Delphinidin-3-glucoside is a major anthocyanin pigment responsible for blue-purple coloration in plants such as blueberries, grapes, and eggplants. It consists of the anthocyanidin delphinidin glycosylated at the 3-position with a glucose moiety. This compound exhibits pH-dependent color changes, appearing red in acidic conditions and blue in neutral to alkaline environments due to structural transformations between flavylium cation, quinoidal base, and carbinol forms. It functions as a potent antioxidant, scavenging free radicals and chelating metals, contributing to anti-inflammatory and cardioprotective effects in dietary intake. Widely studied for stability in food processing and potential nutraceutical applications.