Effect of Citric Acid Treatment on the Quality of Fresh-Cut Apple Slices during Storage

The effect of citric acid treatment on the quality of fresh-cut apple slices was studied. Fresh-cut ‘Hanfu' apple slices were soaked in 0.5%, 1.0% and 1.5% citric acid solutions for 2 min, respectively. After draining off the liquid, the apple samples were packaged in PE bags(0.11 mm thick) and stored at 4 ℃. Physiological and biochemical indicators related to fruit maturation and ageing were measured every 2 days during the cold storage. The results indicated that treatment with citric acid at appropriate concentration maintained the sensory quality, inhibited nutritional loss, and reduced microbial levels in apple slices. Treatment with 1.5% citric acid exerted the best preservative effect on apple slices stored for 8 days at 4 ℃. This treatment could delay effectively the process of flesh browning, reduce browning degree and inhibit the decreases of hardness, total soluble solid(TSS), titratable acids and VC contents and the increases of relative conductivity, malondialdehyde(MDA), and suppress polyphenol oxidase(PPO) and peroxidase(POD) activities.