건오디, 건오디박, 오디 농축액의 품질특성 및 항산화성

Abstract

Mulberry pomace, a by-product obtained from mulberry juice, has not been utilized as food. In this study, antioxidant activities, proximate composition and physiochemical characteristics of mulberry pomace were evaluated and compared with those of mulberry fruit or mulberry concentrate. Mulberry fruit was pressed and filtered. The filtrate and residue were used as mulberry juice and mulberry pomace, respectively. Mulberry juice was evaporated, after which a concentrate (24.7° Brix) was obtained. Moisture contents of mulberry concentrate, freeze-dried mulberry, and pomace were 68.7%, 6.03%, and 7.32%, respectively. Reducing sugar contents were 45.7% in freeze-dried mulberry, 24.5% in pomace, and 30.9% in mulberry concentrate. The pH and acidity of the three samples ranged from 5.80～5.92 and, 0.035～0.080%, respectively. Carbohydrate and crude ash contents were the highest in mulberry fruit, whereas crude protein, fat, and fiber contents were the highest in pomace. Redness of the Hunter color system was 4.7 in mulberry and 4.3 in pomace. Total phenolic content was the highest in mulberry fruit, whereas total flavonoid content was the highest in pomace. Antioxidant activities (DPPH, hydroxyl, and ABTS radical scavenging activities) were enhanced in the order of mulberry fruit> pomace> mulberry concentrate. Especially, antioxidant activities, such as DPPH and hydroxyl radical scavenging activities, of mulberry pomace were similar with those of mulberry fruit. Based on these results, freeze-dried mulberry pomace may be considered as a functional as well as an additive material for food processing.