梅果汁加工之研究（三）加工條件對果汁品質之影響

Studies on the Preparation of Japanese Apricot Fruit Juice (3): Effect of Processing Parameters on The Quality of Japanese Apricot (Prunus mume) Juice

梅汁製程中主要步驟為殺菁、分解果膠、保持色澤防止褐變及殺菌。梅子經催熟後採用95±5°C熱水的2分鐘可制止過氧化酶等觸媒作用。破碎的梅子中加入果膠分解酶（Ultrazym-100）50ppm在30°C品溫，可於1小時內達到90%果膠在梅汁中被分解的效果。梅子破碎時如加入500ppm益鮮美亦稱異抗壞血酸鈉（sodium erythorbate）為保色劑，可有效防止加工過程中梅汁的褐變。破碎梅汁時同時將梅子種核破碎，使核仁中所含的杏仁苷分解酶（β-glucosidase）在室溫進行脫苦味反應，結果發現在4小時內達到滿意的程度。梅子濃漿果汁經糖水調製，再稀釋成為果汁飲料，經品評結果無論在色澤、香氣、口味（taste）、苦味接受性（bitterness）等獲得一致的好評。

The objective of this study is to find a better preparation and processing method for Japanese apricot fruit nectar and juice drink. The main procedures including blanching, depectin, inhibiting browning reaction and pasteurizing. The results indicate that ripened yellow mei fruits blanched at 95° ±5°C hot water for 2 minutes can inhibit the peroxidase activity well, but not inhibit to the β-glucosidase of seed kernel. There about 90% of pectin in mei fruit juice can be completely degraded by adding 50 ppm ultrazym-100 as a depectin enzyme at 30°C for 1.5 hours. Addition of 500 ppm sodium erythorbate as antioxidant into the mei fruit juice in preparing can efficiently decrease the juice browning reaction. The bitter taste substances present in mei fruit juice can be hydrolyzed by the β-glucosidase from the crushed mei fruit seed kernels at room temperature for 11 hours. A flow sheet for Japanese apricot nectar preparation is suggested in figure 1 by this study. Results of sensory evaluation on Japanese apricot juice drink prepared by this experiment are discussed in detail.