Parsing of Compositions and Micro-Structural Characteristics for Rust-Spots of Pear Pericarp

Rust of pear pericarp threatened economic sustainability, high performance liquid chromatography (HPLC), liquid chromatography-mass spectrometry (LC-MS) and transmission electron microscope (TEM) were employed to analyze these rusty spots. Therefore, chemical compounds of four eluates were identified successfully as rhein, aloe-modin, chrysophanol and emodin by contrasting retention times, such as elution 1 (E1, 25.055 min), elution 2 (E2, 18.998 min), elution 3 (E3, 44.028 min), and elution 4 (E4, 35.177 min) with standard retention times of rhein (25.068 min), aloe emodin (18.981 min), chrysophanol (43.948 min), and emodin (35.022 min), respectively. With micro-structural characteristics, these eluates were the main factors affecting commercial quality of pear's pericarp during the AC, which was also a sign resisting the undesirable stress of the external environment to pear's pericarp.