Knowra Anthocyanin Anthocyanin Anthocyanins are water-soluble plant pigments that produce red, purple, or blue hues in many flowers, fruits, and leaves. Their visible color shifts with acidity and molecular structure.
Flavylium ion : A positively charged molecular form that gives many anthocyanins their red color in acidic solution. Strong acidity favors this red form, explaining one end of anthocyanin color shifts.
Flavonoid : A large family of plant polyphenols with roles in pigmentation, signaling, and defense. Anthocyanins are a colored subgroup of this broader plant-chemical family.
Food coloring : Substances added to foods to impart, restore, or standardize their color. Anthocyanins serve as natural colorants, though acidity and processing can change their hue.
Richard Willstätter : A German chemist who studied plant pigments and received the 1915 Nobel Prize in Chemistry. His research established influential early chemical accounts of plant pigments, including anthocyanins.
Pollination syndrome : A set of flower traits associated with attracting particular groups of pollinators. Anthocyanin colors contribute to floral signals that pollinators can perceive.
Anthocyanidin : The sugar-free molecular backbone of an anthocyanin, responsible for much of its characteristic color. Anthocyanins are glycosides built from these colored backbones.
Polyphenol : A broad class of compounds characterized by multiple phenol groups, common in plants. Anthocyanins belong to plant polyphenols, whose structures influence their reactivity.
Red cabbage indicator : A pH indicator made from red cabbage extract, whose anthocyanins change color across acidity levels. Its familiar color sequence demonstrates the pigment’s sensitivity to solution acidity.
Robert Boyle : A seventeenth-century natural philosopher whose experiments helped establish modern chemistry. His observations of plant color changes with acids and alkalis anticipated pH-sensitive pigment studies.
Seed dispersal : The movement of seeds away from their parent plant by animals, wind, water, or other means. Anthocyanin-rich fruit colors can make ripe fruits conspicuous to animals that disperse seeds.
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