Assessing `Bing' Sweet Cherry Tolerance to a Heated Controlled Atmosphere for Insect Pest Control

Quality of heat-treated strawberry fruit during refrigerated storage

Phytosanitary restrictions for insect pests can interfere with the marketing of fresh sweet cherries (Prunus avium L.). The objective of this research was to compare the quality of controlled atmosphere temperature treated (CAT) sweet cherries to methyl bromide fumigated cherries and non-heated, non-fumigated control fruit. Two CAT doses were evaluated: a 25-min exposure to 47 °C (117 °F) that heated the cherry center to 46 °C (115 °F), and a 40-min exposure to 45 °C (113 °F) that heated the cherries to a center temperature of 44 °C (111 °F). These heat doses approximated a heat dose that provides quarantine security against codling moth (Cydia pomonella Lw.) and western cherry fruit fly (Rhagoletis cingulata Lw.). An atmosphere of 1 kPa oxygen and 15 kPa carbon dioxide was established inside the treatment chamber for 21 min prior to heating. The influence on fruit quality of hydrocooling prior to the CAT treatment, cooling after treatment, and 2 weeks of cold storage after treatment in air or controlled atmosphere was evaluated. Each CAT dose was replicated four times using freshly harvested, `Bing' sweet cherries acquired from similar grower lots. Quality attributes evaluated included: stem and fruit color, firmness, soluble solids concentration, titratable acidity, decay, and sensory evaluations. Hydrocooling prior to treatment, cooling method after heating and storage atmosphere had no significant influence on cherry quality after cold storage. The stem color of fumigated cherries was less green after storage than CAT treated cherries or untreated, control cherries. Cherries heated for 25 min were rated after cold storage by untrained panelists as similar to non-heated, non-fumigated control fruit. Heated cherries and methyl bromide fumigated cherries were less firm after cold storage than control fruit.

Flesh browning is the main postharvest disorder limiting the storage life of feijoa fruit produced in southern Brazil. The aim of this study was to evaluate the relationship between the activity of polyphenol oxidase (PPO), peroxidase (POD) and phenylalanine ammonia-lyase (PAL) and incidence of flesh browning in five Brazilian genotypes of feijoa: cultivars 'Alcântara', 'Helena', 'Mattos' and 'Nonante', and the access 2316. Fruit of all genotypes were harvested at commercial maturity in 2013, and cold stored for 7 and 14 days (4±1°C/90±5% RH), followed by 48 h of shelf life (23±1°C/75±5% RH). The activities of PPO, POD and PAL and incidence of fresh browning were assessed at the harvest and after 7 and 14 days of cold storage (followed by shelf life). On average of all genotypes, the activity of PPO increased 29% from harvest to 7 days of cold storage, and 37% from 7 to 14 days of cold storage. PPO activity after 14 days of cold storage was highest in 'Mattos' and lowest in 'Helena'. POD activity was low in all genotypes and decreased from harvest until 14 days of cold storage. In all genotypes, PAL activity did not change from harvest until 7 days of cold storage but increased from 7 to 14 days of cold storage (by 11-28%) in 'Alcântara', 'Helena' and 'access 2316'. 'Mattos' had the highest PAL activity, which did not change from harvest until 14 days of cold storage. The severity of pulp browning after 14 days of cold storage (followed by shelf life) was higher in 'Mattos', 'Alcântara' and 'access 2316', and lower in 'Nonante' and 'Helena'. The results show that the occurrence of flesh browning in the fruit of feijoa genotypes cultivated in southern Brazil is associated fruit senescence, and related to the increase of PPO and PAL activities during storage (especially of PPO). POD activity was low in all genotypes of feijoa and, therefore, the enzyme seems to have little effect on the internal browning.

Cold storage is widely used to prolong the storability of peach fruit. However, prolonged storage at low temperatures results in chilling injury (CI) in some susceptible peach cultivars during or after cold storage. Prestorage high CO2 and 1-methylcyclopropene (1-MCP) treatments are among the methods reported to alleviate CI and maintain the firmness of peach fruit. Hence, this study investigated CI, ripening-related physicochemical parameters, sensory qualities, total phenolics and flavonoids, and antioxidant activities of “Madoka” peach fruit to observe the effectiveness of prestorage treatment with high CO2 and 1-MCP during the storage at 0 and 5°C. Based on the CI index, control fruits were acceptable for marketing up to 20 and 16 days of storage at 0 and 5°C, respectively, while the treated fruits could be marketable up to 28 days of storage. The results of firmness and firmness-related parameters [pectin content and polygalacturonase (PG) activity] also revealed that both high CO2 and 1-MCP treatments were effective in delaying the ripening process of Madoka peach, and the storage at 0°C showed better results than at 5°C. However, based on the overall sensory evaluation results, the treated and control fruits were acceptable for marketing up to 20 and 12 days of storage, respectively, in both storage conditions. After deciding on fruit marketability based on the combined objective postharvest quality parameters and subjective sensory qualities, we analyzed the changes in total phenolics, flavonoids, and antioxidant activities at harvest, on the 12 and 20th days of cold storage. Storage of Madoka peach at 0°C maintained total phenolics, flavonoids, and antioxidant activities regardless of prestorage treatment with high CO2 and 1-MCP. In summary, storing Madoka peach fruit at 0°C after treating it with 30% CO2 for 6 h or 0.5 μl L–1 1-MCP for 24 h reduces CI, prolongs storability, and maintains sensory quality and antioxidant properties.

Changes in phenolic compounds and antioxidant activity of sour–sweet pomegranates cv. ‘Hicaznar’ during long-term storage under modified atmosphere packaging

Quarantine regulations require domestic sweet cherries (Prunus avium) exported to Japan to be treated to control codling moth [Cydia pomonella (Lepidoptera: Tortricidae)]. The current procedure, methyl bromide fumigation, may be discontinued because of health, safety, and environmental concerns. To examine a potential alternative method, `Bing' sweet cherries were each infested with a codling moth larva, submerged in a 38 °C water bath for 6 minutes pretreatment, then exposed to various temperatures generated by radio frequency and held at that temperature for different times: 50 °C for 6 minutes, 51.6 °C for 4 minutes, 53.3 °C for 0.5 minutes, and 54.4 °C for 0.5 minutes. Insect mortality was evaluated 24 hours after treatment and fruit quality was evaluated after treatment and after 7 and 14 days of storage at 1 °C. No larvae survived at the 50 and 51.6 °C treatments. Fruit color of non-infested cherries was darkened as temperature increased. Stem color was severely impacted after 7 days of storage, even in a warm water bath of 38 °C for 6 minutes, as was fruit firmness at the same treatment. Fruit quality loss increased after 14 days of storage, compared to after 7 days of storage. The amount of pitting and bruising of cherries increased with temperature and again this increase was more evident after 14 days of storage.

'Douradão' peach is a perishable product and when cold stored is subject to chilling injury. The objective of the experiment was to evaluate the effect of modified atmosphere packaging (MAP) and cold storage on quality and storage life of these peaches. Fruits were packed in polypropylene (PP) trays and placed inside low density polyethylene (LDPE) bags (30, 50, 60, 75 μm thickness) with active modified atmosphere (10 kPa CO2 + 1.5kPa O2, balance N2). The control was made with peaches held in nonwrapped PP trays. Fruits were kept at 1 ± 1 °C and 90 ± 5% relative humidity (RH) for 28 days and CO2 and O2 within packages was monitored every two days. After 14, 21 and 28 days, samples were withdrawn from MAP and kept in air at 25 ± 1 °C and 90 ± 5% RH for ripening. On the day of removal from the cold storage and after 4 days, peaches were evaluated for weight loss, decay incidence, flesh firmness, woolliness incidence, soluble solids content (SSC), titratable acidity (TA) and juice content. The results showed that MAP had influence on reducing weight loss and prevented postharvest decay. MAP of 1-2 kPa O2 and 3-6 kPa CO2 at 1 °C (from 50 and 60 μm LDPE films) were effective for keeping good quality of 'Douradão' peaches during 28 days of storage, the ripe fruits showed reduced incidence of woolliness, adequate juiciness and flesh firmness. Packages of 30 and 75 μm LDPE films were ineffective for reducing woolliness during cold storage. MAP fruits showed lower SSC and no relevant effect on TA. Control fruits did not present marketable conditions after 14 days of cold storage.

A conservação refrigerada da lima ácida 'Tahiti' sob baixa temperatura permite o aumento no período de comercialização dos frutos, entretanto, a perda da coloração verde da casca é o principal entrave que impede este prolongamento. O objetivo do presente trabalho foi verificar o efeito da aplicação do 1-metilciclopropeno (1-MCP), associado ao uso de cera e ácido giberélico (GA), sobre a conservação refrigerada de lima ácida 'Tahiti'. Foram aplicados os tratamentos: T1:Controle; T2: 1-MCP (1 mg. L-1) durante 12 horas a 20ºC; T3: Cera (0,1 mL por fruto); T4: Ácido giberélico - GA (10 mg. L-1); T5: 1-MCP + Cera; T6: 1-MCP + GA; T7: Cera + GA; T8: 1-MCP + Cera + GA; T9: T2 + re-aplicação de 1-MCP após 30 dias de armazenamento. Os frutos foram armazenados durante 30 e 60 dias a 10C e 90% UR. A cera foi suficiente para retardar a perda de coloração verde da casca até 30 dias de conservação a 10ºC. O 1-MCP também mantém a coloração verde até 30 dias de conservação refrigerada, enquanto que a sua reaplicação após este período não apresenta efeito para a manutenção da coloração verde da casca. No presente trabalho não foi pronunciado o efeito do ácido giberélico. Após 60 dias de armazenamento os frutos não se apresentavam comercializáveis.

The oxidation of myofibrillar and sarcoplasmic proteins of thin‐lipped mullet (Liza ramada) in different ages during refrigerated storage (4C), and in vitro oxidation of muscle after 2 and 24 h incubation with Fe+2/H2O2 at 4C were evaluated by means of protein carbonyl content. Changes in myofibrillar and sarcoplasmic proteins were estimated by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis. The carbonyl content of myofibrillar proteins exhibited a regular increase at 2 years of age during the refrigerated storage for 10 days (P < 0.05), and increased at 4 and 6 years of age after 5 days of cold storage (P > 0.05), and then did not significantly change between 5 and 10 days of storage (P > 0.05). Sarcoplasmic proteins showed a decrease in the carbonyl content at 2 years of age during 10 days of storage. However, no significant changes were observed in carbonyl content of sarcoplasmic proteins at 4 and 6 years of age (P > 0.05). An increase in carbonyl content of whole muscle, but not statistically significant, was found at 2, 4 and 6 years of age during 10 days of cold storage. There were no significant differences in oxidation of thin‐lipped gray mullet proteins in all ages between 2 and 24 h of incubation with Fenton‐like oxidation system (Fe+2SO4/H2O2) at 4C (P < 0.05). However, there was a tendency to find an increase in carbonyl content in all ages after 24 h of incubation. Electrophoretic studies in the presence and absence of β‐mercaptoethanol showed that high‐molecular weight polymers via disulfide cross‐linking and/or degradation/digestion by proteolysis could be formed in the myofibrillar proteins in different ages. Slight changes were observed in sarcoplasmic proteins of thin‐lipped gray mullet both in the absence and presence of a disulfide‐splitting agent. These results suggest that there is a probable link between protein oxidation and protelytic degradation of myofibrillar proteins during postmortem storage, and the effects of cold storage on oxidation and possible changes in myofibrillar and sarcoplasmic proteins could be changed depending on ages in same species.PRACTICAL APPLICATIONSThe degradation of muscle proteins caused by proteolysis is one of the most important quality attributes of fish muscle throughout cold storage. However, knowledge about the effect of oxidative process on proteins and their effect on postmortem quality of fish is less known. In this study, we found a probable link between protein oxidation and degradation of thin‐lipped mullet myofibrillar proteins, and their proteolysis may be stimulated by oxygen radicals during postmortem storage. These determinations are important to prevent protein degradation and improve the shelf life of thin‐lipped mullet during postmortem storage.

The effects of fast cold chain alone and combination with modified atmosphere–modified humidity packaging (MA/MH) on the fruit quality, the activities of polyphenol oxidase (PPO), polygalacturonase (PG), individual sugars, organic acids and total anthocyanin amount of early-harvested "0900 Ziraat" sweet cherries were investigated after 8 days of cold storage at 0C and subsequent 2 days of ambient temperature storage (simulating shelf life). Results showed that, combination treatment with fast cold chain and MA/MH packaging decreased the weight losses, fruit elasticity, pitting amount, PG, PPO activities, stem visual appearance and preserved the fruit's initial quality better than the controls after the studied storage times. We determine that using MA/MH packaging, even in a short distribution chain circumstances, will protect the quality of early-harvested crops throughout their shelf life. Pratical Applications Cherries have a relatively short storage life and exporters typically prefer to purchase the early season fruit over a short time period without modified atmosphere packaging, which results in a larger amount of decay and a poor market quality. The present study was undertaken to determine the effects of fast cold chain and MA/MH packaging on quality attributes, main physicochemical and cell wall enzymatic activities of the 0900 Ziraat sweet cherry.

Sweet cherry (Prunus avium L.) is becoming increasingly popular in China, but its postharvest quality deteriorates significantly during harvest storage and transport. Here, we investigated the efficiency of different modified atmosphere packaging (MAP) treatments on the quality and physiology of ‘Meizao’ sweet cherry during 60 days of cold storage (0 ± 0.5 °C). Fruits were sealed in four types of MAP low-density polyethylene (LDPE) liners (PE20, PE30, PE40, and PE50), with unsealed 20 μm LDPE packaging bags used as the control. Our findings demonstrated that PE30 packaging established an optimal gas composition (7.0~7.7% O2 and 3.6~3.9% CO2) that effectively preserved ‘Meizao’ sweet cherry quality. It maintained the fruit color, firmness, soluble solid content (SSC), titratable acidity (TA), and vitamin C (Vc) content while simultaneously delaying deteriorative processes such as weight loss, pedicel browning, and fruit decay. These results indicate that PE30 was the most suitable treatment for preserving the quality of ‘Meizao’ sweet cherries during cold storage. Furthermore, physiological research showed that significant inhibition of respiration rate was achieved by PE30, accompanied by maintained activities of antioxidant enzymes (CAT, POD, and SOD), which consequently led to reduced accumulations of ethanol and malondialdehyde (MDA) during cold storage. To date, no systematic studies have investigated the physiological and biochemical responses of ‘Meizao’ to different thickness-dependent LDPE-MAP conditions. These observations highlight the power of the optimized PE30 packaging as an effective method for extending the fruit storage life, delaying postharvest senescence, and maintaining fruit quality of ‘Meizao’ sweet cherry.

Blueberries (Vaccinium corymbosum L.) are highly valued for their health-promoting potential, yet they are extremely perishable. Controlled atmosphere (CA) strategies reduce blueberry respiratory metabolism, slowing down senescence. However, the sudden change of atmosphere could elicit a physical abiotic stress in the fruit, negatively affecting quality. We propose an innovative approach based on controlled graduation to slowly reach optimum gas storage conditions as an alternative to standard CA. For two consecutive seasons, “Duke” blueberries were subjected to four different storage conditions: control (air); standard CA (sudden exposure to 5 kPa O2 and 10 kPa CO2 across the experiment); GCA3 and GCA7 (gradually reaching 5 kPa O2 and 10 kPa CO2 in 3 and 7 days, respectively). Fruit were stored for 28 days at 0 ± 0.5°C. Real-time respirometry provided an in-depth insight to the respiratory response of blueberries to their gas environment. Blueberries subjected to the graduated application of CA (GCA) treatments had a lower steady-state respiration rate compared to control and standard CA fruit. This indicated a reduction in metabolic activity that positively impacted quality and storage life extension. For example, GCA3 and GCA7 blueberries had a 25% longer storage life when compared to control, based on reduced decay incidence. In addition, GCA fruit were 27% firmer than control and CA fruit after 28 days of cold storage. GCA3 had a positive effect on maintaining individual sugars concentrations throughout the experiment, and both GCA treatments maintained ascorbic acid content close to initial values compared to a decrease of 44% in the control fruit at the end of the experiment. This work provides a paradigm shift in how CA could be applied and a better understanding of blueberry physiology and postharvest behavior.

The transition from cold storage to ambient temperature alters apple quality through accelerated softening, flavor and color changes, and development of physiological peel disorders, such as superficial scald, in susceptible cultivars. To reveal global metabolism associated with this transition, the 'Granny Smith' peel metabolome was evaluated during storage of 6 months and shelf life periods. Treatment with the antioxidant diphenylamine (DPA) reduced scald, creating a metabolic contrast with untreated fruit, which developed superficial scald. Superficial scald symptoms developed on control fruit after 120 days of storage, and symptoms progressed following transition to ambient-temperature shelf life. The metabolic profile of control and DPA-treated fruit was divergent after 30 days of cold storage due to differing levels of α-farnesene oxidation products, methyl esters, phytosterols, and other compounds potentially associated with chloroplast integrity and oxidative stress response. Hierarchical cluster analysis revealed coregulation within the volatile synthesis pathway including control of the availability of methyl, propyl, ethyl, acetyl, and butyl alcohol and/or acid moieties for ester biosynthesis. Overall, the application of metabolomics techniques lends new insight into physiological processes leading to cell death and ripening processes that affect fruit flavor, appearance, and overall quality.

BackgroundPesticide residues on harvested fruits and vegetables pose significant public health concerns. While consumers commonly use home-type washing treatments to remove these residues, their effectiveness requires scientific validation. This study investigates the effects of pre-harvest pesticide applications and post-harvest washing methods on pesticide residue removal, physicochemical quality parameters, and storage behavior of sweet cherry fruits (Prunus avium L.) during 28 days of cold storage at 1 °C.ResultsPre-harvest application of commonly used pesticides (malathion, boscalid + pyraclostrobin) followed by post-harvest washing treatments (distilled water, 5% vinegar, and 5% sodium bicarbonate) significantly influenced residue levels and quality of sweet cherries during storage. Distilled water was the most effective method for reducing pesticide residues, followed by sodium bicarbonate (NaHCO₃) and vinegar. However, NaHCO₃ treatments resulted in greater mass loss and negatively impacted fruit firmness. Pesticide treatments increased soluble solids content but generally reduced titratable acidity and antioxidant capacity by the end of storage. Pesticide and carbonate treatments contributed to undesirable changes in overall fruit quality.ConclusionsWashing treatments, especially with distilled water, effectively reduced pesticide residues from cherries, promoting safer consumption. Washing treatments involving distilled water and vinegar had a positive impact on the preservation of fruit quality. Nevertheless, some treatments had a negative impact on storage quality. These findings highlight the need for further research to identify optimal combinations of washing agents and storage strategies tailored to different pesticides and fruit types.

Postharvest handling of peach (Prunus persica) fruits is challenging as they deteriorate quickly under ambient conditions. Cold storage slows detrioration but causes chilling injury (CI), reducing quality of fruits. To overcome this challenge the influence of fruit maturity on antioxidant capacity and CI development in “Ryan sun” peach fruits was investigated. Fruits were harvested from commercial farms in Lleida in Spain. Optimum harvest date (OHD) was determined on-tree visually by ground skin colour when 70% of skin turned reddish using colour discs. Fruits were harvested 7 days before OHD (OHD-7) and seven days after OHD (OHD+7) with OHD fruits serving as control. The fruits were stored at 5 oC for 15, 30 and 45 days. Fruits were evaluated for CI manifestations such as lack of juiciness (wooliness) and flesh bleeding. The lack of free juice released upon crushing fruit flesh through cheese cloth reveals symptoms of wooliness. Percentage CI resistance was calculated (100% - %CI incidence) for each group. Antioxidants were extracted and analysed using the Ferric Reducing Antioxidant Property (FRAP) method. Fruits harvested earlier (OHD-7) recorded the highest antioxidant capacity of 1.080 mgTE/g followed by control fruits (OHD) with antioxidant capacity of 0.976 mgTE/g. Fruits harvested late (OHD+7) recorded the lowest antioxidant capacity of 0.471 mgTE/g. After 15 days of cold storage, OHD resisted CI by 70% followed by OHD+7 (60%) and OHD-7 fruits (55%). After 30 days of storage, OHD-7 fruits recorded 0 resistance to CI but OHD and OHD+7 fruits resisted by 20% each. Fruits of all harvest dates showed no resistance to CI after 45 days of storage. Fruit maturity and cold storage length were found to significantly (P< 0.05) influence CI resistance. For good keeping quality, “Ryan sun” peach fruits should be harvested mature for long keeping but harvested earlier when intended for best antioxidant property.