수확기, 온도 및 Ethephon 처리에 따른 떫은감 (Diospyros kaki Thunb.)의 연화

Softening of Astringent Persimmon (Diospyros kaki Thunb.) as Affected by Harvest Time, Temperature, and Ethephon Treatment

본 연구는 떫은감 "청도반시"를 조기착색과는 9월 21일, 적숙과는 10월 11일에 수확하여 수확시기에 따른 연화정도를 조사하고, 연시제조의 적정온도를 설정하고자 10, 15, $20^{\circ}C$에서의 품질변화를 조사하였다. 경도는 처리온도 15, $20^{\circ}C$에서 처리 2일만에 전체 경도 감소량에 70% 정도 감소되었으며, 6일 이후에는 경도의 감소가 완만하게 되었다. 처리온도 $10^{\circ}C$는 다른 처리온도에 비하여 높은 경도를 나타내어 연시제조에는 효과가 없었다. 가용성탄닌은 수확시기에 관계없이 15, $20^{\circ}C$의 처리구에서 6일째에 급격히 감소하였으나, 무처리구는 가용성탄닌이 약간 감소되었다. 조기수확과의 Hunter 'L', 'b' value는 모든 처리온도에서 2일째까지 증가한 후 감소하였고, 적숙과는 초기부터 감소하기 시작하여 8일째부터는 비교적 일정한 경향을 보였다.

This study was conducted to evaluate the effect of harvest time, temperature and ethephon on the softening of astringent persimmon 'Cheongdobansi'. The persimmon was harvested on Sep. 21 (early season harvesting) and Oct. 11 (optimum season harvesting). Quality changes were evaluated at 10, 15 and $20^{\circ}C$ after ethephon treatment. Seventy percent of hardness decrease occurred during the first 2 days of treatment at 15 and $20^{\circ}C$, and hardness was slowly decreased after 6 days. The treatment of $10^{\circ}C$ was not effective on inducing fruit softening. Soluble tannin content was sharply decreased 6 days after ethephon treatment at 15 and $20^{\circ}C$ regardless the harvest time, whereas this was much slower in control. Hunter 'L' and 'b' values were increased until 2 days, and then decreased with the early harvested persimmon. The Hunter values were decreased until the 8th day of storage in fruit harvested at optimum season.