Food Safety Focus (235th Issue, Feb 2026) – Article 4

Is the Colour in Purple Sweet Potatoes Safe to Eat?

Some people suspect that purple sweet potatoes have colour added and unsafe to eat. Purple sweet potatoes naturally contain anthocyanin, a vibrant pigment that can give plants different colours depending on pH. Anthocyanin looks red when acidic, purple when neutral and blue when alkaline. Anthocyanin is also found in many foods of plant origin like berries, cherries, peaches, grapes, pomegranates, plums, black currents, apples (skin) and dark vegetables like eggplants (skin), red cabbages, red onions, black rice and black beans. Colourful crop varieties like red broccoli, red potatoes etc. are selectively bred for their attractive hues, increasing their appeal to consumers without dying them.

During boiling or washing, it is normal for some of these water-soluble pigments to leach out, which may stain the water or one’s hands. However, this is a natural phenomenon of purple sweet potatoes and there is no need for any undue concern while enjoying purple sweet potatoes.

Illustration: Purple sweet potatoes