Understanding proteases’ mechanisms for production of pea protein hydrolysates

Rebeca Garcia (1, 2) , Kevin Crouvisier Urion (3, 4) , Wafa Guiga (1, 2) , Laure Degrand (5, 1)

1 CNAM - Conservatoire National des Arts et Métiers [CNAM]
2 SayFood - Paris-Saclay Food and Bioproduct Engineering
3 ONIRIS - École nationale vétérinaire, agroalimentaire et de l'alimentation Nantes-Atlantique
4 GEPEA - Laboratoire de génie des procédés - environnement - agroalimentaire
5 GENIAL - Ingénierie, Procédés, Aliments

Food protein demand is increasing due to the world’s population growth, nutritional aspects (consumers’ specific / healthier diets) but it cannot be filled with animal proteins. Plant-based proteins are attracting more and more attention due to their contribution to food system sustainability and they are arising as an interesting alternative to their animal counterparts. Pulses like pea, lentil and chickpea appear as a promising source of proteins due to their well-balanced amino acid composition / bioavailability and their environmental benefits. With their low allergenicity, their non-transgenic status and they coming from a sustainable crop, pea proteins are given particular attention for food applications. However, their poor functional (low solubility, emulsification capacity, foaming) and sensory properties (beany flavour, bitterness) limit their application in food products formulation. Several authors suggested that enzymatic hydrolysis could highly improve their properties. In this context we studied the mechanisms of two commonly used food proteases: Alcalase (alkaline metallo aminopeptidase) and Flavourzyme (neutral serine endoprotease). We showed that Alcalase can be classified as a “one-by-one type” protease in the Linderstrom-Lang model (the molecules are broken one by one to peptides and no appreciable amounts of intermediary products are found in the system) whereas Flavourzyme can be classified as a “zipper type” protease (formation of a wide range of peptides with intermediate products). As a consequence, hydrolysates produced by each enzyme differ in size and properties. Alcalase and Flavourzyme were shown to be able to hydrolyse both water-soluble and water-insoluble pea proteins in controlled pH hydrolysis conditions but also in uncontrolled pH media (no alkali addition). According to that, enhanced solubility at neutral pH can be attributed to size reduction of the proteins but also because water-insoluble proteins are substrate of the enzyme. When enzymes are used in combination, the hydrolysis is not improved (no additive effect) but it could lead to an interesting mix of peptides as the action of one protease can create new cleavage sites for the other one. The controlled enzymatic generation of peptides is of great interest for food applications.

Mots clés: pea protein; flavourzyme; alcalase; protein hydrolysate; protein solubility; protease mechanism

Domaines: Sciences du Vivant [q-bio]

Rebeca Garcia, Kevin Crouvisier Urion, Wafa Guiga, Laure Degrand. Understanding proteases’ mechanisms for production of pea protein hydrolysates. 7th international ISEKI Food conference, Jul 2023, PALAISEAU, France. ⟨hal-04488261⟩