Peanut proteins as food supplements: A compositional study of selected Virginia and Spanish peanuts

Three peanut cultivars (Virginia, red‐skinned, and white‐skinned Spanish) were analyzed and compared as potential protein supplements for food uses. The seeds were solvent‐extracted in the laboratory to yield defatted flours with 9–10% nitrogen contents. Protein isolates were prepared from the flours by subsequent extraction with dilute salt solutions buffered at pH 7.0. Various parameters were compared, such as total protein contents, soluble proteins, amino acid compositions of flours and protein isolates, free amino acids and free sugars of defatted flours, and certain trace minerals in flours and soluble proteins. The application of these results to the selection of certain types of peanuts for potential uses as protein supplements in food products is discussed.