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1.
为探讨添加剂及其添加量对秘鲁鱿鱼肌原纤维蛋白热诱导凝胶特性的影响,以秘鲁鱿鱼为原料,在单因素试验基础上选择4种添加剂(壳聚糖、转谷氨酰胺酶、卡拉胶、海藻酸钠),通过响应面法建立肌原纤维蛋白凝胶硬度和添加剂用量之间的响应模型。结果表明,4种添加剂的最适添加量分别为:壳聚糖0.40%、转谷氨酰胺酶0.50%、卡拉胶0.90%、海藻酸钠0.25%,在此条件下秘鲁鱿鱼肌原纤维蛋白热诱导凝胶硬度达最大值859.85 g,保水性为96.34%。此复合添加剂能显著改善秘鲁鱿鱼肌原纤维蛋白的凝胶特性。研究结果为生产高品质的秘鲁鱿鱼凝胶制品提供了理论依据。  相似文献   

2.
人血清白蛋白的研究进展   总被引：1，自引：0，他引：1  
人血清白蛋白作为血浆容量扩充剂用途广泛，是当前的研究热点之一。本文综述了其结构组成、功能和表达现状。用基因工程大幅度提高rHSA的表达产量是目前重组人血清白蛋白研究的关键问题。  相似文献   

3.
苹果渣多酚提取工艺的优化   总被引：1，自引：0，他引：1  
为优化苹果渣中多酚提取工艺,并得到提取工艺和多酚组成之间的关系,利用微波辅助提取法设计了由物料颗粒、液料比、乙醇浓度、微波功率和微波提取时间5个因素构成的多酚提取优化试验流程,构建了涵盖黄酮、原花青素2种典型多酚物质和抗氧化能力的提取工艺评价指标体系。采用证据理论对不同工艺在评价指标下的焦元进行识别,并基于信度函数和似真函数得到了不同提取工艺的效用区间和优化方案。优化结果为：物料颗粒60目,液料比30?mL/g,乙醇体积分数60%,微波功率600?W,提取时间70?s,此条件下苹果渣多酚的提取量为213.83?mg/100g,黄酮提取量为83.21?mg/100g,原花青素提取量为52.79?mg/100g,抗氧化的EC50值为3.71?mg/100mL,验证了采用证据理论进行苹果渣多酚提取工艺优化的有效性。  相似文献   

4.
氧化是调控肉类品质的一种潜在工具,肉类蛋白氧化调控理论的完善有助于其在食品工程中的应用。为了研究不同氧化体系下,牦牛肌原纤维蛋白化学修饰与功能性质之间关系,该研究分析了离子氧化体系(Iron Oxidizing System,IOS)和高铁肌红蛋白(Metmyoglobin Oxidizing System,MOS)氧化体系下在特定氧化程度(蛋白羰基含量)下牦牛肌原纤维蛋白的生化特性、二级结构和功能特性。结果发现,随着氧化强度的提升,牦牛肌原纤维蛋白会发生显著的巯基丧失、二硫键生成、二酪酸增加以及表面疏水性下降现象(P0.05)。当羰基浓度达到(1.51±0.13) nmol/mg以后,MOS体系的二硫键和表面疏水性变化比IOS系统更明显。此外,随着氧化程度的增加,α-螺旋结构比例会持续减少,而β-折叠与β-转角结够会持续增加。通过对蛋白质功能性功能性研究,还发现适当的氧化对牦牛肌原纤维蛋白的溶解性和乳化性有一定改善作用,其改善峰值和范围因氧化体系不同而有所差异,MOS的功能特性影响对氧化强度更敏感。通过相关性分析可以发现,二硫键与溶解度、浊度、乳化性等功能特性相关性显著,二级结构大多数指标则与溶解性和浊度相关性显著。综上所述,不同氧化体系对于肌原纤维蛋白的生化及功能特性的影响存在差异,MOS系统能够在较小的氧化程度下对功能特性产生改善作用,这与其同时带来的二硫键和表面疏水性更显著的变化有关。  相似文献   

5.
黑莓原花青素超声波辅助提取优化及抗氧化性研究   总被引：16，自引：3，他引：13  
论文采用响应曲面法研究了超声波辅助提取时温度、时间、料液比、超声波功率及其交互作用对黑莓原花青素提取效果的影响,同时研究了黑莓原花青素对二苯代苦味酰自由基(DPPH)、·OH及·O2-的清除效果.用SAS软件确定了黑莓原花青素超声波提取的工艺参数为:提取温度为70.9℃,料液比为1∶9.14,时间为30.5 min,超声波功率为526.9 W.黑莓原花青素对DPPH、·O2-及·OH 3种自由基具有显著的清除效果,且明显优于茶多酚,当浓度为3.0 μg/mL时,对DPPH、·O2-及·OH 3种自由基的最大清除率分别可达到82.54%、79.90%和65.90%,且黑莓原花青素对3种自由基的清除效果与其浓度之间存在明显的量效关系.  相似文献   

6.
以筛选从丹皮中提取丹皮酚的理想溶剂及最佳工艺参数为目的，通过高效液相色谱测定研究了不同溶剂提取丹皮酚的效果，通过正交试验设计研究了四氯化碳提取丹皮酚的最佳条件。结果表明，溶剂法提取丹皮中丹皮酚的理想溶剂为四氯化碳。以牡丹根皮为材料，以四氯化碳为溶剂，最佳工艺参数为料液比1∶25(w/v)、丹皮粒径0.90 mm、浸提时间6h。按此最佳工艺参数，一次提取，丹皮酚提取量11.428 g/kg，占提取总量的89.857%；两次提取合计丹皮酚提取量12.30 g/kg，占提取总量的96.79%。  相似文献   

7.
沙枣果肉原花青素的提取、纯化及抗氧化性能的研究   总被引：4，自引：1，他引：4  
该文对沙枣果肉中原花青素的提取工艺进行了研究，通过单因素试验，在中心组合试验基础上得出了提取沙枣果肉原花青素的最佳工艺条件：提取温度76℃、提取时间86 min、乙醇浓度72％、提取液pH值5.0、料液比1∶9、提取3次。在此条件下提取率达95.9%。采用固相萃取法对沙枣果肉提取物中原花青素进行纯化，产物纯度为89.91％，原花青素的得率为4.23％；同时对纯化后沙枣果肉原花青素的抗氧化性能进行了测定，结果显示沙枣果肉原花青素有较好的抗脂氧化能力。  相似文献   

8.
法夫酵母虾青素提取工艺的优化研究   总被引：12，自引：3，他引：12  
从破壁方法、浸提溶剂及提取条件等方面对法夫酵母虾青素提取工艺进行了优化研究。用单因子试验对破壁方法及浸提溶剂进行选择，结果表明二甲亚砜(DMSO)法是法夫酵母破壁提取虾青素的最佳方法，丙酮是理想的提取溶剂。用析因试验对破壁提取的条件进行了分析研究，结果表明破壁的温度、破壁的时间、浸提溶剂的添加量及浸提温度等都会对法夫酵母破壁提取虾青素产生显著影响，但以破壁的温度及丙酮的添加量影响最大。通过最速上升和中心组合设计试验，优化得到适宜的提取条件为：二甲亚砜加量25 mL/g(以干菌体计，下同)、破壁温度75.6℃、破壁时间20 min、丙酮添加量77.4 mL/g、浸提温度为40℃，优化后提取液中虾青素的浓度为3.145 μg/mL，比未优化时增加了27.02%。  相似文献   

9.
刘智喜  李键 《核农学报》1995,9(1):55-61
分别以１７β－雌二醇－６－（Ｏ－羧甲基）肟－人血清白蛋白（试验组）和人血清白蛋白（对照组）为抗原，按两个免疫程序，对２４只新西兰公兔进行主动免疫。其中，一个免疫程序（Ａ、Ｂ组），以１个为间隔，给每兔行皮内多点注射，共５次，另一个免疫组（Ｃ、Ｄ组）先于第０、２和４周给各兔肌肉注射，又于第６、１０和１４周行耳静脉注射，在最后一次注射后１０天，每隔６小时采集血样１次，连续２４小时，用ＲＩＡ测定血浆１７β  相似文献   

10.
畜禽养殖产生的粪便已经成为我国农村面源污染的主要来源之一,粪便中磷流失也越来越引起人们的重视.以牛粪、猪粪、鸡粪和鸭粪为研究对象,采用H2O、NaHCO3独立提取与H2O+NaHCO3连续提取两种方法,根据磷在H2O和0.5 mol·L-1NaHCO3溶液中的溶解性来研究粪便中磷的形态及其分布特征.研究结果表明,4种粪便全磷含量的变化范围是4.21～40.17 g·kg-1.H2O、NaHCO3独立提取与H2O+NaHCO3连续提取法中,牛粪无机磷平均含量分别为2.37、4.95和5.75 g·kg-1,占全磷含量的26%、53%和62%;猪粪无机磷平均含量分别为5.42、11.58和12.67 g·kg-1,占全磷含量的28%、60%和67%;鸡粪无机磷平均含量分别为4.01、5.94和6.89 g·kg-1,占全磷含量的28%、42%和48%;鸭粪平均无机磷分别为2.82、4.06和4.79 g·kg-1,占全磷含量的18%、26%和31%.H2O和NaHCO3连续提取法测得的畜禽粪便无机磷含量略高于NaHCO3独立提取法测得的结果,差异不显著,两种提取方法测得的结果呈显著正相关关系.各提取液中的磷均以无机磷为主,占总提取磷的60%～99%,猪粪在各提取液中无机磷和总提取磷含量均显著高于其它3种粪便.  相似文献   

11.
A procedure for a fast and simple purification of bovine plasma transglutaminase was developed, which resulted in a homogeneous enzyme preparation. Two different procedures were developed for the purification of pig erythrocyte transglutaminase, both of which resulted in partial purification. Both enzymes were used in cross-linking reactions of alpha-lactalbumin, beta-lactoglobulin, bovine serum albumin, casein, hemoglobin, glycinin, and myosin. The substrate specificity was compared to that of bacterial transglutaminase isolated from Streptoverticillium mobaraense. The bacterial transglutaminase caused cross-linking of a wider range of proteins and, thus, exhibited a lower substrate specificity than the blood transglutaminases. In addition, differences exist in the necessity of the addition of reducing agents. These differences allow specific applications of blood and bacterial transglutaminases at protein cross-linking in single or complex protein systems.  相似文献   

12.
Fourier transform (FT) Raman spectroscopy was used to elucidate heat-induced structural changes of albumin, globulins, serum, and plasma protein solutions (15% w/w) as affected by pH (4.5, 6.0, and 7.5). Reduction of alpha-helix and formation of beta-sheet, disulfide bond reactions, and exposure and buriedness of hydrophobic groups and amino acid residues were observed. All of these features contributed to the formation of strong, irreversible heat-induced gels. The application of a dimensionality reducing technique such as principal component analysis proved to be useful to determine the most influential qualities of protein samples, as well as the pH-dependent behavior of some of the attributes of both unheated and heated solutions. Analysis of Raman spectra in terms of differences demonstrated the interactions of albumin and globulins in co-occurrence and the significant role of fibrinogen on the gel's attributes.  相似文献   

13.
The liquid chromatographic (LC) method described, suitable for use with both blood plasma and urine, is applicable for determination of zearalenone and alpha-zearalenol at levels as low as 0.5 ng/mL plasma and 5 ng/mL urine. The sample is incubated overnight with beta-glucuronidase to analyze for both conjugated and unconjugated forms of zearalenone. The next day, the sample is acidified with H3PO4, extracted with chloroform, and evaporated to dryness. The residue is dissolved in toluene and loaded onto a silica gel cartridge which is washed with toluene and eluted with toluene-acetone (88 + 12). The eluate is evaporated, and the residue is dissolved in chloroform, extracted with 0.18M NaOH, neutralized with H3PO4, and re-extracted with chloroform. The chloroform extract is evaporated, dissolved in mobile phase for LC, and injected onto a normal phase column under the following chromatographic conditions: mobile phase of water-saturated dichloromethane containing 2% 1-propanol, and fluorescence detector, excitation wave-length 236 nm, and 418 nm cut-off emission filter. Recoveries of zearalenone and its metabolites from blood plasma and urine are 80-89% in the range 2.0-10 ng standard/mL plasma, and 81-90% in the range 10-30 ng standard/mL urine. This method was used to analyze blood and urine samples from a pig fed zearalenone-contaminated feed (5 mg/kg), corresponding to 80 micrograms/kg body weight. Zearalenone was rapidly metabolized to alpha-zearalenol, which appeared in the blood only 30 min after feeding. Almost all zearalenone and alpha-zearalenol was found conjugated with glucuronic acid in both blood plasma and urine.  相似文献   

14.
A novel fibrinolytic enzyme was purified from fermented shrimp paste, a popular seasoning used in Asian countries. The enzyme is a monomer with an apparent molecular weight of 18 kDa, and it is composed primarily of beta-sheet and random coils. The N-terminal amino acid sequence was determined to be DPYEEPGPCENLQVA. It is a neutral protease with an optimal activity from pH 3 to 7. No inhibition was observed with PMSF, Pepstatin A, E64, and 1,10-phenanthroline, but the enzyme was slightly inhibited by EDTA and Cu(2+). It was relatively specific to fibrin or fibrinogen as a protein substrate, yet it hydrolyzed none of the plasma proteins in the studies. In vitro, the enzyme was resistant to pepsin and trypsin digestion. It also had an anticoagulant activity measured with activated partial thrombin time and prothrombin time tests. The novel fibrinolytic enzyme derived from traditional Asian foods is useful for thrombolytic therapy. In addition, this enzyme has a significant potential for food fortification and nutraceutical applications, such that its use could effectively prevent cardiovascular diseases.  相似文献   

15.
The effects of short-term moderate beer consumption (MBC) on plasma circulating fibrinogen (PCF) in patients suffering from coronary atherosclerosis were investigated by use of 2-dimensional electrophoresis (2-DE), circular dichroism (CD), and Fourier transform infrared spectroscopy (FT-IR). Forty-eight volunteers after coronary bypass surgery were divided into experimental (EG) and control (CG) groups, each of 24. Patients of the EG group consumed 330 mL of beer/day (about 20 g of alcohol) for 30 consecutive days, and CG volunteers drank mineral water instead of beer. Blood samples were collected before and after the experiment. In 21 out of 24 patients after beer consumption the plasma circulating fibrinogen was compromised: changes in its secondary structure were found. These changes were expressed in relatively low electrophoretic mobility and charge heterogeneity, decrease in alpha-helix and increase in beta-sheet, and in slight shift of amide I and II bands. Our findings indicate that one of the positive benefits of moderate beer consumption is to diminish the production of fibrinogen and its stability, which reduces the potential risk exerted by this protein. Thus, in most of beer-consuming patients some qualitative structural changes in plasma circulating fibrinogen were detected.  相似文献   

16.
Magnetic resonance imaging (MRI) and textural and physicochemical analyses were carried out to evaluate the effect of fibrinogen and thrombin (Fibrimex) addition to meat systems formulated with and without NaCl. For this purpose, different model systems were elaborated: fibrinogen and thrombin (FT), meat emulsion (ME), and meat emulsion with fibrinogen and thrombin (MEFT), with 0, 1, and 2% of NaCl. The addition of fibrinogen-thrombin to meat emulsions results in a gel network with modified physicochemical and textural characteristics, increasing the hardness and springiness. The addition of NaCl at 2% to FT and MEFT systems reduced the gel hardness. MRI parameters (T2, T1, and apparent diffusion coefficient) indicated that systems with fibrinogen and thrombin (FT and MEFT) presented a structure with many and large pores, bulk water, and higher translational motion of water. Significant correlations were found between MRI, texture, and physicochemical parameters.  相似文献   

17.
鸡、猪BPI氨基端的基因克隆和鉴定   总被引：1，自引：0，他引：1  
为了克隆杀菌/通透性增加蛋白(BP I)N端cDNA,构建重组体pM D 18-T-BP I,并进行序列鉴定,应用RT-PCR技术,参照G enB ank报道的预测序列,从鸡多形核白细胞(PM N)mRNA中扩增出杀菌/通透性增加蛋白(BP I)氨基端95个氨基酸的基因片段,并与pM D 18-T连接,构建BP I氨基端的基因重组体,进行酶切鉴定和序列测定;从猪PM N的总mRNA中扩增出BP I氨基端48个氨基酸的基因片段,进行测序鉴定。获得鸡BP I N端长度为285 bp的基因片段。序列分析证实该片段中有3个点突变,但均不在活性中心;获得猪BP IN端长度为146 bp的基因片段。成功克隆出BP I N端基因,经序列测定,确认为BP I基因,为进一步表达该基因奠定了基础。  相似文献   

18.
The contents of the bioactive compounds in the pummelo-grapefruit hybrid juice named Israeli Jaffa Sweetie and their influence on humans suffering from hypercholesterolemia were studied. It was found that Sweetie juice has a high content of bioactive compounds and a high antioxidant potential. Then 72 hypercholesterolemic patients, ages 43-71 years, after coronary bypass surgery recruited from the Institute pool of volunteers, were randomly divided into two experimental (EG1 and EG2) groups and one control (CG) group, each comprising 24 patients. The diets of EG1 and EG2 patients were daily supplemented with 100 or 200 mL of fresh Sweetie juice, respectively. Before and after diet consumption serum lipid levels, albumin and fibrinogen fractions, and their antioxidant capacities were determined. After 30 consecutive days of Sweetie juice supplemented diets, improvements in serum lipids levels were found in EG1 and EG2 versus CG: (a) total cholesterol, 7.34 versus 8.02 mmol/L, -9.5%, and 6.73 versus 8.02 mmol/L, -16.1%, respectively; (b) low-density lipoprotein cholesterol, 5.63 versus 6.37 mmol/L, -11.6%, and 5.03 versus 6.37 mmol/L, -21.0%, respectively; (c) total glycerides, 2.01 versus 2.27 mmol/L, -11.5%, and 1.71 versus 2.27 mmol/L, -24.7%, respectively. Serum albumin concentration was increased but not significantly in EG1 and EG2 versus CG: 47.5 versus 44.5 g/L, +6.7%, and 47.9 versus 44.5 g/L, +7.6%, respectively. A significant increase in the serum, albumin, and fibrinogen antioxidant capacities in EG2 and to a lesser degree in EG1 was observed. No changes in the CG were found. In conclusion, fresh Sweetie juice contains high quantities of bioactive compounds and has a high antioxidant potential. Diet supplemented with this juice positively influences serum lipid, albumin, and fibrinogen levels and their antioxidant capacities. Addition of fresh Sweetie juice to generally accepted diets may be beneficial for hypercholesterolemic patients.  相似文献   

19.
The aim of this investigation was to evaluate the dose-dependent influence of commercial garlic on rats fed cholesterol-containing diets. It was found that commercial garlic contains high concentrations of dietary fibers, microelements, and total polyphenols, and its total antioxidant capacity as determined by two independent assays [1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azinobis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS)] was similar to that of the original garlic samples. Wistar rats (35) were randomly divided into five diet groups, named control, Chol, Garlic500, Garlic750, and Garlic1000. Control rats were fed basal diet (BD), which included wheat starch, casein, soybean oil, and vitamin and mineral mixtures. To the BD of the Chol group was added 1% of cholesterol. To the BD of the other three groups (Garlic500, Garlic750, and Garlic1000) were added 1% of cholesterol and commercial garlic equal to 500, 750, and 1000 mg of raw garlic per kilogram of animal weight. After 4 weeks of the experiment only in rats from the Garlic500 group were a significant hindering in the rise in plasma lipids and also a significant hindering in a decrease of plasma antioxidant activity registered. A significant decrease in plasma circulating fibrinogen and an increase in the clotting time were found in the same group of rats (P < 0.05 in both cases). The fibrinogenolytic effect of garlic diets was visualized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. In the fibrinogen fraction of Garlic500 the 66, 24, and 14 kDa protein bands were detected with weaker protein intensity than in the corresponding ones in the Garlic750 and Garlic1000 diet groups. In conclusion, the positive influences of commercial garlic on plasma lipids, proteins, antioxidant activity, and some indices of blood coagulation are dose-dependent. Therefore, commercial garlic (Elena, Zelazków, Poland) could be a valuable component of atherosclerosis-preventing diets only in optimal doses.  相似文献   

20.
Elastin hydrolysate has apparent beneficial effects, and the food-derived peptide prolyl-glycine (Pro-Gly) is present in human blood after oral ingestion. Following ingestion of elastin hydrolysate (10 g/60 kg body weight) by healthy human volunteers, peripheral blood was used to prepare plasma samples from which peptides were extracted by solid phase extraction and fractionated by size-exclusion chromatography (SEC). Peptides in the SEC fractions were derivatized with phenyl isothiocyanate (PITC) and resolved by reversed phase (RP)-HPLC. Pro-Gly was the major food-derived elastin peptide, reaching a maximum (18 μM) at 30 min after ingestion, and decreasing to approximately 20% at 4 h after ingestion. Finally, in cell culture, levels of Pro-Gly in the medium above 0.1 μg/mL significantly enhanced elastin synthesis of normal human dermal fibroblasts (NHDF) without affecting the rate of cell proliferation.  相似文献   

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