Purple sweet potato (Ipomoea batatas L.) is rich in anthocyanin pigments, which are valuable constituents
of the human diet. Techniques to identify and quantify anthocyanins and their antioxidant potential are
desirable for cultivar selection and breeding. In this study, we performed a quantitative and qualitative
chemical analysis of 30 purple sweet potato (PSP) cultivars, using various assays to measure reducing
power radical-scavenging activities, and linoleic acid autoxidation inhibition activity. Grey relational
analysis (GRA) was applied to establish relationships between the antioxidant activities and the chemical
fingerprints, in order to identify key bioactive compounds. The results indicated that four peonidin-based
anthocyanins and three cyanidin-based anthocyanins make significant contributions to antioxidant activity.
We conclude that the analytical pipeline described here represents an effective method to evaluate
the antioxidant potential of, and the contributing compounds present in, PSP cultivars. This approach
may be used to guide future breeding strategies.