Horticultural Science and Technology 원예과학기술지 ISSN:1226-8763(Print) 2465-8588(Online)

Hot water dipping test was conducted for chicon to restrict red discoloration of its basal part which impairs the product value during sales. Hot water dipping treatment was given to chicon for 4 min and for 8 min at 38°C and for 2 min and 4 min at 42°C, and for 1 min and 2 min at 45°C, along with control (for one min at 20°C). The red discoloration indices of basal part of chicon during sensory evaluation on the sixth day of storage under the storage temperature at 10°C was lower at 42°C for 2 min, 42°C for 4 min and 45°C for 1 min treatments. The color change value of the basal part in chicon measured by colorimeter showed that the lowest △a* and △h were maintained in the basal part of chicon treated at 42°C for 2 min. Whereas, color changes in 42°C for 2 min and 45°C for 1 min treatments were significantly low as compared with that of control. The contents of total phenolic compounds which are the substances that cause red discoloration of basal part in chicon were lowest at 42°C for 2 min, 42°C for 4 min and 45°C for 1 min treatments. The activity of phenylalanine ammonia lyase (PAL) resposible for in the synthesis of phenolic substances was the least in 42°C for 2 min treatment. Whereas, PAL activity of the chicons treated at 42°C for 2 min and at 45°C for 1 min were significantly lower than that of control. However, red discoloration was progressed as similar level with that of control in the basal part of chicon at 45°C for 2 min. The contents of total phenolic compounds and PAL activity in this treatment were not significantly different from those in control. The polyphenol oxidase (PPO) activity which causes red discoloration of cut tissues was low in all the treatments including 42°C and 45°C treatment at which no inhibition effects of the red discoloration of basal part of chicon were observed. When the correlation coefficient between each investigated index was tested, most of them showed high correlation except the PPO activity and particularly and the red discoloration index and sensory evaluation △h values, and PAL activity and total phenolic compounds content were r = 0.927**, and r = 0.942**, respectively.