Reduction of enzymatic browning of fresh-cut Chinese yam (Dioscorea opposita) by UV-C treatment

Abstract

Herein, we studied the effect of UV-C (shortwave ultraviolet) irradiation on the quality and inhibition of the browning of fresh-cut Chinese yam (Dioscorea opposita). The irradiation of 0, 4, 8, 12, and 24 kJ m-2 were applied to fresh-cut Chinese yam, and quality characteristics were evaluated during 16 days of storage at 4°C. The results indicated that UV-C treatment (8 KJ m-2) effectively decreased the browning degree, polyphenol oxidase (PPO) and peroxidase (POD) activities, and total bacteria count (TBC). However, the phenylalanine ammonia lyase (PAL) activity, PAL gene expression, respiration rate, and total phenol content increased. The UV-C treatment of 8 kJ m-2 resulted in a lower degree of membrane damage, as evidenced by the lower soluble quinone accumulation and browning index (BI), and retained the soluble solid content and hardness during storage. Increasing irradiation intensity would enhance cell damage while did not reduce browning. The results also showed that UV-C treatment alone had great potential to inhibit the browning of fresh-cut vegetables.