High pressure structuring of pea protein concentrates

This work demonstrates the use of high pressure processing (HPP) to induce structural modifications in pea protein concentrates (PPC). Reconstituted PPC with 8-24 g protein /100 g water were subjected to HPP at 250-550 MPa for 15 min, at 20-33 degrees C, or heat treatments at 95 degrees C for 15 min. Structural changes were investigated using dynamic rheology, scanning electron microscopy, differential scanning calorimetry, and mid-infrared spectroscopy. Gel formation occurred at 16 g protein /100 g water concentration and 250 MPa for the HPP-treated samples, and at 12 g protein /100 g water concentration for the heat-treated samples. Gel strength increased with both pressure level and protein concentration. Heat-treated samples exhibited greater gel strength than pressure-treated samples at the same protein concentration. A greater extent of protein denaturation, aggregation, and network formation occurred with increasing pressure level, due to protein tertiary and quaternary conformation changes. Starch granules present in PPC retained their structure and were not gelatinized even at 550 MPa. These findings can be used to create novel pea protein products with interesting structures and superior sensory and nutritional properties. Practical Applications This work shows that a range of unique pea-based products, such as puddings or tofu analogs, can be created by low temperature HPP treatment of pea protein concentrates at different pressure levels and protein concentrations. This process has the potential to better preserve the organoleptic and nutritional properties of the final products compared to traditional, heat based processing methods. These findings can be also extended to create other pulse protein products using high pressure processing.