Micronutrient Laboratory, Institute of Nutrition and Food Technology, University of Chile, 5524 El Libano, Macul, Santiago, Chile.
University of Bio-Bio|, Concepcion, Chile.
Biol Trace Elem Res. 2018 Jan;181(1):38-43. doi: 10.1007/s12011-017-1036-9. Epub 2017 May 12.
Pectins are a type of soluble fiber present in natural and processed foods. Evidence regarding the effect of esterification degree of pectins on iron absorption in humans is scarce. In the present study, the effect of pectins with different degrees of esterification on non-heme iron absorption in women was evaluated. A controlled experimental study was conducted with block design, involving 13 apparently healthy, adult women. Each subject received 5 mg Fe (FeSO) without pectin (control) or accompanied by 5 g citrus pectin, two with a low degree of esterification (27 and 36%), and one with a high degree of esterification (67 to 73%), each on different days. Each day, the 5 mg Fe doses were marked with radioactive Fe or Fe. Radioactivity incorporated into erythrocytes was determined in blood samples 14 days after the marked Fe doses were consumed. On days 18 and 36 of study, 30 and 20 mL blood samples were obtained, respectively, and blood sample radioactivity incorporated into erythrocytes was determined. Body iron status was determined from blood taken on day 18. Whole body blood volume was estimated for calculate iron bioavailability; it was assumed that 80% of absorbed radioactivity was incorporated into the Hb. All women participants signed an informed consent of participation at baseline. Iron bioavailability (mean geometric ±1 SD) alone (control) was 18.2% (12.3-27.1%), iron + pectin27 was 17.2% (10.2-29.2%), iron + pectin36 was 15.3% (9.5-24.6%), and iron + pectin67 was 19.5% (10.0-38.0%). No statistically significant differences between iron bioavailability (repeated measures ANOVA, p = 0.22) were observed. Pectin esterification degree does not influence the bioavailability of non-heme iron in women.
果胶是存在于天然和加工食品中的一种可溶性纤维。关于果胶酯化程度对人体铁吸收影响的证据很少。本研究评估了不同酯化程度的果胶对女性非血红素铁吸收的影响。采用块设计的对照实验研究，共纳入 13 名健康成年女性。每名受试者分别接受 5mg Fe（FeSO）无果胶（对照）或 5g 柑橘果胶，其中 2 种果胶低酯化程度（27%和 36%），1 种果胶高酯化程度（67%至 73%），每天服用一种。每天摄入的 5mg Fe 剂量均用放射性 Fe 或 Fe 标记。摄入标记 Fe 剂量 14 天后，从血液样本中测定红细胞内的放射性。在研究的第 18 天和第 36 天，分别采集 30 和 20ml 血样，测定血样中红细胞内的放射性。第 18 天采集血样以确定机体铁状态。根据第 18 天采集的血样估计全身体液量，用以计算铁生物利用度；假设吸收的放射性 80%掺入到 Hb 中。所有女性参与者均在基线时签署了参与研究的知情同意书。单独铁生物利用度（均值几何±1 SD）（对照）为 18.2%（12.3-27.1%），铁+果胶 27 为 17.2%（10.2-29.2%），铁+果胶 36 为 15.3%（9.5-24.6%），铁+果胶 67 为 19.5%（10.0-38.0%）。铁生物利用度（重复测量方差分析，p=0.22）无统计学差异。果胶酯化程度不影响女性非血红素铁的生物利用度。
