The impact of spray drying conditions on the physicochemical and emulsification properties of pea protein isolate

Abstract

Pea protein isolate (PPI) is a promising candidate for plant-based emulsification, but there is currently a gap in functionality between commercially and laboratory produced PPI. To help address this gap, this research investigated the impact of variation in spray drying conditions on the physicochemical and emulsification properties of PPI. When the spray drying inlet temperature increased, the surface hydrophobicity, protein particle size, and emulsion droplet size also increased. Compared with the inlet temperature, the spray drying pH (5.0, 7.0, or 9.0) had a larger effect, and pH 9.0 produced the best solubility and emulsifying properties. The use of propylene glycol to inhibit hydrophobic interactions during drying partially prevented protein aggregation and therefore improved the stability of resultant emulsions. When PPI was heated above the denaturation temperature prior to spray drying, the solubility and emulsification properties significantly decreased. These results suggest that spray drying pH, handling temperature, and hydrophobic interactions play a major role in controlling the functionality of PPI. This information can be used to design better production methods and protection methods for the isolation of PPI, to better maintain its functional properties during commercial production.