Approaches to Enhance the Functional Properties of Pea Protein through Processing

Pea protein is a trending food ingredient because it has commercial availability, low cost, low allergenicity, non-GMO status, and good sustainability. However, the utilization of pea protein is limited by the relatively poor functional properties of commercial proteins. The functional properties of commercial proteins are reduced because of the effects of denaturation that occurs during the isolation process. By better understanding and controlling the damage that occurs during the commercial isolation process, the functional properties can be increased, promoting wider use in the food industry. To better understand the reduced functionality of commercial pea proteins, five commercial proteins were evaluated for their physicochemical and emulsification properties. Four of the five commercial proteins exhibited low solubility, high surface hydrophobicity, and an abundance of large insoluble aggregates. Commercial isolates are typically spray dried, while laboratory isolates are freeze dried, which suggested that the spray drying process is related to the reduced functional properties of pea protein. To evaluate the impact of spray drying on the physicochemical and emulsification properties of pea proteins, the spray drying temperature and pH were varied. Spray drying temperature had a minimal effect, while spray drying at pH 9.0 improved the solubility and emulsifying properties. The utilization of molecular interaction inhibitors indicated that hydrophobic interactions played a key role in the reduction of pea protein functional properties. Spray drying alone was not the only cause for the poor functional properties exhibited by commercial proteins. Heating the protein during isolation to encourage denaturation reduced the functional properties to the level of commercial proteins. High-pressure homogenization and optimized isolation conditions were investigated to determine their effect on the functionality of heated pea protein. The combination of homogenization during heating and drying at elevated pH (9.0) was able to effectively protect the protein during the isolation process and resulted in similar solubility and emulsification properties to an unheated sample. This information can be used to design better production methods for the isolation of pea protein