Proulx Amy K, Reddy Manju B
Department of Food Science and Human Nutrition, Iowa State University, Ames, Iowa 50011, USA.
J Agric Food Chem. 2006 Feb 22;54(4):1518-22. doi: 10.1021/jf052268l.
Heme iron has been identified in many plant sources-most commonly in the root nodules of leguminous plants, such as soy. Our objective was to test the effectiveness of soy root nodule (SRN) and purified soy hemoglobin (LHb) in improving iron bioavailability using an in vitro Caco-2 cell model, with ferritin response as the bioavailability index. We assessed bioavailability of iron from LHb (either partially purified (LHbA) or purified (LHbD)) with and without food matrix and compared it with that from bovine hemoglobin (BHb), ferrous sulfate (FeSO4), or SRN. Bioavailability of each treatment was normalized to 100% of the FeSO4 treatment. When iron sources were tested alone (100 ug iron/mL), ferritin synthesis by LHbD and BHb were 19% (P > 0.05) and 113% (P < 0.001) higher than FeSO4, respectively. However, when iron sources were used for fortification of maize tortillas (50 ppm), LHbA and BHb showed similar bioavailability, being 27% (P < 0.05) and 33% (P < 0.05) higher than FeSO4. Heat treatment had no effect on heme iron but had a significant reduction on FeSO4 bioavailability. Adding heme (LHbA) iron with nonheme (FeSO4) had no enhancement on nonheme iron absorption. Our data suggest that heme iron from plant sources may be a novel value-added product that can provide highly bioavailable iron as a food fortificant.
已在许多植物来源中发现血红素铁，最常见于豆科植物（如大豆）的根瘤中。我们的目标是使用体外Caco-2细胞模型，以铁蛋白反应作为生物利用度指标，测试大豆根瘤（SRN）和纯化的大豆血红蛋白（LHb）在提高铁生物利用度方面的有效性。我们评估了有或没有食物基质情况下，LHb（部分纯化的（LHbA）或纯化的（LHbD））中铁的生物利用度，并将其与牛血红蛋白（BHb）、硫酸亚铁（FeSO4）或SRN的生物利用度进行比较。每种处理的生物利用度均以FeSO4处理的100%进行标准化。当单独测试铁源（100μg铁/ mL）时，LHbD和BHb的铁蛋白合成分别比FeSO4高19%（P>0.05）和113%（P<0.001）。然而，当将铁源用于强化玉米饼（50 ppm）时，LHbA和BHb表现出相似的生物利用度，分别比FeSO4高27%（P<0.05）和33%（P<0.05）。热处理对血红素铁没有影响，但显著降低了FeSO4的生物利用度。添加血红素（LHbA）铁和非血红素（FeSO4）铁对非血红素铁的吸收没有增强作用。我们的数据表明，来自植物来源的血红素铁可能是一种新型增值产品，可作为食品强化剂提供高生物利用度的铁。
