鱼蛋白的浓缩分离及其凝胶性的研究进展

从食品蛋白配料角度出发,对传统冷冻鱼糜(Surimi)技术以及新兴分离鱼蛋白(FPI)技术在水产品加工中的研究及应用情况进行了系统回顾。从蛋白质的分离回收效果以及脱脂与脱色作用等方面对Surimi及FPI技术进行了对比分析,并围绕蛋白质的凝胶功能特性展开了讨论。结果表明:使用FPI法的蛋白回收率明显高于Surimi法,使用酸溶方法 (AC-FPI)的蛋白回收率普遍高于碱溶方法 (AL-FPI);FPI法的脱脂效果优于Surimi法;Surimi法的脱色效果优于FPI法,而AL-FPI法的脱色效果明显优于AC-FPI法,几乎接近Surimi法;Surimi凝胶与AL-FPI凝胶特性相似,且均优于AC-FPI凝胶;用3种方法分离的蛋白及其凝胶的贮藏稳定性,AL-FPI法最优,Surimi法次之,AC-FPI法最差。分析认为,今后FPI的研究和应用可从低值鱼蛋白资源出发,以蛋白质的结构变化为核心,蛋白质的食品功能特性为基础而开展。     

箭齿鲽肌肉分离蛋白功能特性的研究

以箭齿鲽Atheresthes stomias为原料,对其肌肉蛋白进行分离提取,并研究了蛋白质的功能特性。采用pH调节方法,分别提取得到酸分离蛋白和碱分离蛋白,同时以原料肌肉蛋白和传统漂洗鱼糜为对照。利用SDS-PAGE法对分离蛋白的分子量分布进行分析,结果表明,碱分离蛋白中肌原纤维蛋白分子保持完整,而酸分离蛋白有明显的肌球蛋白重链和肌动蛋白降解现象产生。对分离蛋白的功能特性包括溶解性、持水性、持油性、乳化性、起泡性、凝胶特性进行分析,结果表明,与原料鱼肉和漂洗鱼糜相比,酸分离蛋白和碱分离蛋白均表现出明显的乳化性能,碱分离蛋白具有最佳的凝胶强度,而在其他功能特性方面,分离蛋白则没有明显的优势。对分离蛋白的基本理化特性进行分析,结果表明,分离蛋白的脱脂效果比漂洗鱼糜更加明显,且与原料鱼肉(13.00%)相比,碱分离蛋白脂肪含量最少(1.23%),其次是酸分离蛋白(1.96%)和漂洗鱼糜(3.30%)。从分离前后的色度变化可以看出,分离蛋白的白度明显优于漂洗鱼糜和原料鱼肉。研究表明,箭齿鲽分离蛋白在食品加工中作为一种蛋白配料具有一定潜力。     

预乳化半连续种子乳液聚合制备聚合物水泥防水涂料用丙烯酸酯乳液

采用分子设计、粒子形态的概念,用甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)为原料,以十二烷基硫酸钠(SDS)和烷基酚聚氧乙烯醚(OP-10)的混合乳化剂为乳化体系,过硫酸铵为引发剂,引入甲基丙烯酸(MAA)功能性单体、N-羟基丙烯酰胺(或丙烯酰胺)活性交联单体和对甲基苯酚(或三聚氰胺)耐水性单体,采用预乳化半连续种子乳液聚合工艺,制备出高弹性、高稳定性、高防水性丙烯酸酯乳液。研究了预乳化阶段影响预乳化液稳定性的因素以及种子乳液聚合阶段影响产品性能的因素。研究结果表明:设计低玻璃化温度、引入功能性单体、活性交联单体和耐水性单体可以提高丙烯酸酯乳液的弹性、稳定性和防水性。     

黑豆蛋白质的制取方法

<正>黑豆蛋白的加工是在提取油脂的基础上利用豆粕在进一步加工。豆粕主要用于饲料和制取蛋白质。其蛋白的种类有浓缩蛋白、分离蛋白、组织蛋白、细粒组织蛋白、蛋白肽等。下面主要介绍浓缩蛋白、分离蛋白和组织状蛋白的生产。1浓缩蛋白的生产从豆粕中除去非蛋白成分的制品叫做大豆浓缩蛋白。浓缩蛋白以干物质计算,其蛋白质含量不低于70%,具有乳化性、吸油性和吸水性。制取黑豆浓缩蛋白的方法有:含水酒精浸提法、稀酸浸提法     

菲律宾蛤仔闭壳肌组织学及其蛋白特性

为探讨菲律宾蛤仔Ruditapes philippinarum的加工特性与肌肉蛋白质特性的关系,对菲律宾蛤仔闭壳肌的组织形态、肌原纤维蛋白(Myofibrillar,Mf)的分布特性,以及与其低温凝胶化相关的特性等进行了分析。结果表明:闭壳肌肌纤维具有高度同向性,横纹肌呈直线柱状,平滑肌呈螺旋柱状;利用SDSPAGE电泳对两种类型肌肉的蛋白分布分析显示,横纹肌肌浆蛋白组分中存在相对分子质量为23 000的差异蛋白,且溶出更多的粗丝蛋白,平滑肌的Mf组分中存在标志性蛋白Myorod,且副肌球蛋白含量高,肌球和原肌球蛋白含量低,肌动蛋白含量接近;整个闭壳肌Mf的溶解性依赖于离子强度和有无三磷酸腺苷(Adenosine Triphosphate,ATP)的添加;Ca⁽²⁺⁾-ATPase活性在中等离子强度(KCl浓度为0.30 mol/L)时最高,偏离中等离子强度后活性逐渐降低;参与交联的蛋白包括肌球蛋白、副肌球蛋白、原肌球蛋白,离子强度越高交联作用越显著。本研究结果可为探究经济贝类软体可食部位蛋白特性提供参考。     

菲律宾蛤仔闭壳肌组织学及其蛋白特性

为探讨菲律宾蛤仔Ruditapes philippinarum的加工特性与肌肉蛋白质特性的关系,对菲律宾蛤仔闭壳肌的组织形态、肌原纤维蛋白(Myofibrillar,Mf)的分布特性,以及与其低温凝胶化相关的特性等进行了分析。结果表明:闭壳肌肌纤维具有高度同向性,横纹肌呈直线柱状,平滑肌呈螺旋柱状;利用SDSPAGE电泳对两种类型肌肉的蛋白分布分析显示,横纹肌肌浆蛋白组分中存在相对分子质量为23 000的差异蛋白,且溶出更多的粗丝蛋白,平滑肌的Mf组分中存在标志性蛋白Myorod,且副肌球蛋白含量高,肌球和原肌球蛋白含量低,肌动蛋白含量接近;整个闭壳肌Mf的溶解性依赖于离子强度和有无三磷酸腺苷(Adenosine Triphosphate,ATP)的添加;Ca~(2+)-ATPase活性在中等离子强度(KCl浓度为0.30 mol/L)时最高,偏离中等离子强度后活性逐渐降低;参与交联的蛋白包括肌球蛋白、副肌球蛋白、原肌球蛋白,离子强度越高交联作用越显著。本研究结果可为探究经济贝类软体可食部位蛋白特性提供参考。     

PVA/CS水凝胶的制备与性能研究

采用戊二醛蒸汽交联法制备了聚乙烯醇/壳聚糖(PVA/CS)水凝胶。通过扫描电子显微镜观察了不同质量配比的PVA/CS水凝胶的形貌。研究表明,随着壳聚糖的增加,凝胶比表面积增大且更加通透。当壳聚糖浓度达到某一临界值时,所得的水凝胶的形貌最好,比表面积最大。测试戊二醛蒸汽交联制得的水凝胶的接触角,考察了不同质量配比的PVA/CS水凝胶的亲水性能。研究发现,随着加入的壳聚糖的量的增加,水凝胶的亲水性能降低,接触角增大。交联后的PVA/CS水凝胶有望在负载和释放功能性的药物和其它生物医学方面得到应用。     

二氧化硅气凝胶保温材料研究进展

具备高孔隙率、高比表面积且质轻的二氧化硅气凝胶因其具有极低导热系数和高耐火性能在防火隔热领域具有广阔的应用前景.然而,目前二氧化硅气凝胶存在成型性差、力学强度低等问题.近年来,国内外众多学者围绕二氧化硅气凝胶材料的增强改性做了大量研究,采用复合或交联等方法可显著提高气凝胶的强度、韧性和整体性,使得二氧化硅气凝胶保温材料的实际应用成为可能.文章综述了当前二氧化硅气凝胶保温材料的最新研究进展,并对其今后的发展趋势提出了展望.     

不同硅源制备二氧化硅气凝胶研究进展

近年来,二氧化硅气凝胶凭借其优异性能在诸多领域被广泛应用。硅源作为制备SiO₂气凝胶最重要的组成部分,对获得结构完整、性能优良的SiO₂气凝胶至关重要。本文综述了多种硅源为前驱体的SiO₂气凝胶发展历程及制备。硅源种类划分为单一硅源和复合硅源。单一硅源主要有水玻璃、硅溶胶、工农业含硅废料及常见硅醇盐;复合硅源通过引入疏水性和功能性基团来改善结构性能,从而实现其在不同领域的应用。最后对SiO₂气凝胶硅源的选择、研究现状及前景进行探讨。     

智能水凝胶的发展与应用

智能水凝胶是一类对外界环境微小的物理和化学刺激，如温度、压力、pH 值、光、电场、离子强度、化学物质等能产生敏感响应的交联聚合物。本文重点阐述智能水凝胶在服饰中的实践教学与应用研究，增强服饰的功能性，创造市场价值。     

Altering protein conformation to improve fermentative hydrogen production from protein wastewater

One important reason for low hydrogen production from protein wastewater is due to the native folded conformation of protein. In this study the enhancement of bio-hydrogen production from protein wastewater by altering protein conformation via pretreatment was reported. Firstly, the effect of different pretreatment methods (acid, alkali, heat, and ultraviolet) on hydrogen production from synthetic protein wastewater was compared. The hydrogen production from the ultraviolet pretreated wastewater was 111.3 mL/g-protein, which was 3.79-, 3.73-, 3.54-, and 1.36-fold of that from the unpretreated (blank), acid, alkali, and heat pretreated wastewater, respectively. Then, the reasons for ultraviolet pretreatment showing significantly higher hydrogen production than other pretreatments were investigated. It was found that all pretreatments did not cause the cleavage of peptide bond, but the ultraviolet one caused much greater damage of hydrogen bonding networks and unfolding of protein. Thus, during anaerobic fermentation much higher protease activity and protein utilization were observed, which resulted in the bio-hydrogen production being remarkably improved. Further studies indicated that the photo-oxidization of aromatic residues in protein was not the reason for ultraviolet pretreatment remarkably improving bio-hydrogen production. Finally, the application of ultraviolet pretreatment to enhance hydrogen production from real protein wastewater was testified.     

双下肢水肿-反复骨折-M蛋白

在并发骨质疏松症的情况下，以骨折为主要临床表现的多发性骨髓瘤（mulitiple myoloma，MM）容易被漏诊。现报告1例72岁男性，因肾病综合征长期使用糖皮质激素后出现严重骨质疏松症，但规律抗骨质疏松过程中反复发生椎体骨折。结合既往多次免疫固定电泳提示IgGκ型单克隆球蛋白（monoclonal protein，M蛋白），骨髓穿刺见克隆性浆细胞，考虑并发MM。本文同时对骨质疏松症及MM的相关文献进行复习。     

哲罗鲑雌性蛋白的研究

采用柱层析、蛋白质免疫印迹和电泳等方法,对哲罗鲑Hucho taimen的雌性蛋白进行了系统研究。结果表明:哲罗鲑血清和卵黄中均存在雌性蛋白,其雌性蛋白的性质相同,均为糖脂磷蛋白;与血清雌性特异蛋白一样,卵黄雌性特异蛋白的相对分子质量也为460 000,由相对分子质量分别为137 800、84 200和10 800的3个亚基组成,等电点为5.60;卵黄雌性蛋白的兔抗血清均与哲罗鲑雌性血清发生免疫反应,不与雄性血清发生免疫反应,表明这两种蛋白均具有雌性特异性;两种蛋白的抗血清可以相互检测,表明哲罗鲑雌鱼血清中雌性蛋白与卵黄中的雌性蛋白在免疫原性上和结构上具有较高的同源性。     

骨形态发生蛋白与骨代谢

骨形态发生蛋白(BMPs)是多功能细胞因子,其家庭成员参与骨骼形成、分化、吸收等过程,对成骨细胞、破骨细胞和软骨细胞均有不同程度的影响。本文就BMPs对成骨细胞、破骨细胞及软骨细胞作用的研究进展进行综述。     

Batch foam separation of a soluble protein

Removal of protein dissolved in water by batch foam separation was conducted with using ovalbumin (OA) as a model protein in the light of wastewater treatment reducing organic loading. The removal efficiency had a maximum value near the i.e.p. of OA (pH 4.6); thus, most experiments were conducted at pH 4.6. Typical experimental conditions; superficial gas velocity, U(g): 1.97 x 10(-2)-5.37 x 10(-2)cm/s; initial bulk concentration of OA, C(i): ca. 0.05-0.25 g/L; liquid volume, V: 600 cm(3). A model estimating bulk concentration profile was proposed by taking into account a mass balance of the present system. The model predicted that OA could be removed perfectly, however, was not all removed experimentally. The residual OA concentration of the bulk liquid within the column reached plateau value, which correspond to ca. 18% of the initial OA concentration. The plateau value of the bulk concentration was attained for ca. 100-500 min with U(g)=1.97 x 10(-2)-5.37 x 10(-2)cm/s. Foaming ability test revealed that the foaming limit concentration of OA at pH 4.6 was 9.72 x 10(-3)g/L. These results suggested that OA molecules could be damaged by interaction of bubble surface in the dispersed phase, since there were the residual OA concentrations over the limit concentration. To take account of this phenomena and correct the model, average surface density, X(d), which should convert protein molecule into the denatured protein molecule, was introduced. The corrected model could explain well the time profile of OA bulk concentration.     

揭开三聚氰胺的蛋白质伪装——非法食品添加物“三聚氰胺”解读

三聚氰胺的化学性质及用途三聚氰胺俗称"蛋白精",英文名为Melamine,是一种三嗪类含氮杂环有机化合物。常温下,三聚氰胺为白色单斜晶体,没有显著异味,性质较稳定。它易溶于热水,微溶于冷水,可溶于甲醇、甲醛、乙酸、乙二醇、甘油、吡啶等,不溶于丙酮、醚类。呈弱碱性,遇到酸性物质能形成三聚氰酸,对身体有害。三聚氰胺用途相当广泛,可以作阻燃剂、减水剂、甲醛清洁剂等等,但最主要是作为生产三聚氰胺甲醛树脂的原料。这种树脂硬度比     

Studies on the recovery of sludge protein

The effect of sodium hydroxide and sodium chloride alone as well as in combination on sludge protein solubilization was investigated. Sodium hydroxide treatment was found superior as a maximum protein solubilization (90%) was obtained by its use at pH 12.5. For the extraction of protein hydrochloric acid, sodium lignosulphonate, sulphuric acid, acetic acid and ammonium sulphate, as protein precipitating agents, were also tried. Of all the precipitants used ammonium sulphate (40%) was found most effective giving a maximum protein recovery (91%).Four parameters were mainly studied for the characterization of recovered protein. These include determination of total protein, moisture, ash and heavy metals. It was also found that protein recovery unit processes removed most of the metals originally present in the primary sludge and the recovered product contained all the essential amino acids which could serve as an animal feed supplement.     

过期蛋白泡沫灭火剂的再生

半个多世纪以来 ,蛋白类泡沫灭火剂以其优良的性能一直占领着泡沫灭火剂市场的“大哥大”的地位 ,这些优良性能是其他类型的泡沫灭火剂不能替代的。其一 ,蛋白泡沫灭火剂灭火的可靠性大 ,安全系数高 ,在供泡沫灭火的过程中以及在灭火之后 ,对火场的保护性能佳。其二 ,它有优良的生物降解性。蛋白泡沫灭火剂的原料是各种天然蛋白质 ,产品组成主要是蛋白质水解中间产物———多肽。到目前为止 ,它是唯一可以1 0 0 %被生物降解的纯天然环保型泡沫灭火剂。事实上 ,现在国外也还没有一种合成泡沫灭火剂可以被生物 1 0 0 %降解。曾经自己宣传为环…     

蛋白类泡沫灭火剂的降解与处理

针对用量较大的蛋白类泡沫灭火剂报废后对自然环境的影响，分析不同种类蛋白泡沫灭火剂的污染物的主要成分及含量，探讨其生物可降解性。针对难降解的氟蛋白泡沫灭火剂，提出相应的技术对策，分析新型环保型氟碳表面活性剂研究现状，展望研究前景。     

The kinetics of protein removal by activated sludge

The removal of bovine serum albumin (BSA) by BSA acclimated activated sludge took place in two stages. Removal during stage 1 was attributed to adsorption. The removal of BSA during stage 2 was slower than stage 1. There was never an accumulation of protein degradation products and removal was accompanied by an increase in the metabolic activity of the activated sludge. The removal of BSA per unit biomass during stage 2 was influenced by both the concentration of BSA and the concentration of activated sludge At high concentrations of BSA, removal was preceded by a lag phase. The rate of removal during stage 2 was constant. Within limits the rate of removal of BSA was related to the substrate to biomass ( ) ratio of the system and to the concentration of BSA expressed per unit biomass remaining in equilibrium following stage 1 of BSA removal.