Altering almond protein function through partial enzymatic hydrolysis for creating gel structures in acidic environment

Jia Zhao; Bhesh Bhandari; Claire Gaiani; Sangeeta Prakash

doi:10.1016/j.crfs.2022.03.012

Altering almond protein function through partial enzymatic hydrolysis for creating gel structures in acidic environment

Curr Res Food Sci. 2022 Mar 29:5:653-664. doi: 10.1016/j.crfs.2022.03.012. eCollection 2022.

Authors

Jia Zhao¹, Bhesh Bhandari¹, Claire Gaiani², Sangeeta Prakash¹

Affiliations

¹ School of Agriculture and Food Sciences, The University of Queensland, St Lucia, QLD, 4072, Australia.
² Université de Lorraine, Laboratoire d'Ingénierie des Biomolécules LIBio, 2 avenue de la Forêt de Haye, TSA 40602, Vandoeuvre-lès-Nancy, 54518, France.

Abstract

Protein inadequacy is the major problem for most plant-based dairy yoghurt substitutes. This study investigated three limited degree of hydrolysis (DH: 1%, 5%, and 9%) of almond protein and the combined effect of DH and hydrolysed almond protein (HP) to non-hydrolysed almond protein (NP) ratios (HP/NP: 40:60, 20:80, 10:90 and 5:95) on the physicochemical properties of resulting fermentation induced almond-based gel (yoghurt). The gel microstructure, particle size, firmness, pH, water holding capacity (WHC), lubrication, flow, and gelation characteristics were measured and associated with the DH, composition, and SDS-PAGE results. The results show significant differences in gel samples with the same HP/NP (40:60) ratio of protein but different protein DH. A higher DH (9%) resulted in samples with lower hardness (6.03 g), viscosity (0.11 Pa s at 50 s-1), cohesiveness (0.63) and higher friction (0.203 at 10 mm/s) compared to sample with 1% DH with higher hardness - 7.34 g, viscosity at 50 s^-1 - 0.16 Pa s, cohesiveness - 0.86 and friction at 10 mm/s - 0.194. Comparing samples with the same DH (5%) but different HP/NP ratios showed smaller coarse microgel particles (21.36 μm) and lower hardness (7.17 g), viscosity (0.14 Pa s at 50 s^-1) and friction value (0.189 at 10 mm/s) in samples with high HP/NP (40:60) compared to sample with low HP/NP (5:95) that contained significantly large coarse microgel particles (34.61 μm) with the gel being very hard (9.38 g), highly viscous (0.32 Pa s at 50 s^-1), and less lubricating (0.220 at 10 mm/s).

Keywords: Acid-induced; Almond protein hydrolysates; Fermentation; Gel properties; Limited hydrolysis.