椪柑、桶柑與柳橙在長期貯藏中各品質指標值之變化

uantitative Changes in Each Component of Quality Attributes in ‘Ponkan’ Mandarin (Citrus reticulata Blanco), Tankan (C. tankan Hayata), and ‘Liucheng’ Orange (C. sinensis Osbeck) During Long­term Storage

椪柑（Citrusreticulata Blancocv.‘Ponkan’）、桶柑（C.tankan Hayata）與柳橙（C.sinensis Osbeck cv.‘Liucheng’）皆可在15℃貯藏3個月或3個月以上。但在貯藏中腐損漸增而品質不斷變化。本研究貯藏椪柑3個月、貯藏桶柑及柳橙各5個月；每隔15日取樣評定腐爛率、綠蒂率與失重率，然後測定代表果皮顏色之CIELABL*、a*、b*值及計算彩度（h°）與色度（C*），並搾汁測定可溶性固形物及酸度。椪柑與桶柑在貯藏期間之腐爛率≤2.5%，綠蒂率≥87%。柳橙貯藏頭3個月的腐爛率亦低，但後2個月快速上升；而綠蒂率則一直下降，到5個月後 ‘Ponkan’ mandarin (Citrus reticulata Blanco), tankan (C. tankan Hayata), and ‘Liucheng’ orange (C. sinensis Osbeck) were individually wrapped in polyethylene bags and stored at 15℃ for 90, 150, and 150 days, respectively. Samples were taken at 15­day intervals for evaluation of decay, button (stem plus calyx) color, weight loss and quality attributes including color measurements, total soluble solid (TSS) content, titratable acidity (TA), and soluble solids/acid ratio (TSS/TA). ‘Ponkan’ and tankan had ≤ 2.5 % decay and ≥ 87 % green button at the end of storage. ‘Liucheng’ had little decay in the first 90 days of storage, but increased decay percentage rapidly thereafter. Besides, the percentage of ‘Liucheng’ fruit with green button dropped steadily from 100 % to < 40 % in 150 days. Weight loss was more prominent in the first 15 days than in later days, but not at all severe. ‘Ponkan’ lost 3.5 % weight in 90 days while tankan and ‘Liucheng’ each lost about 5 % weight in 150 days. Partially green ‘Ponkan’ turned yellow rapidly within 30 days while L*, a*, b* values increased and h° decreased. The rind color then gradually became redder and redder while a* increased and L*, b*, and h° decreased. Tankan was orange yellow at harvest and became slightly redder during first 30 days in storage while a* increased and L*, b*, and h° decreased. There were little changes afterward. ‘Liucheng’ was yellow colored at harvest and slowly but steadily became redder throughout the storage period while a* increased and L*, b*, and h° decreased. All three kinds of citrus slightly increased TSS in the first 30 days and then gradually decreased TSS thereafter. TA declined steadily and TSS/TA ratio increased gradually throughout storage periods. ‘Ponkan’, tankan, and ‘Liucheng’ had TSS of 11.1°, 11.1°, and 13.9°Brix and had TSS/TA ratio of 28, 21, and 25, respectively, after 90 days of storage. Tankan and ‘Liucheng’ had TSS of 10.3° and 12.6°Brix and had TSS/TA ratio of 27 and 31 respectively, after 150 days of storage. All of them had acceptable to good quality at the end of storage.