Effect of Pea Legumin-to-Vicilin Ratio on the Protein Emulsifying Properties: Explanation in Terms of Protein Molecular and Interfacial Properties.

In isolates from different pea cultivars, the legumin-to-vicilin (L:V) ratio is known to vary from 66:33 to 10:90 (w/w). In this study, the effect of variations in the L:V ratio on the pea protein emulsifying properties (emulsion droplet size ( d 3,2 ) vs protein concentration ( C p )) at pH 7.0 was investigated using a purified pea legumin (PLF sol ) and pea vicilin fraction (PVF sol ). Despite a different Γ max,theo , the interfacial properties at the oil-water interface and the emulsifying properties were similar for PLF sol and PVF sol . Hence, the L:V ratio did not affect the pea protein emulsifying properties. Further, PLF sol and PVF sol were less efficient than whey protein isolate (WPI sol ) in stabilizing the emulsion droplets against coalescence. This was explained by their larger radius and thus slower diffusion. For this reason, the difference in diffusion rate was added as a parameter to the surface coverage model. With this addition, the surface coverage model described the d 3,2 versus C p of the pea protein samples well.