Enrichment and recovery of pea (Pisum sativum L.) proteins using foam fractionation for simultaneous enhancement of their functional properties

Peas (Pisum sativum L.) are an extensively grown export crop in Canada. Pea protein flour (PPF) produced from milled peas typically consists of 19.8 % protein (dry weight basis). The separation and concentration of proteins from pea flour can be made more cost-effective through foam fractionation, which may also impact functional protein properties. This study investigates foam fractionation as a technique for the enrichment and recovery of pea flour proteins from a solution using a two-stage foam fractionation process and evaluates the functional properties of the recovered proteins in the foamate. Process parameters such as protein concentration in the starting solution (C), pH, air flow rate (V) and liquid loading volume (L) on protein recovery percentage (R, %) and enrichment ratio (E) were studied. First stage foam fractionation achieved a high protein recovery R (%) 86.66 +/- 3.55 %, with E of 2.106 +/- 0.180 at C of 1.05 g/L, pH 4.5, V of 800 mL/min and L of 4000 mL. Second stage fractionation achieved a high protein enrichment E of 5.83 +/- 0.14 at pH 4.5, V of 300 mL/min and L of 1500 mL. Foamate powder consisted of similar proteins with higher purity than the pea protein flour and had improved functional properties, such as soluble content (at pH 3, 7, and 8), foaming, emulsification, and oil and water holding capacities. Thus, foam fractionation can recover and purify pea protein fractions from dilute solution and simultaneously improve their nutritional value and functional properties for application as novel ingredients in food systems.