Chiang Mai Journal of Science

Para-rubber seeds are a by-product of Hevea brasiliensis from agricultural crops grown in Thailand as well as other Southeast Asian nations. Recently, Para-rubber seed oil from RRIM 600 cultivar has been recognized as an unconventional oil source for cosmetic products. To obtain good quality oil, an extraction method with a high percent yield, optimal physicochemical properties and a cost-effective production for further application in an industrial scale production, is needed. This study aimed to investigate five different extraction methods including maceration, reflux, soxhlet, hydraulic compression and super-critical carbon dioxide. Suitable solvents, including n-hexane and petroleum ether, used in maceration, reflux and soxhlet methods were evaluated. Soxhlet with n-hexane resulted in the highest percentage of extraction yield (42.64 ± 0.98%). Components of fatty acid including linoleic acid, oleic acid, linolenic acid, palmitic acid and stearic acid contained in the rubber seed oil, were not significantly different (P>0.05) among the extraction methods. All of the studied extraction methods indicated that physicochemical properties of the extracted oil are acceptable according to a standard range for a commercial-grade vegetable oil. In summary, the soxhlet extraction with n-hexane is the most effective method for Para-rubber seed oil extraction in terms of oil quality, antioxidant (TEAC 55.53±2.92mg/100g oil) and a reasonable cost of extraction 240 USD/kilogram).