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The effects of high CO2 (5% and 10%), on respiratory metabolism and quality of sweet cherries ("Rainier" and "8–102" varieties), were evaluated following storage at 0°C for 60 d. Quality (respiration rate, weight loss, firmness, etc.) in sweet cherries was significantly improved by high CO2 in storage. And high CO2 enhanced pentose phosphate pathway, decreased in the glycolytic pathway and tricarboxylic acid cycle in aerobic respiration proved by elevated the contents of NADP(H), source, and fructose, as well as alleviated the levels of NAD(H). Cell membrane integrity was also better in these conditions, with higher activities of pyruvate kinase, phosphofructokinase b, and adenosine triphosphatase and lower activities of polyphenol oxidases and cytochrome C oxidases. Moreover, high CO2 decreased anaerobic respiration by inhibiting the accumulations of pyruvic acid, ethanol, and acetaldehyde, as well as by reducing the activities of pyruvate decarboxylase and alcohol dehydrogenase. Novelty impact statement: High CO2 (5% or 10%) enhanced the NAD(P)H levels in sweet cherries held at 0°C for 60 d.Respiratory metabolism was higher following the use of 10% CO2 during such storage.High CO2 maintained cell membrane integrity in sweet cherries stored at 0°C for 60 d. [ABSTRACT FROM AUTHOR]

BACKGROUND: Blueberries are appreciated by consumers for their rich natural antioxidants and their good nutritional and health functions. However, blueberries are very perishable due to microbial infection and metabolic aging after harvest. Ethanol has been shown to have the effect of controlling postharvest microorganisms and improving storage quality of fruits and vegetables. This study aimed to clarify the effects of ethanol on the appearance quality and flavor attributes of postharvest blueberries. Blueberries were treated with ethanol (250, 500, and 1000 μL L−1) and stored at 0 ± 0.5 °C, 90% relative humidity (RH), for 40 days. RESULTS: The results indicated that ethanol treatment could slow the decline of blueberry firmness and reduce the decay rate significantly in a dose‐dependent manner. The soluble solids content (SSC) and titratable acidity (TA) of ethanol‐treated blueberries increased significantly (P < 0.05), improving the taste of the blueberries. The activities of alcohol dehydrogenase (ADH) and pyruvate decarboxylase (PDC) were stimulated with the accumulation of ethanol in blueberries, which catalyzed the conversion of ethanol, acetaldehyde, and pyruvate, increasing their levels in blueberries. More volatiles, especially esters, were detected in ethanol‐treated blueberries, e.g. methyl acetate, ethyl acetate, ethyl propanoate, ethyl isobutyrate, ethyl 2‐methylbutanoate, ethyl isovalerate, ethyl 3‐methyl‐2‐butenoate, diethyl sebacate, and isopropyl myristate. CONCLUSION: The preservative effect of ethanol on blueberry was significantly affected by ethanol concentration. In this study, the effect of 500 μL L−1 ethanol fumigation on blueberry was the best in terms of appearance quality (firmness and decay rate) and flavor attributes (SSC, TA, and volatiles). © 2019 Society of Chemical Industry [ABSTRACT FROM AUTHOR]