O'Leary K, Sheehy P J
Nutritional Sciences, Department of Food Science and Technology, University College, Cork, Republic of Ireland.
Br J Nutr. 2001 Apr;85(4):441-6. doi: 10.1079/bjn2000288.
An increasing number of foods fortified with varying levels of folic acid are appearing in the market place, targeted either at the general population or at specific consumer groups. Although it is assumed that the folate in these products should be highly bioavailable, there is a need to carry out studies to ascertain that this is, in fact, the case. The present study investigated the ability of selected folic acid-fortified foods (targeted at different types of consumer) to increase the folate status of folate-deficient rats. Forty-two weanling male rats (Wistar strain) were fed a folate-deficient diet containing 1 % succinyl sulfathiazole (w/w) for 28 d. Following depletion, seven rats were randomly assigned to each of five repletion diets containing folic acid, Complan, Slim Fast, Opti-Fuel2 or Cola Coa calculated to provide 200 microg folate/kg of each diet. Calculations were based on folate information from the product labels. After a further 28 d, plasma, liver and kidney folate concentrations were determined by microbiological assay. Plasma homocysteine was measured by HPLC as a functional indicator of folate status. The folate content of the foods was measured by tri-enzyme extraction followed by microbiological assay. Our analyses suggest that there may be considerable inaccuracies on the part of the manufacturers in relation to the folate declarations on the product labels. Despite this, the four foods evaluated were highly effective in elevating plasma, liver and kidney folate and lowering plasma homocysteine concentrations in rats. These results lend support to the policy of food fortification with folic acid as a means of raising the folate status of the population, and in particular to the fortification of specific foods which may target areas of the population where increased folate status is most needed.
市场上出现了越来越多添加不同水平叶酸的食品，这些食品的目标受众是普通大众或特定消费群体。尽管人们认为这些产品中的叶酸应具有很高的生物利用率，但仍有必要开展研究以确定实际情况是否如此。本研究调查了选定的添加叶酸食品（针对不同类型消费者）提高叶酸缺乏大鼠叶酸水平的能力。42只断乳雄性大鼠（Wistar品系）被喂食含1%琥珀酰磺胺噻唑（重量/重量）的叶酸缺乏饮食28天。耗尽后，将7只大鼠随机分配到五种补充饮食中的每一种，这些饮食分别含有叶酸、康宝莱奶昔、速瘦纤、奥普帝蒙2或可拉奥饮料，经计算每种饮食每千克提供200微克叶酸。计算基于产品标签上的叶酸信息。再过28天后，通过微生物测定法测定血浆、肝脏和肾脏中的叶酸浓度。通过高效液相色谱法测量血浆同型半胱氨酸，作为叶酸状态的功能指标。食品中的叶酸含量通过三酶提取后进行微生物测定。我们的分析表明，制造商在产品标签上的叶酸声明可能存在相当大的不准确之处。尽管如此，所评估的四种食品在提高大鼠血浆、肝脏和肾脏叶酸水平以及降低血浆同型半胱氨酸浓度方面非常有效。这些结果支持了用叶酸强化食品作为提高人群叶酸水平的一种手段的政策，特别是支持对特定食品进行强化，这些食品可能针对最需要提高叶酸水平的人群。
