Effect of process parameters on the antioxidant activity of Vietnamese tea (Camellia sinensis O. Kuntze) seed oil

Abstract

This research was carried out on Tea (Camellia sinensis O. Kuntze.) seeds (containing 22.01% oil) harvested from Trung du tea trees varieties, cultivated in Phu Tho, Vietnam to select the most suitable processing methods which enhance the high antioxidant activity of the oil in the seed oil extraction. The objective of this research is to study the effects of particle size, material/solvent ratio, temperature, time, speed of solvent movement, and extraction cycle on antioxidant properties of the oil (by analysing IC50, total polyphenol content, total carotenoid, and total tocopherol value). The suitable extraction conditions were determined as follows: particle size was 0.25-0.5 mm, the solid-solvent ratio was 1/8-1/10, the extraction temperature was 35-45oC, the extraction time was 7-9h, speed of solvent movement was 200-250 r/m and the extraction cycle was two times. The tea seed oil extracted under the suitable conditions had the DPPH radical scavenging activity (IC50), total polyphenol content, total carotene, and total tocopherol of 62.19 mg/ml, 4.45 mgGAE/g dry weight, 89 mg/kg, and 710 mg/kg, respectively. The high content of antioxidants makes tea seed oil has a good antioxidant capacity, high oxidation stability, and relatively long shelf life. Therefore, research on using wasted tea seed sources to extract oil has great potential for the vegetable oil industry and a high potential of application in food technology.