Technology for aqueous extraction of camellia seed oil by salt effect

To improve the lower free oil yield triggered due to severe emulsification in aqueous extraction process of oil, new technology of aqueous extraction of camellia seed oil by salt effect was explored. With sodium carbonate solution as the extractant, effects of liquid-solid ratio, extraction time, extraction temperature and agitation speed on free oil yield of camellia seed oil were investigated, and parameter optimization of the main factors was carried out through Box-Behnken experimental design. Among the main factors, extraction temperature has the greatest effect on free oil yield, followed by liquid-solid ratio, and extraction time with the minimal effect. The optimal parameters of aqueous extraction of camellia seed oil by salt effect were as follows: liquid-solid ratio of 3.39 mL/g, extraction time of 1 h, extraction temperature of 65℃, and agitation speed of 140 r/min. Under the optimal conditions, the free oil yield of camellia seed oil was up to 96.33%. It indicates that salt effects can significantly prevent the emulsion formation during aqueous extraction of camellia seed oil, and markedly improve the free oil yield. This method also provides a new strategy for other vegetable oils to obtain higher free oil yield.