Prevention of quality deterioration of 'Comte de Paris' pineapple harvested at different seasons and during postharvest storage

• The sugar content could serve as a reference for regulating production period. • The increase of fructose and glucose content were biological markers for the IB occurrence. • The 2 % citric acid treatment delayed the occurrence of IB after harvest. The year-round supply of ‘Comte de Paris’ pineapple, largely achieved to meet market demand, but ‘Comte de Paris’ pineapple is highly vulnerable to internal browning (IB) during postharvest storage, severely impacting its commercial attributes. Therefore, understanding the patterns of the IB variation is essential to produce high-quality and flavorful pineapple. Our study evaluated the quality and the IB occurrence rate of pineapple harvested monthly for three consecutive years. The sugar content exhibited significantly seasonal difference and could serve as a reference for regulating production period to ensure high-quality of fruits. The occurrence rate of IB also showed significant seasonal difference and was highly correlated with the temperature of harvest month and sugar content. The increase of fructose and glucose content could be the biomarker for potential IB. The occurrence of IB led to significant decrease in the contents of sucrose and organic acids, particularly citric acid, which is crucial for maintaining the flavor and quality of pineapple. Based on those findings, the application of 0.2 % of citric acid significantly reduced the occurrence of IB by increasing ascorbic acid content, enhancing peroxidase and phenylalanine ammonia-lyase activities, while decreasing polyphenol oxidase activity. This study indicates that the occurrence of IB is a complex process regulated by multiple factors and provided an insightful explanation and prevention strategy of the inconsistent quality of pineapple harvested at different seasons. The results could be used to guide the cultivation and production for consistently harvesting high-quality pineapple at different seasons and storage.