Extraction of Cinnamomum longepaniculatum deciduous leaves essential oil using solvent-free microwave extraction: Process optimization and quality evaluation

The optimal process conditions for solvent-free microwave extraction(SFME)of essential oils from Cinnamomum longepaniculatum deciduous leaves after moisture conditioning were established by response surface methodology(RSM).A Box-Behnken design(BBD)was applied to evaluate the effects of three independent variables:moisture content(A:54%–74%),microwave power(B:300–500 W)and microwave time(C:20–40 min),on the extraction yield of essential oil.The compounds of the essential oils obtained by SFME,hydro-distillation and microwaveassisted hydro-distillation(MADE)were identified by gas chromatography-mass spectrometry(GC-MS),and the total lipids of C.longepaniculatum fresh leaves and deciduous leaves were analyzed.The correlation analysis of the response regression model indicated that quadratic polynomial model could be employed to optimize the extraction of essential oil.The optimal extraction condition was A:58%,B:400 W and C:28 min.In the optimal condition,the maximum extraction yield was 4.475 mL/100 g dw and higher than that by MADE.The main compound of the essential oil was eucalyptol(63.54%),and total oxygenated compounds was 78.95%,mainly caused by SFME and the metabolism of endophytic bacteria with decreasing content of phospholipids and fatty acids.Analysis of variance under the extraction condition illustrated high fitness of the model and the success of RSM for optimizing and reflecting the expected process condition.SFME combined with moisture regulation was an effective method for extracting essential oil from C.longepaniculatum deciduous leaves.

油樟叶提取物对人肝癌BEL-7402细胞增殖的抑制作用

采用水蒸汽蒸馏和系统溶剂提取获得油樟叶的不同提取物,运用MTT法考查油樟叶各提取物对人肝癌BEL-7402细胞增殖抑制作用的影响。结果表明,油樟叶各提取物对BEL-7402细胞的增殖具有不同程度的抑制作用,呈现明显的量效关系;各提取物抑制作用的大小顺序为:乙酸乙酯萃取物>石油醚萃取物>乙醇提取物>1,8-桉叶油素>油樟叶精油>正丁醇萃取物;低浓度时1,8-桉叶油素与油樟叶精油的差异有统计学意义(P<0.05);高浓度时油樟叶精油、乙醇提取物、石油醚萃取物和乙酸乙酯萃取物之间的差异无统计学意义(P>0.05)。油樟叶提取物有一定抑制肝癌细胞增殖的作用,油樟叶精油的主要活性成分可能是1,8-桉叶油素,去精油后残渣的活性组分存在于石油醚部分和乙酸乙酯部分。

油樟油副产物对细菌性皮肤致病菌的抑制作用

[目的]研究白樟油等几种油樟油副产物对4种常见细菌性皮肤致病菌的抑制作用.[方法]采用滤纸片扩散法和试管二倍稀释法测定白樟油等几种油樟油副产物对4种常见细菌性皮肤致病菌的最低抑菌浓度和最低杀菌浓度,并通过平板菌落计数法绘制抑菌曲线.[结果]白樟油等几种油樟油副产物对大肠杆菌、变形杆菌、金黄色葡萄球菌和痤疮杆菌有不同程度的抑制作用,属于浓度依赖型,其最低抑菌浓度（MIC）值在3.13～12.5 μL/mL,最低杀菌浓度（MBC）值在6.25～25 μL/mL.[结论]白樟油等几种油樟油副产物有较好的抑菌活性,具有治疗细菌性皮肤病的潜力.

基于响应面法对油樟籽油超声波提取工艺的优化

为了提高油樟籽油的提油率和品质,通过响应面分析法优化超声波提取油樟籽油工艺。采用单因素试验方法,对其提取溶剂、提取时间、料液比及提取功率进行筛选,并利用响应面试验中的Box-Benhnken试验设计对提取工艺进行优化。结果表明,模拟得到的二次多项式回归方程拟合性好,油樟籽油提取的最佳工艺条件为:以石油醚为溶剂,提取时间44 min、料液比1∶21 g/m L、提取功率161 W,提取率可达37.54%;油樟籽油各项理化性质测定结果,碘值5.354 g I/100 g、酸值0.168 mg KOH/g、皂化值285.73 mg KOH/g、折光指数1.439 1和相对密度0.924 0 g/cm3;其脂肪酸的成分含有油酸(1.15%)、亚油酸(0.83%)、亚麻酸(0.18%)、癸酸(56.03%)、月桂酸(36.08%)、肉豆蔻酸(1.05%)、棕榈酸(0.24%)和硬脂肪酸(0.71%);油樟籽油的理化性质、脂肪酸组成符合用作生物柴油、医药和功能性油脂生产的原料。

响应面法优化微波辅助水蒸气蒸馏法提取油樟精油工艺

为了解决油樟精油传统提取工艺时间长、效率低、耗能高和成本高等问题,本文遵循绿色提取理念,采用微波辅助水蒸气蒸馏法提取油樟精油并优化最佳提取工艺。根据单因素试验并结合响应面法建立二次回归模型进行方差分析和诊断,考察物料粒度、微波提取时间和微波提取功率对油樟精油得率的影响,确定最佳提取工艺并对理论结果进行实验验证。结果表明,在油樟精油得率相似的情况下,与传统的水蒸气蒸馏法(2h)相比,微波辅助水蒸气蒸馏法(10min)具有提取时间更短、效率更高和更节约能源的优势。通过二次多项式回归模型极显著(P<0.01),失拟项不显著(P>0.05),决定系数为R2=0.989等分析结合诊断图表明该模型对数据拟合良好。微波辅助水蒸气蒸馏法提取油樟精油最佳提取工艺为:物料粒度10目,微波提取时间11min,微波提取功率630W,此条件下油樟精油得率为4.479%,与实验验证结果(4.442%±0.16%)基本一致,验证了二次回归模型的可靠性。该技术较传统工艺提取时间短、效率高、耗能少、成本低,更加绿色安全且容易实现产业化,有望提高油樟精油在日化、美容、医药等各个领域的应用价值。