The Use of Spirulina Powder to Enrich Honey with Antioxidants and Highly Digestible Protein

Despite the presence of numerous bioactive compounds, honey is naturally low in protein, which limits its nutritional value. Adding spirulina powder, abundant in protein and antioxidants, seems to be a good way to increase the nutritional value of honey. Two commercially available dietary supplements of spirulina were used to enrich rapeseed honey (0.15–1.2%) during the creaming process. Obtained products were analyzed after 1, 3, and 6 months of storage at room temperature regarding basic physicochemical parameters, protein and phenolic content, and antioxidant capacity. Moreover, the bioaccessibility of antioxidants, as well as the protein digestibility, was assessed using an in vitro digestion model followed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The study demonstrated that 1.2% enrichment of blue spirulina significantly increased the easily digestible protein content and antioxidant capacity. All of the tested parameters were maintained during storage. Spirulina-enriched honey can be recommended as a novel functional product with unique sensory features and evidenced health-promoting properties and can be a valuable dietary supplement.