Continuous flow microwave-assisted aqueous extraction of pomace phytoactives for production of protein-polyphenol particles and a protein-enriched ready-to-drink beverage

Muscadine grape (MG) and blueberry (BB) pomaces processed via water-based continuous flow microwave-assisted extraction (CFMAE) yielded flavonoid-rich extracts, which were complexed with chickpea [CH] or pea:rice [PR] protein and spray dried (SD) into protein-polyphenol aggregate particle treatments: BB-CH, BB-PR, MG-CH and MG-PR. Particles were characterized for physicochemical characteristics, phytochemical composition and functional attributes. The volume-weighed mean diameter for protein-polyphenol particles (20.75-24.67 µm; p > 0.05) were significantly smaller (p < 0.05) than original protein sources CH and PR (57.77-71.10 µm). Highly polymerized proanthocyanidins (PAC) were captured in BB treatments (up to 79 % of total PAC), while monomers predominated in muscadine-derived particles (∼56 % of total PAC). BB-CH particles had highest protein solubility (51-62 %). BB-CH and BB-PR had good emulsifying capacity (∼8.73 m2/g), and particle treatments had higher emulsifying stability than unmodified proteins CH and PR alone. BB-CH particles were prioritized to produce a RTD smoothie beverage rated to have pleasant sensory properties. CFMAE proved to be a sustainable strategy to recover residual phytochemicals from fruit by-products (using only water as the solvent) for use in versatile value-added protein-polyphenol particle ingredients.