柚子不同部位多酚和矿物质与抗氧化能力相关性研究

测定柚子不同部位的总酚、总黄酮、花青素、矿物质含量,并进行抗氧化性研究,探讨各组分含量与还原力及对·OH、DPPH·清除性能之间的相关性。结果表明,柚子不同部位总酚含量由高到低依次为黄皮、白皮、囊衣、果肉、柚籽,其中黄皮总酚质量比达12.68mg/g；总黄酮含量由高到低依次为囊衣、柚籽、白皮、黄皮、果肉,囊衣总黄酮质量比为1.146mg/g；花青素含量果肉最高；柚子中含有丰富的对人体有益的K、Ca、Mg、Mn、Na、Fe等元素,黄皮更易富集矿物质,而白皮中矿物质种类及含量极低；柚子各部位醇提液还原力由高到低依次为黄皮、果肉、柚籽、白皮、囊衣,对·OH清除率由大到小依次为黄皮、囊衣、白皮、柚籽、果肉；而囊衣醇提液对DPPH·清除率最高,达到95.24%；相关性分析表明,3种多酚类物质与还原力、DPPH·清除率均无显著相关性(P>0.05),总酚与·OH清除率显著相关(P<0.05),K、Ca、Mg与还原力、·OH清除率均存在极显著正相关(P<0.01),而与DPPH·清除率不存在显著相关性(P>0.05)。

Study on Correlations Between Polyphenols, Mineral Elements and Antioxidant Capacities in Different Parts of Pomelo

The contents of total phenols, total flavonoids, anthocyanins and mineral elements in different parts of pomelo were determined, and the correlation between polyphenols contents and antioxidant activities, such as reduction ability, OH and DPPH radical scavenging ability were explored. The results showed that the total phenols content of each parts of pomelo in descending order were yellow peel, white peel,capsule dressing, pulp, and pomelo seed and the total phenols content in yellow peel was 12.68mg/g. The contents of total flavonoids in different parts were as follows:capsule dressing > pomelo seed > white peel > yellow peel > pulp, which was 1.146mg/g in capsule dressing. The highest content of anthocyanins was found in pulp. Pomelo was rich in K, Ca, Mg, Mn, Na, Fe and other elements. And the mineral elements were mainly concentrated in yellow peel, while were hardly detected in white peel. The reduction abilities of alcohol extracts in different parts of pomelo were as follows:yellow peel > pulp > pomelo seed > white peel > capsule dressing. The scavenging rates of ·OH were as follows:yellow peel > capsule dressing > white peel > pomelo seed > pulp. Alcohol extracts of capsule dressing had the highest scavenging rate of DPPH radical (95.24%). Correlation analysis indicated that, the content of total polyphenols, total flavonoids and anthocyanins had no significant correlations with reducing ability or scavenging rate of DPPH radical(P>0.05), while total polyphenols contents were significantly associated with scavenging rate of OH radical(P<0.05). The content of K, Ca, and Mg had highly significant positive correlations with reducing ability and scavenging rate of OH radical(P<0.01), but no significant correlation with scavenging rate of DPPH radical(P>0.05).