低温萃取法提取杏仁油的研究

杏仁是油脂和蛋白质含量均高的原料,该研究旨在采用低温法萃取杏仁油,达到既萃取油又减少蛋白质变性程度的目的。首先经过一系列水酶法萃取试验后发现,不同萃取条件对于出油率的影响很大,从中筛选出水酶法萃取的最佳条件为：选取进口（日本Yakult公司）纤维素酶与木瓜蛋白酶的复合酶（1∶1）,加酶量3%,作用时间3 h,料液比1∶2,反应温度40℃。初步油质检验表明, 水酶法比浸出法制得的毛油更清亮,酸价略低,磷脂少,油质稳定。然后进行CO₂为溶媒的超临界流体萃取试验,通过7因素2水平正交试验并对其结果进行单指标直观分析发现：浸泡时间短的仁用杏出油率较高;粒度越小,出油率越高;以1∶1搀和二氧化硅粉与仁用杏的出油率较1.5∶1的为高;20 MPa压力的出油率较8 MPa的略高等,在此基础上筛选出了最适工艺路线。对上述结果进行了6因素无交互作用方差分析,结果表明仅有浸泡时间对出油率的影响是显著的,浸泡的时间越短出油率越高,其余条件对出油率的影响并不显著,按其影响程度从大到小依次为粒度、二氧化硅与杏仁比例、压力、杏仁种类、流速,这与直观分析极差所示结果一致。最后液相色谱法测定显示萃取出的仁用杏油中90%以上的脂肪酸为不饱和脂肪酸。

Extracting Apricot Kernel Oil With Low Temperature Methods

The study is aimed at making oil from apricot kernel with low temperature method s, 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 d etermined as follows: the combination of Papain and Yakult cellulase(1∶1), enz yme 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 valu e and phosphorus level than that made from solvent extraction. Then, 27 orthog onal design was employed to screen the optimum processes to increase apricot ker n el oil-extracting rate by SFE-CO2. Yates' Algorithm analysis result indicate d 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 po wder 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 t he only factor, which significantly contributed to the oil-extracting rate, was soaking time. At last HPLC test showed above 90% fatty acids of aprico t kernel oil samples for this study were unsaturated.