Effects of postharvest citric, oxalic acid and modified atmosphere packaging applications on fruit quality and biochemical properties in persimmon.

backgroundThis study aims to investigate the effects of postharvest oxalic acid (OA), citric acid (CA) and modified atmosphere packaging (MAP) applications on fruit quality and preservation of biochemical content in persimmon. This research conducted on "Rojo brillante" variety persimmon (Diospyros kaki L), evaluated the effects of various treatment methods on fruit quality during 90 days of storage period. In the study, the parameters such as weight loss, total soluble solids (TSS), titratable acidity, fruit firmness, respiration rate, ethylene production, gas composition, phenolic content, antioxidant activity and organic acids were investigated.

methodIn the study, each application consisted of three replications. The first group was control, the second group was 1 mmol CA, the third group was 1 mM OA, the fourth group was MAP, the fifth group was 1 mmol CA + MAP and the sixth group was 1 mM OA + MAP. The fruits were kept in control, CA and OA solutions for 15 min. The fruits were stored for 90 days at 5 °C and 85 ± 5% relative humidity.

resultsDuring storage period, fruit weight loss, water loss and natural physiological changes increased. OA and CA acid applications were not effective in reducing fruit weight loss, but OA + MAP applications were more effective in preserving fruit quality. MAP prevented water loss and preserved fruit quality by decreasing oxygen levels and increasing carbon dioxide levels. The changes in TSS ratio were observed while MAP and OA + MAP treatments kept TSS constant. Application of OA + MAP increased acidity by preserving the stability of acidic compounds. Flesh firmness decreased with storage time, but MAP and OA + MAP combinations gave better results. As the storage period progressed, color changes and respiration rate increased, MAP application slowed down fruit respiration and delayed ripening. An increase in carbon dioxide levels was observed during storage, the highest levels were recorded in OA + MAP and CA + MAP applications. MAP application kept nitrogen levels the highest, the nitrogen levels reached equilibrium with the combination of OA and MAP. In addition, OA and CA applications increased phenolic content and antioxidant activity while it decreased in MAP and control groups. In terms of acidic compounds, the combination of OA and MAP was effective in preserving fruit acids. CONCLUSSION: OA + MAP treatments were more effective in preserving fruit quality by reducing water loss, maintaining acidity, and improving flesh firmness compared to other applications. MAP treatment also slowed respiration, delayed ripening, and maintained nitrogen levels, contributing to overall fruit preservation during storage. The study revealed the potential use of these methods in extending fruit quality and shelf life.