Abstract: To provide key data for the medicinal development and superior germplasm screening of Rongan kumquat(Citrus japonica), steam distillation was employed, and the extraction process of volatile oil was optimized using single-factor tests combined with an L₉(3⁴) orthogonal test with solid-to-liquid ratio, sodium chloride concentration, and extraction time as variables. The components of the volatile oil and kumquat dew were quantitatively analyzed using gas chromatography-mass spectrometry (GC-MS). The results showed that the optimal extraction process for the volatile oil from Rongan kumquat peel was a solid-to-liquid ratio of 1∶8 (m/V), a sodium chloride concentration of 3%, and an extraction time of 3 h. The average extraction yield in the verification test was 2.7%, with a relative standard deviation (RSD) of 3.7%, indicating a stable and reliable process. Seventeen and sixteen compounds were identified in the volatile oils of Youpi Kumquat and Huapi Kumquat, respectively, including (+)-limonene, myrcene, and pinene. Eight and twelve compounds were identified in the kumquat dew of Fuyuan Kumquat and Cuimi Kumquat, respectively, including 2-hexenal, (+)-limonene, and 3-furaldehyde. There were 11 common components in the volatile oils of Youpi Kumquat and Huapi Kumquat, and 6 common components in the kumquat dew of Fuyuan Kumquat and Cuimi Kumquat. Differences existed among the four varieties in fruit traits, volatile oil yield, and chemical composition.

Key words: Rongan kumquat (Citrus japonica), volatile oil, extraction process, chemical components, gas chromatography-mass spectrometry (GC-MS)