Tracking Browning mechanistic pathway of postharvest pine resin using comparative metabolomics

The color degradation of postharvest pine resin, a raw material used as a beverage additive, is a major concern in the pine resin industry. Herein, integrated proteomics and metabolomics approach was employed to systematically identify and quantify the molecules involved in the browning process. Physicochemical studies of pine resin showed that the browning index is lowest in sterile water (STW) and deionized water (DEW), followed by crude pine resin in pond water (POW), and highest in tap water (TAW). And 17 metabolites were identified as potential endogenous browning inhibitors by comparative metabolomics. The 7, 27, 34, and 19 KEGG pathways in these water samples induced varying degrees of resin browning, respectively. The combined analysis of proteomics and metabolomics indicates that 6-phosphogluconate dehydrogenase, SDH, and IDH are key enzymes involved in carbon metabolism. This work provides key information for developing efficient inhibitors against browning during the storage of pine resin.