Valorization Potential of Oilseed Press Cakes from Pumpkin (Cucurbita pepo) and Hemp (Cannabis sativa)

The use of non-traditional oilseeds for food purposes has increased significantly in recent years. Due to the high content of unsaturated fatty acids, the production of cold-pressed oils from pumpkin and hemp seeds is growing at a steady pace. This results in the accumulation of a by-product (oilseed press cake), from which high-quality proteins can be derived. Protein hydrolysates based on these raw materials offer further potential for valorization. This review summarizes classical and modern methods for obtaining protein isolates from pumpkin and industrial hemp oilseed cakes, as well as possible approaches for their modification to enhance their nutritional and functional properties. Furthermore, it provides an overview of the methods for producing protein hydrolysates rich in bioactive peptides. The presence of peptides with antioxidant, antihypertensive, or hypoglycemic properties makes hydrolysates a valuable source of nutraceutical components with potential applications in the development of functional foods or dietary supplements. However, most studies to date have been conducted using in vitro systems. Further research involving animal models or clinical observations is required to determine dosage regimens and applications of these hydrolysates. Regarding protein isolates, the challenges for their broader use in the food industry are related to increasing solubility, removing anti-nutritional factors, and improving techno-functional properties.