Extraction of squalene from camellia oil by silver ion complexation

•Separation of Squalene from camellia oil by silver ion complexation was feasible.•The UV and FT-IR analyses indicated that a complex could be formed.•The complexation number was estimated under simulated conditions.•The conclusions may help to increase the efficiency of squalene extraction.

Separation of squalene, a type of terpenoid hydrocarbons with important biological properties, from camellia oil by silver ion complexation was studied. We showed that the UV–visible absorption wavelength of squalene in AgNO3-methanol solution was obviously red-shifted, and the infra-red vibration wavelength of CC bond slightly decreased, indicating that complexation between squalene and Ag+ took place. The distributions of squalene in AgNO3 methanol solution/petroleum ether under different conditions were further investigated. We found that the fraction of squalene in AgNO3-methanol phase was enhanced with increased percentage of methanol and AgNO3 concentration and decreased extraction temperature. The distribution coefficient of squalene was up to 7.87 under optimum extraction conditions with 70% methanol (v/v), 0.6 mol/L AgNO3, reaction time of 12 h, and at the temperature of 0 °C. Furthermore, under the optimum conditions, extraction of squalene from the unsaponifiable portion of camellia oil exhibited high selectivity with a raffinate rate and a back-extraction rate of 73.9% and 72.5%, respectively. The purity of extracted squalene was 37.8%, 108 times more concentrated than that in the starting material.

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