熱處理與磨皮對長實金柑全果汁飲料苦味與貯藏期間色澤與揮發物質之影響

Effects of Heat Treatment and Peel Abrasion on Bitterness, Color and Volatile Contents of Comminuted Kumquat (Fortunella margarita Swingle) Juice Drink during Storage

本研究使用新鮮長實金柑（Fortunella margarita Swingle）果實製作金柑全果系果汁飲料時，探討熱處理與磨皮對果汁飲料室溫貯藏期間理化性質之變化，作為改善加工條件之參考。金柑果汁飲料經熱處理後，檸檬苦素含量及苦味感官評分皆隨熱處理時間的增加而上升。果實經磨皮處理（5%、7.5%、10%果實重）製成果汁後，總類胡蘿蔔素含量與揮發性成分包括檸烯（limonene）、香葉烯（myrene）及松油萜（α-pinene）含量均顯著降低，其中以磨皮7.5%處理之減少最多，最高可降低總類胡蘿蔔素含量21.1%，檸烯59.9%，香葉烯54.4%和松油萜43.9%。果汁飲料於25℃貯藏180天後，經磨皮處理之果汁飲料總類胡蘿蔔素含量減少皆在30.0%以下，較未經磨皮處理之38.1%為低。主要揮發性成份檸烯於未經磨皮處理者含量減少23.7%，磨皮處理減少20.2%-24.2%，香葉烯減少量兩者各為19.1%與23.1%-34.5%，松油萜減少量兩者各為45.5%與42.9%-50.0%。磨皮處理對揮發性成分含量變化無巨大之影響，顯示磨皮處理不會影響果汁飲料內主要揮發性物質之安定性。金柑果汁飲料明色澤隨貯藏時間增加由亮黃色轉為暗紅褐色，磨皮處理使亮度（L值）降低、紅綠值（a值）升高、與黃藍值（b值）降低。於貯藏時間增加時，隨著磨皮率的增加，色澤變化程度減緩。 This study was to understand the effects of peel abrasion and heat treatments on physical and chemical changes of comminuted kumquat juice drink during room temperature (25℃) storage as a basis for improving the processing conditions. After heating treatments, limonin content and bitterness increased as the heating time increased. By peel abrasion treatment (7.5% of fruit weigh), the contents of total carotenoid, limonene, myrcene and α-pinene were reduced by 21.1, 59.9, 54.4, and 43.9% at most. The losses of major volatiles compound, (d-limonene) in juice drink made from peel abraded kumquat fruits were from 20.2 to 24.2% which are similar among peel abrasion treatments during storage. The stability of volatiles in juice drink was not affected by peel abrasion treatment during storage. Color of kumquat juice drink made from abraded fruits turned dark brown gradually during storage at 25℃; however, the change could be inhibited by increasing the percentage of abrasion.