Application of widely targeted metabolomics strategy to reveal the evolution of phenolic color-contributing metabolites during the high pressure processing and thermal processing of blueberry juice.

The correlation among blueberry juice (BJ) color, anthocyanins and antioxidant capacity is well established. However, it remains unclear whether the color change in processed BJ is caused by the generation of phenolic color-contributing metabolites. This study integrated biochemical data and widely targeted metabolomics (WTM) to investigate the evolution of color related metabolites in BJ. The results showed that thermal processing (TP) promoted the darkening of BJ color and increased the content of total phenols and anthocyanins than high pressure processing (HPP). Fifty differential phenolics related to color changes in BJ were further identified and screened through WTM. TP enhances the phenylalanine biosynthesis and the anthocyanins C-ring cleavage pathways, and increases the degradation products of 1,3,5-benzenetriol and 4-hydroxybenzoic acid, indicating that TP triggers thermally induced reactions for anthocyanin synthesis, release, and degradation. This study aims to provide new insights into the color evolution process during BJ processing.