Changes of respiration intensity and quality of different varieties of fresh walnut during cold storage

The purpose of this research was to discuss the quality changes of ‘Liaohe4’, ‘Xifu1’and ‘Xifu2’ fresh walnut which were packed in 0.03 mm polyethylene bag and stored at about (0±1)℃, the relative humidity of 70%-80% , and the main indicators were determined regularly. The results indicated that, during the initial storage (15 d), the respiration rate of fresh walnut showed downtrend sharply, then low and stabilized. There were obvious differences on the content of moisture, fat, protein and amino acid among the three cultivars. Protein content changed slightly, the fat, vitamin E and fatty acid content showed a downward trend. The amino acid content was the highest when storing for 30 d, then followed by the overall downward trend. Acid value and peroxide value showed an upward trend and acid value, peroxide value, fine fruit rate and sensory quality dropped drastically after 60 days’ storage. The results show that the different varieties have obviously different qualities, the suitable storage period is 60 d for fresh walnut and L4 is the best in quality during storage.