Mixtures of corn or rice with dehulled soybeans (70:30) were extruded at three cone openings. Processing temperatures were inversely correlated with cone opening. As cone opening increased fat retention and nitrogen solubility index increased, while dispersibility, protein nutritive value and acceptability (as “atole”) by school children decreased. The PER and NPR of the mixtures were significantly (P < 0.05) correlated with processing temperature (r = 0.90 for both) and sensory score (r = 0.83 and 0.82, respectively). No correlation was observed between protein nutritive value and residual antiphysiological factors of the products. After storage of mixtures for 12 wk at 4° and 25° C, fat acidity values were lower than 2%; those stored at 35°C showed nearly 10%. All samples were equally acceptable.