A Possible Role and Mode of Action of UV-C Illumination and Inducing Chilling Stress Tolerance in Banana Peel
N. Pongprasert, Y. Sekozawa, S. Sugaya and H. Gemma
Book of Abstracts, Asia-Pacific Symposium on Assuring Quality and Safety of Agri-Foods, August 4-6, 2008, Radisson Hotel, Bangkok, Thailand.
2008
บทคัดย่อ
A Possible Role and Mode of Action of UV-C Illumination and Inducing Chilling Stress Tolerance in Banana Peel
In order to better understand the possible role and mode of action of UV-C illumination on inducing chilling stress tolerance. Banana (Musa (AAA group), Gavendish subgroup cv. Cavendish) fruits were treated with three UV-C duration and dosages 10, 15 and 20 sec, (0.002, 0.03 and 0.05 kJm-2) prior to storage at 5, 8 and 25°C. As the results, different temperature obviously showed difference response. The chilling injury (CI) symptom was severe at 5°C as compared with 8°C but UV-C treatment reduced CI, corresponding with lower in IC50 values of 1-diphenyl-2-picrylhydrazyl (DPPH)-radical scavenging activity in treated fruit when stored at 5 and 8°C rather than control. Ethylene production and respiration rate of fruits stored at 25°C were activated by UV-C. A higher activity of phenylalanine ammonia lyase (PAL) and total free phenolics also found in treated fruits at 5°C while at 8°C with lower level in comparison with control. In additions, UV-C treatment inhibited increasing of malondialdehyde (MDA) content in fruits stored at 25°C while fruits stored at 5 and 8°C showed higher content of MDA compared with control. It is possible that UV-C at 0.03 kJm-2 compared with dosage would be available for alleviating CI symptom occurrence in the case of banana. Also these results implied that UV-C could play a role in activation of plant defense mechanisms and antioxidant systems, assisting in reducing chilling stress. However, the study of associated mechanisms in response to UV-C should be elucidated.