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

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 degrees C, 4 min) and heat treatment (95 degrees 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.