Climacteric Peak Research Articles

Correlation between ethylene emission and skin colour changes during papaya (Carica papaya L.) fruit ripening

The skin colour changes and ethylene emission rates were monitored during papaya (C. papaya L.) fruit ripening. Two groups of papaya ('Formosa' and 'Solo') were applied in this study. The total colour difference was used as measured parameter and the corresponding half time of its saturation was used as correlation parameter. A high correlation factor between the saturation half time and corresponding climacteric peak time was found. It was concluded that high ethylene emission rate in 'Solo' fruit promotes a quick change of the total colour difference.

TOMATO FRUIT QUALITY RETENTION DURING STORAGE BY 1-MCP TREATMENT AS AFFECTED BY CULTIVAR AND RIPENING STAGE AT HARVEST

Four tomato cultivars ('Daniela', 'Patrona', 'Cherry' and 'Raf') at two ripening stages (pink and red, for the 3 first cultivars, and breaker and light pink for 'Raf') were treated with two 1-MCP doses (0.3 and 0.5 μL L -1 ). Fruit were stored at 10°C and 90% RH for 4 weeks. Samples were taken weekly, half to study fruit quality parameters during cold storage and half left at 20°C for 1 week (shelf- life). Weight loss, colour, ethylene production, °Brix/titratable acidity ratio, firmness and decay were analysed. For all cultivars and ripening stages, the treatments were effective in reducing weight loss and rate of softening, and retarding colour changes and °Brix/titratable acidity ratio changes, either during cold storage or shelf-life. A positive relationship could be established between 1-MCP dose and the different analysed parameters, the 0.5 μL L -1 dose being the most effective during cold storage and further shelf-life. For most cultivars and ripening stages, no reduction of ethylene production was detected, as a consequence of 1-MCP treatments. This might be because in tomato fruit, the ethylene climacteric peak occurred at the breaker stage, and thus at harvest all cultivars were climacteric, and only decreases in ethylene production were observed during cold storage and shelf-life. However, blocking of the ethylene receptors by 1-MCP treatment inhibited changes in fruit quality properties which are likely to be ethylene-dependent. Also, a reduction in decay was observed for those tomato fruit treated with 1-MCP, especially with the 0.5 μL L -1 1-MCP dose and harvested at the late ripening stage; almost no decay was observed during cold storage and between 2-4 fold lower recorded during shelf-life.

The effects of 1‐methylcyclopropene treatment on the shelf life and quality of cherry tomato (Lycopersicon esculentum var. cerasiforme) fruit

SummaryThe use of 1‐methylcyclopropene (1‐MCP) to extend the shelf life of cherry tomato (Lycopersicon esculentum var. cerasiforme) was investigated. Higher concentrations of 1‐MCP delayed the ethylene induced climacteric peaks in mature green (MG) and breaker (BR) fruits. Thirteen days after treatment, control fruits were 55% as firm as fruit treated with 0.11 μL L−1 1‐MCP. The initiation of fruit softening, chlorophyll degradation and accumulation of lycopene and carotenoids was delayed in treated fruits. Higher 1‐MCP concentrations inhibited the accumulation of lycopene and carotene such that the colour of the fruit did not reach that of control fruit. Treatment of MG cherry tomatoes with 1‐MCP enhanced shelf life optimally, while treatment of BR fruits was beneficial where full colour and high content of lycopene and carotenoids is important. Differentiation of the different stages of ripening before application of 1‐MCP is needed in order to succeed in accomplishing different postharvest objectives.

The climacteric-like behaviour of young, mature and wounded citrus leaves

Although leaves and other vegetative tissues are generally considered as non-climacteric, citrus leaves show a climacteric system II behaviour after detachment. Upon harvest, young, fully expanded 'Valencia' orange (Citrus sinensis) leaves ( approximately 60-d-old) exhibited two phases of ethylene production. The first phase, up to 6 d after detachment, was characterized by a low and constant ethylene production (system I pathway), associated with a constitutive expression of ACC synthase 2 (CsACS2), CsERS1, and CsETR1. ACC synthase 1 (CsACS1) was not expressed during this phase and autoinhibition of ethylene production was apparent following treatment with exogenous ethylene or propylene. The second phase, 7-12 d after detachment, was characterized by a climacteric rise in ethylene production, preceded by the induction of CsACS1 and ACC oxidase 1 (CsACO1) gene expression in the system II pathway. This induction was accelerated and augmented by exogenous ethylene or propylene, indicating an autocatalytic system II ethylene biosynthesis. Mature leaves (6-8-months-old) behaved similarly, except that the climacteric peak in ethylene production occurred earlier (day 5). Young and mature leaves varied in the timing of the climacteric ethylene rise and CsACS1 and CsACO1 induction. The two phases of ethylene production, system I and system II, were also detected in wounded leaf discs of both young and mature leaves. The first phase peaked 15 min after excision and the second phase peaked after 6 h.

Ripening and quality responses of mamey sapote fruit to postharvest wax and 1-methylcyclopropene treatments

Abstract Mamey sapote (Pouteria sapote (Jacq.) H.E. Moore and Stearn) fruit is highly appreciated in the Caribbean region; however, marketable life is significantly limited by abrupt softening during postharvest handling. Postharvest wax and 1-methylcyclopropene (1-MCP) treatments were evaluated for potential of extending mamey sapote postharvest life. Fruit of the cv. Magana were harvested at mature green (G), light orange (LO) and orange (O) stages of the pulp color, and brushed to remove excess epidermal fiber. Waxed (carnauba emulsion) and unwaxed fruit (G and LO stages) were held at 13 °C for 7 days, then transferred to 20 °C for ripening; those at O stage were held constantly at 20 °C. In a subsequent test, ‘Magana’ fruit were harvested at a preclimacteric stage (LO), brushed, and treated with ±carnauba wax and ±1-MCP (1 μl l−1 at 20 °C for 24 h). Fruit from all treatments were subsequently stored at 20 °C and 85–90% relative humidity. Unwaxed ‘Magana’ fruit reached climacteric maxima in 10–11 days, irrespective of harvest maturity or storage regime (Exp. 1). At 20 °C, peak CO2 production ranged from 90 to 137 ml kg−1 h−1 and peak ethylene production from 116 to 209 μl kg−1 h−1, respectively. Waxed fruit generally had higher CO2 and C2H4 production rates than unwaxed fruit. When LO fruit was stored continuously at 20 °C (Exp. 2), wax treatment alone hastened the onset of respiration and ethylene climacteric peaks by 5 days over unwaxed fruit. 1-MCP treatment alone delayed the onset of respiration and ethylene climacteric maxima by 6 and 5 days, respectively. Marketable life for wax-only fruit stored continuously at 20 °C was 10 days, while that for control, wax + 1-MCP and 1-MCP-only fruit was 13, 14, and 14 days, respectively. Mamey sapote fruit treated with wax lost less weight during continuous storage at 20 °C. At the full-ripe stage, no treatment effects were noted for pulp soluble solids content (23.4%) or pH (5.7). Mamey sapote fruit treated with wax + 1-MCP, however, retained total titratable acidity (0.25%) and lost less acid during storage than wax-only fruit (0.14%).

EFFECT OF SUCROSE ON ETHYLENE BIOSYNTHESIS IN CUT SPRAY CARNATION FLOWERS

Various concentrations of sucrose (0, 2.5, 5.0, 7.5, 10.0 or 15.0%) were fed to cut spray carnation flowers cv. Barbara. Vase life, ethylene production, ACC production and ACO activity were measured. Sucrose at 5.0% extended flower vase life the most. Its effect on vase life was associated with a delay in the petal climacteric ethylene peak. The same delay was found in gynoecium ethylene production. It is concluded that sucrose apparently inhibits climacteric ethylene production by inhibiting ACO activity. This effect may be indirect, by affecting gene expression.

Suppression of Ripening and Softening of `Galia' Melons by 1-Methylcyclopropene Applied at Preripe or Ripe Stages of Development

`Galia' (Cucumis melo var. reticulatus L. Naud. `Galia') melons exhibit relatively short postharvest longevity, limited in large part by the rapid softening of this high quality melon. The present study was performed to characterize the physiological responses of `Galia' fruit harvested at green (preripe) and yellow (advanced ripening) stages and treated with 1-methylcyclopropene (1-MCP) before storage at 20 °C. Treatment with 1.5 μL·L-1 1-MCP before storage delayed the climacteric peaks of respiration and ethylene production of green fruit by 11 and 6 d, respectively, and also significantly suppressed respiration and ethylene production maxima. Softening of both green and yellow fruit was significantly delayed by 1-MCP. During the first 5 d at 20 °C, the firmness of green control fruit declined 66% while 1-MCP-treated fruit declined 46%. By day 11, firmness of control and 1-MCP-treated green fruit had declined about 90% and 75%, respectively. The firmness of control yellow fruit stored at 20 °C declined 70% within 5 d while 1-MCP-treated fruit declined 30%. The 1-MCP-induced firmness retention was accompanied by significant suppression of electrolyte leakage of mesocarp tissue, providing evidence that membrane dysfunction might contribute to softening of `Galia' melons. The mesocarp of fruit harvested green and treated with 1-MCP eventually ripened to acceptable quality; however, under the treatment conditions (1.5 μL·L-1 1-MCP, 24 h) used in this study, irreversible suppression of surface color development was noted. The disparity in ripening recovery between mesocarp versus epidermal tissue was considerably less evident for fruit harvested and treated with 1-MCP at an advanced stage of development. The commercial use of 1-MCP with `Galia'-type melons should prove of immense benefit in long-term storage and/or export situations, and allow for retention of quality and handling tolerance for fruit harvested at more advanced stages of ripening.

Ethylene Production and Vase Life of Cut Carnation Flowers under High Temperature Conditions

Cut flowers of carnation ‘Excerea’, treated with or without silver thiosulfate (STS) showed the same vase life as when kept in Misaki, a commercial preservative, or 1 to 2% fructose with germicide at 32°C. In-rolling of petals did not occur at 32°C until day 14, even though flowers were not treated with STS. However, flowers without STS treatment showed in-rolling on day 9 at 24°C. Flowers without STS treatment, reached a climacteric peak of ethylene during day 8 to 10 at 24°C, whereas flowers at 32°C produced very little ethylene. Flowers, kept at 32°C and then transferred to 24°C, showed a climacteric peak of ethylene, but the peak was lower than that at continuous 24°C. Flowers, kept at 24°C for 1-5 days and then transferred to 32°C, produced very little ethylene. These results suggest that high-temperature keeping conditions inhibit ethylene production in cut carnation flowers.

Effect of phytohormones on pectate lyase activity in ripening Musa acuminata

A differential activity peak of pectate lyase (PEL) was observed during ripening of banana fruits ( Musa acuminata Harichhal) receiving different hormone treatments. Exposure of fruits to 25 ppm ethylene for 24 h, as well as dipping of M. acuminata fruits in 1 mM 2,4-dichlorophenoxy acetic acid (2,4-D) for 4 h, hastened fruit ripening. Both PEL activity peak and climacteric peak were observed on the 4th and 10th days of treatment with ethylene and 2,4-D, respectively, compared to the 16th day in control fruits. Gibberellic acid (GA) treatment retarded fruit ripening and both PEL activity and climacteric peaks were observed on the 19th day. Treatment of fruits with ethylene or 2,4-D also advanced the appearance of a polygalacturonase (PG) peak and GA delayed its appearance, but the activity peaks always appeared in post-climacteric fruits, in contrast to PEL activity peaks coinciding with the respiratory peaks.

Could the 1-MCP treatment effectiveness in plum be affected by packaging?

Abstract Plum fruit (Prunus domestica L., cv. ‘President’) were harvested at a pre-climacteric stage of ripeness. They were packaged in small cardboard boxes or in bulk, and treated with 1-methylcyclopropene (1-MCP) at 0.3 or 0.5 μl l−1 for 24 h. Then fruit were stored at 1 °C during 0–5 weeks, and weekly removed for 7 days at 20 °C for a shelf-life period. All 1-MCP treatments inhibited the typical ethylene climacteric peak and delayed the change in properties related to fruit ripening, such as fruit softening, decrease in titratable acidity and colour chroma index, and increase in soluble solids content. Nevertheless, these effects were significantly higher when 1-MCP application was performed in plums packaged in small and ventilated cardboard boxes than in bulk, and the storability was extended for up to 5 weeks of cold storage plus 7 days at 20 °C. Thus, for commercial purposes, and in order to obtain the maximum benefit of the 1-MCP, treatments should be carried out in plums already packaged, since gas could diffuse homogenously to the fruit surface, and all ethylene receptors would be blocked by 1-MCP.

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

AbstractPeach 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

POSTHARVEST RIPENING OF ‘TOMMY ATKINS’ MANGOES ON TWO MATURATION STAGES TREATED WITH 1-MCP

The effects of postharvest application of 1-MCP on fruit ripening were evaluated in 'Tommy Atkins' mangoes harvested at two stages of maturity as defined by growers' standards based on pulp color. Fruits were exposed to 1-MCP for 12 hours in sealed containers, and then stored for up to 14 days at room temperature. The experiment was carried out as a 2x4x6 factorial design, with two stages of maturity (S2 and S3), four concentrations of 1-MCP (0, 30, 120 and 240 nL.L 1- ) and six evaluation periods (0, 4, 7, 9, 12 and 14 days), with five replications. Respiration rate, weight loss, pulp firmness, pH, total titratable acidity (TTA), total soluble solids (TSS) and TSS/TTA ratio were evaluated. Effects of 1-MCP concentrations of 30 and 120 nL.L -1 were noticed on ripening of mangoes harvested at S2, as delayed climacteric peak, reduced respiration rate, reduced fresh weight loss, firmer pulpand higher total titratable acidity as compared to non-treated fruits. Generally, fruits harvested in more advanced maturity stages are less susceptible to 1-MCP application. 'Tommy Atkins mangoes harvested at S3 maturity stage are not significantly affected by 1-MCP applications. Nevertheless a trend to delay ripening could be noticed.

Electrode Configuration and Polarity Effects on Physicochemical Properties of Electric Field Treated Apples Post Harvest

The trial compared the use of needle and plate electrode configuration (corona discharge) with parallel plate electrode configuration for postharvest treatment of apples ( Malus domestica Borkh, cv. Fuji and Golden Delicious) during storage. The effect of electric field direction on physicochemical properties of fruit was also investigated. In Fuji apple storage, physicochemical parameters varied with water core content. Treatment of apples kept between parallel plate electric field suppressed weight loss unlike in the corona discharge field. Respiration and climacteric peak were suppressed in apples kept between parallel plate electric field. In corona discharge, after 7 days more respiration was noted in the treated than the untreated samples. The ‘reversed’ electric field treatment (apples on cathode plate) gave higher weight loss than the corresponding ‘forward’ electric field treatment (apples on anode plate) in the parallel plate arrangement. In corona discharge, the multiple of evaporation rate (ratio of water loss in treated sample to that of untreated sample) was higher for the ‘forward’ electric field direction (negative needle polarity) than the ‘reversed’ electric field direction (positive needle polarity).

Effects of silverleaf whitefly feeding on tomato fruit ripening

Silverleaf whitefly (SLW) (Bemisia argentifolii Bellows and Perring) feeding on tomato (Lycopersicon esculentum Mill.) plants induces a disorder in the fruit known as irregular ripening. The effects of silverleaf whitefly feeding on ripening of tomato fruit both attached to and detached from the plant are described. ‘Florida Petite’ tomatoes free of SLW, attached to the plant, began an ethylene climacteric between 40 and 45 days after anthesis (DAA), coincident with a rapid increase in red color and loss of firmness. The ethylene climacteric began between 45 and 50 DAA in tomato fruit from plants infested with SLW, and the fruit developed less red color and softened less than did fruit from plants free of SLW. Fruit harvested 45 DAA from plants free of SLW reached the respiratory and ethylene climacteric peak 3 days after harvest, developed normal red color, and softened similar to fruit ripened on the plant. In contrast, fruit harvested 45, 50 or 55 DAA from SLW-infested plants showed no respiratory or ethylene climacteric, had poor color development, and did not soften to the same extent as did fruit from plants free of SLW.

Effects of exogenous putrescine on improving shelf life of four plum cultivars

Abstract Four plum cultivars (‘Golden Japan’, ‘Black Diamond’, ‘Black Star’ and ‘Santa Rosa’) were treated with 1 mM putrescine, and then stored at 20 °C. Storage duration was different for each cultivar, but the effect of putrescine in terms of increased shelf life, delayed ripening process, and higher quality attributes when compared with controls was significant for all cultivars. In addition, putrescine-treated plums showed delay and/or reduction on ethylene production, the intensity of reduction being dependent on the maximum of ethylene production at the climacteric peak. Also, higher fruit and flesh firmness, lower soluble solids concentration and titratable acidity evolution, reduced weight loss and delayed colour changes were found after putrescine treatment during storage. Moreover, higher putrescine and spermidine levels (free forms) were observed in putrescine-treated plums. The results revealed that plum storability could be extended by putrescine treatment due to its effect on delaying the ripening processes.

Ripening pawpaw fruit exhibit respiratory and ethylene climacterics

Abstract The ripening behavior of the native American pawpaw (Asimina triloba (L.) Dunal.) fruit was studied immediately after harvest and after 1 month of 4 °C storage. Fruit were harvested at two different maturity stages. Fruit that were unripe (minimal softening evident) at harvest exhibited respiratory and ethylene climacterics at 3 and 5 days postharvest, respectively, at ambient temperature, and a precipitous decline in fruit firmness was evident prior to the climacteric peaks. Fruit classified as having commenced ripening (some softening evident) at harvest exhibited both respiratory and ethylene climacteric peaks at 3 day at ambient storage temperature. Fruit in cold storage at 4 °C for 28 days exhibited minimal to no loss of firmness, and upon removal to ambient temperature both respiratory and ethylene climacterics occurred within 7 days for both harvest maturities. The maximum rates of respiration and ethylene production in these studies were: CO2 production 90 mg kg−1 h−1 and C2H4 production 14.4 μg kg−1 h−1, respectively. These results indicate that pawpaw fruit ripening is climacteric.

Respiration and climacteric patterns of apples treated with continuous and intermittent direct current electric field

Negative corona discharge and parallel plate electrode configurations were used to investigate the efficacy of intermittent and continuous electric field treatment in retardation of respiration and suppression of climacteric peak in apples ( Malus domestica Borkh, c.v. Fuji, Sansa, Starking Delicious and Golden Delicious) post-harvest. Direct current electric field was generated by a 50 Hz alternating current supply. The electrodes were kept 8 cm apart. Climacteric peak CO 2 evolution in apples stored at 0, 10 and 23 °C were affected by high electric field treatment. Treatment of apples in high electric field suppressed CO 2 evolution at climacteric peak. Both treatments in a uniform field of parallel aluminum plate electrode and a negative corona discharge field retarded respiration in apples. Further, the direction of electric field using the parallel aluminum plate electrode influenced apple respiration.

Pectic polysaccharides during ripening of mango (Mangifera indica L)

AbstractThe content of pectin decreased from 2.0 to 0.7% fresh weight (FW) and there was a concomitant increase in free galacturonic acid from 36 to 168 mg% FW during ripening of mango. Ion exchange chromatography on DEAE/cellulose resolved the pectic fraction into seven distinct peaks, with all of them showing a drastic decrease in pectin content and molecular weight as fruit ripening progressed, which indicated significant depolymerisation in vivo. Fraction I appeared to be an arabinogalactan‐type polymer, while fractions II and III were heterogalacturonans containing more than 60% galacturonic acid. Hydrolases implicated in pectin depolymerisation were polygalacturonase (PG), pectin methyl esterase (PME), galactanase, arabinanase and β‐galactosidase. They all showed a climacteric peak in activity during ripening, except for PME which showed a continuous decrease in activity after an initial increase. These results are discussed in the light of fruit softening during ripening. Copyright © 2003 Society of Chemical Industry

Changes in pectic enzymes and cellulase activity during guava fruit ripening

Changes in activities of the cell wall degrading enzymes, pectinesterase (PE), polygalacturonase (PG) and cellulase, were studied during the ripening of white- and pink-fleshed guava fruit types. PE activity increased in both guava types up to the climacteric peak of respiration (flesh firmness of 1.21 kg/cm 2) and subsequently decreased. Activities of PG and cellulase increased progressively during the ripening of both guava fruit types with a high correlation between the increase in the activity of the two enzymes and the loss of fruit flesh firmness.

Pectate lyase activity during ripening of banana fruit

Pectate lyase (PEL) activity was demonstrated in ripe banana fruits on supplementing the homogenizing medium with cysteine and Triton X-100. The enzyme was characterized on the basis of alkaline pH optimum, elimination of the activity by EDTA and activation by Ca 2+. PEL activity was not detected in preclimacteric banana fruits . PEL activity increased progressively from early climacteric and reached maximum level at climacteric peak and declined in post climacteric and over ripened fruits. Replacing pectate with pectin in PEL assay manifested enzyme activity even in preclimacteric fruits. In contrast to PEL, polygalacturonase activity progressively increased during fruit ripening even in postclimacteric fruits.