UV-C treatment affects browning and starch metabolism of minimally processed lily bulb

• Published in: Postharvest biology and technology 2017-06, Vol.128, p.105-111
• Main Authors: Huang, Hao, Ge, Zhiwei, Limwachiranon, Jarukitt, Li, Li, Li, Weirong, Luo, Zisheng
• Format: Article
• Language: English
• Subjects: Alternative technology; Ammonia; Amylases; Antioxidants; Browning; Lily bulb; Metabolism; Microorganisms; Minimally processed; Oxidase; Peroxidase; Phenolic compounds; Phenols; Phenylalanine; Phosphorylase; Polyphenol oxidase; Quality; Starch; Starch phosphorylase; Studies; Sugar; Ultraviolet radiation; UV-C; Vegetables; α-Amylase; β-Amylase
• ISSN: 0925-5214; 1873-2356
• DOI: 10.1016/j.postharvbio.2017.02.010

[Display omitted] •UV-C radiation maintained quality of minimally processed lily bulb effectively.•UV-C radiation decreased browning by suppressing PPO and POD activities.•UV-C radiation increased PAL activity, phenolic content and antioxidant activity.•UV-C radiation inhibited starch degradation. The effects of 4.5kJm−2 UV-C radiation on the quality of minimally processed lily bulb, such as browning, growth of microorganism, total phenolic content, starch, total soluble sugar, reducing sugar content, the activities of phenylalanine ammonia lyase (PAL), polyphenol oxidase (PPO), peroxidase (POD), α-amylase, β-amylase, starch phosphorylase and the antioxidant activity were studied. Results showed that UV-C treatment inhibited browning index and microbial growth by approximately 37% and 32% respectively. Compared with the control, PPO and POD activities of UV-C treated minimally processed lily bulb were reduced by about 26% and 18% respectively, while total phenolic content was increased by 13%. UV-C treatment down-regulated the activities of α-amylase, β-amylase and starch phosphorylase, which resulted in higher content of starch, total soluble sugar content and lower content of reducing sugar. The antioxidant activity and PAL activity were higher than the control during storage. These results indicated UV-C treatment could effectively maintain quality of minimally processed lily bulb stored at 4±1°C. Therefore, UV-C radiation might be an effective and safe alternative technology for minimally processed lily bulb.