Abstract
Plants are sources of compounds with important effects on health, but plant-based food industry generates substantial waste amounts, especially in oil production. This study aimed to characterize flours derived from oilseed by-products, pumpkin, sunflower, and apricot seed residues, and compare them with conventional grain flours (white and whole wheat). Nutritional composition was analyzed with emphasis on amino acid profiles performed by ion chromatography. Mineral profiles were determined by ICP-MS. Total phenolics and antioxidant activity were assessed using in vitro colorimetric microassays. Oil press cake flours showed significantly higher levels of protein and fiber compared to wheat flours (p < 0.05), while the latter contained more carbohydrates. Among the examined flours, pumpkin and apricot seed flours stood out with the highest potassium, while sunflower seed flour led in calcium content. Despite higher polyphenol content in wheat flours, apricot seed flour exhibited the greatest antioxidant activity, likely due to its diverse profile of hydrophilic and lipophilic bioactive compounds. These findings highlight oil press cakes as nutritionally valuable ingredients for protein-enriched and other innovative food products, aligning with circular economy principles and promoting resource efficiency in the agri-food sector.