Extracting Apricot Kernel Oil With Low Temperature Methods

The study is aimed at making oil from apricot kernel with low temperature methods, namely, Aqueous Enzymatic Extraction(AEE) and Supercritical Fluid Extraction-carbon dioxide (SFE-CO₂). Firstly, after a series of screening, the optimum variables for aqueous enzymatic extraction in this particular experiment were determined as follows: the combination of Papain and Yakult cellulase(1∶1), enzyme concentration 3%, reaction time 3h, reaction temperature 40℃, and dilution ratio 1∶2. The result of oil quality evaluation indicated that the oil sample made from aqueous enzymatic extraction had a clearer texture, lower acidity value and phosphorus level than that made from solvent extraction. Then, 2⁷ orthogonal design was employed to screen the optimum processes to increase apricot kernel oil-extracting rate by SFE-CO₂. Yates' Algorithm analysis result indicated that soaking apricot kernel for shorter time produced higher yield; the finer the kernel was crushed, the higher yield the oil was extracted; mixing SiO₂ powder with crushed kernel at the ratio of 1∶1 produced higher yield than that at the ratio of 1.5∶1, etc.. Analysis of variance (ANOVA) result indicated that the only factor, which significantly contributed to the oil-extracting rate, was soaking time. At last HPLC test showed above 90% fatty acids of apricot kernel oil samples for this study were unsaturated.