Review on Protein Isolation from Cold Pressed Defattened Sunflower (Helianthus annuus L.) Oilcake: Challenges and Opportunities

Rapid worldwide population growth and climate change have brought food security and undernutrition challenges. Forecasts on protein sources indicate a limitation of protein supply for human consumption in the near future. The primary protein source for human consumption is from animals. However, animal proteins are expensive, have a potential risk of cardiovascular health complications, and are unsustainable in supply. This necessitates the adoption of sustainable and innovative protein provision methods, which can be achieved, among other methods, by the circular economic model of converting waste and agricultural residue into food. Residues from oil extraction from seeds are rich in proteins and minerals, and can be exploited for protein isolation. Furthermore, these residues are underutilized in their current uses, despite their balanced amino acid composition. They, therefore, can be used as food supplements or for food fortification purposes to meet human protein requirements. This review work aimed at seeking information on the challengesfaced in protein isolation from cold-pressed sunflower oilcake, and the economic opportunities to be exploited in commercializing the valorization process. This was achieved by surveying articles published in the last 15 years on sunflower meal proteins and plant protein biorefinery. Published results show that the presence of anti-nutritive components in sunflower oilcake, structural and functional differences between plant and animal proteins and the absence of an extraction method that does not denature proteins hinder the utilization of proteins isolated from sunflower oilcake. Moreover, there is limited technological advancement in plant protein biorefinery, which is a setback in large-scale plant protein isolation. This review work provides useful information that can be used to address the United Nations Sustainable Development Goals: No. 2 on ‘Zero hunger’, No.3 on ‘Good health and well-being’, No. 9 on ‘Sustainable industrial development and technological progress’ and No.12 on ‘Sustainable food production and consumption.