Peer review

The protein quality of Opaque-2 corn in comparison to common corn as a component of vegetable protein mixtures was evaluated by growth and PER experiments. The results indicated that mixtures which have a lysine deficiency are improved in quality when prepared with Opaque-2 corn. Mixtures whose main protein source is soybean flour are not improved in protein quality as a result of preparation with Opaque-2 corn. Amino acid supplementation of the various mixtures made with common and Opaque-2 corn gave results which explained the responses observed. The results of additional studies indicated that the proteins of Opaque-2 corn and cottonseed flour do not complement each other. Opaque-2 corn and soybean protein complement each other in the range of 80 to 40% of the dietary protein from soybean, and 20 to 60% of the same from Opaque-2 corn. Similar values were found between Opaque-2 corn and cooked black beans. These results were interpreted in terms of the lysine concentration in Opaque-2 corn and the other proteins tested.

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