Protein extraction from apple seeds for waste valorization for sustainable food systems

Abstract

Proteins are essential to the food industry because they provide both functional and nutritional advantages. This study explores apple seeds, a largely overlooked agro-industrial by-product, as a sustainable source of plant proteins. Utilizing apple seed proteins can add value to agro-industrial waste, promote sustainability, and support circular economy. Apple seed hydrolysate (ASPH) and protein concentrate (ASPC) were prepared through extraction and enzymatic hydrolysis and assessed for their composition, functional properties, and antioxidant activity. ASPC exhibited a protein content of 59.21%, while ASPH achieved a higher protein content of 77.48% due to enzymatic hydrolysis. ASPH demonstrated enhanced solubility (72.5%) at neutral pH, and superior water absorption capacity (2.45 g g⁻¹), and emulsifying properties compared to ASPC. Additionally, ASPH showed stronger antioxidant activity, with DPPH and ABTS scavenging rates increasing by 28% and 35%, respectively. These results highlight the potential of apple seed proteins for use in nutraceuticals, bakery products, and plant-based food formulations.