외생 에틸렌 처리 후 저장 온도에 따른 키위프루트 ‘감록’, ‘헤이워드’, ‘골드원’, ‘제시골드’ 과실의 후숙 특성

Abstract

This study aimed to understand the fruit ripening characteristics according to kiwifruit cultvars and investigate the post-harvest management method appropriate for cultivar grown in Korea. In the experiment, fruit ripening characteristics were investigated according to storage temperature after exogenous ethylene treatment. The cultivars of kiwifruit used in the experiments were as follows: 3 domestic cultivars (Actinidia deliciosa 'Garmrok', A. chinensis 'Goldone' and 'Jecy Gold') and a New Zealand cultivar (A. deliciosa 'Hayward'). The experiments were performed with the kiwifruit classified as two different species: A. deliciosa and A. chinensis. The exogenous ethylene was treated with A. deliciosa and A. chinensis at 1,000 mu L.L-1 and 100 mu L.L-1 for 24 hours, respectively. After the treatment, the fruits were stored in the low temperature chamber at three different temperatures of 5, 15, and 20 degrees C. Quality changes of fruit were occurred more rapidly at higher storage temperature. Soluble solids content (SSC) was 18 degrees Brix for 'Garmrok' kiwifruits stored at both 20 degrees C and 15 degrees C at 6 and 9 days of storage, respectively., The SSC of 'Hayward' kiwifruits was increased by three days later at all three storage temperatures compared to 'Garmrok' kiwifruits. The highest SSC values for 'Goldone' and 'Jecy Gold' kiwifruit were recorded at 9 and 12 days of storage at 20 degrees C and 15 degrees C, respectively. Titratable acidity (TA) of 'Garmrok' kiwifruit was 1% at both 20 degrees C and 15 degrees C at 3 days of storage. However, the decreasing of TA of 'Hayward', 'Goldone', and 'Jecy Gold' kiwifruits at 15 degrees C storage was delayed compared to TA of kiwifruits at 20 degrees C. Deceasing of kiwifruit firmness was higher with the increasing storage temperatures in an order of 5 degrees C, 15 degrees C, and 20 degrees C for all kiwifruit cultivars used in the experiment. Further, higher respiration rate and ethylene production was recorded at high storage temperature for all cultivars. The ripening characteristics were not observed from kiwifruits from all four cultivars until 30 days of storage at 5 degrees C. Based on the findings in this study, it was determined that 'Garmrok' kiwifruit retained their quality for a shorter period of time than the 'Hayward' kiwifruit during low-temperature storage, and unlike A. chinensis cultivars, which generally have a short quality retention time, the 'Goldone' and 'Jecy Gold' cultivars showed quality retention properties, similar to that of the 'Hayward' kiwifruit. Our findings in this study are valuable to understand the fruit ripening characteristics of kiwifruit for different varieties and for post-harvest management of domestic cultivars.