Increasing Yield and Dietary Fiber Content of Carambola Juice by Enzyme Treatment

• Main Authors: Clement Yah, 葉蔭桓
• Other Authors: 陳雪娥
• Format: Others
• Language: zh-TW
• Published: 1997
• Online Access: http://ndltd.ncl.edu.tw/handle/82496564964849984944

碩士 === 輔仁大學 === 食品營養學系 === 85 === The purpose of this experiment was to study the effect of yield, dietary fiber content and quality of carambola juice from residue treated with four used commercial pectinases. Among four tested pectinases Ultra-SPL had the highest activities of pectinesterase (PE, 73.9 units/ml), polygalacturonase (PG, 17750 units/ml) and hemicellulase (516.8 units/ml). Biomacerase-3 had the lowest activity of PE (28.5 units/g) and PG (578 units/g). Biopectinase-Jec had the lowest hemicellulase activity. The cellulase activity of Ultrazym-100G (976 ncu/g) was the highest and that of Biopectinase-Jec the lowest among the tested pectinases. Under the treatment of carambola residue juice with 0.05% Ultrazym-100G for 60 minutes, the yield and total soluble solids content of carambola residue juice was the highest when three fold water was added to the residue. In this study three fold of water was added to the residue to get the carambola residue juice. The residue of carambola was treated at 50℃ with four pectinases in different concentration (0.025 to 0.25%) and for reaction time from 30 to 180 minutes. Juice yield could reach up to 71.0 % after 120 min reaction time. It showed that the treatment of commercial pectinase can increase the juice yield effectively. The pH value, titrable acidity, total soluble solids, total insoluble solid, Hunter L value, total phenolic compound, condensed tannin, turbidity and formol nitrogen of carambola residue juices increased during the 120 min reaction time by using 0.05% four different commercial pectinases. However, the viscosity decreased and no significant change was found in ash content. The dietary fiber content of juices which were treated by commercial pectinases (Ultrazym-100G, 0.82%; Biopectinase-Jec, 0.81%; Ultra-SPL, 0.78%; Biomacerase-3, 0.67%) was more than that of control(0.63%). The results of sensory evaluation showed that the flavor profile of carambola residue juices treated with different enzymes was similar. No significant change was found in aftertaste of carambola, sweet and cured carambola flavors after enzyme treatment. Generally acidic and astringent flavor of treated juices was stronger than that of untreated one. However, the fresh carambola flavor of treated juices was weaker than that of the untreated. With regard to fresh carambola acidic aroma there was no significant difference between the treated and untreated juice with an exception that this aroma of the Ultrazym-100G treated juice was weaker than that of the untreated one. The treatment of carambola juice with Ultrazym-100G, Ultra-SPL, Biopectinase-Jec could improve the cured aroma of carambola residue juice; however, Biomacerase-3 did not affect this kind of aroma in the treated juice significantly.