AbstractA protein seldom serves independently as a source of dietary amino acids—it works in concert with other proteins. Hence, the most important characteristic of each protein in the diet is its ability to fill gaps between the quantities of essential amino acids needed and those supplied by other foods. When examined from this viewpoint, oilseed proteins differ somewhat, but they all appear to be more valuable as supplementary proteins than their individual protein qualities imply. In general, feeding tests substantiate the theoretical supplementary values. Properly processed oilseed flakes, flour or concentrates of proteins prepared from them have great potential value as human food.