Abstract: The effect of 0.05 g/L kojic acid treatment on the browning of the stem cut section of baby cabbages and its mechanism were studied. The stem cut section was dipped in 0.05 g/L kojic acid or ultrapure water as a control for 1 min and stored at 20 ℃ and 90% relative humidity for up to five days. Samples were taken every day to measure the appearance, respiration intensity, ethylene release rate, total phenolic content, flavonoid content and the activity of browning-related enzymes. The results showed that kojic acid treatment could effectively maintain the sensory quality of baby cabbages, inhibit the browning of the stem cut section, reduce the mass loss percentage and the content of malondialdehyde (MDA), and increase the content of flavonoids and total phenols. Moreover, it inhibited the activity of peroxidase (POD) and polyphenol oxidase (PPO) (by 29.7% and 28.5% relative to the untreated control group on day 5, respectively), but enhanced the activity of phenylalanine ammonia lyase (PAL) and catalase (CAT) (by 1.0% and 12.4% in contrast to the control group on day 5, respectively). Consequently, we concluded that kojic acid treatment could effectively inhibit the browning of the stem cut section of baby cabbages, maintaining the commerciality and nutritional quality and extending the shelf life.

Key words: baby cabbage; kojic acid; browning; quality preservation during storage