In this study, we investigated the interaction of Vaccinium bracteatum Thunb. leaf (VBTL) pigment and
rice proteins. In the presence of rice protein, VBTL pigment antioxidant activity and free polyphenol con-
tent decreased by 67.19% and 68.11%, respectively, and L * of the protein–pigment complex decreased sig-
nificantly over time. L * values of albumin, globulin and glutelin during 60-min pigment exposure
decreased by 55.00, 57.14, and 54.30%, respectively, indicating that these proteins had bound to the pig-
ment. A significant difference in protein surface hydrophobicity was observed between rice proteins and
pigment–protein complexes, indicating that hydrophobic interaction is a major binding mechanism
between VBTL pigment and rice proteins. A significant difference in secondary structures between pro-
teins and protein–pigment complexes was also uncovered, indicating that hydrogen bonding may be
another mode of interaction between VBTL pigment and rice proteins. Our results indicate that VBTL pig-
ment can stain rice proteins with hydrophobic and hydrogen interactions.