Physicochemical properties and anthocyanin bioaccessibility of downy rose-myrtle powder prepared by superfine grinding

The downy rose-myrtle berry is regarded as a healthy food due to its high content of anthocyanin and other antioxidant phytochemicals. The berries are sometimes dried, ground into a powder and used as a natural food coloring agent or functional food additive. This study aimed to determine the physicochemical properties and anthocyanin bioaccessibility of superfine ground downy rose-myrtle powders. Compared with shear pulverized coarse particles, the superfine ground particles of berry powders had decreased bulk density and fluidity while improved water-holding capacity and solubility. In addition, the amounts of polyphenols and anthocyanins released from the superfine powders were significantly higher than those from coarse powders during in vitro gastrointestinal digestion. These results indicate that after superfine grinding treatment, downy rose-myrtle powder could serve as a potential resource of natural bioactive compounds for food and nutraceutical applications.