FURTHER-STUDIES ON THE ENRICHMENT OF LIME-TREATED CORN WITH WHOLE SOYBEANS

A series of experiments were performed to study further the effect of supplementing corn with whole soybeans processed in a batch home process and in a continuous industrial operation on chemical composition, presence of antiphysiological substances and protein quality of tortillas. Variables studied with the conventional home cooking process included levels of whole soybeans from 0‐20%, cooking times at atmospheric pressure and 96°C from 0‐90 min at a constant corn‐to‐soybean ratio of 85:15 and lime concentration of 0, 1 and 2%. In the industrial process a 90:10 mixture of corn to whole soybeans was used, and processing conditions were those normally employed for corn alone. Although addition of whole soybeans to corn increased total protein and fat content, both the PER and weight data suggest that the optimum amount of soybeans to add to maize falls between 8 and 12%. Levels of soybeans above 12%, did not significantly improve PER any further. Antiphysiological factors were inactivated after 30 min of cooking independent of lime concentration in the home process. These factors were also inactivated in the industrial process as measured chemically and by biological assays. The study demonstrated the feasibility of producing an enriched tortilla flour at the industrial scale, which besides containing a higher protein content and quality, also provides an increased amount of calories to the consumer. Copyright © 1979, Wiley Blackwell. All rights reserved