Disparity Mechanisms in Browning of Golden Nectarine and Chun Xue Peach Fruit during Postharvest Storage and Pulping: Biochemical Characteristics and Oxidative Stress

Preliminary investigation showed a notable disparity in the browning of Golden Nectarine (GN) and Chun Xue (CX) during postharvest storage and pulping. Elucidating these underlying mechanisms might bring novel avenues for browning inhibition. To achieve this objective, GN and CX were stored at 25°C and 90 ± 5% relative humidity for 6 days, and then the biochemical changes were investigated. With the extended storage time, the post−ripening developed more noticeably in CX, resulting in sensory deterioration. In addition, a browning exacerbation was observed in CX after pulping, which had higher levels of polyphenol, reactive oxygen species (ROS) accumulation, ascorbic acid and carotenoid degradation, and POD activity but lower superoxide dismutase (SOD) activity. Cluster correlation analysis and validation experiments verified that higher polyphenol levels, antioxidant degradation, and ROS accumulation during pulping were associated with browning aggravation. In conclusion, peach pulping induced oxidative stress and promoted antioxidant metabolism, thus exacerbating browning.