Blueberries are blue on the outside but green on the inside due to the presence of natural pigments called anthocyanins and chlorophyll.
The outer skin of blueberries contains high concentrations of anthocyanins, which are water-soluble pigments that reflect blue light, making the berries appear blue. These pigments are part of the plant’s defense mechanism, protecting it from UV radiation and attracting pollinators.
Inside the berry, the flesh contains chlorophyll, the same pigment found in leaves that is responsible for photosynthesis. Chlorophyll absorbs red and blue light, reflecting green light, which is why the inside of the blueberry appears green.
This combination of pigments not only gives blueberries their distinctive color but also contributes to their nutritional value, as both anthocyanins and chlorophyll have antioxidant properties.