Abstract: Essential oil from grapefruit is an important kind of citrus essential oil, which is popular in the world as a natural fragrant agent with fresh and fullbodied characteristic fruity flavor. To investigate the effects of extraction methods on apparent properties, physical characteristics and chemical compositions of grapefruit essential oil, the oil was extracted from grapefruit peels through distillation and coldpress methods respectively, and compounds contained were detected by gas chromatographymass spectrometry (GC-MS). Yield of essential oil from distillation method was much higher than that of coldpress. However, the color, luster and odor of oil from coldpress method were much more close to those of fresh grapefruits, and its refractive index and relative density were higher, too. There were 39 detectable compounds in the oil from distillation, including 18 oxides with a total content of 14.11 %, while 37 compounds were found in the oil from coldpress, which contained 16 oxides with their total content of 17.18 %. More importantly, the concentrations of characteristic aroma substances, such as linalool, decanal and citral in cold pressed oil, were all higher than those in distillated oil. The results indicated that coldpress method was more suitable to extract grapefruits essential oil with good quality than distillation method.

Key words: grapefruit, essential oil, extraction, properties composition