Impact of different drying methods on the physicochemical and functional properties of pigeon pea protein concentrates

Drying processes play a key role in the functionality of protein-rich ingredients. Knowing the impacts caused by different drying methods is important to choose the right process for the desired functionality of these ingredients. In this work, pigeon pea protein concentrates were dried by spray-, freeze- and oven-drying and the physicochemical and functional properties of the powders were evaluated. The functionality of the protein curd (non-dried) was assessed as a control. Protein recovery ranged from 32 to 47%, while extraction yield ranged from 9 to 13% for the different methods. All powders produced showed suitable flow properties. Spray-dried powders showed lower reconstitution properties, which can be explained by the greater tendency of these powders to agglomerate and form lumps. Oven-dried powders showed a darker color, which may be indicative of Maillard reaction. Freeze-drying better preserved the foaming properties of pigeon pea proteins after drying, whereas the protein curd showed better solubility and emulsifying properties when compared to all powdered extracts. Protein curd is a viable alternative for application in liquid formulations, shortly after extraction, such as in the production of protein-rich drinks. For powdered applications, spray- and freeze-drying are suitable methods of maintaining protein functionality.