title: Analysis of Functional Constituents in Mulberry (Morus alba L.) Twigs by Different Cultivars, Producing Areas, and Heat Processings.
abstract: Four functional constituents, oxyresveratrol 3'-O-β-D-glucoside (ORTG), oxyresveratrol (ORT), t-resveratrol (RT), and moracin (MC) were isolated from the ethanolic extract of mulberry (Morus alba L.) twigs by a series of isolation procedures, including solvent fractionation, and silica-gel, ODS-A, and Sephadex LH-20 column chromatographies. Their chemical structures were identified by NMR and FABMS spectral analysis. Quantitative changes of four phytochemicals in mulberry twigs were determined by HPLC according to cultivar, producing area, and heat processing. ORTG was a major abundant compound in the mulberry twigs, and its levels ranged from 23.7 to 105.5 mg% in six different mulberry cultivars. Three other compounds were present in trace amounts (<1 mg/100 g) or were not detected. Among mulberry cultivars examined, "Yongcheon" showed the highest level of ORTG, whereas "Somok" had the least ORTG content. Levels of four phytochemicals in the mulberry twigs harvested in early September were higher than those harvested in early July. Levels of ORTG and ORT in the "Cheongil" mulberry twigs produced in the Uljin area were higher than those produced in other areas. Generally, levels of ORTG and ORT in mulberry twigs decreased with heat processing, such as steaming, and microwaving except roasting, whereas those of RT and MC did not considerably vary according to heat processing. These results suggest that the roasted mulberry twigs may be useful as potential sources of functional ingredients and foods.
authors.affiliation: Department of Food Science and Nutrition, Catholic University of Daegu, Gyeongbuk 712-702, Korea.
authors.forename: Sang Won
authors.initials: SW
authors.lastname: Choi
authors.affiliation: Department of Food Science and Nutrition, Catholic University of Daegu, Gyeongbuk 712-702, Korea.
authors.forename: Yeon Jeong
authors.initials: YJ
authors.lastname: Jang
authors.affiliation: Department of Food Science and Nutrition, Catholic University of Daegu, Gyeongbuk 712-702, Korea.
authors.forename: Yu Jin
authors.initials: YJ
authors.lastname: Lee
authors.affiliation: Department of Natural Product, Institute for Korea Traditional Medical Industry, Gyeongbuk 712-260, Korea.
authors.forename: Hyun Hee
authors.initials: HH
authors.lastname: Leem
authors.affiliation: Functional Food Center, Korea Institute of Science and Technology (KIST) Gangneung Institute, Gangwon 210-340, Korea.
authors.forename: Eun Ok
authors.initials: EO
authors.lastname: Kim
keywords: cultivars; functional constituents; heat processing; mulberry (Morus alba) twigs; producing area