Abstract: In order to explore the effect of heat shock treatment (HT) on the storage quality of fresh-cut lily bulbs, changes in the quality characteristics of lily bulb slices (Lilium davidii var. unicolor Cotton) exposed to heat shock treatment (hot water at 55 ℃, 2 min) were examined during storage at 4 ℃. The results demonstrated that HT effectively maintained the color of fresh-cut lily bulbs during storage and preserved the cell wall structure. The activities of peroxidase (POD), polyphenol oxidase (PPO), phenylalanine ammonia lyase (PAL) were suppressed by HT. Meanwhile, the accumulation of total phenolics (TP) and malondialdehyde (MDA) and the increase of relative electric conductivity (REC) were delayed, which led to reduced mass loss, decay rate, and browning degree. Comparison with the control group, the activities of POD, PPO and PAL in the HT group decreased by 95.26%, 21.74% and 41.65%, respectively. The decay rate, browning degree, MDA content, REC and TP content in the HT group were 10.56%, 1.55, 0.13 μmol/g, 19.71% and 3.51 mg/g, respectively, which were all significantly lower than those in the control group (P < 0.05), and the hardness, whiteness and soluble protein content were 1 848.09 g, 79.65 and 7.62 mg/g, respectively, which were all significantly higher than those in the control group (P < 0.05). After 40 days of storage, mass loss rates of 0.85% and 0.66% and soluble sugar contents of 14.04% and 14.78% were observed respectively for the control and HT groups, with no significant difference being found between the groups (P > 0.05). Furthermore, plasma membrane dissolution did not appear in the HT group until the 40th day, which was 30 days later than the control group. Therefore, HT effectively delayed the quality deterioration of fresh-cut lily bulbs during storage and prolonged the storage time.

Key words: fresh-cut lily bulbs; heat shock treatment; enzyme browning; storage quality; fresh-cut fruits and vegetables