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Biomedical subjects

J G Reinhold

Publications and source records attributed to J G Reinhold.

5 recordsLinked to original sources
PubMed1979

Fiber of the maize tortilla.

Fiber concentrations were measured in maize tortillas and in masa, the lime-treated dough from which they are made, with the aid of Van Soest's methods. Neutral detergent fiber of tortillas was 6.60 +/- 0.98% (mean and SD) and acid detergent fiber 3.75 +/- 0.83% of the dry weight corrected for ash. The hemicellulose fraction was 2.89 +/- 0.94%. Both neutral and acid detergent fiber were significantly higher in tortilla than in masa. The gain in fiber by tortillas during baking is attributed to the formation of browning reaction (Maillard) products resistant to the detergent-containing fiber reagents.

Cellulose↗
PubMed1977

Binding of zinc and iron to wheat bread, wheat bran, and their components.

Wholemeal wheat bread decreases the availability and intestinal absorption of divalent metals. To define this action further, binding of zinc in vitro to a wheat wholemeal bread (Tanok), dephytinized Tanok, and cellulose was determined at pH 5.0 to 7.5. Zinc binding by each was highly pH-dependent and reached a maximum at pH 6.5 to 7.5. Removal of phytate from Tanok did not reduce its binding capability. Wheat bran at pH 6.5 and 6.8 bound 72% of iron (0.5 microgram/ml of solution) and 82.5% of zinc (1.43 microgram/ml solution), respectively. Lignin and two of the hemicellulose fractions of wheat bran and high binding capabilities for zinc (85.6, 87.1, and 82.1%, respectively) whereas a third had a lower zinc-binding capability (38.7%). Binding of zinc to various celluloses and dextrans is also demonstrated. Formation of complexes of these metals with wheat fiber can explain, at least in part, the decreased availability of dietary iron and zinc in wholemeal wheat bread.

Bread↗
PubMed1977

Effects of cellulose added to diets of low and high fiber content upon the metabolism of calcium, magnesium, zinc and phosphorus by man.

Addition of 10 g of cellulose dispersed in 150 g of apple compote to the daily diet with a low fiber content for a 20-day period caused the fecal excretion of calcium and zinc of three men to increase significantly. Balances of both metals became negative and their concentrations in plasma decreased. Magnesium balances became negative in two subjects while phosphorus balance changed to negative in one. In a similar experiment in which the cellulose was added to a fiber-rich diet, fecal excretions of calcium and zinc increased significantly in each of two men and excretion of magnesium in one. Previously negative balances became more negative, and calcium and zinc concentrations decreased in plasma. The dependence of fecal dry weight upon fecal fiber content measured by the acid-detergent method was confirmed. However, increments of dry matter per g of fiber were less fecal fiber concentrations were high. Fecal calcium content correlated significantly with fecal fiber in two subjects, and fecal fiber and zinc in one. No correlations were demonstrated in the subject who apparently digested fiber most effectively. Our findings indicate that high intakes of fiber can explain to a considerable extent the impaired utilization of zinc, calcium, and magnesium among villagers in rural Iran.

Adult↗
PubMed1975

Phytate destruction by yeast fermentation in whole wheat meals. Study of high-extraction rate meals.

Destruction of phytate by yeast fermentation is compared in sponges prepared from Iranian whole wheat meals of different extraction rates. Phytate was destroyed rapidly in whole meals of 75 to 85 and 85 to 90 per cent extraction, but destruction was retarded in those of 95 to 100 per cent extraction. Production of acid-soluble phosphorus kept pace with phytate destruction in the two whole meals of lower extraction rates but was delayed with less-than-expected yield in those of 95 to 100 per cent rate. Unleavened whole meal bread contains little acid-soluble phosphorus. Leavened breads made from whole meals of slightly lower extraction rate average five times as much. Since phytate phosphorus appears to remain unavailable in the small intestine in many circumstances, dependece on unleavened whole meal bread may result in critically low intakes of available phosphorus when other sources are lacking in the diet. It is concluded that replacement of the whole meals of 95 to 100 per cent extraction rate, presently the main staple of the diet of rural Iran, by those of somewhat lower rate is an important preliminary to the introduction of leaven and fermentation into village bread-making methods.

Bread↗