Integrated HS-SPME-GC-MS and HS-GC-IMS Analysis for Identifying Key Volatiles during the Development of “Akizuki” Pear ( <i>Pyrus pyrifolia</i> )

The delightful aroma of pear fruit is a critical factor in appealing to consumers and enhancing market competitiveness. Currently, the aroma characteristics of “Akizuki” pears during fruit development remain unclear. This study integrated headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) and headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) techniques to comprehensively analyze the volatile organic compounds (VOCs) in developing “Akizuki” pear (Pyrus pyrifolia). This dual-platform approach leveraged the high sensitivity of HS-GC-IMS for rapid detection and the extensive compound identification capabilities of HS-SPME-GC-MS. HS-SPME-GC-MS identified 133 VOCs, while HS-GC-IMS detected 75 VOCs. Through multivariate analysis (variable importance in projection), odor activity value quantification, and sensory descriptor alignment, potential biomarkers were proposed: (1) butyl formate, 2-hexenal, (E,E)-2,4-hexadienal, (E)-2-nonenal, (E,E)-2,4-nonadienal, 4-methyl-1-pentanol, ethyl 2-methylbutanoate, and (E)-2-hexen-1-ol as “green/fruity” indicators; and (2) methyl acetate as a primary “fruity” marker. The temporal evolution of these biomarkers during maturation was characterized. This work demonstrates the efficacy and synergy of combined HS-SPME-GC-MS/HS-GC-IMS for VOC profiling and identifies critical biomarkers for assessing pear aroma development and quality.