Physical Modification of Food Waste Proteins

Food waste is increasing rapidly, resulting in large amounts of edible food being discarded. This issue is gaining attention from the food processing sector and regulators focused on sustainable waste management. A major interest lies in finding innovative ways to repurpose food waste, especially as a source of valuable nutrients like proteins, which are essential for muscle growth and tissue maintenance. Notably, certain food waste materials, such as defatted residuals obtained from oil extraction processes, are increasingly recognized as accessible and cost-effective sources of these proteins. This burgeoning recognition is paralleled by a rising consumer demand for plant-based proteins, which are lauded for their nutritional benefits and positive environmental impact, especially in comparison to traditional animal-based protein sources. The extraction and modification processes for proteins derived from both animal and plant sources typically utilize a range of physicochemical and thermal techniques. The choice of methodologies can profoundly affect both the nutritional quality and functional properties of proteins. With the increasing emphasis on sustainability, the emergence of green technology has prompted researchers to investigate non-thermal and eco-friendly extraction techniques. These advanced methods seek to enhance extraction efficiency while reducing protein degradation, thus improving the overall quality of protein products. This chapter explores various cutting-edge food processing techniques that have demonstrated potential in protein extraction from food waste. Detailed examinations include pulsed electric field (PEF) processing, high-pressure treatment (HP), ultrasound-assisted extraction, supercritical fluid extrusion, microwave processing, gamma irradiation, cold plasma processing (CPP), and ultrafiltration. These methodologies operate at lower temperatures and promote waste-free approaches, enhancing the quality and energy efficiency of protein functionality. They accelerate protein extraction while significantly altering attributes like yield, structure, and nutritional profile. This chapter emphasizes the need to explore novel physical processing parameters for proteins from food waste, as these factors influence the nutritional and functional characteristics of the final protein products, promoting more sustainable food processing practices.