Effect of UV-C treatments on quality and browning-related enzyme activity of fresh-cut eggplant (Solanum melongena L.) during cold storage

Abstract

The effect of UV-C (1, 2, 5, and 10 kJ/m2) on sensory attributes, browning index (BI), ascorbic acid (AA), total phenolic compounds, and browning-related enzymes (i.e., polyphenol oxidase, PPO; phenylalanine ammonia lyase, PAL) of fresh-cut eggplants throughout 10 days at 4°C was studied. Untreated samples were used as control. Treatments with 5 and 10 kJ/m2 presented higher values of PPO activity and BI, with a loss of 50% and 30% of AA and phenols compared with the control, and sensory quality fewer than 4 days. In contrast, 1 and 2 kJ/m2 did not affect PAL activity and 1 kJ/m2 showed sensory acceptance for at least 6 days, with significantly low BI values and PPO activity, and higher phenol and AA content, compared with the other treatments. Therefore, 1 kJ/m2 could be an effective technology to maintain quality and delay the browning of fresh-cut eggplants. Novelty impact statement: Enzymatic browning is the main factor limiting the shelf life of fresh-cut eggplants. Therefore, to reduce this problem, the effect of UV-C radiation on the quality of this vegetable was studied. The dose of 1 kJ/m2 had a beneficial impact on the reduction of enzymatic browning since it induced the least increase in PPO activity, the highest retention of AA and total phenols, and not affected PAL activity.