose of gaseous 1-MCP, and was further increased under a combined treatment of 1-MCP together with 5 kPa CO2. However in the presence of exogenous ethylene, CO2 strongly suppressed the 1-MCP induced ethylene production.  相似文献   

2.
Ethylene action can be counteracted by 1-methylcyclopropene (1-MCP), which has been used during postharvest storage to maintain quality. In this work, we evaluated the effect of 1-MCP treatments on eggplant quality and phenolic metabolism during refrigerated storage. Eggplants (cv. Lucía) were harvested at commercial maturity, treated with 1-MCP (1 μL/L, 12 h at 20 °C), stored at 10 °C for 21 d and subsequently held at 20 °C for 2 d. Corresponding controls were stored at 10 °C and then transferred to 20 °C for 2 d. During storage calyx color, damage and chlorophyll content, fruit weight loss and firmness, pulp sugar content, acidity, browning and total phenolics were measured. In addition, polyphenol oxidase (PPO), pyrogallol peroxidase (POD), and phenylalanine ammonia-lyase (PAL) activities were evaluated. Fruit calyxes showed reduced damage and remained greener in 1-MCP treated than in control fruit. 1-MCP treated eggplants showed lower weight loss. Pulp browning was clearly prevented as a consequence of 1-MCP exposure, and this was associated with delayed senescence, lower accumulation of total phenolics and reduced activity of PAL. The activity of the enzymes PPO and POD involved in the oxidation of phenolics compounds was also decreased in 1-MCP treated fruit. Results suggest that 1-MCP treatments delay senescence, prevent browning and are beneficial to complement low temperature storage and maintain quality of non-climacteric eggplant fruit.  相似文献   

3.
Fruit of cv. Monthong durian (Durio zibethinus) were treated with 0 (control) or 500 nL L−1 1-MCP for 12 h at 25 °C. Fruit were then stored at 15 °C. To determine storage life, every 3 days a batch of fruit was transferred to 25 °C. The time to ripeness (adequate eating quality) at 25 °C in controls (no 1-MCP) decreased from 5 days in freshly harvested fruit to 3 days after 18 days of storage at 15 °C. Storage life was considered adequate if the time to ripeness was ≥3 days. The storage life at 15 °C of control fruit (no 1-MCP) was therefore 18 days. After the 1-MCP treatment the time to ripeness at 25 °C was 7 days in fresh fruit, while in fruit stored at 15 °C for 30 days it was about 3 days. The storage life at 15 °C of 1-MCP-treated fruit was therefore 30 days. Pulp firmness and pulp total soluble solids (TSS) were determined after 3 day storage intervals at 15 °C and when the fruit was ripe at 25 °C. These parameters were only slightly affected by the 1-MCP treatment. Furthermore, 1-MCP had no effect on pulp color, but delayed yellowing of the fruit exterior. It is concluded that treatment with 1-MCP before storage at 15 °C extended storage life from 18 to 30 days.  相似文献   

4.
Senescence of detached spinach leaves either untreated or treated with 0.1 or 1.0 μL L?1 1-MCP has been investigated. 1-MCP treated leaves had higher chlorophyll content and photosystem II potential quantum yield (Fv/Fm) and lower solute leakage than untreated leaves after storage in darkness at 23 °C for 6 d, indicating a delay of senescence. Ethylene production was increased in spinach supplemented with 1-MCP after 3 d storage and then declined to the rates of untreated leaves. 1-MCP treated spinach had higher ascorbic acid and glutathione concentrations, and a low oxidised/reduced ratio for both antioxidants. Accumulations of ammonium and protein degradation were reduced by 1-MCP. The results presented here indicate that inhibition of ethylene sensitivity can be successfully used to extend the postharvest life of spinach leaves.  相似文献   

5.
This study aimed to investigate the application of microbubble technology for delaying banana ripening. A preparation of 1-MCP designed for use as a form of aqueous micro bubble (MBs) solutions was formulated. Banana fruit were immersed in 500 nL L−1 of aqueous 1-MCP microbubbles (1-MCP-MBs) or fumigated with 500 nL L−1 1-MCP, then stored at 25 °C for 8 days. 1-MCP-MBs were more effective in delaying postharvest ripening than conventional 1-MCP fumigation. 1-MCP-MBs reduced the respiration rate and ethylene production compared to the control and 1-MCP fumigated fruit. Moreover, 1-MCP-MBs delayed yellowing and maintained firmness of banana fruit during storage. These results indicate that 1-MCP-MBs can be used as an alternative method for delaying the postharvest ripening of banana fruit, and its application for other commodities needs to be further elucidated.  相似文献   

6.
Fresh basil (Ocimum basilicum L.) is a highly perishable leafy green vegetable with a storage life of 4–5 d at room temperature. Exposure of basil leaves to temperatures below 12 °C during storage results in chilling injury; therefore, refrigeration cannot be used to extend postharvest life of basil. Typically, leafy vegetables are stored in darkness or extremely low irradiance. Darkness is known to induce senescence, and the initial phase of senescence is reversible by exposure to light. In this work, we studied the effects of low-intensity white light pulses at room temperature on postharvest senescence of basil leaves. Daily exposure for 2 h to 30–37 μmol m−2 s−1 of light was effective to delay postharvest senescence of basil leaves. Chlorophyll and protein levels decreased, ammonium accumulated and leaves developed visual symptoms of deterioration (darkening) during storage in darkness. Light pulses reduced the intensity of these senescence symptoms. The photosynthesis light compensation point of basil leaves was 50 μmol m−2 s−1 i.e., higher than the intensity used in this study, and the effect of treatment with red light was the same as with white light, while far red light was ineffective. Light pulses exerted a local effect on chlorophyll loss, but the effect on protein degradation was systemic (i.e., spreading beyond the illuminated parts of the leaf blade). The results of this study indicate that daily treatment for 2 h with low intensity light (30–37 μmol m−2 s−1 every day) during storage at 20 °C is an effective treatment to delay postharvest senescence of basil leaves. The delay of postharvest senescence by low intensity light pulses seems to be mediated by phytochromes, and it is systemic for protein, and partially systemic for chlorophyll degradation.  相似文献   

7.
Lilium cv. Brindisi inflorescences were stored at 2.5 °C for 5, 10, 15 or 20 d, comparing dry storage with storage of the stem ends in water. Prior to storage, inflorescences were treated with 20 or 100 g L−1 sucrose in water, for 20 h at 20 °C. After storage the inflorescences were individually placed in water at 20 °C. The floral buds were still closed at the end of cold storage. In experiments carried out in summer, the time to bud opening was hastened by storage at 2.5 °C in water, more so after a longer period of cold storage. The time to tepal senescence after cold storage in water decreased with the time of storage. The time to tepal abscission was about 1 day longer than the time to tepal senescence. Repeat experiments in late fall and winter additionally showed early leaf yellowing after cold storage. Compared to the experiments in summer, more desiccated floral buds were found in the fall. Pulse treatment with 100 g L−1 sucrose prior to cold storage reduced the number of desiccated buds. However, leaf yellowing was aggravated by the 100 g L−1 sucrose pulse treatment. Compared to cold storage in water, dry storage at 2.5 °C further hastened the time to bud opening and also further hastened tepal senescence and abscission. Dry storage also produced more buds that desiccated or opened poorly. Sucrose treatment (100 g L−1) alleviated the effects of dry storage on tepal senescence and bud desiccation. The data showed that lily cv. Brindisi inflorescences are prone to chilling injury, but can be stored, depending on the treatment, for 5–10 d, during most of the year.  相似文献   

8.
Guava (Psidium guajava L. cv. ‘Allahabad Safeda’) fruit harvested at the mature light-green stage were exposed to 300 and 600 nL L−1 1-methylcyclopropene (1-MCP) for 6, 12 and 24 h at 20 ± 1 °C, and held in either cold storage (10 °C) for 25 days or ambient conditions (25–29 °C) for 9 days. Most of the physiological and biochemical changes during storage and ripening were affected by 1-MCP in a dose dependent manner. Ethylene production and respiratory rates were significantly suppressed during storage as well as ripening under both the storage conditions depending upon 1-MCP concentration and exposure duration. 1-MCP treatment had a pronounced effect on fruit firmness changes during storage under both the conditions. The reduced changes in the soluble solids contents (SSC), titratable acidity (TA) and vitamin C content showed the effectiveness of 1-MCP in retarding fruit ripening. Vitamin C content in 1-MCP-treated fruit was significantly higher than in non-treated fruit, and those treated with 300 nL L−1 1-MCP for 6 h. The development of chilling injury symptoms was ameliorated to a greater extent in 1-MCP-treated fruit during cold storage and ripening. A significant reduction in the decay incidence of 1-MCP-treated fruit was observed under both the storage conditions. 1-MCP at 600 nL L−1 for 12 h, in combination with cold storage (10 °C) seems a promising way to extend the storage life of guava cv. ‘Allahabad Safeda’ while 1-MCP at 300 nL L−1 for 12 and 24 h or 600 nL L−1 for 6 h, may be used to provide 4–5 days extended marketability of fruit under ambient conditions.  相似文献   

9.
The potential of 1-MCP for controlling ripening in ‘Angeleno’ plum fruit under air and controlled atmosphere (CA) storage was explored, and the possibility that 1-MCP can inhibit development of brown rot caused by Monilinia laxa and internal breakdown in ‘Fortune’ and ‘Angeleno’ plums tested. After harvest, fruit were exposed to 300 and 500 nl l−1 (in 2003) and 500 nl l−1 1-MCP (in 2004) at low temperatures (0–3 °C) for 24 h. After treatment the plums were stored in air at 0 °C and ‘Angeleno’ fruit were also stored in CA storage (1.8% O2 + 2.5% CO2). Following storage, fruit were kept at 20 °C. In ‘Angeleno’ fruit, 1-MCP was effective in delaying the loss of firmness and colour changes during holding at 20 °C. 1-MCP reduced brown rot in fruit stored in CA but no significant reduction was found in air storage. Internal breakdown, a major physiological storage disorder in plums, was inhibited by 1-MCP treatment. Furthermore, since 1-MCP applied in air storage showed better results than the control in CA conditions, an application of 1-MCP before air storage could be the best way to reduce the ripening process for short or medium storage periods (40 and 60 days). CA storage plus 1-MCP treatment could be used for long periods (80 days).  相似文献   

10.
Ethylene production is enhanced by wounding during fresh-cut processing and the accumulation of this gas within the packages of fresh-cut fruit can be detrimental to their quality and shelf-life. The effect of 1-methylcyclopropene (1-MCP), an ethylene action blocker, applied before or after processing, on the quality of fresh-cut kiwifruit, mangoes and persimmons was evaluated during storage at 5 °C. Fresh-cut ‘Hayward’ kiwifruit slices softened at a slower rate and their ethylene production rate was decreased in response to 1-MCP application (1 μL L−1 for 6 h at 10 °C) either before or after processing. A 2-min dip in 0.09 M (1%, w/v) CaCl2 synergistically increased the effect of 1-MCP on firmness retention and 1-MCP did not affect the color (L* value) of fresh-cut kiwifruit slices. Softening and browning (decreasing L* value) were delayed when 1-MCP was applied directly on fresh-cut ‘Kent’ and ‘Keitt’ mango slices. Respiration rate of mango slices was not influenced by 1-MCP whereas the ethylene production was affected only towards the end of their shelf-life. Fresh-cut ‘Fuyu’ persimmons treated with 1-MCP after processing presented higher ethylene production rate, slower softening rate and slower darkening of color (decrease in L* value), whereas the respiration rate was not affected.  相似文献   

11.
This study investigated the effects of ethylene in storage and 1-methylcyclopropene (1-MCP) pretreatment on post-storage leaf senescence as measured by changes in photosynthesis and chloroplast degradation of two Aglaonema cultivars. Potted plants of ‘Chalit's Fantasy’ and ‘White Tip’ with or without 1-MCP treatment (600 nL L−1 1-MCP for 6 h) were exposed to 3.0 μL L−1 ethylene, while being stored for 5 d at 16 °C in the dark, and then placed under an indoor environment for further observation. Plants that did not receive 1-MCP and ethylene served as controls. Ethylene did not affect the stomatal conductance in either cultivar. Ethylene reduced the net CO2 assimilation rate and Fv/Fm (potential photochemical efficiency of photosystem II) in ‘White Tip’, but not in ‘Chalit's Fantasy’. Chloroplast number in a palisade or spongy mesophyll cell did not differ among treatments in ‘Chalit's Fantasy’. However, ethylene-treated ‘White Tip’ had fewer chloroplasts in the mesophyll cells, had more and larger plastoglobules in the chloroplasts, and had looser granal stacking with enlarged thylakoid lumens. ‘Chalit's Fantasy’ plants that were treated with 1-MCP before exposure to ethylene had higher net CO2 assimilation rates and stomatal conductance than the control or plants that were exposed to ethylene without 1-MCP pretreatment. 1-MCP pretreatment mitigated the injurious effect of ethylene on ‘White Tip’ by increasing net CO2 assimilation rate and Fv/Fm, and maintaining the quantity and structural integrity of chloroplasts.  相似文献   

12.
Gaseous 1-methylcyclopropene (1-MCP) has been widely employed for delaying ripening and senescence of harvested fruit and vegetables; however, details on ingress of gaseous1-MCP in plant tissues, which might contribute to differences in responsiveness of different horticultural commodities to 1-MCP, have not been reported. In this study, we used spinach and bok choi leaves, disks from tomato epidermis, stem-scar and avocado-exocarp tissues, and whole tomato fruit to examine ingress of gaseous 1-MCP. Using a dual-flask system, equilibration of 20 μL L−1 (831 μmol m−3) 1-MCP through leaf tissue was reached within 1–2 h, and paralleled 1-MCP transfer through glass-fiber filter paper. For disks derived from fruit tissues, changes in 1-MCP concentrations in the dual-flask system showed anomalous patterns, declining as much as 70% in source flasks with negligible accumulation in sink flasks. The pattern of 1-MCP distribution was markedly different from that of ethylene, which approached equal distribution with tomato stem-scar and avocado exocarp but not tomato epidermis tissues. 1-MCP ingress was further addressed by exposing whole tomato fruit to 20 μL L−1 1-MCP followed by sampling of internal fruit atmosphere. Tomato fruit accumulated internal gaseous 1-MCP rapidly, reaching approximately 8–9 μL L−1 within 3–6 h at 20 °C. Internal 1-MCP concentration ([1-MCP]) declined around 74 and 94% at 1 and 3 h after exposure, respectively. Ingress was similar at all ripening stages and reduced by 45% in fruit coated with commercial wax. Blocking 1-MCP ingress through stem- and blossom-scar tissues reduced accumulation by around 60%, indicating that ingress also occurs through epidermal tissue. Fruit preloaded with 1-MCP and immersed in water for 2 h retained about 45% of post-exposure gaseous [1-MCP], indicating that 1-MCP is not rapidly sorbed or metabolized by whole tomato fruit. Rapid ingress of gaseous 1-MCP was also observed in tomato fruit exposed to aqueous 1-MCP. Both accumulation and post-exposure decline in internal gaseous [1-MCP] are likely to vary among different fruit and vegetables in accordance with inherent sorption-capacity, surface properties (e.g., waxes, stoma), volume and continuity of gas-filled intercellular spaces, and tissue hydration.  相似文献   

13.
Fruit of cv. Gros Michel banana were treated with 1-MCP (1000 nL L−1 for 4 h at 25 °C) and then packed in non-perforated polyethylene (PE) bags for modified atmosphere storage (MAP). The bags were placed in corrugated cardboard boxes and stored at 14 °C. Fruit were removed from cool storage and ripened at room temperature using ethephon. The length of storage life was determined by the change in peel color to yellow, after this ethephon treatment. Fruit treated with 1-MCP + MAP had a storage life of 100 days. The storage life of control fruit (no 1-MCP and no MAP) was 20 days. Fruit held in PE bags without 1-MCP treatment had a 40 day storage life, and the same was found in fruit treated with 1-MCP but without PE bags. 1-MCP is an inhibitor of ethylene action, but also inhibited ethylene production, mainly through inhibition of ACC oxidase activity in the peel. MAP inhibited ethylene production mainly through inhibition of ACC oxidase, both in the peel and pulp. The combination of 1-MCP treatment and MAP storage resulted in much lower ethylene production due to inhibition of both ACC synthase and ACC oxidase activity.  相似文献   

14.
The effects of postharvest application of aminoethoxyvinylglycine (AVG) and 1-methylcyclopropene (1-MCP) on ethylene production and fruit quality, and thus on transportation and shelf-life, were evaluated in melting-flesh peaches. AVG (150 mg L−1) significantly reduced ethylene production, and the effect was enhanced in combination with 1-MCP (1 μL L−1). However, fruit treated with AVG alone softened to untreated control levels 2 d after harvest (DAH). Treatment with 1-MCP significantly reduced the rate of softening until 2 DAH, but the fruit rapidly softened thereafter, and reached untreated control levels by 4 DAH. A combination of AVG and 1-MCP significantly reduced fruit tissue softening throughout ripening. The effect of each chemical on flesh firmness indicated that 1-MCP affected fruit response in the early stages of ripening up to 4 DAH, and AVG significantly reduced softening in the latter stages from 4 to 9 DAH. Peaches treated with AVG and 1-MCP retained their ground color during ripening, but the effect of each chemical on color is unclear. The present study indicates that combined treatment with AVG and 1-MCP significantly delays the ripening of melting-flesh peaches.  相似文献   

15.
The effect of multiple 1-MCP treatments prior to the establishment of controlled atmosphere (CA) storage on the quality of ‘McIntosh’ and ‘Empire’ apples [Malus × sylvestris (L.) Mill. var. domestica (Borkh.) Mansf.] was investigated. Fruit were harvested on three occasions over a 1 week period, and at each harvest cooled overnight and 1-MCP applied the following day. Fruit from the first or second harvests were treated again or for the first time when fruit from each successive harvest was treated. CA conditions were established after the last 1-MCP treatment and fruit were stored for up to 8 months. Delays in 1-MCP application generally resulted in progressively higher internal ethylene concentrations (IECs) at the time of treatment and lower firmness both at the time of treatment and after storage. Multiple 1-MCP applications kept IECs low and maintained firmness compared with single applications that were applied after 4 d. For ‘McIntosh’, external CO2 injury was more prevalent after storage if fruit were treated without delays after harvest for earlier harvests while later harvests were less affected. For ‘Empire’, flesh browning was more prevalent in fruit from later harvests and 1-MCP treated fruit had higher levels than untreated fruit. Either early 1-MCP treatment or multiple treatments reduced senescent breakdown in ‘McIntosh’, and core browning and greasiness in ‘Empire’.  相似文献   

16.
To investigate the effects of postharvest application of 1-MCP on ethylene production and fruit softening, activities of ethylene biosynthesis and fruit softening enzymes were measured during postharvest ripening of plum (Prunus salicina Lindl. cv. Tegan Blue) fruit after being exposed to 1-MCP (0, 0.5, 1.0 or 2.0 μL L−1) at 20 ± 1 °C for 24 h. Following the treatments, fruit were allowed to ripen at ambient temperature (20 ± 1 °C), and ethylene production in fruit, activities of ACS and ACO, ACC content and fruit softening enzymes (PE, EGase, exo-PG and endo-PG) in fruit skin and pulp were recorded at different intervals. Postharvest application of 1-MCP significantly delayed and suppressed the climacteric ethylene production with reduction in the activities of ethylene biosynthesis enzymes (ACS, ACO) and ACC content, and fruit softening enzymes (PE, EGase, exo-PG and endo-PG) in the skin as well as in pulp tissues. The reduction was more pronounced with increased concentrations of 1-MCP. 1-MCP treated fruit showed different rates of fruit softening and activities of ethylene biosynthesis enzymes in the skin and pulp tissues which warrant further investigation on regulation of gene expression related to these enzymes with the inhibitory effect of 1-MCP.  相似文献   

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19.
After three months storage at 0.5 °C one quarter of a lot of ‘Anjou’ pears (Pyrus communis L.) were treated with 1 μL L?1 of 1-methylcyclopropane (1-MCP) for 8 h at 20 °C and three quarters of the fruit were left untreated at 20 °C for the same time. Treated and untreated pears were then sliced, dipped in a commercial anti-browning solution and packaged in modified atmospheric bags. Packages, containing slices from 1-MCP treated fruit, were labelled as MCP1. Slices from two thirds of the untreated fruit had one of two secondary treatments applied: (1) multi-functional co-release sachets added to the package at the time of sealing (NT), or (2) an injection of 1-MCP to sealed packages to achieve a final concentration of 1 μL L?1 (MCP2). The last third of the slices from the untreated lot of pears were sealed into packages with no further treatment (CK). The packages were kept at 5 °C. In-package ethylene concentrations were significantly lower for the NT treated slices. NT also significantly delayed and reduced net oxygen consumption in the package headspace compared with other treatments. The NT treatment also reduced incidence of browning induced by enzymes of microbial origin, termed secondary browning (SB), and better maintained the measured juiciness of slices. In contrast, the CK, MCP1 and MCP2 treatments showed a more rapid appearance and severity of SB. Slices in packages treated with NT retained higher tissue levels of butyl, hexyl and pentyl acetate, 6-methyl-5-hepten-2-one, butanol and hexanol during storage than any of the other three treatments.  相似文献   

20.
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