六种试剂盒提取血液基因组DNA效果比较

为筛选一种高效、快捷的血液基因组DNA提取试剂盒,采集24份新鲜西藏绵羊血液样本,选用6种市售商业化试剂盒（LifeFeng柱式试剂盒DK601和非柱式试剂盒DK602,康为世纪非柱式试剂盒CW0544和柱式试剂盒CW0546,上海生工非柱式试剂盒SK8224和柱式试剂盒SK8254）,比较所提DNA的浓度、纯度、得率以及对嗜吞噬细胞无形体16S rRNA进行巢式PCR扩增,综合评价不同试剂盒DNA提取效果.结果表明,应用LifeFeng柱式试剂盒DK601提取的DNA浓度和纯度均最高,得率较高,分别达到75.63 ng/μL、1.894（OD260/OD280）、18.91 ng/μL;且嗜吞噬细胞无形体16S rRNA基因的PCR扩增条带清晰度最优.因此,LifeFeng DK601可作为提取绵羊血液基因组DNA及嗜吞噬细胞无形体（Anaplasma phagocytophilum）病原鉴定的首选试剂盒.     

Microemulsion-based palm kernel oil extraction using mixed surfactant solutions

This study introduces a novel technique using surfactant microemulsion-based oil seed extraction. To achieve this objective, microemulsion formation with palm kernel oil was studied first. Then, the selected microemulsion system was used for palm kernel extraction. The results showed that the mixed surfactant of 3 wt% Comperlan KD and either 0.1 wt% Alfoterra145-5PO or 145-8PO provided an ultralow interfacial tension with the palm kernel oil (0.0197 and 0.0359 mN/m, respectively). By using those two aqueous surfactant systems for palm kernel oil extraction, the extraction efficiency was 93.99 and 94.13% at the optimum crushed kernel size between 0.212 and 0.425 mm, using 1 g seed load to 10 ml of solution and 30 min of contact time. The extracted oil quality was evaluated for water content, fatty acids composition and surfactant partitioning into oil phase. The results showed that the quality of the oil obtained using the surfactant microemulsion-based technique is of similar or better quality than when extracted by hexane solvent.     

2种糊化方式对小麦面粉流变及回生特性影响的比较

对传统加热糊化和微波糊化小麦面浆的过程进行了比较。在相同反应温度与时间的条件下,分别考察体系的糊化特性、流变学特性、贮藏回生特性及其回生后的超微结构。结果表明：小麦面粉经微波糊化后体系均匀、黏度较大、剪切恢复性小、超微结构致密,传统加热糊化不充分、体系黏度较低、存在剪切恢复性、超微结构不均匀;微波糊化只能在短时间内延缓淀粉体系的回生作用,不能降低其最终回生度。     

极香罗勒芳香油成分GC-MS分析

采用超临界CO2萃取技术,对极香罗勒芳香油进行了萃取,并利用气相色谱—质谱法(GC-MS)对芳香油成分进行了鉴定。结果表明:芳香油的主要成分为萜类物质共34种,占总芳香油的46.47%;脂肪酸类3种,占总芳香油的34.61%;芳香族醚类化合物有3种,总芳香油的7.84%;酯类有2种,占总芳香油的3.91%;烃类2种,占总芳香油的1.86%。芳香油中相对含量最高的是亚麻酸,占总芳香油的27.69%;其次是芳樟醇,占总芳香油的12.96%;其它含量较高的成分依次是(+)表-双环倍半水芹烯(7.53%)、m-丁香酚(5.88%)。     

解淀粉芽胞杆菌HAB-6抑菌活性成分的分析

为明确解淀粉芽胞杆菌Bacillus amyloliquefaciens HAB-6菌株的抑菌活性物质,采用平板对峙法检测其对17种植物病原真菌的拮抗能力,通过硫酸铵沉淀法、酸沉淀法、有机溶剂萃取法提取HAB-6菌株的活性物质,并检测其稳定性。结果表明:解淀粉芽胞杆菌HAB-6菌株对17种植物病原真菌均具有良好的抑菌活性,抑制率可达45.48%~72.20%;不同提取方法中仅正丁醇粗提物有抑菌活性,在5 mg/m L浓度下抑菌圈直径达21.49 mm;正丁醇粗提物经紫外线照射120 min后,抑菌活性为对照的78%,而经100℃高温处理后抑菌活性仍为对照的91%,表明HAB-6菌株的活性物质具有较好的热稳定性;但不耐强酸强碱,其适宜的p H为5.0~9.0。正丁醇粗提物可抑制芒果炭疽病菌孢子萌发和菌丝生长,能有效抑制芒果炭疽病菌对芒果果实的侵染。表明HAB-6菌株抑菌谱广,其正丁醇提取物具较强的抑菌活性和较好的稳定性,具有良好的开发应用前景。     

野生稠李色素提取工艺研究

以野生稠李果实为原料,将色素溶液进行1∶20的比例稀释,放在400～700nm的波长范围内扫描,表明532nm处为最大。通过乙醇浓度、温度、物料固液比、提取时间,进行四因素三水平正交实验,确定野生稠李色素最佳提取工艺。结果表明:稠李色素最佳的提取条件为乙醇浓度30%,提取温度75℃,固液比为1∶10,提取时间90min。     

酸与碱处理对海带多糖提取及其抗氧化活性的影响

本试验采用柠檬酸提取法和碱提取法从海带中提取多糖组分,以总抗氧化能力和羟自由基（·OH）为衡量抗氧化活性指标,比较这两种提取方法得到海带粗多糖产率和抗氧化活性。试验结果表明：柠檬酸提取法和碱提取法的提取率分别为15.92%和6.05%,所提取的海带粗多糖具有良好的抗氧化活性,且柠檬酸提取法抗氧化活性更高。 [关键词] 柠檬酸提取法|碱提取法|海带多糖|抗氧化活性     

Protein extraction from defatted wheat germ by reverse micelles: Optimization of the forward extraction

In this work, the forward extraction of defatted wheat germ protein (DWGP) by reverse micelles was studied. The reverse micellar systems were formed by sulphosuccinic acid bis (2-ethylhexyl) ester sodium salt (AOT), isooctane and KCl solution. The effects of AOT concentration, pH, KCl concentration, extraction time, the amounts of defatted wheat germ flour (DWGF), W₀ (the molar ratio of water to surfactant, i.e. W₀ = [H₂O]/[AOT]) and temperature on the forward extraction efficiency of DWGP were tested. On the basis of single-factor experiments, the optimum extraction was achieved by response surface methodology (RSM). The experimental results lead to the conclusion that the highest forward extraction efficiency of DWGP was reached at the AOT concentration 0.06 g/mL, pH 8, KCl concentration 0.1 mol/L, time 30 min, the amounts of DWGF 0.500 g, W₀ 25 and temperature 36 °C. Under these conditions, the forward extraction efficiency of DWGP achieved 37%.     

超临界CO_2提取茶叶中咖啡碱

用超临界萃取技术分离提取茶叶中的咖啡碱，再用CH2Cl2萃取分离，得到纯度为95．16％的咖啡碱，萃取率和得率分别为16．85％、0．55％。试验结果还表明，在一定条件下，利用超临界萃取技术能够有效地分离茶多酚和咖啡碱。