Yüksek hidrostatik basıncın (YHB) bezelye protein izolatının fonksiyonel özellikleri üzerine etkisi

Pea proteins as plant-based proteins have attracted much interest and are preferred in the food industry due to their low allergenicity, high availability, high nutritional value, and low price in recent years. Thus, they are considered a good replacer for commonly used animal-based protein ingredients; however, better functional properties are required for the industry. The aim of this work was to investigate the influences of high hydrostatic pressure (HHP) on the functional properties of pea protein isolate (PPI). For this purpose, PPI was exposed to a pressure range of 300, 400 and 500 MPa at 25 and 50°C for 5 min. The concentration of samples was kept constant at 45% (w/v) PPI in solutions at desired pH. This process was carried out at different pH levels 3, 5 and 7 to understand the impacts of change in pH with HHP on the pea protein functionalities. WHC (water holding capacity), solubility by Lowry method, emulsion activity, viscosity, change in secondary structure analysis by Fourier transform infrared (FTIR) spectroscopy and hydration behavior by NMR Relaxometry experiments were performed on pressurized and control samples. This study showed that HHP treatments enhanced the solubility of pea protein isolate (PPI) approximately 60% at neutral pH compared to other pH values and control (p<0.05). WHC of PPI significantly was reduced by HHP treatment at pH 3 compared to control and other pHs (p<0.05) and 500 MPa-50°C-pH 5 processing condition improved WHC of PPI significantly (p<0.05). Moreover, FTIR results showed that pressure treatments caused changes in the secondary structure of native PPI due to irreversible unfolding. In addition, significantly lower hydrated PPI at pH 3 was found under HHP treatment, especially at 300 MPa, compared to the control (p<0.05), and other processing factors affected hydration behavior of PPI insignificantly (p>0.05). Also, at pH 3, HHP treatments resulted in higher emulsion capability compared to control samples. Furthermore, HHP treatments caused a reduction in viscosity of PPI for all processing conditions (p<0.05). Therefore, HHP could be an excellent alternative to improve the functional properties of pea protein through conformational, structural, and surface change modifications, and this study can help develop new products, including pea proteins.