SDS/异辛烷(正辛醇)反胶束体系萃取植物蛋白的研究

利用十二烷基磺酸钠(SDs)/异辛烷(正辛醇)反胶束体系萃取植物蛋白.主要研究SDS/异辛烷(正辛醇)反胶束体系萃取棉籽粕和大豆蛋白的萃取,分析各种因素对蛋白萃取率的影响.主要讨论含水量Wo对萃取丰的影响及物料的性质对反胶束萃取植物蛋白的影响.并与AOT/异辛烷反胶束体系萃取棉籽粕和大豆蛋白的萃取率作了比 较.结果表明:SDS/异辛烷(正辛醇)反胶束体系萃取大豆时的萃取率较高.     

高压均质对天然和热变性大豆蛋白-磷脂水包油型乳状液功能性质的影响

为揭示大豆蛋白和大豆卵磷脂在油-水界面层的交互作用及复合微乳体系的稳定机制,探究了温度(20、60℃)和均质压力(0~80 MPa)的协同作用对蛋白质-磷脂复合乳化体系功能性质的影响。结果显示:相比于天然大豆蛋白与磷脂(native soybean isolate-lecithin,NSI-Lec)形成的乳状液,热变性大豆蛋白与磷脂(denatured soybean isolate-lecithin,DSI-Lec)的乳状液功能性质随均质压力的变化更明显。NSI-Lec乳液在均质压力达到80 MPa时乳化性、乳化稳定性及电位变化不再显著,但DSI-Lec乳液在该条件下功能性质继续提高。当均质压力高于40 MPa时,DSI-Lec乳液的乳层析指数明显下降,说明乳液更加稳定。粒径分布结果表明:NSI-Lec乳液呈双峰粒径分布,DSI-Lec乳液在均质压力高于20 MPa后粒度分布曲线向小粒径方向移动,且当均质压力达到80 MPa时粒径分布呈现单峰。激光共聚焦显微镜结果显示,DSI-Lec乳液随均质压力的提升分布更均匀,乳液连续性较好。     

硝酸介质中DCH_(18)C_6对Sr~(2+)的萃取行为研究

文章研究了硝酸介质中二环己基-18-冠醚-6(DCH18C6)对锶的萃取行为。通过考察稀释剂、相比(O/A)、萃取剂浓度及硝酸浓度对萃取过程中分配比和萃取率的影响,得出了DCH18C6在硝酸介质中对Sr2+的萃取规律。实验结果表明,该萃取体系在硝酸介质中能够有效地萃取锶,在萃取相比为1∶4,DCH18C6的浓度为0.1 mol/L,硝酸浓度为1.0 mol/L时,一次萃取率高于90%,用去离子水反萃四次,反萃率可达100%。     

乳化剂、油浓度及油滴粒径对乳状液中油脂氧化稳定性的影响

以过氧化值(POV)为指标,研究了乳化剂类型、油浓度及油滴粒径对O/W乳状液中油脂氧化稳定性的影响.以用十二烷基硫酸钠(SDS)和Tween-80为乳化剂制备的含红花籽油的乳状液为研究对象,结果表明,乳化剂类型和油浓度对乳状液体系中油脂氧化有较显著的影响.用阴离子型表面活性剂SDS稳定的乳状液中的油脂氧化速率明显大于用非离子型Tween-80稳定的乳状液;随着油浓度下降,油脂氧化速率增大.油滴粒径和油脂氧化速率没有显著的相关性.     

两种反胶束体系对大豆蛋白前萃的比较研究

主要研究了以SDS/异辛烷/正辛醇反胶束体系萃取大豆蛋白的前萃过程,并分析了各因素对蛋白前萃率的影响,与AOT/异辛烷反胶束体系萃取大豆蛋白进行比较,SDS/异辛烷/正辛醇反胶束体系提取大豆蛋白的前萃率高于AOT/异辛烷反胶束体系。SDS/异辛烷/正辛醇反胶束体系萃取低温脱溶豆粕中蛋白质的最佳前萃工艺条件为:SDS浓度0.08 g/mL,加料量0.1000 g,反胶束溶液中含水量18,萃取时间30 m in,萃取温度40℃,增溶水pH 7,KC l浓度0.1 mol/L。     

双水相萃取大豆苯丙氨酸研究

采用十六烷基三甲基溴化铵(CTAB)和十二烷基硫酸钠(SDS)表面活性剂体系形成双水相,研究大豆蛋白水解液中L–苯丙氨酸分配及萃取效果。CTAB/SDS双水相体系萃取L–苯丙氨酸结果表明,当双水相体系CTAB与SDS摩尔比为0.256,提取液初始苯丙氨酸含量为0.02克,Na2SO4浓度为0.23mol/L时,萃取率最高可达96.9%。     

不同烟碱盐对电子烟烟碱释放行为的影响

为研究不同烟碱盐对电子烟气溶胶中烟碱释放行为的影响,以酒石酸烟碱盐、苹果酸烟碱盐、苯甲酸烟碱盐和水杨酸烟碱盐为研究对象,通过对剑桥滤片所用的萃取剂体积、萃取时间进行优化,建立了电子烟气溶胶中烟碱的气相色谱检测方法,并考察了烟碱盐浓度及抽吸口数对烟碱释放量的影响。结果表明:(1)优化后的萃取剂体积为60 mL,萃取时间为30 min。(2)随着烟碱盐浓度及抽吸口数的增加,烟碱释放量线性增加(R~20.9)。(3)方差分析表明,烟碱盐浓度、抽吸口数及烟碱盐种类均对气溶胶中烟碱释放量有显著影响;偏η2值比较表明,烟碱盐浓度的影响略大于抽吸口数及烟碱盐种类。(4)在相同抽吸口数下,苯甲酸烟碱盐的烟碱释放量较高;随着抽吸口数的增加,烟碱释放量存在明显波动。     

乳化和引发体系对高固含量苯丙微乳液性能的影响

本文以苯乙烯(St)、丙烯酸丁酯(BA)、甲基丙烯酸甲酯(MMA)、丙烯酸(AA)为原料,采用种子乳液聚合法合成了高固含量苯丙微乳液;研究了乳化剂的种类及用量、引发剂用量、种子阶段引发剂用量对高固含量苯丙微乳液性能的影响。研究结果表明,单独使用十二烷基硫酸钠(SDS)且其用量为1%时,可制得固含量大于45%的高固含量苯丙微乳液;在本研究范围内引发剂用量为0.3%、且种子阶段引发剂用量为0.15%时制得的高固含量苯丙微乳液性能最好。     

罗非鱼油乳状液体系稳定性影响因素的研究

为了探讨不同乳化剂、油水比例、pH对罗非鱼油/水乳状液稳定性的影响,以一定浓度的tween80、tween20、span20、SDS、酪朊酸钠、大豆卵磷脂等为乳化剂,制备不同的罗非鱼油乳状液,观察罗非鱼油/水乳状液中富水相(下相)的电导率变化规律.结果表明,以0.15%tween80与0.55%大豆卵磷脂复配的乳化剂,在油水比为35:65的罗非鱼油/水乳状体系中,pH 4的乳状液的稳定性低于pH 7与pH 9的乳状液.结论:用电导率法来研究O/W型罗非鱼油乳状体系的稳定性,快速、简捷.     

电子烟液中游离态和质子态烟碱的测定及分布

为对电子烟液中烟碱的形态分布进行研究,建立了一种液液萃取-GC-MS法测定电子烟液中游离态和质子态烟碱的方法。测定了丙二醇-甘油(PG-VG)体系样品和电子烟液样品中游离态和质子态烟碱的质量分数,并研究了二者在PG-VG体系和电子烟液中的分布情况。结果表明:(1)二氯甲烷-水两相液液萃取法具有良好的适用性,可用于电子烟液中烟碱形态分布的定量研究。(2)在PG-VG体系中,烟碱自由基系数(α_(fbn))不受PG-VG配比和烟碱盐添加量的影响,但与体系的pH显著正相关。(3)在相同香精配方的电子烟液中,α_(fbn)与pH显著正相关;而在不同香精配方电子烟液中并无显著规律。(4)电子烟液中的烟碱盐并非完全以质子态存在,而是在香精组成和烟碱添加方式的影响下形成游离态和质子态分布的动态平衡。     

索氏抽提法萃取活性炭滤嘴中吸附的烟碱

研究了采用索式抽提法萃取活性炭滤嘴中吸附的烟碱,包括萃取剂酸碱性的影响、抽提的条件以及方法的精密度和准确度。结果表明：①甲醇的酸碱性对醋酸纤维滤嘴中烟碱的萃取效果无明显影响,酸性甲醇溶液对活性炭滤嘴中的烟碱萃取效果较好;②振荡提取对活性炭滤嘴中吸附的烟碱量萃取不完全;③索式抽提法对萃取活性炭滤嘴中吸附的烟碱效果较好,回收率大于98%;④采用索式提取-气相色谱法测定活性炭滤嘴中的烟碱,重复性变异系数小于4%。     

花椒油的超声提取及其成分分析

以花椒籽核为原料,研究了超声波提取花椒油的工艺条件,考查了提取介质、温度、时间和液固比对花椒油提取率的影响。实验结果表明:用体积分数95%乙醇为提取介质,在液固比为3∶1(mL∶g)、60℃温度下超声提取90 min,花椒油的提取率可达7.8%,比加热提取法高48.9%。花椒油经气相色谱-质谱联用仪分析,鉴定出16种成分,其中有9种为烯烃化合物。     

Efficient Extraction of Olive Pulp and Stone Proteins by using an Enzyme‐Assisted Method

An efficient protein extraction protocol for proteins from olive pulp and stone by using enzymes was developed. For this purpose, different parameters that affect the extraction process, such as enzyme type and content, pH, and extraction temperature and time, were tested. The influence of these factors on protein recovery was examined using the standard Bradford assay, while the extracted proteins were characterized by sodium dodecyl sulfate?polyacrylamide gel electrophoresis (SDS‐PAGE). The best extraction conditions were achieved at pH 7.0 and 5% (v/v) Palatase® 20000 L (lipase) for pulp and Lecitase® Ultra (phospholipase) for stone proteins. The optimal extraction temperature and time were 30 and 40 °C for 15 min for pulp and stone tissues, respectively. Under these conditions, several protein extracts coming from olive fruits of different genetic variety were analyzed, their profiles being compared by SDS‐PAGE. The developed enzyme‐assisted extraction method showed faster extraction, higher recovery, and reduced solvent usage than the nonenzymatic methods previously described in the literature. In the case of stone proteins, different electrophoretic profiles and band intensities were obtained that could be helpful to distinguish samples according to their genetic variety.     

Singlet Oxygen Quenching Effects of Phosphatidylcholine in Emulsion Containing Sunflower Oil

ABSTRACT:  Effects of phosphatidylcholine (PC) on the oxidation of oil by singlet oxygen in a W/O microemulsion and an emulsion food model containing tocopherol-stripped sunflower oil (TSSO) have been studied. The W/O microemulsion consisted of methylene chloride, butanol, and sodium dodecyl sulfate with PC (0, 250, 1000 ppm) and TSSO (0, 3.3, 16.5, 33 mg/mL). Production of singlet oxygen in the microemulsion was done chemically with hydrogen peroxide in the presence of sodium molybdate, and indirectly evaluated by rubrene oxidation at A₅₂₉. The emulsion food model consisted of TSSO, distilled water, and xanthan gum with addition of 250 ppm PC and 4 ppm chlorophyll b, and was placed at 25 °C under fluorescent lights (1700 lux) for 24 h. The oxidation of TSSO was determined by thin-layer chromatography and values of conjugated dienoic acid (CDA) and peroxides (POV). PC significantly decreased the oxidation of rubrene and TSSO in the W/O microemulsion, but its content was decreased to approximately one-half by a 20-min reaction, indicating its degradation. This clearly shows that PC acted as an antioxidant via chemical quenching of singlet oxygen in the W/O microemulsion. A possible synergism between PC and TSSO was observed in singlet oxygen quenching in the microemulsion. PC also significantly decreased the chlorophyll-photosensitized oxidation of TSSO in the emulsion food model, possibly by singlet oxygen quenching. This study clearly suggested that PC be used as an antioxidant to improve the lipid oxidative stability of an emulsion food containing chlorophyll under light.     

Methanolic extract of Coptis japonica Makino reduces photosensitized oxidation of oils

Antioxidative activities of methanolic extracts of 47 plants on the methylene blue-sensitized or chlorophyll-sensitized photooxidations of linoleic acid were studied to select the plant species which possess the strong antioxidative activity in sensitized photooxidation of oil. The methanol extract of Coptis japonica Makino showed the strongest antioxidative activity in both methylene blue-sensitized and chlorophyll-sensitized photooxidations of linoleic acid. The study on the extracting solvent effects indicated that the antiphotooxidative components in the Coptis japonica Makino possess strong polar property, and are easily extracted with highly polar solvent (methanol). The methanol extract of Coptis japonica Makino was fractionated into three fractions (ethyl ether fraction, ethyl acetate fraction and butanol fraction) by liquid–liquid partitioning fractionation. Among the tested fractions, the butanol fraction showed strongest antioxidative activity in both chlorophyll-sensitized and methylene blue-sensitized photooxidation of linoleic acid. The butanol fraction also significantly inhibited the photooxidation of model food emulsion (50% soybean oil emulsion). The treatment with 0.3% (w/w) butanol fraction resulted in 64.9% inhibition of photooxidation of the model food emulsion during 60 h fluorescent light illumination.     

混合型反相微乳体系萃取茶渣蛋白的工艺优化

使用双（2-乙基己基）磺基琥珀酸钠（AOT）、十六烷基三甲基溴化铵（CTAB）、十二烷基硫酸钠（SDS）分别和吐温80（Tween80）混合制备了三种反相微乳体系,并通过单因素实验研究了表面活性剂浓度、离子型表面活性剂含量、水分含量（W₀）、水相pH、萃取温度和萃取时间等因素对蛋白质前萃率和KCl浓度、水相pH和萃取温度对蛋白质后萃率的影响,然后通过正交试验得到了最佳萃取条件。结果表明,Tween80-CTAB微乳体系对茶渣蛋白的提取效果较好,在表面活性剂浓度0.10 mol/L,离子型表面活性剂含量70%,水相pH13.0,W₀ 25,萃取温度40 ℃,萃取时间为40 min的最佳条件下,茶渣蛋白的前萃率达到最大值16.17%,其后萃率在KCl浓度为1.2 mol/L,pH7.0,提取温度40 ℃的最佳条件下可达到94.78%。SDS-PAGE电泳图的结果表明,反相微乳萃取得到的茶渣蛋白分子条带较小,即能够选择性的萃取小分子蛋白。     

豆腐柴叶蛋白提取工艺研究

研究提取温度、提取时间、pH和料液比对豆腐柴叶蛋白提取率的影响,确定最佳提取工艺为:温度为50℃,时间为80min,pH为11,料液比为1∶30,豆腐柴叶蛋白提取率可达到82.04%;豆腐柴叶蛋白等电点为pH4.2.     

棉籽油中DNA不同提取方法的比较研究

在食用油DNA提取的SDS法和国标法基础上,设计5种不同方案对15种来自不同生产厂家及加工精度的棉籽油进行DNA的抽提,通过比较各来源DNA提取液中内源基因tRNALeu的PCR扩增结果判断DNA的提取效率;并对方案5获得的DNA样品进行外源基因FMV35S的PCR扩增以检测转基因成分。结果表明方案5提取棉籽油DNA的效率最高,而且方案5提取到的DNA能用于棉籽油的转基因成分定性检测。     

超临界CO2 反相微乳萃取人参皂甙的研究

利用萃取罐体积为1 L 的超临界CO2 萃取设备,采用琥珀酸二(2- 乙基己基)酯磺酸钠(AOT)/ 乙醇/ 水/ 超临界CO2 反相微乳对人参皂甙的萃取进行了研究。结果表明：最优萃取参数为萃取温度55℃,萃取时间3h,加水量 36ml/100g 人参,萃取压力 30MPa 和 AOT 添加量0.06mol/100g 人参,此时人参皂甙的得率为0.757%;E=0.870 ×(1 － e-0.618t)为超临界CO2 反相微乳萃取人参皂甙的具体动力学模型方程;超临界CO2 反相微乳萃取与超临界CO2 萃取人参皂甙相比是一种相对有效的萃取技术。     

响应曲面法优化超声—微波协同提取百合渣中总皂苷工艺的研究

以宜兴百合淀粉生产过程中产生的副产物百合渣为原料,采用超声-微波协同提取工艺提取其中的总皂苷,通过乙醇浓度、液料比、微波功率、提取时间各单因素实验确定各因素对总皂苷得率的影响。在单因素实验的基础上,根据Box-Behnken实验原理,采用了四因素三水平的响应面分析法,以总皂苷的得率作为响应值,根据所得实验结果进行回归分析,优选出提取的最佳工艺为:乙醇浓度77%,液料比11∶1(mL/g),微波功率503W,提取时间139s,在此最佳条件下,测得总皂苷的得率为6.59‰。该工艺运用了超声与微波的协同效应,集取了超声与微波二者优势,具有提取时间短、效率高的优点。