Which pigment is affected by alkaline conditions to show bluish color?

The correct answer is anthocyanins. These pigments are responsible for a range of colors in fruits and vegetables, particularly blues, purples, and reds. When exposed to alkaline conditions, anthocyanins can undergo a chemical change that shifts their color to a bluish hue. This property makes them especially interesting in food science, as the color change can be used as a natural indicator of pH.

Chlorophyll, while significant in plants and contributing to their green color, does not shift to a bluish color under alkaline conditions; instead, it may degrade or turn brown. Flavonoids encompass a broad group of compounds including anthocyanins but do not specifically exhibit a color change to blue in alkaline environments. Carotenoids, which provide yellow and orange hues, are also stable in alkaline conditions but do not change to blue. Therefore, the distinct property of anthocyanins responding to alkaline conditions to show bluish coloration highlights their unique role in pigment chemistry.