High hydrostatic pressure as a tool to modulate techno-functional properties and its effects on in vitro digestibility of quinoa (Chenopodium quinoa) proteins

Quinoa protein has attracted growing attention of scientists due to its nutritional quality and it is referred to as a sustainable and promising plant-based protein source. Modulating plant-based proteins’ properties has recently received interest in order to make them multifunctional ingredients for food systems. Quinoa protein concentrate (QPC) dispersions (5 %; w/v) were subjected to high hydrostatic pressure-HHP (200, 300, 400, 500 and 600 MPa; 25 °C; 20 min). The effects of HHP on techno-functional properties, i.e., solubility, water and oil holding capacity, foaming capacity and stability, emulsifying activity and stability indexes, and in vitro digestibility (IVDP) of QPC were evaluated. Water absorption capacity of QPC (3.3 g/g) was significantly (P<0,05) improved after HHP, with a maximum at 400 and 500 MPa (4.4 and 4.3 g/g, respectively). Fat absorption capacity (2.5 g/g) was, however, unaffected by the process. Emulsifying activity and stability indexes of QPC (23.12 m2/g and 115.17 min) were both decreased with HHP application. Foaming capacity of QPC (15 %) was slightly reduced above 200 MPa, whereas foam stabilities at 10 and 60 min (87.55 and 83.02, respectively) were punctually reduced by HHP at 200 MPa. The loss of these interfacial properties is closely related to the decrease in protein solubility induced by HHP. The use of HHP did not yield any variations in the IVDP of QPC (average value of 86.05 %). It is noteworthy that modulation of QPC techno-functionalities by HHP treatment was achieved with no noticeable loss of nutritional value. According to these findings, the major changes in QPC properties indicate that HHP was more effective at exposing hydrophilic groups of its amino acids. This could be useful in the development of alternative plant-protein ingredients for gluten-free baked products with better mouthfeel, for example, that are also sustainable and clean-label appealing.