Factors influencing the absorption of iron from soya-bean protein products.
The absorption of iron from soya-bean (Glycine hispida)-based and milk-based infant formulas was assessed in 138 multiparous Indian women, using the erythrocyte utilization of radioactive Fe method. Fe absorption was significantly greater from the basal milk formula (1.5 g protein) than it was from the basal soya-bean formula (2.3 g protein), with geometric mean values of 0.083 and 0.044 respectively. Ascorbic acid markedly increased Fe absorption from the milk-based formula in a dose-dependent fashion. The increase was fivefold when the ascorbic acid:Fe ratio on a weight-for-weight basis was 6:1 and over tenfold when it was 20:1. In contrast, ascorbic acid had a less-marked effect on the absorption of Fe from the soya-bean-based formula, with only a two- to threefold increase at an ascorbic acid:Fe ratio of 20:1. The geometric mean Fe absorption from the soya-bean formula (1.27 mg Fe, 2.3 g isolated soya-bean protein (ISP] was somewhat less than that from the same amounts of ISP and ascorbic acid made up in milk (0.075 and 0.113 respectively). However, a direct comparison between the soya-bean formula in milk and in water showed no significant difference (0.043 and 0.060 respectively). Fe absorption from a drink containing 10 g ISP and 30 mg ascorbic acid was significantly better than that from a similar drink containing the soya-bean flour from which ISP is extracted (0.044 and 0.027 respectively). Heating ISP to 200 degrees for 2 h before its use had no effect on Fe availability.(ABSTRACT TRUNCATED AT 250 WORDS)
D000042:Absorption; D000328:Adult; D000818:Animals; D001205:Ascorbic Acid / Q000494:pharmacology; D002951:Citrates / Q000494:pharmacology; D019343:Citric Acid; D005260:Female; D006358:Hot Temperature; D006801:Humans; D007223:Infant; D007225:Infant Food; D007501:Iron / Q000378:metabolism*; D008875:Middle Aged; D008892:Milk; D009747:Nutritional Physiological Phenomena; D014674:Plant Proteins, Dietary / Q000378:metabolism*; D030262:Soybean Proteins; D013025:Glycine max
D002951:Citrates; D014674:Plant Proteins, Dietary; D030262:Soybean Proteins; D019343:Citric Acid; D007501:Iron; D001205:Ascorbic Acid