Structure and function of pea, lentil and faba bean proteins treated by high pressure processing and heat treatment

Authors: HALL, ALEXANDRA - Cornell University; MORARU, CARMEN - Cornell University

Submitted to: LWT - Food Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/22/2021
Publication Date: 8/23/2021
Citation: Hall, A.E., Moraru, C.I. 2021. Structure and function of pea, lentil and faba bean proteins treated by high pressure processing and heat treatment. LWT - Food Science and Technology. 152. Article 112349. https://doi.org/10.1016/j.lwt.2021.112349.
DOI: https://doi.org/10.1016/j.lwt.2021.112349

Interpretive Summary: Utilization of pulse proteins in food products is increasingly explored, but the effect of processing on their quality and functionality is not well known. The effects of high pressure processing and heat treatment on the structure and functionality of pulse (lentil, pea, faba bean) proteins were evaluated, at protein concentrations characteristic for fortification of beverages and gel formation. Structural changes, sample solubility, water holding capacity, and foaming properties were determined and compared to untreated controls. High pressure processing and heat treatments, under the conditions employed in this study, denatured pulse proteins to a similar extent, although some differences in the functionality of the proteins after the two treatments suggest treatment-dependent conformational differences. At a high enough protein concentration, both treatments induced the formation of gel networks with high water holding capacity. These findings demonstrate that both treatments can lead to changes in pulse protein structure and function, and some of these changes can be harnessed to develop new food products using pulse proteins as ingredients.

Technical Abstract: Utilization of pulse proteins in food products is increasingly explored, but the effect of processing on their quality and functionality is not well known. The effects of high pressure processing (HPP; 600 MPa, 5 °C, 4 min) and heat treatment (95 °C, 15 min) on the structure and functionality of pulse (lentil, pea, faba bean) proteins were evaluated, at protein concentrations characteristic for fortification of beverages (5 g/100 g) and gel formation (15 g/100 g). Structural changes were investigated by differential scanning calorimetry, rheological analyses, and surface hydrophobicity measurements. Sample solubility, water holding capacity, emulsifying and foaming properties were determined and compared to untreated controls. HPP and heat denatured pulse proteins and increased their surface hydrophobicity (p < 0.05). This led to changes in emulsifying and foaming, but the extent of these changes varied by protein type and treatment. Both treatments led to strong gels for 15 g/100 g samples, with heat-induced gels having greater strength (G’) than pressure-induced gels (p < 0.05). Both treatments resulted in higher water holding capacity for 15 g/100 g samples, but lower solubility for 5 g/100 g samples (p < 0.05) compared to untreated controls. These changes can have a significant influence on pulse products and may facilitate new pulse product innovations.