Properties & Stability of Hybrid Pea-Dairy Protein Formulas

Abstract: The aim of this study was to investigate the functional properties and stability of hybrid pea-dairy protein formulas. To achieve this goal, the combination of pea protein isolate (PPI) with dairy proteins such as micellar casein isolate (MCI), sodium caseinate (NaCas), whey protein aggregate (WPA) was evaluated. Samples stored for 2 and 4 weeks at 4oC and 20oC were visually assessed and physicochemical parameters such as color, pH, viscosity, particle size distribution (PSD) and optical microstructure were evaluated. The results indicated that dissolving the different proteins together, rather than separately, did not display any significant differences in the examined parameters. The most stable sample with optimal viscosity and overall stability, was made with a combination of PPI:NaCas:WPA with 14% total protein in a ratio 60:05:35. This sample was further developed into a hybrid ready-to-drink (RTD) by adding fat and sweeteners. Apart from the advantage of being able to reach high levels of protein content by combining different protein sources, this study also identified that the hybrid formula fulfilled the nutritional requirements for human growth and development, as it was determined by the protein digestibility-corrected amino acid score (PDCAAS). In addition, the hybrid RTD was found to have a sensorial difference in comparison to the reference made with the same quantity of PPI, as the sample exhibited a milder beany flavor. This study also considered the packaging selection of the developed hybrid RTD. The packaging chosen was a carton layered with polyethylene and aluminum foil that is used as light and oxygen barrier. This packaging option was chosen due to the potential impact of light and oxygen that can enhance protein and lipid oxidation and due to the susceptibility of high protein products to age gelation that can lower the consumer acceptance. Finally, various recommendations were made for future research in the area of hybrids, for example to conduct a more comprehensive investigation into the mechanism of protein aggregation in the mixed formulas.