Nutritional value of normal, opaque-2 and sugary-2 opaque-2 maize hybrids for infants and children. 1. Digestibility and utilization
Graham, G.G.; Glover, D.V.; Lopez de Romaña, G.; Morales, E.; MacLean, W.C.
Journal of Nutrition 110(5): 1061-1069
1980
ISSN/ISBN: 0022-3166 PMID: 6768856 Document Number: 163212
1. The opaque-2 (o2) gene increases the lysine and tryptophan contents of maize and its protein quality; the sugary-2 (su2) gene improves vitreousness and density but decreases lysine; the double-mutant su2o2 has the improved kernel characteristics and an even higher protein quality than o2. Digestibility of energy and protein, and protein quality of normal, o2 and su2o2, as endosperm (E) and as whole kernel (WK) meals, were studied in 8 convalescent malnourished children 10 to 25 months old. Diets provided 100 to 125 kcal/kg daily, 10% fat, with all of 6.4% protein energy from 1 of 6 maize meals or casein. Endosperm meals provided 83.2, 91.2 and 82.1% of energy. WK meals 73.2, 68.6 and 67.2% of energy in respective diets. Apparent nitrogen retention from E meals was lower than from WK meals, both lower than from casein. For each type of meal (E and WK) there was strong correlation between lysine "absorbed" and N retention, but this was higher from WK at equal lysine intakes. For 50% of children to match N retention from casein, presumably equal to requirement, they would have to consume 204, 148 or 123% of energy requirement as normal, o2 or su2o2 E meals. For WK meals, values were 108, 90 or 84%.