天然和人工富硒茶叶的抗氧化功能比较

目的 :　研究和比较天然和人工富硒茶叶中硒的化学形态 ,生物有效性和抗氧化功能。方法 :　在低硒土壤的茶园施用无机硒肥 ,经茶树的生物转化 ,制备富硒茶叶 ;用低硒饲料饲养大鼠 ,设缺硒对照 ,亚硒酸钠 ,低硒茶提取液 ,天然和人工富硒茶提取液 5个不同硒源处理组 ,饲养8w,测定不同来源硒的吸收利用率和抗氧化指标。结果 :　天然富硒茶和人工富硒茶有机硒和蛋白质硒的比例无显著差异。硒的利用率 ( % ) :人工富硒茶为 68.0 5 ,天然富硒茶为 70 .49,Na2 Se O3为 65 .41 ,人工富硒茶吸收利用率高于无机硒。可显著提高大鼠血液和肝脏的含硒量和 GSH- Px活性 ,降低 MDA含量。富硒茶的抗氧化功能优于 Na2 Se O3。结论 :　通过人工施用亚硒酸钠生产的富硒茶叶具有与天然富硒茶叶相近的硒形态和抗氧化功能 ,人工富硒茶叶是人体安全、有效的补硒资源。

COMPARISON OF ANTIOXIDANT FUNCTION OF TEAS NATURALLY HIGH IN SELENIUM ANDARTIFICIALLY Se-ENRICHED IN RATS

Objective: To study the selenium(Se) chemical forms in Se enriched tea by fertilizing sodiums selenite in soil and tea naturally high in Se and compare their antioxidant function. Methods: The Se enriched tea was produced by fertilization of sodium selenite through biological transformation of tea tree in low Se content soil. Five groups of rats were fed basal low Se diet and basal diet with sodium selenite, extractions of low Se tea, Se enriched tea by fertilizing with sodium selenite, and tea naturally high in Se. The Se chemical forms and antioxidant function of rats fed with different Se resource were detemined after 8 wks. Results: The proportion of organic forms of Se and Se protein were almost the same in Se enriched tea and tea naturally high in Se. The Se absorption and utilization rates were 65.41%, 68.05% ,and 70.49% for sodium selenite, Se enriched tea and tea naturally high in Se respectively. It showed that the availability of Se in Se enriched tea was higher than that in sodium selenite. The Se content of blood and liver, GSH Px activity were significantly increased by feeding extraction of Se enriched tea compared with control, sodium selenite and low Se tea.. Conclusion: The biological effect of organic form Se in Se enriched tea is higher than that of sodium selenite, and the Se enriched tea produced by fertilizing sodium selenite in low Se soil is as effective as tea naturally high in Se. The Se enriched tea is safe and effective in increasing the Se intake of both human and animals in low Se area.