Effect of enzymatic hydrolysis on molecular weight distribution, techno-functional properties and sensory perception of pea protein isolates

Pea protein isolate (Pisum sativum “Navarro”) was hydrolyzed with 11 proteolytic enzymes at different hydrolysis times (15, 30, 60, and 120 min) to improve techno-functional and sensory properties. The degree of hydrolysis and changes within the molecular weight distribution were used as indicators for a reduced allergenic potential. The highest degree of hydrolysis was reached by Esperase hydrolysates (9.77%) after 120 min of hydrolysis, whereas Chymotrypsin hydrolysates showed the lowest (1.81%). Hydrolysis with Papain, Trypsin, Bromelain, Esperase, Savinase, and Alcalase suggested an effective degradation of the 72 kDa-convicilin fraction. Papain and Trypsin hydrolysates showed a degradation of the 50 kDa-mature vicilin after 15 min of hydrolysis. Most hydrolysates showed a significant increase in protein solubility at pH 4.5 at all times of hydrolysis. Trypsin hydrolysates showed the highest foaming (2271%) and emulsifying (719 mL/g) capacities. The bitterness of the hydrolysates was strongly correlated (P < 0.05) with the degree of hydrolysis. In general, enzymatic hydrolysis improved techno-functional properties indicating their potential usage as food ingredients. Industrial relevance: Due to their high protein content, peas are becoming an attractive ingredient for the food industry. However, pea protein isolates are often characterized by poor techno-functional and sensory properties. Enzymatic hydrolysis is known to change the molecular weight distribution of proteins. Consequently, the techno-functional and immunogenic properties might be altered selectively. In this study, enzymatic hydrolysis was applied, resulting in highly functional pea protein hydrolysates with a hypothesized reduction of main allergens. The lower bitter perception highlights their high potential as valuable functional food ingredients.