Comparison of the Characteristics of Two Kinds of Tea Seed Oils: Oil-tea Seed Oil and Green-Tea Seed Oil

Abstract

Physicochemical properties, fatty acid composition, antioxidant compounds and oxidative stability of oil-tea seed oil (Camellia oleifera Abel.) and green-tea seed oil (Camellia sinensis O. Ktze.) were investigated. The refractive index, saponification value, iodine value, acid value, peroxide value, unsaponifiables were determined to assess the quality of the oils. The major fatty acids of green-tea seed oil and oil-tea seed oil were oleic acid, linoleic acid and palmitic acid. Green-tea seed oil was typical oleic-linoleic-oil with 52.13% oleic acid and 24.32% linoleic acid level, whereas oil-tea seed oil was typical oleic-oil with very high oleic acid level (73.67%). The amount of total phenols, α-tocopherol and β-carotene of green-tea seed oil were 8.68 mg/kg, 160.33 mg/kg, 3.20 mg/kg, respectively, whereas they were 17.90 mg/kg, 85.66 mg/kg, 1.18 mg/kg in oil-tea seed oil, respectively. Green-tea seed oil contained high amounts of α-tocopherol which was nearly twice that of oil-tea seed oil. The initial induction period (IP) values of green-tea seed oil and oil-tea seed oil were 6.55h and 6.08h at 110 oC by OSI method, respectively, which shows the oxidative stability of two kinds of tea seed oils were preferable. Therefore, oil-tea seed oil could be a good dietary supplement with high level of monounsaturated fatty acids and similar fatty acid composition of olive oil. Green-tea seed oil was a new oil resource which is rich in α-tocopherol in China.