Functional properties of legumes important for food applications : a study of pea, fava bean, and soy protein

Sammanfattning: The market demand for foods with plant-based protein sources such as meat analogues has increased due to for example consumer awareness of environmental, ethical, and health issues. Meat analogues based on soy have dominated the market due to soybean’s protein quality and eminent functional properties. However, due to sustainability issues in the food supply chain of soy, the need for new plant-based protein sources has increased. Swedish-grown legumes such as pea and fava bean are potential alternatives due to their market availability and cultivation feasibility. Plant-based protein sources such as legumes are often processed, and the proteins are extracted to produce rich-in-pro-tein materials before being utilized in foods such as meat analogues. The aim of this literature study was to do a screening of rich-in-protein materials from pea, fava bean, and soy and to study methods to evaluate the functional properties of these that are relevant in meat analogues. This study found that rich-in-protein materials are utilized in foods both for the nutritional content as well as their functional properties. Functional properties of proteins from soy, pea, and fava beans relevant in meat analogues are solubility, water-holding capacity, fat-absorption capacity, emulsification, and gelation. Some of these functional properties can be affected by internal factors such as surface hydrophobicity, ionic charge, and surface charge of the protein molecules as well as external factors such as pH, temperature, and salt content. Emulsification properties of pea protein isolate was shown to be affected by solubility, surface charge, and surface hydrophobicity. Conditions of parameters such as pH, temperature, and salt content was shown to be of importance in protein extraction, in methods to analyze functional properties as well as in the process of producing meat analogues. To determine the influence of these parameters on the functional properties of rich-in-protein materials an empirical study is required.