New solid formulations of retinol protected at the molecular level by the whey protein β-lactoglobulin.

The fat-soluble vitamin retinol plays a critical role in vision, immune function, and skin health, with deficiencies linked to severe health issues, including blindness and increased risk of infection. Despite its importance to the food industry, it is poorly soluble in water and degrades rapidly when exposed to light, heat, and oxygen, limiting its use as a nutraceutical. This study introduces a novel solid formulation of retinol encapsulated by the whey protein β-lactoglobulin (β-LG) to enhance stability for food fortification applications. Retinol forms molecular complexes with β-LG, which are dried into a solid powder, minimizing degradation. Encapsulation within the β-LG calyx protects retinol at the molecular level, as confirmed by fluorescence quenching, mass spectrometry, and X-ray crystallography. This formulation is able to retain retinol integrity throughout more than 5 months of extended storage, which benefits the practical application of the vitamin, addressing health needs while ensuring stability during processing and storage.