Physicochemical Properties and Functional Compounds of Commercial Green Tea Seed Oil

摘要

Physicochemical properties of green tea seed oil including cold test,color,flash point,gravity,refraction index,moisture content,acid value,iodine value,unsaponifiable matter and saponification value were investigated.Fatty acid composition and catechin content of the oil was determined by GC and HPLC analysis.The oil is stable at low temperature.High flash point(267.8 ± 5.1℃) showed the high thermal stability of green tea seed oil as well,which support for suitability to use as cooking oil.Specific gravity and refraction index of green tea seed oil was found as 0.913 and 1.4679,respectively.Color of the oil was measured as 99.7 ± 0.2 for lightness,1.9 ± 0.1 for greenness and 6.6 ± 0.1 for yellowness.Acid value(KOH mg/ml),iodine value,unsaponifiable matter(%) and saponification value of green tea seed oil were 0.21,104.1,0.11 and 215,respectively.Fatty acids compositions of green tea seed oil was found to be dominated by oleic acid(81.3%) and presence of minor amount of linoleic acid(4.8%),palmitic acid(4.6%),palmitoleic acid(3.3%),linolenic acid(3.2%) and stearic acid(1.0%).The presence of antioxidative compounds such as(-)-epicatechingallate(207.2 ± 0.2 g /g) and(-)-epigallocatechin gallate(99.5 ± 0.6 g/g) in the oil could enhance its shelf life during storage.