Association analysis of color characteristics, anthocyanin profiles, and antioxidant capacity in purple/black agricultural products based on targeted metabolomics.

This study systematically compared color traits, pigment composition, anthocyanin profiles, and antioxidant capacity in 16 representative purple/black agricultural products using electronic eye analysis, HPLC, and targeted UPLC-MS/MS. Pigment distribution, content, and composition differed markedly among samples. Despite similar surface appearance, homogenized samples varied in color, with 10 appearing purple, 4 yellowish, and 2 greenish. Anthocyanins predominated in the 14 purple and yellowish homogenized samples, with the highest total contents in blueberry (1441.13 μg/g) and blackberry (1029.62 μg/g). By contrast, chlorophyll A predominated in black soybean and purple lablab bean, the two greenish homogenates. A total of 92 anthocyanins were identified, with purple grape showing the greatest diversity. Cyanidin-type derivatives, especially cyanidin-3-O-glucoside, were the most widespread. Total anthocyanins were negatively associated with L* and C* values but positively associated with antioxidant capacity, indicating greater antioxidant potential in darker samples. These findings support color-based dietary guidance.