摘要
为研究坛紫菜酚类化合物的抗氧化活性,通过提取和萃取得到坛紫菜4种溶剂组分:石油醚、乙酸乙酯、正丁醇和水溶性组分,对其DPPH自由基清除率和还原力大小进行比较,并研究其中多酚和黄酮类化合物的分布。结果表明:4种溶剂组分在0.2～1.5g/L质量浓度范围内与抗氧化活性均存在显著剂量效应关系,其DPPH自由基清除率和还原力大小均为:乙酸乙酯>正丁醇>石油醚>水溶性组分。在质量浓度为1.5g/L时,乙酸乙酯组分的还原力吸光度为1.97,大于80%茶多酚(1.90),接近于BHT(2.00)。对多酚类化合物和黄酮类化合物而言,同样是在乙酸乙酯组分中分布最多(分别为69.84mgGAE/gmd和299.49mgRE/gmd),在水溶性组分中最少(分别为11.1mgGAE/gmd和32.36mgRE/gmd),因此酚类化合物主要分布在中等极性溶剂中,而不是强极性溶剂中。研究还发现,1g/L坛紫菜4种溶剂组分的多酚类化合物含量与DPPH自由基清除率、还原力间的相关系数为:r=0.9311和r=0.7530,而黄酮类化合物含量与DPPH自由基清除率、还原力间的相关系数为r=0.8899和r=0.7211,可见坛紫菜多酚类化合物为其抗氧化的主要活性成分。
The Soxhlet extraction product from Porphyra haitanensis was fractionized according to solubility difference in different solvents into petroleum ether （PE）-soluble fraction,ethyl acetate （EA）-soluble fraction,n-butanol-soluble fraction and water-soluble,and the extraction product and its fractions were tested and compared for their DPPH radical scavenging capacity and reducing power and their contents of total polyphenols and total flavonoids were also determined.All these fractions had an antioxidant effect in a significant dosage-dependent manner in the range of 0.2 to 1.5 g/L and the EV-soluble fraction exhibited the highest ranking for both DPPH radical scavenging capacity and reducing power and followed by the n-butanol-soluble fraction,the PE-soluble fraction and the water-soluble fraction.The EA-soluble fraction at a concentration of 1.5 g/L exhibited a reducing power absorbance of 1.97,which was higher than that （1.90） of 80% tea polyphenols,a commercial product and close to that （2.00） of BHT.Likewise,the EV-soluble fraction ranked first for both the contents of total polyphenols （69.84 mg GAE/g dry weight） and total flavonoids （299.49 mg RE/g dry weight）,and the water-soluble fraction last,with a total polyphenol content of 11.1 mg GAE/g dry weight and a total flavonoid content of 32.36 mg RE/g dry weight.Therefore,phenolics are mainly distributed in mid-polarity solvents rather than high-polarity ones.Moreover,the contents of total polyphenols and total flavonoids of the Soxhlet extraction product and its four fractions were linearly plotted against their DPPH radical scavenging capacities or reducing power at 1 g/L,respectively,and the results showed that correlation coefficients were 0.9311 and 0.7530 for the relationship between total polyphenol content and DPPH scavenging capacity or reducing power and 0.8899 and 0.7211 for the relationships between total flavonoid content and DPPH scavenging capacity or reducing power,respectively.Based on these investigations,it can be co
出处
《食品科学》
EI
CAS
CSCD
北大核心
2010年第17期186-191,共6页
Food Science
基金
上海高校创新团队建设项目
上海市教育委员会重点学科建设项目(J50704)
