title: Chemical composition of clarified bayberry (Myrica rubra Sieb. et Zucc.) juice sediment.
abstract: Clarified bayberry juice turned hazy upon storage at 25 degrees C for 6 months, and the chemical composition of centrifugally separated sediment was analyzed. Bayberry juice haze was mainly protein-tannin haze. The lyophilized sediment contained 20.4 +/- 4.3% of protein, 70.2 +/- 2.6% of total polyphenols, 7.2% of monosaccharides, and 6.7 +/- 0.6% of ash. Amino acid analyses and molecular weight distribution estimation indicated that bayberry proteins were haze-active proteins with a molecular weight less than 8 kDa. Gallic acid, quercetin hexoside, quercetin deoxyhexoside, and quercetin were found in the methanol-dissolved sample, while gallic acid, protocatechuic acid, cyanidin, ellagic acid, and quercetin were detected in the acid-hydrolyzed sample. Ellagic acid was the dominant individual phenolic (9.9 +/- 0.19 g/100 g dry weight, 55.3% of the total amount) in the sediment. Monosaccharides of rhamnose, arabinose, mannose, glucose, and galactose in the sediment were most probably the glycoside moieties of the anthocyanins, flavonols, and elllagitannins. Metal ions of calcium, magnesium, potassium, iron, and copper also indicated the heterogeneous characteristics of the sediment.
authors.affiliation: Key Laboratory of Food Science & Safety, Ministry of Education, Southern Yangtze University, Wuxi 214036, China.
authors.forename: Zhongxiang
authors.initials: Z
authors.lastname: Fang
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
authors.forename: Guangjun
authors.initials: G
authors.lastname: Tao
authors.forename: Yunfei
authors.initials: Y
authors.lastname: Sun
authors.forename: Jingcai
authors.initials: J
authors.lastname: Sun
mesh_terms: D000596:Amino Acids / Q000032:analysis; D001628:Beverages / Q000032:analysis*; D005419:Flavonoids / Q000032:analysis; D005638:Fruit / Q000737:chemistry*; D008903:Minerals / Q000032:analysis; D009005:Monosaccharides / Q000032:analysis; D031641:Myrica / Q000737:chemistry*; D010636:Phenols / Q000032:analysis; D010940:Plant Proteins / Q000032:analysis; D059808:Polyphenols; D013634:Tannins / Q000032:analysis
chemical_list: D000596:Amino Acids; D005419:Flavonoids; D008903:Minerals; D009005:Monosaccharides; D010636:Phenols; D010940:Plant Proteins; D059808:Polyphenols; D013634:Tannins