Insights into the metabolism of membrane lipid fatty acids associated with chilling injury in post-harvest bell peppers

•Membrane lipid fatty acids are involved in responses associated with chilling injury.•Long-term storage of peppers at 4 °C reduced unsaturated fatty acid synthesis.•Reduced unsaturated fatty acid synthesis led to the disruption of cell membranes.•Higher activity of LOX and increased MDA content accompanied chilling injury.•Electrolyte leakage and membrane rigidity are associated with unbalanced ROS. Bell peppers are susceptible to chilling injury (CI). To uncover the metabolism of membrane lipid fatty acids (FAs) accompanying CI, a gas chromatography-mass spectrometry (GC-MS)-based approach was used to quantitatively profile major membrane lipid FAs in bell peppers. RT-qPCR was performed to investigate the expression of the key genes that regulate the synthesis of unsaturated FAs. Additionally, we used microstructural, organoleptic, and physicochemical investigations to monitor the primary physiological metabolism of bell peppers. The study revealed that CI symptoms mostly resulted from the destabilization of the cytomembrane, which was induced by decreasing FA desaturation. Moreover, three times lower level of the double bond index in chilled fruits, than the control, further proved that membrane FA unsaturation can be considered a key factor during CI. In conclusion, this study revealed that the metabolism of membrane lipid FAs is involved in responses to CI.