Respiratory metabolism and quality in postharvest sweet cherries ( Prunus avium L.) in response to high CO 2 treatment

Abstract

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 (PPP), decreased in the glycolytic pathway (EMP) and tricarboxylic acid cycle (TCA) in aerobic respiration proved by elevated the contents of NADP(H), source and fructose, as well as alleviated levels of NAD(H). Cell membrane integrity was also better in these conditions, with higher activities of pyruvate kinase (PK), phosphofructokinaseb (PFK), adenosine triphosphatase (ATPase) and lower activities of polyphenol oxidases (PPO) and cytochrome C oxidases (CCO). Moreover, high CO2 decreased anaerobic respiration by inhibited accumulations of pyruvic acid, ethanol and acetaldehyde, as well as by reduced the activities of pyruvate decarboxylase (PDC) and alcohol dehydrogenase (ADH).