Image recognition technology provides insights into relationships between anthocyanin degradation and color variation...

To identify interesting relationships between anthocyanin degradation and color variation during food processing, black carrot slice (BCS) was dried by air-impingement jet drying (AIJD) and hot air drying (HAD). AIJD was a better technology for drying BCS than HAD. Results of colorimeter determination showed that the color of BCS was significantly changed during AIJD at 50, 60 and 70 °C. UHPLC-QqQ-MS/MS analysis found that AIJD-induced degradations of main BCS anthocyanins, cyanidin-3-xylosyl(feruloylglucosyl)galactoside and cyanidin-3-xylosyl(sinapoylglucosyl)galactoside, belonged to non-spontaneous endothermic reactions, which followed the 0.5- and 1-order kinetic equations, respectively. Anthocyanin content and colors obtained from colorimeter presented strong positive correlation, particularly the a* and chroma values. We further developed a Python script based on image recognition technology to visualize the correlation matrixes between the anthocyanin contents and colors of BSC images. The plots revealed that strong positive correlations between anthocyanins and colors primarily concentrated in the sample's periphery following a concentric pattern.