Isothermal Storage Delays the Senescence of Post-Harvest Apple Fruit through the Regulation of Antioxidant Activity and Energy Metabolism

The purpose of this work was to elucidate the influence of TF (5 +/- 5 degrees C, and 5 +/- 1 degrees C) and CT (5 +/- 0.1 degrees C served as an isothermal state) storage environment on the antioxidant ability and energy metabolism in post-harvest apple fruit during storage. Specifically, compared with fruit in TFs groups, the quality attributes of apples in the CT group, including firmness, fresh weight, contents of SSC, and TA were maintained at a higher level. In addition, fruit stored in the CT environment revealed a suppressed respiration rate and EL, lower MDA, O-2(center dot-), and H2O2 accumulation but increased the activities of SOD, CAT, APX, and GR. At the end of storage, the SOD, CAT, APX, and GR activities of fruit in the CT group were 38.14%,48.04%, 115.29%, and 34.85% higher than that of the TF5 group, respectively. Fruit in the CT environment also revealed higher AsA, GSH, total phenols, and total flavonoid content. In addition, fruit stored in the CT environment maintained higher ATP content, EC, and more active H+-ATPase, Ca2+-ATPase, CCO, and SDH. At the end of storage, the SDH and CCO activities of fruit in the TF0.1 group were 1.74, and 2.59 times higher than that in the TF5 group, respectively. Taken together, we attributed the fact that a constant temperature storage environment can retard the fruit senescence to the enhancement of antioxidant capacities and maintaining of higher energy status in apple fruit.

Automated summary

The aim of this study was to investigate the effects of different temperature and constant temperature (CT) storage environments on antioxidant ability and energy metabolism in post-harvest apple fruit. Compared to variable temperature (TF) groups, fruit stored in the CT environment showed higher quality attributes, suppressed respiration rate, and lower lipids and reactive oxygen species accumulation. The activities of antioxidant enzymes were also higher in the CT group. Moreover, the CT environment resulted in higher levels of antioxidants and better maintenance of energy status. Thus, constant temperature storage can delay fruit senescence through enhancing antioxidant capacities and maintaining higher energy status in apple fruit.