A Novel Aqueous Extraction for Camellia Oil by Emulsified Oil: A Frozen/Thawed Method

Abstract

Emulsion is inevitable during the aqueous extraction of oil from oilseeds. In this study, a new aqueous extraction method for camellia oil is investigated. During the extraction, the emulsified oil is collected, frozen, and thawed, and the free oil is obtained (AEEF). The optimal processing conditions are as follows: three times as much water as camellia seed powder (w/w), grinding at 70 °C for 6 min, repeating 2 cycles to collect the emulsified oil; then the emulsified oil is frozen (−20 °C) /thawed (50 °C) for 2 cycles. The yield of camellia oil is 89.37 ± 0.51%, which is significantly higher (p < 0.05) than that of microwave‐assisted aqueous enzymatic extraction (MAAEE, 83.05 ± 1.14%), and is similar to that of cold press extraction (CPE, 90.85 ± 2.05%), as well as solvent extraction (SE) coupled with refining. Additionally, the total oxidation value (TOTOX) of the free oil extracted by using AEEF (AEEF‐Oil, 6.82 ± 0.12%) is significantly lower (p < 0.05) than those of MAAEE, CEP, or SE. In comparison to SE‐Oil and CEP‐Oil, AEEF‐Oil has higher (p < 0.05) contents of α‐tocopherol and squalene, and lower (p < 0.05) benzo(a)pyrene contents, and contains more favorable natural volatile compounds. The results indicate that the novel AEEF may be a promising aqueous extraction method.Practical Application: The novel aqueous extraction method for camellia oil by emulsified oil – frozen/thawed has acceptable oil yields. The obtained camellia oil has high levels of bioactive components, low contents of hazardous substances, and more characteristic volatile flavor compounds. AEEF is an improved aqueous extraction technology for edible oil without refining and using n‐hexane, which could be potentially applied in industrial production of camellia oil due to its safety, nutrition, and environment‐friendly treatments.Aqueous extraction is a promising technique for edible oil extraction from oilseeds. The novel technology of aqueous extraction for camellia oil through emulsified oil – frozen/thawed (AEEF) is investigated. In comparison to solvent extraction, cold press extraction, and microwave‐assisted aqueous enzymatic extraction of camellia oil, the obtained camellia oil by AEEF has an acceptable oil yield, high quality, and nutritional value. AEEF is a safe, simple and environmental‐friendly aqueous extraction technology.