Nutritional evaluation of sunflower-seed protein products.

Defatted sunflower-seed meal, sunflower-seed protein concentrate and protein isolate were fed to protein-depleted chicks. The effect of the enrichment of meal and of protein isolate with lysine, methionine, or a mixture of both on the nutritional value was investigated. Sunflower-seed protein products are primarily limited in lysine. Food consumption, weight gain and protein/efficiency ratio reveal superior performance of lysine- and methionine-enriched meal or protein isolate, as compared to the corresponding non-enriched products. Methionine enrichment does not improve the nutritional quality and even result in inferior performance. Non-enriched protein isolate supports better growth than non-enriched meal specially at later stages of chick growth.