Search

Optimization of controlled atmosphere (CA) storage of pome fruit crucially depends on understanding of respiratory gas exchange. Different fruit properties are involved in describing gas transfer and respiration kinetics, which can vary between cultivars, fruit batches and individual fruit. Determination of these properties currently requires a combination of different time-consuming techniques and data analysis procedures. This study introduces a more efficient single method for O 2 gas exchange characterization of fruit based on the non-destructive pathlength-resolved GASMAS (gas in scattering media absorption spectroscopy) technique. GASMAS was used to measure the absolute intercellular O 2 concentration in fruit of different apple cultivars (Malus x domestica Borkh.) with distinct porosity including 'Jonagold', 'Braeburn', and 'Nicoter'. To resolve the ambiguity between variation in pathlength and O 2 concentration inherent to GASMAS, the pathlength travelled through pores cavities was quantified through a second GASMAS measurement at the absorption line of H 2 O vapour. Dynamic experiments were then performed in which the fruit was subjected to varying external O 2 concentrations while measuring the internal O 2 response. The observed dynamic profiles of external and internal O 2 concentration were fitted with a lumped -respiration model to estimate the effective mass transfer coefficient, maximum respiration rate and Michaelis Menten constant of intact fruit. The model showed a good fit (R 2 >0.95) with the measured data and reliable estimates for the model parameters. The proposed method provides a novel and more efficient way to estimate the gas exchange properties of fruit that are essential for optimizing CA storage conditions. Future challenges for the proposed method are with applications to other gasses such as CO 2 and ethylene. • Non-destructive and quantitative internal O 2 measurement of apple using GASMAS. • GASMAS measurement on an intact apple in diffuse transmittance mode. • Fast determination of O 2 exchange and respiration kinetic parameters of apple. [ABSTRACT FROM AUTHOR]

This article presents the application of the laser speckle imaging method, a nondestructive and contactless method monitoring the gas exchange rate of intact apples. Red and infrared lasers in a typical setup for laser speckle imaging were used. A new parameter, speckle pattern relaxation time, has been proposed to evaluate speckle dynamics. Machine learning methods were used to develop a set of predictive models calibrated and validated against the respiration rate of two apple fruit cultivars measured with the flush system. The model with the highest performance used three variables: the speckle pattern relaxation time (τ RED or τ IR), fruit mass, and categorical variables describing apple varieties. This model provided satisfactorily low values of mean absolute prediction errors of 6.04%. Data from laser light scattering measurements combined with modern machine learning algorithms provided a nondestructive and fast method for estimating the apple fruit respiration rate. The developed solution has the potential for a wide range of industrial applications, especially in fruit storage, where the fruit respiration rate indicates optimal storage conditions. • Laser speckle imaging was used to build a predictive model of fruit respiration rate. • Laser light scattering was a good predictor for apple fruit respiration rate. • Speckle signal, mass and variety of apples were used as input for optimal models. • Near infrared laser provided best prediction capabilities. [ABSTRACT FROM AUTHOR]

‘Gem’ is a crisp, juicy European pear ( Pyrus communis L.) that can be consumed immediately at harvest or directly from cold storage. Alternatively, ‘Gem’ pears can ripen (5 d of 20 °C) to a soft, buttery, juicy texture once fruit accumulate 30 to 60 d of low temperature chill. In either condition, ‘Gem’ has a relatively short postharvest storage life of 5 months in regular air (RA). The purpose of this work was to evaluate two concentrations of 1-methylcyclopropene (1-MCP), 0.15 and 0.3 μL L −1 , to maintain crisp, juicy textural properties and extend the postharvest storage life of ‘Gem’. Fruit were treated with 1-MCP, held in −1.1 °C RA and evaluated monthly (+1 d at 20 °C) for 7 months. Only minor differences were observed between 0.15 and 0.3 μL L −1 1-MCP for any of the response factors assessed. The respiration (Rs) and ethylene production rates of non-treated fruit increased ∼2- and 30-fold, respectively, between 2 and 7 months. Fruit firmness (FF), peel chlorophyll content (I AD ), and titratable acidity (TA) all decreased linearly over the 7-month storage period. Treatment with 1-MCP completely inhibited internal ethylene production for the first four months. Ethylene production increased linearly between 5 and 7 months to a maximum value ∼15% of non-treated fruit. 1-MCP similarly suppressed Rs. FF, I AD , and TA were all significantly higher for 1-MCP-treated fruit than non-treated fruit. 1-MCP maintained the crisp and juicy textural properties of non-ripened fruit throughout the entire 7-month experiment by inhibiting ripening, despite a five-day 20 °C ripening treatment. In contrast, non-treated ‘Gem’ ripened after 2 months; however, the eating quality of non-treated fruit decreased after 5 months. Poor eating quality was associated with mealiness and insufficient softening after ripening. Internal browning and scald were first observed in non-treated fruit following five months of RA and reached levels of 26% and 85%, respectively, after seven months. The development of scald was closely associated with the accumulation of α-farnesene and conjugated trienols (CTols) in the fruit skin. 1-MCP significantly reduced the incidence of internal browning and completely inhibited the development of scald. Overall, 0.15 μL L −1 1-MCP maintained texture and fruit quality for 7 months RA and reduced the incidence of physiological disorders. [ABSTRACT FROM AUTHOR]

This study was carried out to investigate the effects of rain protective covering (RPC) together with Parka and gibberellic acid (GA 3 ) treatments on cracking rates and quality attributes of jujube fruits. RPC was mounted 5 weeks before the commercial harvest date. 1% Parka (containing 7.5% stearic acid, 5% cellulose and 1% calcium) and GA 3 (15 mg L −1 ) were sprayed to experimental trees 3 and 2 weeks before the commercial harvest date. As compared to the control, all treatments (Parka, GA 3 and GA 3 +Parka) yielded lower cracking rates. Cracking rates were also significantly lower in covered trees than in uncovered trees. However, GA 3 +Parka treated fruit had significantly lower cracking rates than both the control and the other treatments. GA 3 treated fruits had significantly higher weight, width, hue angle and firmness values, but significantly lower L* values than the control fruits. As compared to the control, all treatments yielded a significantly lower respiration rate and soluble solids content, but higher titratable acidity, vitamin C and total phenolics. The covered fruits had significantly higher hue angle, respiration rate, vitamin C, total phenolics, total flavonoids and antioxidant activity (free radical scavenging activity on DPPH and FRAP) than the uncovered ones. It was concluded based on the present findings that rain-protective covering could be used as an efficient tool to reduce cracking rates in jujube fruits without any negative effects on the other quality attributes. It was also concluded that Parka and GA 3 treatments reduced cracking rates significantly and such a reduction was more remarkable with combined GA 3 +Parka treatments. [ABSTRACT FROM AUTHOR]

The effect of the biocontrol agent (BCA) Pseudomonas graminis CPA-7 on the accumulation of CO 2 and ethylene (C 2 H 4 ) in fresh-cut apples at two maturity stages was evaluated in refrigerated conditions. Factors involved in the preservation strategy applied upon commercial conditions such as the antioxidant (AOX) treatment and the storage system were included in the analysis. Regardless of the maturity stage, the BCA reduced C 2 H 4 levels within the MAP atmosphere in AOX-untreated apples wedges, by 29 and 43% in immature and mature apples, respectively. Nevertheless, the addition of ascorbate as antioxidant counteracted this effect. In vitro tests suggested that the reduction of C 2 H 4 levels was not associated to the uptake of this molecule by CPA-7. Interestingly, in non-inoculated samples AOX treatment showed contradictory effects on C 2 H 4 production in MAP conditions by significantly reducing C 2 H 4 levels in immature apples (by 23%) while increasing it in mature ones (by 40%). Similarly, CPA-7 had opposite effects on the CO 2 accumulation pattern depending on the storage system or the fruit maturity stage. In this sense, CPA-7 was associated to a higher fruit respiratory activity at an advanced maturity stage yet without inducing the fruit fermentative metabolism or altering the fruit quality during a week of refrigerated storage. Overall, these results show that CPA-7 may contribute to the maintenance of the microbiological and physicochemical quality of fresh-cut apple by modulating the fruit ethylene production and/or respiration. [ABSTRACT FROM AUTHOR]

Chlorine dioxide (ClO 2 ) is an antimicrobial compound used in fresh produce sanitation. Compared to its aqueous form, gaseous ClO 2 has an enhanced antimicrobial effect. This research proposed a novel generating method of ClO 2(g) that utilized carbon dioxide and moisture naturally released from tomato during respiration to react with sodium chlorite for ClO 2(g) generation. The results showed that the generated ClO 2(g) not only effectively reduced the surface-inoculated Salmonella by 4 log CFU/fruit to an undetectable level (<5 CFU/fruit) within 24 h, but also did not impact the surface color and firmness of the fruits within the entire storage period (144 h) at 22 °C. The effects of NaClO 2 amount (0.05, 0.1 and 0.2 g), CO 2 concentration (7.5 and 15%), RH (45 and 95%), temperature (10, 22 and 35 °C) and pH (4, 5, 7 and 9) on the release of ClO 2(g) were evaluated. The D and z values of Salmonella under different temperatures were obtained. A sachet system was successfully developed for the practical applications of this novel ClO 2(g) generating method. [ABSTRACT FROM AUTHOR]

The influence of the addition of calcium lactate (CaLac) and ascorbic acid (AA) to sucrose (Sue) osmotic solutions on osmotic dehydration kinetics and endogenous metabolic heat production of apple tissue was evaluated. Our research goal was to characterize mass transfer and endogenous metabolic phenomena of the tissue to obtain minimally processed apples. The presence of CaLac and AA in solution affected the mass transfer of water and solutes, which was attributed to the changes in the cellular structure and thus to spaces available for solute transport. The metabolic heat production in samples treated in sucrose solutions was slightly lower than in untreated samples, and it was further reduced with CaLac addition. However, samples impregnated with AA exhibited a higher heat production due to a metabolic response of the tissue to AA treatment. When combined with CaLac, the heat production decreased to a level lower than untreated samples, except for those that were treated for 120 and 240min (higher impregnation), achieving the highest heat production values. These results confirm previous findings, suggesting that AA solution can promote a stress response on specific fresh-cut vegetable tissues, as well as an increase of their endogenous metabolic activity, as confirmed by the higher O2 consumption observed with the head space gas determination. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the effect of pretreatment with 1-methylcyclopropene (1-MCP) and the application of edible coatings (xanthan, sodium alginate or gellan) on the ripening rate, quality parameters and shelf life of pre-cut jackfruit. The jackfruit bulbs dipped in potassium sorbate/calcium chloride “PS/CC” (T 1 ) and PS/CC/1-MCP (T 2 ) showed a more rapid ripening and greater microbial growth at 7 and 12 days of storage. However, jackfruit bulbs with PS/CC/1-MCP and covered with xanthan, sodium alginate or gellan (T 3 , T 4 , and T 5 , respectively), showed a decrease in the ripening rate; thus weight loss and respiration rate were lower and the higher quality values as colour (°Hue), total soluble solids (TSS), titratable acidity (TA) as well as pH were achieved until 12 days of storage. Firmness values were higher in bulbs under T 3 , T 4 , and T 5 compared to bulbs under T 1 and T 2 . Microbial growth was delayed until the 12th day of storage in jackfruit bulbs with T 3 , T 4 , and T 5 . In general, manually peeled jackfruit stored at 5 °C and coated with 1-MCP/edible coatings, maintained the quality and sensory acceptability of fresh-cut jackfruit and with a longer shelf life than previously reported. [ABSTRACT FROM AUTHOR]

The ethylene perception inhibitor 1-methylcyclopropene (1-MCP) has been critical in understanding the hormone's mode of action. However, 1-MCP may trigger other processes that could vary the interpretation of results related until now to ethylene, which we aim to understand by using transcriptomic analysis. Transcriptomic changes in ethylene and 1-MCP-treated ‘Navelate’ ( Citrus sinensis L. Osbeck) oranges were studied in parallel with changes in ethylene production, respiration and peel damage. The effects of compounds modifying the levels of the ethylene co-product cyanide and nitric oxide (NO) on fruit physiology were also studied. Results suggested that: 1) The ethylene treatment caused sub-lethal stress since it induced stress-related responses and reduced peel damage; 2) 1-MCP induced ethylene-dependent and ethylene-independent responsive networks; 3) 1-MCP triggered ethylene overproduction, stress-related responses and metabolic shifts aimed to cope with cell toxicity, which mostly affected to the inner part of the peel (albedo); 4) 1-MCP increased respiration and drove metabolism reconfiguration for favoring energy conservation but up-regulated genes related to lipid and protein degradation and triggered the over-expression of genes associated with the plasma membrane cellular component; 5) Xenobiotics and/or reactive oxygen species (ROS) might act as signals for defense responses in the ethylene-treated fruit, while their uncontrolled generation would induce processes mimicking cell death and damage in 1-MCP-treated fruit; 6) ROS, the ethylene co-product cyanide and NO may converge in the toxic effects of 1-MCP. [ABSTRACT FROM AUTHOR]

The present study used three experiments to investigate the respiratory and ethylene production patterns of mangaba fruit and the physical and chemical changes that occur during ripening, as well as the temperature coefficient of the fruit. In the first experiment, 12 mature fruits were used to assess the patterns of respiration and ethylene production at 25 °C. In the second experiment, mature fruits were kept at 25 °C and left to ripen. They were analyzed, in ten replicates, at maturation, at the beginning of ripening and when totally ripe. In the third experiment, mature fruits were stored at different temperatures (5, 10, 20 and 25 °C) to determine the Q 10 , in five replicates. The following analyses were performed: weight (fresh mass), circumference, respiration rate, ethylene production, firmness, soluble solids, pH, titratable acidity and external color ( L* , a* , b* , C* and hue angle). Mangaba fruit shows respiratory and ethylene production patterns typical of climacteric fruits, with high rates of respiration and ethylene production. The ripening of mangaba fruit is characterized by softening and an increase in soluble solids, as well as by the reddening of the peel. Q 10 of mangaba fruit is dependent on the temperature range, increasing as the temperature lowers. [ABSTRACT FROM AUTHOR]

There has been recent interest in pomegranate fruit production and research due to its high nutritional and health benefits. The increase in demand of the fruit necessitates the need to improve quality, storability and shelf life to meet consumers’ expectations of consistent supply of quality fruit. However, pomegranate fruit is susceptible to various postharvest quality problems including high weight loss, decay and susceptibility to physiological disorders such as chilling injury and husk scald. To improve fruit storability and shelf life, physical and chemical postharvest treatments have been applied. However, these treatments have varied effects on the external and internal quality attributes of fruit. This review therefore discusses the different postharvest treatments applied to enhance storage of pomegranate whole fruit and arils and highlights the effects of the treatments on the fruit quality. [ABSTRACT FROM AUTHOR]

The changes in ripening parameters of ‘Spadona’ pears were monitored from 95 days after full bloom (DAFB) until the end of the harvest season in 2 orchards during 3 years, in an attempt to predict the timing of the pre-climacteric minimum (PCM), as a tool for determining the optimum harvest maturity for extended controlled atmosphere (CA) storage. A model based on the pre-harvest rates of changes of fruit weight, firmness, starch degradation and seed colour was found to predict the timing of the PCM with an accuracy of 24 h of its occurrence ( R 2 = 0.9925). Changes in soluble solid content (SSC) and titratable acidity (TA) did not improve the model. Fruit quality assessed at removal from CA storage after 6 months, followed by 2 weeks of shelf-life at 20 °C, verified that the optimal time for harvest of ‘Spadona’ pears was at the PCM. [ABSTRACT FROM AUTHOR]

In recent years there has been renewed interest in locally grown and underutilized wild species as sources of bioactive compounds. Barberry ( Berberis microphylla G. Forst) is among the southernmost growing fruit bearing species worldwide. The aim of this study was to characterize this species. We evaluated the antioxidant capacity of ripe barberry fruits as compared to pear, orange, apple, strawberry and blueberry. In a second set of experiments ripe barberry fruit was harvested and treated with ethylene and 1-MCP and the changes in ethylene production and respiration rate during storage were assessed. Finally, ripe barberries were harvested and stored at 0, 5 or 10 °C for 0, 3, 7, 11 or 15 days. During this period we determined weight loss, respiration rate, the percentage of rotten and physiologically decayed berries, firmness, sugar content, acidity, pH, anthocyanins, phenolics and antiradical capacity. Barberries showed 10-fold higher antioxidant capacity than apple, orange and pear and superseded four times that of antioxidant-rich fruits such as blueberry. 1-MCP treatments increased ethylene production suggesting that the hormone auto inhibits it biosynthesis. The fruit stored best at 0 °C and this should be the recommended temperature to minimize deterioration and prevent losses of bio-active compounds. The fruits show a non-climacteric physiology, with ethylene biosynthesis being under negative feedback control. Barberries are an extraordinary high source of antioxidants among fruits. [ABSTRACT FROM AUTHOR]

Highlights: [•] HRW can reduce the rot incidence inhibited the respiration intensity of kiwifruit. [•] HRW delays the decrease of firmness by alleviating pectin solubilization in kiwifruit. [•] HRW reduces the lipid peroxidation level and activates superoxide dismutase in kiwifruit. [•] HRW excites the radical scavenging activities in kiwifruit. [ABSTRACT FROM AUTHOR]

Highlights: [•] Two cherimoya varieties showed important differences in respiration rates after harvest. [•] Both varieties had characteristic double-sigmoid respiration curves. [•] Overall aroma was mainly determined by esters and terpenes in both varieties. [•] There were differences in pattern changes within each aroma-related compound. [•] Activity of alcohol acyl transferase increased during fruit ripening concomitant with ester accumulation. [ABSTRACT FROM AUTHOR]

Fruit ripening is a genetically programmed process which leads to an assortment of physiological and metabolic changes that irreversibly alter its characteristics. Depending on the species, fruit maturation can be either climacteric or non-climacteric. In both cases there is a metabolic shift from normal development conditions toward the fully mature state, but climacteric fruit is characterized by a sharp increase in respiration. In non-climacteric fruit, that generally does not display this feature, respiration changes can be affected by processes related to postharvest storage. This review describes some of the many ways in which mitochondrial metabolism is implicated in this crucial reproductive stage, such as the connection between ethylene production and respiration rate, the involvement of alternative oxidase (AOX) and plant uncoupling mitochondrial protein (PUMP) during the ripening and the common alterations of this organelle in fruits affected by different stress conditions. [ABSTRACT FROM AUTHOR]

Highlights: [•] At 0°C cherry respiration rate was not affected by O2 at 21–10% but declined at 10–1%. [•] MAP with 9.9–14.4% O2 +5.7–12.9% CO2 had little effect on inhibiting flavor loss. [•] MAP with 1.8–8.0% O2 reduced fruit respiration rate and acid loss and maintained flavor. [•] MAP with 5–8% O2 may be suitable for commercial application to maintain cherry flavor. [ABSTRACT FROM AUTHOR]

Highlights: [•] Chitosan applied pre- or postharvest slows respiration and ethylene production in raspberry fruit. [•] Chitosan is able to control decay incidence and weight loss in raspberries. [•] The postharvest chitosan application maintained anthocyanin contents of the fruit. [•] The postharvest life of raspberries was prolonged by chitosan. [ABSTRACT FROM AUTHOR]

Highlights: [•] Transportation of Euterpe oleracea fruit in open or closed systems was simulated. [•] Fruit already suffered three fermentations after 3h: alcoholic, lactic, and acetic. [•] Respiration rate and phenolic degradation were highly more severe in closed systems. [•] Transportation in open systems strongly attenuates spontaneous fermentation. [•] A short time between picking and processing of Euterpe oleracea fruit is important. [Copyright &y& Elsevier]

Highlights: [•] Responses of tomato fruit to 1-MCP treatment under hypoxic hypobaria were investigated. [•] Mid-climacteric fruit exposed to 1-MCP/hypoxic hypobaria showed acute interruption of ripening. [•] A respiratory climacteric was not observed following 1-MCP/hypoxic hypobaria treatment. [•] Responses to hypoxic hypobaria were not a consequence of reduced internal ethylene. [•] Ingress of 1-MCP was enhanced nearly 10-fold during exposure under hypoxic hypobaria. [Copyright &y& Elsevier]

Highlights: [•] Hyperbaric pressures at room temperature were evaluated for tomato storage. [•] Hyperbaric treatment had minor effects on tomato respiration. [•] Hyperbaric pressure was as effective as 13°C in delay tomato ripening. [•] Hyperbaric treatment confers similar quality retention to tomato held at 13°C. [ABSTRACT FROM AUTHOR]

Abstract: Banana and broccoli are two major fruits in tropics and subtropics areas. It is of great value to treat them for shelf life delaying and to improve commercial value. The fresh harvested banana and broccoli were treated with forchlorfenuron (CPPU) and gibberellic acid (GA3) in different concentrations respectively, and then stored at 25±2°C, 75–95%RH after air dry. Changes of peel color, flesh firmness, fruit respiration rate, brown and fungal incidence were investigated during the storage. The results showed that, as compared with the control fruits, 10mgl−1 CPPU with different concentrations of GA3 had good effect on the fruit and vegetable. Especially in the group treated with 10mgl−1 CPPU+50mgl−1 GA3, surface color change was obviously retarded, fruit respiration rate was inhibited, and the natural browning was significantly inhibited as well. In addition, the accumulation of soluble sugars in the fruit was reduced, and the water loss rate (4.55±0.04%) was also inhibited. These treatments not only can delay maturing and softening of banana and broccoli, but also can maintain the color and resist the fungal infection to extend the shelf life. [Copyright &y& Elsevier]