貯藏溫度對台灣1號和黑葉荔枝果實貯藏壽命和品質之影響

Abstract

‘台農1號’與‘黑葉’荔枝果實分別貯藏在2℃、4℃、6℃和25℃（室溫）經28天後調查果實失重率、褐化率、腐爛率與可溶性固形物含量。果實失重率達2.0%以上及果皮褐化率超過51%皆判斷為無商品價值。結果顯示在25℃、2℃與6℃貯藏28天後，兩品種荔枝果實隨貯藏天數增加而失重率、褐化面積與腐爛率亦相對增加，且失重率達2.0%以上、褐化率超過51%、果實發生腐爛，故皆無商品價值，且可溶性固形物含量亦隨貯藏天數增加而下降。而貯藏在4℃，兩品種荔枝果實失重率下降緩慢，皆在2.0%以下，亦無腐爛發生，可溶性固形物含量隨貯藏天數增加而緩慢遞減，故4℃為此二品種荔枝果實最適貯藏溫度。‘台農1號’與‘黑葉’荔枝果實貯藏在4℃褐化率分別為48.9%±2.4%、77.3%±3.2%，顯示‘台農1號’耐貯性較‘黑葉’荔枝果實佳。將‘台農1號’與‘黑葉’荔枝果實分別放在2℃、4℃、5℃與25℃貯藏下，觀察果實呼吸率及乙烯產生量之情形。結果顯示兩品種之呼吸率在25℃貯藏者較高。在低溫下，‘台農1號’與‘黑葉’荔枝果實呼吸率隨著貯藏天數緩慢下降，‘台農1號’與‘黑葉’荔枝果實呼吸率並無明顯差異。‘台農1號’與‘黑葉’荔枝貯藏在2℃、4℃、5℃下之乙烯產生量非常低，而貯藏在25℃下由於病害發生嚴重導致乙烯量增加。 Fruits of litchi 'Tainung No.1' and 'Hak Ip' were stored at 2, 4, 6, and 25℃ for 28 days. Poststorage quality was evaluated and measured as changes in weight loss, peel browning area, decay, and total soluble solids (TSS) during storage. Fruits were considered unsalable when fresh weight loss exceeded 2% or browning area exceeded 51% after storage. Results showed that fruit weight loss, peel browning area, and decay percentage increased, and TSS decreased with time in both cultivars when stored at 25, 2, and 6℃, and all these stored fruits were unsalable. In contrast, fruit weight loss did not exceed 2%, fruit TSS decreased more slowly, and no decay were recorded in fruits of both cultivars stored at 4℃. Peel browning area were 48.9%±2.4% and 77.3%±3.2%, respectively for 'Tainung No.1' and 'Hak Ip' fruits stored at 4℃for 28 days, indicating that fruits of 'Tainung No.1' were more tolerant to 4℃ storage than 'Hak Ip'. Respiration and ethylene production were measured in fruits of 'Tainung No.1' and 'Hak Ip' stored at 2, 4, 5, and 25℃. Results showed that CO2 evolution was highest in fruits stored at 25℃. When stored at low temperatures of 2-5℃, fruit CO2 evolution of both cultivars decreased with time, and the respiration rate did not differ between two cultivars. Fruits stored at 2-5℃ had low ethylene production for both cultivars, and those stored at 25℃ had significant higher ethylene production due to disease infection.