摘要
目的测定菠菜中β-胡萝卜素（β-C）在人体内转化为维生素A的效率。方法将菠菜培植在25%重水（2^H2O）营养液,氘随机标记在类胡萝卜素分子上,其中全反式β-C同位素丰度分布的最高值出现在分子量547（2H10全反式β-C）。给予10名健康成年（43-56岁）男性5.8μmol（2.0mg）溶于油的13^C10视黄醇醋酸酯,作为参考VA。7天后,每位受试者摄入100g蒸熟的菠菜（含有7.0μmol或3.8mgβ-C）。56天试验期内,从每位受试者采集血样40次,用HPLC,GC-ECNCI-MS和LC-APCI-MS分析视黄醇和β-C浓度及标记的视黄醇和β-C丰度。试验期间受试者维持低VA和类胡萝卜素膳食。结果标记视黄醇血清反应曲线显示,每1nmol菠菜β-C产生了（0.25±0.10）nmol视黄醇,以13^C10视黄醇醋酸酯为参照,菠菜β-C转化为VA的效率是质量比（9.0±4.5）∶1。结论菠菜β-C可以在体内有效的转化为视黄醇,食用菠菜也提高了血清叶黄素的水平。
Objective Methods To determine the vitamin A equivalence of spinach y-carotene （β-C） in human body. Methods Spinach grown in 25 atom% 2^H2O cultural solution was intrinsically labeled by deuterium. The highest enrichment of spinach trans-β-C isotopomers was at the molecular mass of 547 （2 ^H2O trans-β-C）. Ten healthy Chinese male adults （43 - 56y） were given a dose of 5.8μmol 13^C10 retinyl acetate as vitamin A reference dose. One week later, each subject was given 100g of steamed spinach （containing 7.0μmol β-C）. Forty blood samples were collected over 56 days from each subject. A HPLC method was used to detect the concentrations of retinol and β-C in serum, and a GC-MS method was used to detect the enrichment of the labeled retinal. Kinetic curves of the labeled retinol from the reference dose and the spinach β-C were compared to determine the vitamin A equivalence of spinach β-C. Results The results showed that 1 nmol spinach β-C provided （0.25 ± 0.10） nmol retinol. The mean conversion factor of spinach β-C to vitamin A was （9.0 ± 4.5） ： 1 by weight. Conclusion The bioconversion of spinach β-C to vitamin A was determined in 10 Chinese male adults by stable isotope tracer and reference techniques, and the mean conversion factor was 9.0 to 1 on a weight basis.
出处
《卫生研究》
CAS
CSCD
北大核心
2007年第4期449-453,共5页
Journal of Hygiene Research
基金
国家自然科学基金资助项目(No.30271121)
浙江省科技厅项目(No.2005F13026)
浙江省卫生高层次创新人才培养工程项目
