番石榴果實之貯運技術

Abstract

本試驗調查低溫貯藏對番石榴果實品質之影響，品種包括‘水晶拔’、‘珍珠拔’、‘梨仔拔’、‘世紀拔’等。除‘水晶拔’、‘珍珠拔’外，貯藏於1℃及5℃下14-21 日後，在移至25℃下3 日後，表現出嚴重寒害徵狀，而其餘供試品種貯存於1℃及5℃下7-21 日後，在移至20-25℃下3-4 日，就有寒害症狀出現，寒害症狀表現因品種而異：‘水晶拔’在果皮出現褐化症狀；‘珍珠拔’則表現果皮褐化及果心呈水浸狀之病徵；‘世紀拔’則先出現果肉褐化現象，其次果皮褐化；‘泰國拔’在高濕下亦先出現果肉褐化症狀，而貯藏末期(1℃, 21 日)才有果皮褐化症狀。‘梨仔拔’的寒害症狀計有 果實無法正常後熟、果肉褐化及果心呈水浸狀等；整體而言，番石榴耐寒性由高而低依序為‘水晶拔’、‘珍珠拔’、‘泰國拔’、‘世紀拔’及‘梨仔拔’。低溫貯藏時，果實在PE 袋包裝及加濕下可延緩果皮皺縮情況及果皮褐化之表現。最適貯藏溫度為5-10℃貯藏壽命平均為14-21 天。番石榴‘水晶拔’、‘珍珠拔’等品種可利用1℃ 15 天進行低溫檢疫並以1、5、10℃低溫貨櫃船運具7 至14 天之貯運壽命，但櫥架販售需維持5 或10℃低溫下可維持較佳之品質。 Effects of low temperature storage and heat treatment on fruit qualities of guava (Psidium guajava L.) were evaluated under controlled environmental condition. Guava cultivars, ‘Li-Tzy Bar’, ‘Shyh-Jii Bar’, ‘Tai-Kuo Bar’ and ‘Jen-Ju Bar’, were used in the experiment. Symptom of chilling injury appeared when fruits were stored at 1℃ or 5℃ for a period of 7-12 days and then placed at 20-25℃ for 3 to 4 more days. The symptoms of chilling injury were abnormal ripening, pulp browning and water-soaking core in ‘Li-Tzy Bar’. In the case of ‘Shyh-Jii Bar’ only peel and pulp browning were observed. The water-soaking core usually became visible at the terminal stage. Pulp browning emerged at an early stage and then spreader to the peel of ‘Tai-Kuo Bar’ at 1℃ for 21 days. Fruit of ‘Jen-Ju Bar’ exhibited only brown peel as well as water-soaking core. This seemed to suggest that ‘Jen-Ju Bar’ was most chilling resistant, while ‘Tai-Kuo Bar’ was less tolerant. Cultivars such as ‘Shyh-Jii Bar’ and ‘Li-Tzy Bar’ were found most sensitive to low temperature. In the mean time, the guava fruit was individually wrapped up in a polyethylene bag under high humidity condition with a view to reducing water loss and preventing sample from shrinking.