Taurine Maintains the Quality of Fresh-Cut Peaches by Regulating the Antioxidant System, Endogenous NO and H2S Biosynthesis, and Phenylpropanoid Metabolism During Storage

The storage quality of fresh-cut peach fruit is compromised by weight loss and chromatic aberration. In this experiment, taurine at 30 mg L−1 was applied to fresh-cut peaches to evaluate its effect on storage quality. Changes in weight loss, chromatic aberration, antioxidant system, endogenous nitric oxide (NO) metabolism, endogenous hydrogen sulfide (H2S) metabolism, and phenylpropanoid metabolism were studied. The results indicated that 30 mg L−1 taurine effectively improved the ability to scavenge ROS, including •OH, O2•−, MDA, and H2O2, by inhibiting the decrease in the activities of SOD and CAT, enhancing POD activity, reducing PPO activity, and maintaining the AsA-GSH cycle. Moreover, taurine treatment increased the activities of 4CL and PAL and retarded the decrease in the activities of SKDH and C4H, thereby improving the accumulation of total phenols, flavonoids, and lignin. These findings showed that taurine mitigated oxidative damage in fresh-cut peaches by enhancing the antioxidant defense system. Exogenous taurine consistently enhanced NOS-like activity while decreasing NR activity in the early storage phase, and elevated the contents of L-Arginine, nitrite, and endogenous NO. Taurine treatment up-regulated the activities of SAT, L-CD, and OAS-TL, thus promoting endogenous H2S content in fresh-cut peaches. Taurine alleviated weight loss and chromatic aberration in fresh-cut peaches during storage by enhancing the antioxidant system and modulating NO, H2S and phenylpropanoid metabolism.