The composition, functionality, and application of special oilseed proteins: A review

Special oilseeds are those with lower yields than bulk ones, richer in oil nutrients, and mainly used for producing nutritious and functional edible oils. Special oilseed proteins are extracted from these special oilseeds and feature high digestibility and an acceptable flavor. They are expected to complement the deficiencies of bulk proteins and expand the plant protein resource pool. Consequently, this paper reviews the enrichment, composition, functional properties, and application status of several common special oilseed proteins (sunflower seed protein, flaxseed protein, sesame seed protein, hemp seed protein, walnut protein, and perilla seed protein). The aim is to understand the development status of special oilseed proteins comprehensively, explore effective strategies to break through their application bottlenecks, and thus expand the possibilities of their applications. At present, special oilseed proteins possess excellent nutritional and functional properties and have broad application prospects. Nevertheless, the enrichment techniques for special oilseed proteins in food processing are restricted compared to the comprehensive application systems of bulk oilseed proteins. The relatively high proportion of non-protein components in the raw materials hampers their extraction, leading to a low extraction rate. Additionally, common issues among plant proteins, such as low solubility and incomplete amino acid composition, also limit their applications. Integrating new and traditional extraction methods, formulating multiple protein combinations, and modifying functional properties will contribute to the further application of special oilseed proteins.