국내 시판 오렌지주스 및 자몽주스의 이화학적 특성과 항산화 활성

Abstract

Thee physicochemical properties, functional ingredient content, and antioxidant activities of the commercial orange and grapefruit juice were investigated. Three types of orange (OJ1, OJ2, and OJ3) and grapefruit (GJ1, GJ2, and GJ3) juices were purchased from the market. Antioxidant activities of the commercial juices were evaluated using DPPH, ABTS, and reducing power assays. The pH of orange juice was higher than grapefruit juice and the acidity of grapefruit juice was higher than orange juice. The soluble solid and reducing sugar contents of the juices were in the range of 9.30-13.60 °Brix and 45.02-71.52 mg/mL, respectively. The total free sugar and organic acid contents of juices were 61.84-98.67 mg/mL and 1.14-1.60 mg/mL, respectively. The major free sugars were sucrose, fructose, and glucose, and six types of organic acids were detected in the commercial juices. The total polyphenol content was the highest in OJ2 (910.7 μg/mL), and the lowest in GJ3 (630.7 μg/mL). The total flavonoid content in grapefruit juices was higher than orange juices. OJ2 showed the highest antioxidant activity in DPPH and ABTS radicals scavenging assays and the reducing power assay. Our results indicate that the functional ingredient content and antioxidant activities were different even in the same type of juice.