Effects the mechanism of micro-vacuum storage on broccoli chlorophyll degradation and builds prediction model of chlorophyll content based on the color parameter changes

The objective of this study was to investigate the mechanism of micro-vacuum (MV) storage on broccoli chlorophyll degradation and builds prediction model of chlorophyll content based on the color parameter changes. The freshly harvested broccoli were subjected to MV storage (70 +/- 5 kPa) and atmospheric pressure storage at 3 +/- 1 degrees C for 49 d; The relationship between broccoli chlorophyll content and its surface color parameters (-a/b value) was studied to build broccoli chlorophyll content prediction model based on the color parameter changes under MV conditions. The results showed the degradation of chlorophyll could be inhibited, activities of CAT, SOD, POD could be improved, superoxide anion (O-2 center dot) release rate, hydrogen peroxide (H2O2) content, malondiadehyde (MDA) content and the increase of membrane permeability could be decreased significantly in MV storage conditions; the correlation analysis showed that relationship between chlorophyll degradation rate and activities of CAT, SOD, POD, the relationship between chlorophyll content and O-2(-)center dot release rate, H2O2 content, MDA content, membrane permeability showed a significant negative correlation; The changes of chloroplast ultrastructure could be inhibited and degradation of chlorophyll could be delayed in MV conditions, yellowing mechanisms of broccoli was revealed by the cellular level in MV conditions. Validation showed that the prediction model could reflect the changes of chlorophyll content during storage, provide theoretical basis for the further application of non-destructive testing technology.