가공방법에 따른 뽕잎차의 기능성성분 및 관능특성 평가

Abstract

This study was conducted to determine the phytochemical constituents and organoleptic properties in mulberry (Morus alba L.) leaf teas (MLTs) prepared by various processing methods, viz., roasting, steaming, and fermentation. Phytochemical constituents, such as polyphenols, 1-deoxynojirimycin (DNJ), and γ-aminobutyric acid (GABA), in three different MLTs were quantified by high-performance liquid chromatography. In addition, their organoleptic properties including color, flavor, taste, and overall acceptability were evaluated. Prior to the preparation of MLTs, the three phytochemical constituents of mulberry leaves collected from seven different cultivars and two harvesting seasons were quantified. Of the seven mulberry cultivars examined, Cheongil mulberry leaves harvested in June and September were found to have moderate polyphenol, DNJ, and GABA contents, as compared with the other cultivars. The the roasted mulberry leaf tea (RMLT) was found to have the highest content of total phenolics (2,714.7 mg/100 g), while the steamed mulberry leaf tea (SMLT) and fermented mulberry leaf tea (FMLT) had the highest contents of DNJ (125.6 mg/100 g) and GABA (245.8 mg/100 g), respectively. The scores of color, flavor, taste, and overall acceptability of RMLT were significantly higher than those of SMLT and FMLT, which had a peculiar color, flavor, and taste. Thus, each of roasted, steamed and fermented MLTs has characteristic phytochemical constituents and organoleptic property, because of which they need to be further developed each suitable processing method.