Effects of ultrasound and high-pressure assisted extraction of pearl millet protein isolate: Functional,...

This study explores the effect of individual and combination treatments of ultrasound (US) and high pressure (HP) on the extraction of pearl millet protein isolate (PMPI). Compared to the conventional extraction technique (control) the millets treated with non-thermal techniques provided a higher protein recovery percentage. The highest recovery of 63.43 % was observed in the high-pressure and ultrasound combination (HU) treatment. The solubility of PMPI was significantly enhanced in all pH levels, the highest solubility was observed at pH 10. Combination treatments demonstrated superior functional properties, including emulsifying capacity, foaming property, surface hydrophobicity, water-holding capacity (WHC), and oil-holding capacity (OHC) compared to individual treatments and control. Significant improvement in protein in-vitro digestibility (IVPD) was identified in non-thermal treated PMPI. The involvement of nonthermal techniques for protein extraction significantly altered the protein's secondary structure, surface characteristics, and molecular weight. These findings underscore the application and advantage of combination treatments in the extraction of millet protein isolates.