Cereal Chem 68:565-570   |  VIEW ARTICLE

Effect of Lime Treatment on the Availability of Calcium in Diets of Tortillas and Beans: Rat Growth and Balance Studies.

S. O. Serna-Saldivar, L. W. Rooney, and L. W. Greene. Copyright 1991 by the American Association of Cereal Chemists, Inc. 

Quality protein maize (QPM), regular corn, and sorghum were lime-cooked (with CaO) and processed into tortillas. Weanling rats were fed raw grain or tortilla-based diets supplemented with dry, cooked pinto beans and a Ca-free or Ca-rich mineral premix. Processing raw grains into tortillas increased the Ca content from 11 to 163 mg/100 g. The raw grain and tortillas from QPM contained 53% more lysine than did raw grains and tortillas from regular corn and sorghum. Rats consuming Ca-supplemented QPM products consumed more feed and gained more weight but had feed conversion ratios similar to those of their counterparts fed regular corn and sorghum. Rats fed raw grains not supplemented with Ca consumed less feed, gained less weight, and had poorer feed conversion ratios than did their counterparts fed Ca-supplemented diets. The negative effect of the lack of Ca was more noticeable as the experiment progressed. The Ca from tortillas was highly available because rats fed tortilla apparently absorbed and retained more Ca than did rats fed unsupplemented raw grains. Rats fed tortilla diets supplemented with Ca had the poorest apparent P absorption and retention values.