补骨脂素和异补骨脂素的分离纯化研究

应用高速逆流色谱技术分离和纯化补骨脂中香豆素类成分补骨脂素和异补骨脂素．以补骨脂干燥成熟果实为原料,经乙醇回流制备补骨脂粗提物,经高速逆流色谱分离,所得样品由高效液相色谱检测纯度,并由对照品确定成分．采用正己烷．乙酸乙酯-甲醇-水（7：3：5：5）作为两相溶剂体系,从补骨脂粗提物中分离得到补骨脂素和异补骨脂素,二者纯度分别达到99．4％,99．1％．该法可以成功用于补骨脂粗提物中补骨脂素和异补骨脂素的分离,并且具有制备量大和分离效率高的优点．     

顶空固相微萃取-气相色谱质谱联用分析汉麻叶挥发性成分

采用顶空固相微萃取法结合气相色谱-质谱联用对汉麻叶的挥发性成分进行分析,考察3种不同萃取纤维（DVB/CAR/PDMS,CAR/PDMS,PDMS/DVB）对分析结果的影响,结果表明较佳萃取纤维为CAR/PDMS.从汉麻叶中检出59种挥发性成分,占挥发油总组分的93.18%,其中醛类3种（0.71%）、醇类1种（0.06%）、烃类37种（57.23%）、杂环化合物类3种（0.19%）、萜烯类12种（34.49%）、其他3种（0.50%）.在鉴定出的成分中含量较多的是[1R-（1R＊,4Z,9S＊）]-4,11,11-三甲基-8-亚甲基-二环[7.2.0]4-十一烯（18.81%）、（1α,3α,5α）-1,5-二甲基-3-甲基-2-亚甲基环己烷（18.18%）、α-石竹烯（11.52%）、异柠檬烯（6.78%）等.     

Effect of hydroxyl and Mo doping on activity and carbon deposition resistance of hydroxyapatite supported NixMoy catalyst for syngas production via DRM reaction

The doping of the second metal Mo is expected to further enhance the carbon deposition resistance of Ni-based catalysts for syngas production via dry reforming of methane (DRM). In this study, the hydroxyapatite (HAP) was used as the support and a small Mo dosage was doped in the Ni-based catalysts to investigate the effect of intrinsic hydroxyl and Mo doping on the catalytic activity and carbon deposition resistance in DRM reaction. The catalyst characterization results show that both Ni and Mo are doped into the HAP structure with relatively uniform dispersion. The basic site strength of Ni4Mo0.2-HAP catalyst containing Mo is significantly higher than that of without Mo. The Mo dopant significantly improves the initial catalytic activity, but has minimal effect on the stability enhancement. Whether the catalyst is pre-reduced or not is crucial to the initial activity of the DRM reaction, the non-pre-reduced catalysts will go through a “self-activation” stage at the beginning of the reaction, where the “hydroxyl group” are proved to play as an “oxygen supply” for the partial oxidation of CH₄ or the oxidation of the carbon deposition in the initial stage. Only trace amount of carbon deposition is found after 100 h of DRM reaction on Ni3Mo0.2-HAP catalyst. The NiMo-HAP catalysts exhibit excellent initial activity and resistance to carbon deposition due to the synergistic effect of Ni–Mo alloy and hydroxyl groups in the hydroxyapatite support.     

酶解燕麦蛋白制备ACE抑制肽的研究

本研究以燕麦蛋白为原料,分别选用Alcalase、Neutrase 和Protamex 进行单独或联合水解,经活性炭YD-303脱色、大孔吸附树脂DA-201C Ⅱ脱盐及分级纯化、Sephadex G-25 凝胶色谱柱进一步分离,以获得高纯度、高活性的血管紧张素转化酶(angiotensin converting enzyme,ACE)抑制肽。结果表明：单酶反应时,Alcalase 水解2h所获得的产物对ACE 的抑制率可达85.40%;YD-303 处理燕麦蛋白酶解液脱色最优工艺为添加量1.5%(W/V)、pH3.5、温度40℃、脱色时间75min。利用75% 乙醇洗脱大孔吸附树脂DA-201C Ⅱ所获得的组分ACE 抑制活性最高,其经Sephadex G-25 进一步分离纯化,得到四个分离组分,第四组分的ACE 抑制活性最高,抑制率为95.6%。     

3株罗伦隐球酵母的26S rDNAD1/D2区序列、代谢指纹图谱及生防效力比较分析

研究3株不同来源的酵母拮抗菌(Crytococcus laurentii)001#、010#和012#的种间亲缘关系、Biolog微生物鉴定系统中的不同碳源物质代谢指纹图谱以及对于不同果蔬的侵染病原菌的生防效力。结果表明:亲缘关系相近的菌株001#和010#间的碳源代谢指纹图谱中存在43种相同的最适碳源和13种相同的可利用碳源,菌株012#则与001#和010#利用碳源情况差异性较大,但是它们分别在梨、油桃和芦笋果实上的生防效力却有一些差别,这可能与不同菌株所特异利用的碳源种类以及果蔬中含有的特异的碳源种类和含量有关。发现不同果实的碳源成分和比例引起的拮抗菌生防效果差异的现象,并揭示亲缘关系能在一定程度上通过菌株的碳源代谢特征表现出来,为酵母拮抗菌在生防效力作用机理研究提供参考。     

1-MCP对桃果实低温贮藏期间挥发性物质的影响——主成分分析法

以大久保桃果实（Prunus persica （L.） Batsch cv.Okubao）为试材,采用固相微萃取与气相色谱-质谱联用技术,对8℃贮藏期间对照组与1-MCP处理组的大久保桃果实挥发性物质进行测定,并使用主成分分析法确定大久保桃果实挥发物的指纹图谱及标志性挥发物.结果表明,大久保桃果实挥发性物质共检测到26种,主要包括酯类、芳香烃类、醛类、内酯类、缩醛类物质.8℃贮藏期间,1-MCP处理显著推迟了醛类和内酯类物质的释放高峰的出现,并且显著抑制了内酯类物质的释放量;在贮藏后期显著促进了乙醇的释放.主成分分析结果表明,2,2-二异丙基-1,3-二恶茂烷和1,1′-双（1,1,2,2-四甲基-1,2-亚乙基）苯是贮藏3 d时1-MCP处理组的标志性挥发物,而乙醇、丙酮、氰基乙酸是贮藏16 d和20 d时处理组的标志性挥发物.     

Anti-allergic effects and related active constituents of mung bean (Vignaradiatus Linn) sprouts

Food Science and Biotechnology - The mung bean (Vigna radiata) is an important food crop with preventative effects against human diseases. The anti-allergic activities of mung bean sprouts of...     

Increasing the filtration rate of phospho-gypsum using surfactant

Phospho-gypsum is a by-product of processing phosphate rock for phosphoric acid production by acidulation with sulfuric acid. The size distribution of phosphor-gypsum is a major factor for the economics of the process as it greatly affects the filterability of the acid. Surface active agents proved to be very effective additive for growth of gypsum crystals. Two phosphate concentrates, one from Egypt (New Valley) and the other from USA (South Florida) were tested for phosphoric acid production with modification of gypsum crystals using non-ionic surfactant (CMR-100) containing a mixture of C₆–C₂₂ sorbitan esters. The studies were carried out using a semi-continuous laboratory-scale unit simulating the dihydrate process conditions.The mean diameter of the phospho-gypsum crystals increases in the presence of surfactant for both phosphate concentrates. The surfactant leads to decreasing the viscosity and modification of gypsum crystals through decreasing the fine size fractions and attainment of large and uniform crystal shape. The mean diameter of New Valley phosphor-gypsum increases from about 30.0 μm to 36.6 μm while the mean diameter of South Florida phospho-gypsum increases from about 30.3 μm to about 38.4 μm. On the other hand, the average surface area of both New Valley and South Florida phosphor-gypsum were decreased from 4461 and 8069 cm²/g without surfactant to 3284 and 3995 cm²/g with surfactant, respectively. In addition, the surfactant leads to an increase in P₂O₅ recovery of 1–2%, which consequently improves plant productivity.     

眼部皮肤常见问题及眼部护理化妆品的发展现状

介绍了眼部皮肤的特点,概述了黑眼圈、眼袋、眼角纹和脂肪粒等眼部常见问题的定义、产生机理及原因,通过调研和总结眼部护理化妆品市场的现状,指明了眼部护理化妆品的发展趋势.     

酵母混合发酵对沙棘果泥成分的影响

采用红曲霉和黄酒酵母对沙棘果泥进行混合发酵,分析黄酒酵母接种量和混合发酵时间对沙棘果泥成分含量变化的影响。结果表明,当黄酒酵母接种量为8%(v/v)、发酵时间96h时,发酵液中蛋白含量提高了0.72倍,总酚含量提高了5倍,总黄酮含量提高了0.24倍,多糖含量降低了94.62%,还原糖降低了98.41%,DPPH清除率提升了4.89%,沙棘发酵液中成分含量为最优。