Abstract Fortified fermented whey beverages represent a sustainable convergence of dairy valorisation and functional nutrition. This review critically analyses recent research regarding the molecular interactions between whey proteins and fruit-derived polyphenols in acidic, microbially active matrices. The literature reveals that non-covalent hydrophobic and electrostatic interactions are the predominant forces stabilising labile polyphenols, particularly anthocyanins from berries and pomegranate, against oxidation and pH-induced degradation during refrigerated storage. While these interactions effectively mask astringency, they induce a masking effect during initial in vitro antioxidant assays, where protein binding sterically hinders the polyphenols. This is not a loss of bioactive potential, as simulated digestion subsequently reverses this trend through proteolysis, releasing bioactive phenolics and peptides, yet simulated digestion studies demonstrate a significant release of bioactive phenolics and peptides in the intestinal phase. Fermentation with specific Lactiplantibacillus and Kluyveromyces species further modulates this matrix, acting as a duplibiotic system where polyphenols stimulate probiotic growth while bacteria enhance bioaccessibility through the bioconversion of glycosides to aglycones. Despite these synergies, significant gaps remain in validating these findings through human clinical trials and industrial scale-up. Future research must prioritise multi-omics approaches to map metabolite evolution and confirm the health benefits of these protein-polyphenol complexes in vivo.
Suttikhana et al. (2026) studied this question.