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To preserve the quality traits of late-harvested 'Galaxy' apples during extended storage, the effects of 1-methylcyclopropene (1-MCP) treatment and storage conditions on postharvest quality were analysed. Alongside quality measures, indicators like ethylene production, respiration rate, aminocyclopropane-1-carboxylic acid oxidase (ACO) activity, and membrane permeability were assessed. Apples were harvested at an optimal harvest date or later and stored for 7 months at 1°C under regular atmosphere or controlled atmosphere. Treatments with 1–MCP at 300, 600 or 900 nL L−1 were applied pre- or post-storage. After 7 days shelf-life, apples subjected to 1-MCP and controlled atmosphere exhibited reduced ethylene production, respiration rate, and ACO activity compared to untreated or regular atmosphere counterparts. While the time of 1-MCP application and its concentration did not impact the respiration rate during shelf-life, controlled atmosphere effectively decreased it. The combination of controlled atmosphere and 1–MCP pre-storage was most effective in lowering ACO activity. Irrespective of conditions, 1-MCP curtailed ethylene production, respiration rate, and ACO activity during shelf-life, alleviating firmness and acidity loss. Only controlled atmosphere preserved quality and minimised disorders for optimally harvested apples, not late-harvested ones. None of the treatments maintained late-harvested apples' quality after long-term storage plus shelf-life. [ABSTRACT FROM AUTHOR]

This research investigates the impact of storage conditions on the quality and preservation of 'Shalimar' apples, a relatively new cultivar known for its resistance to apple scab and powdery mildew. The study explores the efficacy of different storage techniques such as regular atmosphere (RA), controlled atmosphere (CA), and dynamic controlled atmosphere with CO2 Monitoring (DCA-CD), as well as the integration of 1-methylcyclopropene (1-MCP) at different storage temperatures (1 °C and 3 °C). Various fruit quality parameters were monitored under different storage conditions, including firmness, titratable acidity, total soluble solids, background color, respiration, ethylene production, and volatile compounds. The results indicate that the controlled atmosphere (CA) at 1 °C emerges as an efficient method for long-term storage. However, it is noted that CA storage may impact the apple aroma, emphasizing the need for a balance between preservation and consumer acceptability. On the other hand, DCA-CD at variable temperatures (approximately 2.5 °C) offers a promising approach for maintaining fruit quality and a higher concentration of volatile compounds. Integrating 1-MCP enhances firmness, but its impact varies across storage conditions. Principal component analysis (PCA) provides insights into the relationships between storage conditions, fruit quality, and volatile compounds. This study contributes valuable insights into optimizing storage strategies for 'Shalimar' apples, addressing sustainability and quality preservation in apple production. [ABSTRACT FROM AUTHOR]

Highlights • SI can help to determine the right maturity stage of Conference and Alexander Lucas pears destined for 1-MCP application. • Harvest fruits at more mature stage cancel the 1-MCP inhibitory effect on the Conference and Alexander Lucas pear ripening. • ULO decreases the production of aromatic compounds less severely than 1-MCP. • Maturity stage at harvest has no clear effect in Conference and Alexander Lucas pears under ULO. • CA storage has no effect on the ripening in terms of aroma compounds production as compared to CS. Abstract The objective of this investigation was to evaluate the quality parameters and aroma profiles of Conference and Alexander Lucas pears after 7 months of storage. Fruits of both cultivars were harvested at two different maturity stages and stored under cold (CS) (20.9 kPa O 2 + <0.04 kPa CO 2), controlled atmosphere (CA) (2 kPa O 2 + <0.7 kPa CO 2) and ultra-low oxygen condition (ULO) (0.7 kPa O 2 + <0.7 kPa CO 2). CS and CA storage also included treatment with 1-methylcyclopropene (1-MCP) at 300 nL L−1. After seven months of storage at 0 ± 0.1 °C and 94 ± 2% RH plus seven days at 20 ± 2 °C and 60 ± 5% RH, fruits were evaluated for flesh firmness, peel color ('hue' angle = h°), soluble solids content (SSC), titratable acidity (TA), respiratory rate, ethylene production rate, and production of aromatic compounds. Fruits of both cultivars from the first maturity stage treated with 1-MCP did not develop a buttery texture or yellow color and produced significantly less alcohols and esters. A combination treatment (1-MCP + CA) most severely suppressed aroma development, particularly in the Conference cultivar. ULO storage also reduced yellowing, ethylene production and the development of aromatic compounds in both cultivars from the first maturity stage, but this reduction was less pronounced than that observed for 1-MCP treatments. The production of aromatic compounds was lower in fruits from ULO, regardless of their maturity stage. Fruits from the second harvest treated with 1-MCP had significantly more aromatic compounds than did those from the first harvest. In general, the CA condition has no effect on the ripening and production of aromatic compounds in both cultivars compared to CS. [ABSTRACT FROM AUTHOR]

[Display omitted] • DCA-RQ storage reduces superficial scald (SS) in relation to DCA-CF. • α-farnesene and 6-methyl-5-hepten-2-one were inversely correlated to SS. • Higher ethanol concentration in DCA-RQ have a inhibitory effect on SS incidence. • Storage with higher pO 2 and IEC is positively correlated with SS. A positive correlation of α-farnesene and its oxidation metabolites with superficial scald is commonly reported in apples stored in air or controlled atmosphere (CA) systems, where O 2 levels are above the lower oxygen limit (LOL) tolerated by the fruit. Nevertheless, the LOL can be monitored by the dynamic controlled atmosphere (DCA) techniques and to provide different physiological responses. Therefore, this study aimed to evaluate key volatile metabolites from 'Granny Smith' and 'Nicoter' ('Kanzi®') apples stored under dynamic controlled atmosphere (DCA) monitored by respiratory quotient (RQ), i. e. at extremely low oxygen partial pressures (ELO) and correlate their emissions with the incidence of superficial scald (SS). The volatile compounds (VCs) were isolated by solid phase microextraction (HS-SPME) and analyzed by gas chromatography. For the first time, higher concentrations of α-farnesene and its oxidation metabolites (6-methyl-5-hepten-2-one, and 6-methyl-5-hepten-2-ol) were negatively correlated with SS in DCA-RQ. This is likely due to the higher levels of ethanol in fruit stored under this condition having an inhibitory effect on SS incidence even when α-farnesene, 6-methyl-5-hepten-2-one, and 6-methyl-5-hepten-2-ol accumulate. Additionally, SS is more correlated to internal ethylene concentration (IEC) than α-farnesene accumulation and their metabolites, even when fruit were stored under ELO, where ethylene action is reduced. [ABSTRACT FROM AUTHOR]

This study investigated the effects of controlled atmosphere (CA - 1.0 kPa O 2 and < 0.7 kPa CO 2), dynamic controlled atmosphere based on carbon dioxide production (DCA-CD), 1-methylcyclopropene (1-MCP), and raised storage temperatures (1 °C to 3 °C), on fruit metabolism and quality, disorder incidences and the volatile profile of 'Santana' apples after 6 months storage and 7 d shelf life at 20 °C. The evaluation is based on a comparison to a control group of cold storage under regular atmosphere (RA). Low oxygen partial pressures (pO 2) in CA and DCA-CD in combination with 1-MCP slowed down fruit respiration and ethylene production and thus compensated for the ripening-inducing effect of raised storage temperatures. 'Santana' apples stored under CA or DCA-CD with additional 1-MCP, had the highest flesh firmness, titratable acidity, and greener peel coloration after storage and shelf life. CA and DCA-CD reduced core browning and fungal decay in comparison to RA. Low pO 2 and 1-MCP application lowered the abundance of straight-chain alcohols and esters in 'Santana' apples. DCA-CD storage enabled a safe induction of anaerobic metabolism in 'Santana' apples, which increased levels of ethanol and derived ethyl esters. 1-MCP enhanced anaerobic metabolism in DCA-CD. Raised storage temperatures were found to increase alcohol and ester accumulation in DCA-CD. This technology consequently enables the storage of 'Santana' apples at higher temperatures, which could contribute to limiting stress experienced by the fruit and enhancing the formation of key aroma compounds, while also reducing energy usage of the refrigeration system. • Postharvest characteristics of the organic apple cultivar 'Santana' were studied. • Static CA, DCA-CD, and 1-MCP reduced core browning and fungal decay incidences. • DCA-CD + 1-MCP compensated ripening-inducing effects of higher storage temperatures. • Higher temperature reduced low oxygen stress and increased aroma formation. • 'Santana' apples stored under DCA-CD showed higher ethanol and ethyl ester levels. [ABSTRACT FROM AUTHOR]

The aim was to evaluate the isolated or combined effects of ethanol vapor (500 ppm) and ethylene treatments (150 ppm), on the ethylene production, respiration, sugars and organic acids dynamics of 'Elstar' and 'Nicoter' apples after harvest, during 14 d at 20 °C. Another aim was to identify at which step of fruit metabolism ethanol vapor acts. Fruit were exposed to ethanol vapor and/or ethylene for 24 h. Metabolites were evaluated at 0, 7 and 14 d at 20 °C. Ethanol vapor treatment significantly inhibited the effect of ethylene on the ethylene production and respiration, but had no significant effect on the starch metabolization and sucrose dynamics. Its application also resulted in higher succinate, malate and total organic acids concentrations. Ethanol application reduced significantly the sucrose conversion to glucose and fructose, while the ethanol + ethylene treatment resulted in high total sugars, fructose and sorbitol concentration after 14 d at 20 °C. The ethanol application (500 ppm) also affected conversion of succinate to fumarate, suggesting the succinate dehydrogenase activity as one possible action point of ethanol on the apple fruit metabolism. According to the PCA analysis, the combination of ethanol + ethylene treatments had a different response as their isolated application, affecting sugars and organic acids metabolism differently. Additionally, it can be verified that the response to treatments of both apple cultivars is differently affected by the holding time, being the response latter for 'Nicoter' apples when compared to 'Elstar'. • Ethanol and ethylene treatments on sugars and organic acids of apples was studied. • Ethanol reduced the effect of ethylene on apple fruit metabolism. • Ethanol treatment did not affect starch degradation in 'Elstar' and 'Nicoter' apples. • Succinate accumulate in fruit treated with ethanol and ethanol + ethylene. • Ethanol + ethylene induced the accumulation of total sugars, fructose and sorbitol. [ABSTRACT FROM AUTHOR]

• The combined effect of ethanol vapor and ethylene on ripening of apples was studied. • Apple ripening is slowdown by ethanol treatment even when combined to ethylene. • PDC and ADH activity are enhanced by ethanol vapor treatment. • 'Nicoter' apples had better capability to metabolize ethanol than 'Elstar' apples. • No internal and external physiological disorder were induced by ethanol treatment. The present study aimed to evaluate the effect of two ethanol vapor doses (250 and 500 ppm), 1-methylcyclopropene (1-MCP) (0.650 ppm) with or without ethylene application (150 ppm) on the aerobic and anaerobic metabolism and quality of 'Elstar', a fast ripening apple cultivar, and 'Nicoter', a slowly ripening apple cultivar, over 14 d of holding at room temperature (20 ± 2 °C). Fruit were subjected to treatments for 24 h and analyses performed after 0, 7 and 14 d holding at room temperature (20 ± 2 °C). For both cultivars studied, ethanol vapor treatments, especially 500 ppm, inhibited the ripening of apples even when combined with 150 ppm of ethylene, but not as much as 1-MCP treatment in 'Nicoter' apples. Fruit treated with ethanol vapor maintained lower electrolyte leakage, higher flesh firmness, greener color and had more healthy fruit. However, its application increased the pyruvate decarboxylase (PDC) and alcohol dehydrogenase (ADH) activity, acetaldehyde and ethyl acetate accumulation, but in concentrations below the odor threshold reported in the literature. The 1-MCP treatment increased decay incidence, reducing the healthy fruit amount in 'Nicoter' apples after 14 d, but maintained a very low ethylene production and respiration rate, which allowed higher acidity maintenance after 14 d holding at room temperature. There was no incidence of external and internal physiological disorders in both cultivars. [ABSTRACT FROM AUTHOR]