LAUSR

Cold storage can effectively delay the ripening of ‘Nanguo’ pears ( Pyrus ussuriensis Maxim.). However, the aroma-related esters of ‘Nanguo’ pears decreased after cold storage. In this study, we aimed to investigate the effect of intermittent warming (IW) treatment on the formation of aroma-related esters and unsaturated fatty acid synthesis from cold stored pears. IW-treated pears were exposed to 20 ± 1 °C for 1 day every 20 days during storage at 0 ± 0.5 °C, every 21 days was a cycle and a total of 90 days. The pears in control group were stored at 0 ± 0.5 °C for 90 days. After this 90-day storage, both groups of pears (control and IW-treated) were transferred to a shelf life of 12 days at room temperature. The results showed that, compared with the pears in control group, the productions of aroma-related esters and the expression levels of PuLOX1 , PuADH3 , and PuAAT1 in IW-treated pears were significantly higher during the shelf life ( P  < 0.05). At the same time, IW-treated pears maintained significantly higher contents of linoleic acid and linolenic acid ( P  < 0.05), which were precursors of aroma compounds. We also found that the expression of PuFAD2 and PuFAD3 had significant positive correlation with the contents of unsaturated fatty acids ( P  < 0.05). The significantly higher expression levels of PuFAD2 and PuFAD3 in IW-treated pears may have played an important role in the improvement of ester contents ( P  < 0.05). It could be inferred that IW treatment had an impact on the aroma-related esters of cold-stored ‘Nanguo’ pears through regulation of unsaturated fatty acid synthesis.