Functional, Structural, Thermal, and Nutritional Properties of Food Waste Proteins

Proteins are building blocks of the human body and are involved in growth and development of human health. With rising global demand for protein, food waste has emerged as a promising and sustainable protein source. This chapter explores various functional, structural, thermal, and nutritional attributes of proteins derived from food waste. The structural features, including amino acid composition, surface hydrophobicity, and secondary and tertiary conformations, play a critical role in determining protein solubility, emulsification, foaming, and gelation behavior. Functional properties, including water and oil-holding capacities, dispersibility, and foam/emulsion stability, affect texture, shelf life, and consumer acceptability of food products. Thermal properties, such as denaturation temperature and enthalpy, provide insight into protein stability under processing conditions, evaluated through techniques like differential scanning calorimetry and thermogravimetric analysis (TGA). In addition to this, nutritional evaluation methods such as protein efficiency ratio, biological value, digestibility, essential amino acid index, and amino acid score are essential to determine the quality and bioavailability of these proteins. The chapter highlights how valorizing food waste into high-quality protein ingredients contributes to food security, environmental sustainability, and a circular bioeconomy. It supports the development of functional, nutritious food formulations using alternative protein sources.