Postharvest response of ‘Brown Turkey’ figs (Ficus carica L.) to the inhibition of ethylene perception

The potential use of 1‐methylcyclopropene (1‐MCP) alone or as a supplement to cold storage to delay the softening of ‘Brown Turkey’ figs (Ficus carica L.) was studied. Figs were treated with 0, 0.25, 0.5 or 5 µl l^?1 1‐MCP at 25 °C for 8 h and stored at 20 °C until evaluated. Figs treated with 0.5 or 5 µl l^?1 1‐MCP had higher ethylene production and respiration rates but slower softening than untreated fruit and those treated with 0.25 µl l^?1 1‐MCP. Early‐harvested firm figs and late‐harvested soft figs were untreated or treated with 0.5 or 5 µl l^?1 1‐MCP at 25 °C and stored at 0 °C for 19 days. Firm figs treated with 1‐MCP showed an early peak in ethylene synthesis, higher respiration rate and were firmer than control fruit. In contrast, soft figs did not respond to 1‐MCP except for a late increase in respiration rates of fruit treated with 5 µl l^?1 1‐MCP. 1‐MCP appeared to have a relatively limited effect on slowing ripening of ‘Brown Turkey’ figs and its effect was influenced by ripening stage. Copyright © 2005 Society of Chemical Industry     

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     

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.     

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.     

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     

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.     

Influence of post-harvest application rates of cyprodinil,treatment time and temperature on residue levels and efficacy in controlling green mould on ‘Valencia’ oranges

The effectiveness of heat treatments with water and cyprodinil in controlling post-harvest green mould caused by Penicillium digitatum was investigated on artificially inoculated ‘Valencia’ oranges. Residue levels of cyprodinil were determined in the oranges as a function of active ingredient concentration, temperature and treatment time. Cyprodinil residues were significantly dependent on treatment time when applied at 600 mg l^?1 and 20°C, but not when fruit were treated at 150–300 mg l^?1. The application of cyprodinil at 50 or 100 mg l^?1 at 55°C for 30 s produced similar residue levels, while residues increased when the application rate was 150 mg l^?1. Cyprodinil at 100 mg l^?1 and 60°C produced a significant increase in residues compared to treatment at 50 mg l^?1; no significant increase in residues was found when the application rate was raised from 100 to 150 mg l^?1. In comparison to treatments performed at 20°C, the application of a heated cyprodinil mixture resulted in significantly higher residues in fruit. All treatments with cyprodinil at 20°C similarly reduced green mould after 7 days of storage at 20°C. After 18 days, treatment with cyprodinil at 600 mg l^?1 for 30 s was more effective than at 150–300 mg l^?1. When dip time was extended to 90 or 180 s, treatment efficacy was positively related to fungicide concentration. Treatments with water at 55°C for 30 s were as effective as cyprodinil at 50–100 mg l^?1, but less effective than cyprodinil at 150 mg l^?1. After 7 days, treatment with water or cyprodinil at 50–150 mg l^?1 and 60°C were equally effective in controlling green mould; while, after 18 days, treatment with cyprodinil at 150 mg l^?1 was consistently more effective than at 50–100 mg l^?1 or hot water alone.     

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     

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     

Maturity and ripening effects on chemical and sensory properties of apple juice

The effects of harvest maturity and ripening on the chemical composition and sensory characteristics of ‘McIntosh’ and ‘Spartan’ apple juice were evaluated. Juice was extracted from fruit harvested at seven weekly intervals beginning 3–4 weeks before commercial harvest and from fruit held in air storage (1°C) for 1 to 3 months. Internal ethylene concentration and starch index were used as maturity indices. Principal component analysis of juice data (pH. titratable acidity, organic acids, soluble solids, sugars, phenols, turbidity, and Hunterlab colour) showed a distinctive maturity effect on the characteristics of juice extracted from fruit immediately after harvest or after storage. Triangle testing showed aroma and flavour differences in both ‘McIntosh’ and ‘Spartan’ to be first discernable when ethylene was first detected (internal ethylene concentration ≥ 0.1 μl litre^?1) and starch hydrolysis evident (starch index 3.0–5.0 for ‘McIntosh’, 1.5–3.0 for ‘Spartan’), or after 2–3 months of air storage. Sensory profiling of fruity aroma, total aroma, fruit flavour by mouth, sweetness, and sourness in the juices showed increased fruitiness and sweetness and decreased sourness with advancing maturity.     

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

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

USE OF FLEXIBLE POLYMER MATERIAL FOR PACKAGING FRESH PEACHES

Fresh peaches (Prunus persica) were overwrapped in trays with 1 of 3 formulations of flexible polyvinyl chloride (PVC) film that differed in gas transmission rate or they were held in nonwrapped trays (controls). The CO₂ transmission rate at 0°C for PVC type III film was 280 mL/m^2. h (1 atmos); that of type II was 4 times greater and that of type I, about 5 times greater. The peaches were stored either 14 days at 0° or 7.5°C, or 7 days each at 0° and 7.5°C plus 2 days at 20°C to simulate retail display. The mean CO₂ levels were 10, 7.2 and 4.7% in packages that were wrapped with PVC III film and held at 7.5°, 0°/7.5° and 0°C, respectively. CO₂ in packages wrapped with PVC I or II was below 3% at each storage temperature. O₂ concentration remained about 4% in all packages. Weight loss was less and fruit was firmer among those packaged in PVC III than among nonwrapped controls at each of the 3 storage temperatures. Storage temperature had no effect on weight loss or of fruit held in PVC III film. External appearance of fruit packaged with the 3 types of film was significantly better than that of the controls. Internal appearance of the peaches was unaffected by any of the treatments. A microatmosphere favorable for fresh peaches can be maintained within packages overwrapped with polymer films that are selectively permeable to respiratory gases.     

Application of exogenous ethylene on postharvest ripening of refrigerated ‘Ataulfo’ mangoes

Commercial handling of ‘Ataulfo’ mangoes is burdened by lack of uniformity in ripening of the fruit. A viable approach to overcome this problem could be by application of exogenous ethylene. In this work, we evaluated the application to exogenous ethylene on ‘Ataulfo’ mangoes with hot-water treatment after having been stored for 4 days at 13±1 °C, and then transferred to 25±2 °C for ripening. Fruit were exposed to 100, 500 or 1000 μl l⁻¹ ethylene for 6 or 12 h at 25±2 °C. Control fruit were held at 25±2 °C with no previous refrigeration or ethylene exposure; another batch was kept refrigerated for 4 days at 13±1 °C, not treated with ethylene and ripened 25±2 °C. Application of 1000 μl l⁻¹ of ethylene for 12 h caused improper ripening. Best results were observed by application of 100 μl l⁻¹ of ethylene for 12 h, which stimulated the synthesis of 1-amino cyclopropane-1-carboxylic acid (ACC) and increased ACC oxidase activity; these conditions led to a concomitant production of ethylene and the subsequent acceleration of ripening with a net gain of 4 days in the ripening time. External color development of the ethylene-treated fruit was judged as more homogeneous.     

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     

Relationships between volatile production,fruit quality and sensory evaluation of Fuji apples stored in different atmospheres by means of multivariate analysis

Aroma compounds, quality parameters and sensory characteristics of Fuji apples were analysed after 3, 5 and 7 months of storage at 1 °C in normal air (AIR; 210 l m^?3 O₂/0.3 l m^?3 CO₂) and in controlled atmospheres with O₂/CO₂ ratios of 10 l m^?3/10 l m^?3 (ULO1), 10 l m^?3/20 l m^?3 (ULO2) and 30 l m^?3/20 l m^?3 (SCA). After storage the apples were kept at 20 °C for 1, 5 and 10 days. The components that contributed most to the characteristic aroma of Fuji apples were ethyl 2‐methylbutanoate, 2‐methylbutyl acetate and hexyl acetate. The highest aroma compound production was found in ULO1 fruits after 5 months of cold storage and 1 day of shelf‐life. After 3 and 5 months of storage, ULO1 fruits showed the highest firmness after both 1 day and 10 days at 20 °C. After 7 months of storage plus 1 day at 20 °C, ULO2 fruits showed higher titratable acidity and soluble solid content; fruit firmness was also maintained throughout the shelf‐life period. Generally, background and superficial colour were not influenced by storage conditions. A statistically significant correlation was found between aroma compounds, quality parameters and sensory evaluation. Copyright © 2003 Society of Chemical Industry     

Effect of modifiers on thermal behaviour of Se in acid digestates and slurries of vegetables by graphite furnace atomic absorption spectrometry

The influence of sample preparation strategy of vegetables on the electrothermal behaviour of Se without and with chemical modifiers such as Pd(NO₃)₂, Pd(NO₃)₂ + Mg(NO₃)₂, Pd(NO₃)₂ + Cd(NO₃)₂, pre-reduced Pd, Mg(NO₃)₂, and Ni(NO₃)₂ was investigated. Acid digestates and slurries of vegetables (0.1% m/v in 1% v/v HNO₃ + 0.005% v/v of Triton X-100) were used to prepare reference solutions or slurries. For 10 μl of each modifier tested, pyrolysis and atomization temperatures were evaluated using pyrolysis and atomization curves, respectively. Best conditions, such as thermal stability, signal profile, repeatability and sensitivity were attained using Pd(NO₃)₂ as chemical modifier. The following heating program (temperature, ramp/hold time) of the graphite tube of the Varian SpectrAA-800Z atomic absorption spectrometer was used: dry step (85 °C, 5/0 s; 95 °C, 40/0 s; 120 °C, 10/5 s); pyrolysis step (1400 °C, 10/3s); atomization step (2200 °C, 1/2 s); clean step (2600 °C, 2/0 s). This pyrolysis temperature is 800 °C higher than when measuring without any modifier. For 20 μL sample volume and 10 μg Pd(NO₃)₂, analytical curves in the 3.0–30 μg Se l⁻¹ range were obtained. The method was applied for Se determination in acid digestates and slurries of 10 vegetable samples and one standard reference material (rice flower) and results were in agreement at 95% confidence level. Recoveries varied from 89 to 95% for spiked samples. The lifetime of the graphite tube was ca. 250 firings and the relative standard deviations (n=12) for a typical acid digestate and slurry containing 20 μg Se l⁻¹ were 3.8% and 8.3%, respectively. The limits of detection were 2.0 μg Se l⁻¹ and 0.6 μg Se l⁻¹ Se for digestates and slurries, respectively.     

Postharvest storage of Giant Cavendish bananas using ethylene oxide and sulphur dioxide

The potential of ethylene oxide (EO) and sulphur dioxide (SO₂) to prevent ethylene‐stimulated fruit ripening was assessed using Giant Cavendish bananas. Studies were carried out in a cold room at 15 °C and terminated after 6 weeks. Product quality was assessed via visual observations and physiological assessments. Fruits were exposed to EO concentrations in the range 0–400 ppm for 12 h followed by storage in regular atmosphere (RA). Results showed that EO delayed ripening at 50 and 100 ppm for single exposure and at 50 and 200 ppm for repeated exposure. Treatment with 2 and 8 µg kg^?1 SO₂ was efficient in extending the shelf life of bananas for 4 weeks in RA and for 6 weeks under controlled atmosphere (CA). SO₂ preserved the quality of bananas and reduced the incidence of fungal infections during storage; however, a concentration of 15 µg kg^?1 shortened the shelf life. Fruits treated with low concentrations of EO and SO₂ had harvest‐fresh appearance, good colour, minimum mould and excellent marketability compared with controls and store‐bought references. EO and SO₂ are not approved for use on fresh fruits, with the exception of the use of SO₂ on grapes and citrus fruits. © 2003 Society of Chemical Industry     

Influence of post-harvest treatments with fludioxonil and soy lecithin co-application in controlling blue and grey mould and fludioxonil residues in Coscia pears

The residue levels of fludioxonil (FLU) were determined in Coscia pear following a 1-, 2- or 4-min dip in an aqueous mixture of FLU containing 300 or 100 mg l^?1 (active ingredient, a.i.) at 20 and 50°C, respectively, with or without 2% soy lecithin. The efficacy of heat treatment with water and FLU mixtures was investigated on artificially inoculated pears for the control of post-harvest decay caused by blue (Penicillium expansum Link) and grey (Botrytis cinerea Pers. ex Fr.) mould. Treatment with 300 mg l^?1 FLU at 20°C increased residues significantly when treatment time rose from 1 to 2 min; no further increase was recorded when dip time raised from 2 to 4 min. FLU residue rates were unaffected by treatment time when 300 mg l^?1 a.i. was applied in combination with lecithin at 20°C. While treatment with 100 mg l^?1 a.i. at 50°C for 1 and 2 min resulted in similar residue levels, significantly higher residues were detected when dip time increased from 1 to 4 min. Co-application of lecithin significantly decreased FLU residues with respect to fruit treated with FLU alone. Treatments with FLU at 20 or 50°C effectively controlled decay over 10 days of incubation. While co-application of lecithin did not affect the efficacy of FLU at 300 mg l^?1and 20°C, treatment efficacy decreased when lecithin was applied in combination with 100 mg l^?1 FLU and 50°C for 4 min and to a greater extent when dip time was 1–2 min.     

ETHYLENE CAPSULE PROMOTES EARLY RIPENING OF 'd'ANJOU' PEARS PACKED IN MODIFIED ATMOSPHERE BAGS

‘d'Anjou’ pears (Pyrus communis, L.) harvested commercially with flesh firmness of 64.5 N were incapable of ripening normally at 20C within 60 days of air storage at ‐1C (denoted as “under‐chilled” fruits). When under‐chilled ‘d'Anjou’ fruits (8 fruits, total fruit weight of 1.8 kg) were packed in a 3.8‐liter perforated bag inserted with an ethylene capsule, fruit would ripen normally at 20C. The ethylene concentration in the packed bag maintained no less than 100 ppm after 4 days at 20C, and declined to about 25 ppm on day 7. Regardless of the storage length, ripened fruit induced by the ethylene capsule developed high buttery and juicy texture. If ‘d’ Anjou’ fruit had been stored at ‐1C for less than 30 days, ripened fruit lacked high flavor quality. Flavor quality of ripened fruit improved rapidly when the fruit had been stored for longer than 30 days.