|Abstract: ||摘要 紫菜（Porphyra dentata）為一種可食性紅藻，含豐富蛋白質、多醣及許多營養成分，具有免疫及抗氧化等生理活性。本研究旨在探討紫菜酒釀造條件及初步分析其抗氧化活性。市售乾燥紫菜水分含量6.86%，粗蛋白、粗脂肪、粗纖維、醣份及灰分含量分別為30.07%、3.96%、3.37%、47.32%及8.42%。將紫菜粉碎後過篩（0.42 mm mesh）作為原料進行研究，從六種酵素α-amylase、cellulase、α / β-galactosidase、glucoamylase及pectinase中選出pectinase對紫菜懸浮液水解效果最佳，且最適酵素添加濃度為70 U / mL。從78株酵母菌選出耐鹽性較佳32株菌，再由紫菜酒釀製篩選出3株最佳釀酒菌株，分別為Saccharomyces No. 34、No. 47及No. 63。因紫菜多醣黏度大，調整0.25％∼1％紫菜粉末進行發酵，其最適粉末濃度為0.75％，當糖度調至21％及起始pH值為5.0時，可得到酒精度為13∼14％之紫菜酒。將3株酵母菌所釀製之紫菜酒、紫菜熱水萃取液、15％酒精萃取液及pectinase水解液分別進行抗氧化活性分析。15％酒精萃取液其總酚含量為12.87 μg / mL，以No. 34菌株釀製所得紫菜酒之總酚含量為59.95 μg / mL。熱水萃取液、15％酒精萃取液及pectinase水解液其還原potassium ferricyanide（赤血鹽）之還原力相對於維生素C含量分別為11.29、4.75及26.98 μg / mL，No. 47與No. 63酒液其還原力為72.35及105.50 μg / mL。熱水萃取液、15％酒精萃取液及水解液清除50％ DPPH自由基所需濃度（IC50）相對於維生素C含量分別為1.84、1.92及4.32 μg / mL，No.34與No.47酒液為34.00及28.12 μg / mL。|
Abstract Porphyra dentata, one kind of edible red algae, is rich in proteins, polysaccharides, minerals and vitamins. It has several biological activities including immune-modulating activity and antioxidative activity. The aims of this research are to make Porphyra dentata wine and to evaluate its antioxidative activity. The contents of moisture, crude protein, crude fat, crude fiber, carbohydrate and ash in commercially dried Porphyra dentata were 6.86, 30.07, 3.96, 3.37, 47.32 and 8.42%, respectively. P. dentata powder with a size of 0.42 mm mesh is used in this study. Among six tested enzymes of □-amylase, cellulase, □ - and □- galactosidase, glucoamylase, and pectinase, pectinase with final concentration of 70 U / mL was chosen to digest Porphyra dentata. Three strains of Saccharomyces No.34, No.47 and No.63 were chosen as the starters after screening the capabilities of salt tolerance and ethanol production of 78 collected yeast isolates. Due to the limit of high viscosity of Porphyra polysaccharides, the optimal concentration of P. dentata suspension for wine making is 0.75%. The initial pH value and sugar content for wine making are 5.5 and 21%, respectively. After fermentation by 3 yeast starters at 25oC for 10 days the P. dentata wine with ethanol content of 13%-14% is obtained. The total polyphenol contents and antioxidative activity of the hot water extract, 15% ethanol extract, the enzymatic hydrolysate and the wines of Porphyra dentata were further evaluated. The contents of total polyphenol in 15% ethanol extract of Porphyra dentata and No.34 wine were 12.87 and 59.95 μg / mL, respectively. The reducing activities which were expressed as vitamin C equivalents by potassium ferricyanide assay of the hot water extract, 15% ethanol extract, hydrolysate of Porphyra dentata and No.47 and No.63 wines were 11.29, 4.75, 26.98, 72.35 and 105.50 μg / mL, respectively. The IC50 for scavenging the free radical of DPPH were expressed as vitamin C equivalents of the hot water extract, 15% ethanol extract and hydrolysate were 1.84, 1.92 and 4.32 μg / mL, respectively. The IC50 for No.34 and No.47 wines were 34.00 and 28.12 μg / mL.