花椒精油微胶囊工艺的研究

本文研究了以阿拉伯胶、麦芽糊精及大豆分离蛋白作为壁材。采用正交实验法优化确定壁材的最佳配方及工艺条件,采用喷干燥技术进行花椒精油的微胶囊包埋处理以获得固化的花椒精油微胶囊产品。     

肉豆蔻精油微胶囊化及其稳定性研究

目的：肉豆蔻精油因刺激性气味及易挥发的特点限制了其在食品中的应用,为提高肉豆蔻精油的适用性,利用喷雾干燥技术制备肉豆蔻精油微胶囊。方法：以辛烯基琥珀酸淀粉酯/麦芽糊精（OSA/MD）为复合壁材制备微胶囊,采用气相色谱—质谱联用（GC MS）法测定了包埋前后肉豆蔻精油的成分组成及相对含量,并对微胶囊稳定性进行考察。结果：制备的肉豆蔻精油微胶囊包埋率和保留率分别达到99.28%和88.15%,且40℃时保持稳定。结论：以辛烯基琥珀酸淀粉酯/麦芽糊精（OSA/MD）为复合壁材,利用喷雾干燥技术制备肉豆蔻精油微胶囊包埋效果好,且稳定性得到明显提高。     

生姜油树脂微囊化的实验研究

用生姜为原料,经连续渗漉抽提的油树脂为心材,以食用胶为壁材,经均质、乳化、喷雾干燥获得生姜油树脂微胶囊,对其主要技术参数测定结果表明:含水率为3.81％,心材包埋率为96.76％,收得率为92.1％。姜油酮含量为1.7285％(WW)。溶剂残留量为4.5ppm。研究中用日立S-450扫描电镜研究了微胶囊的外形结构,未发现微胶囊破裂情况,在姜油酮检测中,用电位滴定法发展和完善了羟胺法。     

静电喷雾法制备乳酸菌微胶囊的实验研究

目的为解决乳酸菌产品活菌数的不稳定性,对乳酸菌进行微胶囊化包埋。方法用海藻酸钠和明胶的混合体系作为壁材,对乳酸菌进行静电喷雾包埋处理,并让微胶囊化乳酸菌在模拟胃肠液的环境中进行耐酸性和肠溶性实验。结果混合体系的壁材与乳酸菌具有较好的生物相容性,优选得出当芯壁材为12时包埋率最高（96．3％）,微胶囊化乳酸菌在经人工胃液处理2h后,活菌数比未经微胶囊化的对照组高出2个数量级,且在经人工肠液处理40min后,乳酸菌几乎全部释放。结论静电喷雾法制备的乳酸菌微胶囊具有一定耐酸性和肠溶性。     

低粘度辛烯基琥珀酸淀粉钠作微胶囊壁材包埋柠檬油

以蜡质玉米淀粉为原料在优化条件下制备具有乳化能力的低粘度辛烯基琥珀酸淀粉钠(SSOS)。用Brabender粘度仪测定淀粉糊的粘度及其稳定性,发现酶处理前SSOS糊的粘度较蜡质玉米淀粉提高,但稳定性变化不大。研究发现低粘度SSOS微胶囊包埋柠檬油的百分率在57.4%至87.6%(w/w)之间,并取决于SSOS的葡萄糖值。在壁材与芯材的质量比大于3比2,葡萄糖值为12.8时,微胶囊包埋的产率和效率达到最高值。微胶囊在40℃下放置贮存3周后,其微胶囊化效率仅降低3%。通过扫描电镜观察,发现微胶囊为球形的未粘连的颗粒,有些颗粒的表面并不平整。研究结果表明一定葡萄糖值的低粘度SSOS作为微胶囊壁材具有很好的包埋效果。     

灵芝孢子油微胶囊制备技术

灵芝孢子油是从灵芝孢子粉中提取的具有一定药理活性的脂质成分。为提高灵芝孢子油稳定性,以大豆分离蛋白和麦芽糊精为壁材,采用喷雾干燥法和冷冻干燥法制备灵芝孢子油微胶囊。通过试验优化了制备工艺条件并比较了两者干燥方式制备微胶囊的理化性质。结果表明：最佳工艺为大豆分离蛋白和麦芽糊精质量比1:1、固形物含量20%、均质压力30MPa、壁材芯材质量比4:1。两种干燥方式微胶囊流动性、溶解性均较好,差异不显著。但两种微胶囊形态差异较大,喷雾干燥微胶囊整体呈球状、表面紧密无裂缝有凹陷,包埋率为90.84%;冷冻干燥微胶囊结构疏松呈片状,表面多孔。因此喷雾干燥法更适合包埋灵芝孢子油。     

响应面法优化火麻仁油微胶囊喷雾干燥工艺的研究

为了制备包埋率高、稳定性好的火麻仁油微胶囊,拓展其在食品领域的应用范围,以火麻仁油为芯材、单双脂肪酸甘油酯为乳化剂、酪蛋白酸钠为壁材、固体玉米糖浆为填充剂、柠檬酸钠为缓冲盐、抗坏血酸棕榈酸钠为抗氧化剂,通过喷雾干燥法制备60%载油率的火麻仁油微胶囊,以微胶囊包埋率为响应值,在单因素实验的基础上,以干物浓度、进风温度、出风温度为实验因素,采用Box-Behnken响应面分析法进行优化。随后通过扫描电镜观察火麻仁油微胶囊表面形态结构,以确定包埋效果。并利用油脂氧化分析仪检测火麻仁油微胶囊的氧化稳定性。研究确定微胶囊的最佳工艺条件为：干物浓度42%、进风温度168 ℃、出风温度74 ℃,在此条件下制备得到的火麻仁油微胶囊包埋率可达92.15%。通过扫描电镜观察到火麻仁油微胶囊表面圆滑无裂痕,表明火麻仁油微胶囊包埋效果比较理想。经油脂氧化分析仪测定,与对照组（火麻仁油）相比,试验组（火麻仁油微胶囊）的氧化诱导期时间较长,能够达到30 h以上,说明通过对火麻仁油进行微胶囊包埋可以较大程度地提高油脂的稳定性。研究结果为火麻仁油在食品工业领域的开发和应用提供了理论支持。     

紫玉米花青素的微胶囊化研究

花青素作为植物界广泛存在的一种天然食用色素,安全、无毒、资源丰富,而且具有一定营养和药理作用,然而花青素对pH值、氧气、温度、光、金属离子等十分敏感。拟利用微胶囊化技术,保护花青素的抗氧化特性,并比较了2种常用的微胶囊方法（喷雾干燥法和锐孔法）的包埋效果,以期为花青素的使用提供一定参考。结果表明,啧雾干燥法制备紫玉米花青素微胶囊效果较锐孔法更好,而且当选择麦芽糊精和阿拉伯胶1：1作喷雾干燥的壁材,芯材（花青素）与壁材按1：16制备时,其包埋率可达34％,效果最佳。     

膜材与制备过程对血红蛋白微胶囊粒径和包埋率的影响

以单甲氧基聚乙二醇聚乳酸共聚物（PELA）为膜材用复乳溶剂扩散法制备了包含牛血红蛋白（BHb）的微胶囊,微胶囊中BHb的P₅₀和Hill系数分别为3 466 Pa和2.4左右,接近于天然BHb的生物活性。研究发现膜材种类对BHb微胶囊包埋率和粒径的影响最大,使用MPEG2000为亲水性嵌段的PELA共聚物时,包埋率最高,达到90％以上,粒径为3～5 μm左右;随着膜材浓度的增大,微胶囊包埋率和粒径均增加;随着外水相NaCl浓度的增大,微胶囊包埋率升高、粒径减小;随着外水相稳定剂PVA浓度的增大,微胶囊粒径减小,包埋率先升高后降低,在较低浓度下（10 g/L、20 g/L）包埋率较高;初乳化搅拌速率的增大,有利于包埋率的提高,但对粒径影响不大;复乳化搅拌速率的影响较复杂,当复乳液体积较大时,复乳化搅拌速率对微胶囊制备的影响规律性不明显。当固定膜材和初乳化搅拌速率时,包埋率和粒径之间存在着类似抛物线的关系,包埋率随着粒径的减小而降低。     

不同壁材微胶囊饲料对黄姑鱼稚鱼生长和消化酶活力的影响

研究采用湿法制粒流化床包衣工艺, 分别以明胶、乙基纤维素、玉米醇溶蛋白为壁材制备微胶囊饲料, 比较其对黄姑鱼稚鱼生长和消化酶活力的影响. 粒径(178-590) m的3种微胶囊饲料质量均大于50%. 扫描电镜观察微胶囊饲料的表面均有一层较为致密的包衣薄膜. 壁材明胶、乙基纤维素、玉米醇溶蛋白微胶囊饲料的包含率分别为95.4%、95.6%和95.8%; 脂类包埋率分别为72.6%、76.5%和64.3%; 氮保留率分别为53.5%、62.3%和54.6%. 将3种微胶囊饲料分别饲喂15日龄黄姑鱼稚鱼30d. 明胶组和玉米醇溶蛋白组稚鱼的体重、全长均显著高于乙基纤维素组(P0.05), 但成活率差异不显著(P0.05); 明胶组稚鱼的体重、全长和成活率均高于玉米醇溶蛋白组, 但差异均不显著(P0.05). 明胶组稚鱼的胰蛋白酶活力显著高于乙基纤维素组和玉米醇溶蛋白组(P0.05), 但淀粉酶和碱性磷酸酶活力的差异均不显著(P0.05). 与乙基纤维素、玉米醇溶蛋白相比, 明胶更适合作为黄姑鱼稚鱼微胶囊饲料壁材.       

六种藓类植物茎的比较解剖学研究

通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一.     

Photoregulation of seed germination of wild-type and of an aurea-mutant of tomato

Seed germination of an aurea mutant of tomato ( Lycopersicon esculentum Mill.) is promoted by continuous irradiation with red, far-red or long-wavelength far-red (758 nm) light as well as by cyclic irradiations (5 min red or 5 min far-red/25 min darkness). Far-red light applied immediately after each red does not change the germination behaviour. Seed germination of the isogenic wild-type, cv. UC-105, is promoted by continuous and cyclic red light while it is inhibited by continuous and cyclic far-red light and by continious 758 nm irradiation. Far-red irradiation reverses almost completely the promoting effect of red light. The promoting effect (in the aurea mutant) and the inhibitory effect (in the wild-type) of continuous far-red light do not show photon fluence rate dependency above 20 nmol m⁻² s⁻¹. It is concluded that phytochrome controls tomato seed germination throgh low energy responses in both the wild type and the au mutant. The promoting effect of continuous and cyclic far-red light in the au mutant can be attributed to a greater sensitivity to P_fr.     

Cause of Senescence of Nine Sorts of Flowers

The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.     

龙胆科药用植物化学成分的研究现状

龙胆科植物在我国的分布范围很广,且多数为药用植物,其多数种属的药用植物,至今其化学成分尚未被系统研究。综述了目前龙胆科药用植物的化学成分的研究现状及一般提取方法,对近年来发现的环烯醚萜及裂环烯醚萜类化合物进行了总结,为本科药用植物的更深入研究提供了参考。     

Interconnection of parameters of regulation system of lipid peroxidation and of morphophysiological parameters of mouse liver

A complex analysis of seasonal fluctuations of the mean group parameters of the system of regulation of lipid peroxidation has been performed in liver of Balb/c mice. Association of lipid characteristics and morphophysiological parameters is studied in the Balb/c mouse liver. An inter-connection is revealed between the liver index and the amount of lysoforms of phospholipids, the scale and character of the interconnection differing essentially depending on proportion of phos-phatidylcholine in mouse liver phospholipids.     

The effects of glutamine of the maintenance of embryogenic cultures of Cryptomeria japonica

Summary Embryogenic tissues of sugi (Cryptomeria japonica) were induced on a modified Campbell and Durzan (CD) medium containing 1 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 600 mg l⁻¹ glutamine, and subcultured in the medium of the same composition for over 1 yr. This resulted in a mixed culture of embryogenic and non-embryogenic cells. When embryogenic cells were isolated and cultured independently, their capacity to form embryogenic aggregates was lost. Thus, the non-embryogenic cells present within a mixed culture system were essential to the formation of embryogenic aggregates. When embryogenic tissues were isolated and cultured independently on a high glutamine-containing (2400 mg l⁻¹) medium, dry weights and endogenous levels of glutamine increased, and the tissue could generate a large number of embryogenic aggregates. Amino acid analysis of embryogenic and non-embryogenic cells from the maintenance culture indicated a higher level of glutamine was present in the latter. The high endogenous level of glutamine in the non-embryogenic portion of mixed cell masses may be the supplier of glutamine for maintaining the embryogenic property of the tissues.     

Specificity of action of piperidylcholine derivatives as substrates of cholinesterases of various origin

The review deals with study of enzymologic properties of a novel highly specific acetylcholinesterase substrate, N-(β-acetoxyethyl) piperidinium iodomethylate (“piperidylcholine”), and its 30 derivatives that were tested as effectors of cholinesterases of mammals and various species of Pacific squids. It was proven for the first time that responsible for specificity of action was structure of cyclic ammonium grouping of the alcohol part of molecule of the ester substrate. Analysis of specificity is performed based on enzymatic hydrolysis parameters—activity of catalytic center of cholinesterases and bimolecular constant of the reaction rate that are determined at optimal and low substrate concentrations. Among the specially synthesized group of thioester compounds there is revealed one more highly specific acetylcholinesterase substrate—N-(β-acetoxyethyl) piperidinium.     

Physiological characteristics of various species of strains of carboxydobacteria

Seven strains of aerobic carbon monoxide-oxidizing bacteria (carboxydebacteria) when growing on CO as sole source of carbon and energy had doubling times which ranged from 12–42 h. The activity profiles obtained after discontinuous sucrose density gradient centrifugation indicated that the CO-oxidizing enzymes are soluble and the hydrogenases are membrane-bound in all strains examined. The CO-oxidizing enzymes of Pseudomonas carboxydohydrogena, Pseudomonas carboxydoflava, Comamonas compransoris, and the so far unidentified strains OM2, OM3, and OM4 had a molecular weight of 230,000; that of Achromobacter carboxydus amounted to 170,000. The molecular weights of the CO-oxidizing and H₂-oxidizing enzymes turned out to be identical. The cell sonicates were shown to catalyze the oxidation of both CO and H₂ with methylene blue, thionine, phenazine methosulfate, toluylene blue, dichlorophenolindophenol, cytochrome c or ferricyanide as electron acceptors. Methyl viologen, benzyl viologen, FAD⁺, FMN⁺, and NAD(P)⁺ were not reduced. The spectrum of electron acceptors was identical for all strains tested. Neither free formate, hydrogen nor oxygen gas were involved in the CO-oxidation reaction. Methylene blue was reduced by CO at a 1:1 molar ratio. The results indicate that CO-oxidation by carboxydobacteria is catalyzed by identical or similar enzymes and that the reaction obeys the equation CO+H₂OCO₂+2H⁺+2e^- as previously shown for Pseudomonas carboxydovorans.Dedicated to Otto Kandler remembering almost three decades of enjoyable cooperation     

Modulation of allostery of pyruvate kinase by shifting of an ensemble of microstates

Since the introduction of the concepts of allostery about four decades ago, much advancement has been made in elucidating the structure-function correlation in allostery. However, there are still a number of issues that remain unresolved. In this review we used mammalian pyruvate kinase (PK) as a model system to understand the role of protein dynamics in modulating cooperativity. PK has a triosephosphate isomerase (TIM)(α/β)₈ barrel structural motif. PK is an ideal system to address basic questions regarding regulatory mechanisms about this common (α/β)₈ structural motif. The simplest model accounting for all of the solution thermodynamic and kinetic data on ligand-enzyme interactions involves two conformational states, inactive E^T and active E^R. These conformational states are represented by domain movements. Further studies provide the first evidence for a differential effect of ligand binding on the dynamics of the structural elements, not major secondary structural changes. These data are consistent with our model that allosteric regulation of PK is the consequence of perturbation of the distribution of an ensemble of states in which the inactive E^T and active E^R represent the two extreme end states. Sequence differences and ligands can modulate the distribution of states leading to alterations of functions. The future work includes: defining the network of functionally connected residues; elucidating the chemical principles governing the sequence differences which affect functions; and probing the nature of mutations on the stability of the secondary structural elements, which in turn modulate allostery.