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Background: There is a need to determine whether iron absorption from iron amino acid chelates is protected from inhibition by dietary phytate and regulated normally by iron status. Objective: The objective of this study was to compare iron absorption from ferrous sulfate, ferrous bisglycinate, and ferric trisglycinate in whole-maize meal; to determine whether iron from ferrous bisglycinate and ferrous sulfate exchanges in the intestinal pool; and to assess iron absorption from ferrous bisglycinate and ferric trisglycinate over a range of iron statuses. Design: In study 1A, 10 iron-sufficient men consumed ferrous sulfate-fortified whole-maize meal porridge equilibrated with 59 Fesulfate on day 1 and 55 Fe-bisglycinate on day 2. In study 1B, these volunteers consumed ferrous sulfate-fortified porridge equilibrated with 59 Fe-sulfate and 55 Fe-bisglycinate simultaneously. In studies 2A and 2B, iron absorption from 3 mg Fe as 59 Fe-ascorbate, 55 Febisglycinate, or 59 Fe-trisglycinate in water and in porridge was compared in 23 subjects with a range of iron statuses. Iron absorption was determined from blood radioactivity on day 16. Results: In study 1A, geometric mean iron absorption from ferrous bisglycinate was 6.0% (range: 2.6-13.6%), 4 times higher than that from ferrous sulfate (1.7%; range: 1.0-3.3%; P < 0.05). In study 1B, absorption from neither source was different from that in study 1A. In studies 2A and 2B, absorption from all sources was strongly inversely related to serum ferritin, with geometric means of 32.5% (iron ascorbate), 9.1% (bisglycinate), and 15.3% (trisglycinate). Iron from ferric trisglycinate was poorly absorbed (2.3%; range: 0.5-9.2%) from maize. Conclusion: In whole-maize meal, iron from ferrous bisglycinate is better absorbed than is iron from ferrous sulfate and does not exchange with iron from maize or ferrous sulfate in the intestinal pool. Absorption of iron from bisglycinate and trisglycinate is regulated normally by iron status.Am J Clin Nutr 2000;71:1563-9. KEY WORDSIron bioavailability, iron absorption, ferrous bisglycinate, ferric trisglycinate, iron amino acid chelates, iron fortification, iron status, maize, phytate, serum ferritin INTRODUCTIONIron deficiency remains the most prevalent nutrient deficiency in the United States and the rest of the world (1, 2). Iron deficiency is especially prevalent in developing countries, where diets are based on cereals or legumes. Iron fortification of these staples is a potentially feasible approach to preventing iron deficiency and anemia, but absorption of iron from soluble and poorly soluble iron salts added as fortificants is impaired by the phytate in the cereals and legumes to the same extent as is absorption of the native iron (3). Iron fortification of whole-maize meal is especially problematic because of the high phytate content of wholemaize meal (1 mg/g maize meal), which inhibits iron absorption, and the high polyunsaturated fat content (60% of total fatty acids), which is readily oxidized by soluble iron...

The macroscopic and sensory properties of breads supplemented with 50%, 55%, 60%, and 65% sweetpotato flour were evaluated. Moisture contents of the breads fluctuated during storage. Protein value was highest for the bread supplemented with 50% sweet-potato flour. Carbohydrate contents ranged from 18.2% to 24.4%. ␤ ␤ ␤ ␤ ␤-carotene contents and loaf volumes were highest in the breads supplemented with 65% and 50% sweet-potato flour, respectively. The breads were similarly firm, with comparable vitamin C contents at the end of storage. The bread with 65% sweet-potato flour had the most intense yellow-orange color. Twelve perceived sensory attributes, which could be used to differentiate the appearance, texture, and flavor of sweet-potato breads, were generated.

Monitoring the development of warmed-over flavor (WOF) is critical for the quality control of meat products. This study was to modify the acid-extraction method for analyzing thiobarbituric acid-reactive substances (TBARS) as an indicator of WOF in cooked meats. After centrifuging the extract of cooked beef, the supernatant of the extract was reacted with 80 mM TBA solution at 40°C. The reaction between TBA and malonaldehyde was completed within 90 min, and interfering agents such as sucrose did not form any detectable color interference. The TBARS values in cooked beef samples after storage at 4°C for zero and 7 d were 2.1 and 10.8 mg/kg, respectively. The recovery rate was between 92 and 102%. This method could be used to measure TBARS in cooked beef.