To explore the micromechanism of hardness changes of fresh Lingwu long jujube during storage, the degradation law of polysaccharide nanostructure in the cell wall of long jujube was analyzed by atomic force microscopy, and the correlation analysis between the activity of degrading enzyme, water content and fruit hardness was also carried out. The results showed that the first 8 days were the rapid softening period of fruit, and the A23 of free water decreased simultaneously with the hardness (P<0.05). Polygalacturonase (PG), pectin methylesterase (PME), β-galactosidase(β-Gal), cellulase (CE) and other cell wall degrading enzymes were involved in the fruit softening process. β-Gal promoted the decrease of fruit hardness, and the contribution rate was 0.272 9. With the prolonging of storage time, the long chain structure and aggregates in the chelating pectin CSP gradually degraded, and the occurrence and frequency of short chains (15.625, 19.531, 23.438, 31.252 nm) increased, and their contribution rate to the hardness was 0.478 0. This study provids theoretical support for the development of storage and preservation technology of Lingwu long jujube.
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