Abstract: Essential oil was extracted from poknkan mandarin peels by steam distillation and its chemical composition was analyzed by GC-MS. A total of 39 compounds were identified. Among them, the predominant compounds were limonene (12.18%), followed by β-linalool (10.88%), γ-terpinene (9.37%), cycloheptene, 5-ethylidene-1-methy (9.37%), β-myrcene (9.36%), β-pinene (8.12%), 2-carene (7.8%), α-pinene (6.74%), octanal (5.14%), α-thujene (3.99%) and β-phellandrene (3.31%). Meanwhile, the effect of the essential oil on the spore germination and mycelium growth of Penicillium digitatum was measured. The results revealed that the spore germination and mycelium growth of Penicillium digitatum could be promoted by the essential oil could promote at a concentration not exceeding 0.25% but be inhibited at a concentration exceeding 0.5%. In conclusion, this study demonstrates that essential oil from poknkan mandarin peels has a notable inhibitory effect on the growth of Penicillium digitatum.

Key words: essential oil, GC-MS, Penicillium digitatum, inhibitory effect