Process optimization and characterization of fatty acids and lipid concomitants in the aqueous extraction of camellia oil

Abstract

This study established an aqueous-based method for extracting camellia oil (CO). The optimized process, determined on the basis of bulk oil yield, consisted of sequential procedures: steaming (20 min), enzymatic hydrolysis (1% cellulase, 1% alkaline protease) and aqueous extraction. This process was named steaming aqueous enzymatic extraction (SAEE). Compared with the unheated sample, steaming pretreatment contributed to a 17.56% enhancement in the extraction rate of bulk oil, which was attributed to its degrading effect on cell wall structure and its reduction effect on cellulose crystallinity. In addition, CO was further evaluated in terms of fatty acid profile, deterioration indicators and lipid concomitants. Oleic, linoleic, palmitic and stearic acids were the dominant fatty acids, and oleic acid had the highest content (77.34% ± 0.38% to 77.58% ± 0.24%). The acid values ranged from 0.30 ± 0.02 to 0.35 ± 0.03 mg KOH per g, and the peroxide values were between 0.03 ± 0.00 and 0.04 ± 0.00 g per 100 g. Moreover, phenolics, α-tocopherol, squalene and phytosterols were present in the CO, and α-tocopherol was the distinguishing component, ranging from 277.62 ± 0.77 to 281.33 ± 4.86 mg kg⁻¹. These results suggested that SAEE could be a promising method for producing high-grade CO.