Thursday, August 11, 2016
Georgia Ballroom (Sheraton Hotel Atlanta)
This study was conducted to evaluate the effect of ethylene on astringent persimmon at different concentration and application temperature. The varieties (Bansi and Daebong) used for the study were grown in Korea and harvested in November, 2015. Ripening was done at 15°C and 25°C, with 80 ± 5% RH conditions using ethylene producing tablet for 6 days at 50ppmv and 100ppmv concentration. The quality was examined in every 2 days interval. Firmness in the case of ‘Bansi’ decreased from 14.8N to 3.5N at 15°C ripening condition within 4 days while the control group were 11.2N. At 25°C ripening, the firmness reduced fast to 3.6N within 2 days while the control group were 10.8N. In the case of ‘Daebong’ firmness after ripening at 15°C was continuously reduced from 14.3N to 2.8N within 6 days but in the control group the softening proceeded slightly and the firmness was 11.2N. Similar trends were observed in case of treatments at 25°C. Soluble solids content in case of 'Bansi' reduced as the ripening period proceeds from 18.6°Brix to about 15°Brix within 6 days. In case of ‘Daebong’ SSC reduced from 14.9 to 13.8°Brix, there was no significant difference between the treatments and the control. Hunter ‘L’ values tended to decrease during the ripening period of both cultivars, showed a more reduced values in the treatment groups compared to the control. Hunter ‘a’ value in case of ‘Bansi’ was reduced from 23.0 to 16.2 and 10.5 in the control and treated groups respectively at 15°C within 6 days. However, in case of 25°C the value was increased slightly up to 2 days 26.1 and then reduced rapidly to 4.78. The higher the ethylene concentration the higher was reduction of Hunter ‘a’ value. In case of ‘Daebong’ at both 15°C and 25°C the change in Hunter ‘a’ value was similar. Soluble tannin content was 625mg/100g immediately after harvesting in case of ‘Bansi’ and then in 15°C condition, control group reduced to 529mg/100g within 6 days. However in the treatment groups, soluble tannin was reduced to about 335mg/100g regardless of ethylene concentration. In 25°C condition, in the treatment group, soluble tannin was reduced rapidly to 49mg/100g after 2 days. The control group reduced slightly to 528mg/100g within 6 days. Similar results were observed in ‘Daebong’. From the result, in both varieties, ripening quality was improved after 6 days at 15°C and after 3-4 days at 25°C regardless of ethylene concentration.