Acetylation of chicken feathers for thermoplastic applications

Poultry feathers are renewable resources, inexpensive and abundantly available, but have limited applications. Although keratin extracted from feathers has been chemically modified, there are no reports on the chemical modification or development of thermoplastics from poultry feathers. Acetylation is an inexpensive and environmentally friendly approach to make biopolymers thermoplastic. Several biopolymers have been acetylated and used to produce fibers, films, and extrudates. In this research, chicken feathers were acetylated, and the structure and properties of the acetylated feathers were studied. Acetylation conditions such as concentration of chemicals and catalyst and time and temperature of acetylation were optimized. Acetylation of feathers was confirmed using Fourier transform infrared (FTIR) and pyrolysis-gas chromatography-mass spectrometry (P-GC-MS). The acetylated feathers were analyzed using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) to understand their thermal behavior. Acetylated feathers were thermoplastic and could be compression molded to form transparent films despite the relatively low percentage of acetyl content.     

用辐射甘蔗渣接枝法制备高吸水剂初探

利用60Coγ射线辐照引发甘蔗渣与丙烯酸钠的接枝聚合反应制备高吸水剂,研究丙烯酸与蔗渣的不同配比、辐照剂量等因素对辐射接枝聚合产物吸水率的影响。结果表明:辐射剂量为2.0kGy,丙烯酸与蔗渣的比例(V/W)为2∶1时,产物达到其最大的吸水倍数,吸自来水可达干重的220倍,吸去离子水可达干重的798倍。     

马铃薯淀粉与丙烯酸甲酯接枝共聚反应的研究

为加快马铃薯淀粉的改性和开发利用,对影响马铃薯淀粉与丙烯酸甲酯接枝共聚反应的主要因素进行了较详细的观察,实验结果表明:引发剂硝酸铈铵的浓度为7.298mmol/L,丙烯酸甲酯浓度为2.06mol/L,反应温度为40℃,反应时间在120～150min为最佳反应条件。     

Modification and characterization of biodegradable methylcellulose films with trimethylolpropane trimethacrylate (TMPTMA) by γ radiation: effect of nanocrystalline cellulose

Methylcellulose (MC)-based films were prepared by solution casting from its 1% aqueous suspension containing 0.25% glycerol. Trimethylolpropane trimethacrylate (TMPTMA) monomer (0.1-2% by wt) along with the glycerol was added to the MC suspension. The films were cast and irradiated from a radiation dose varied from 0.1 to 10 kGy. Then the mechanical properties such as tensile strength (TS), tensile modulus (TM), and elongation at break (Eb) and barrier properties of the films were evaluated. The highest TS (47.88 PMa) and TM (1791.50 MPa) of the films were found by using 0.1% monomer at 5 kGy dose. The lowest water vapor permeability (WVP) of the films was found to be 5.57 g·mm/m(2)·day·kPa (at 0.1% monomer and 5 kGy dose), which is 12.14% lower than control MC-based films. Molecular interactions due to incorporation of TMPTMA were supported by FTIR spectroscopy. A band at 1720 cm(-1) was observed due to the addition of TMPTMA in MC-based films, which indicated the typical (C═O) carbonyl stretching. For the further improvement of the mechanical and barrier properties of the film, 0.025-1% nanocrystalline cellulose (NCC) was added to the MC-based suspension containing 1% TMPTMA. Addition of NCC led to a significant improvement in the mechanical and barrier properties. The novelty of this investigation was to graft insoluble monomer using γ radiation with MC-based films and use of biodegradable NCC as the reinforcing agent.     

江西地方鸡种的AFLP多态性及其群体遗传关系

摘要：利用15对AFLP引物组合,检测了8个地方鸡种(南城黑鸡、余干五黑鸡、崇仁麻鸡、宁都三黄鸡、万载康乐黄鸡、广丰白耳黄鸡、东乡绿壳蛋鸡和泰和丝羽乌骨鸡)、1个培育品种（景德黄鸡）和1个外来鸡种（以色列隐性白羽鸡）池DNA的遗传变异,计算了10个鸡种的遗传相似系数,其中南城黑鸡与余干五黑鸡的遗传相似系数最高（0.7790）,其次为广丰白耳黄鸡与景德黄鸡（0.6726）,崇仁麻鸡和以色列隐性白羽鸡的遗传相似系数最低（0.2801）。在UPGMA聚类关系图中,8个江西地方鸡种及培育鸡种景德黄鸡聚成一大类,其中余干五黑鸡与南城黑鸡、广丰白耳黄鸡与景德黄鸡分别两两相聚,以色列隐性白羽鸡另聚成一类。实验结果表明,江西省地方鸡种和引进品种之间的亲缘关系较远;南城黑鸡和余干五黑鸡的遗传距离最近,两者有着极密切的亲缘关系。结合生产性能、体形外貌及此前RAPD研究结果,认为南城黑鸡和余干五黑鸡可能是“同种异名”。广丰白耳黄鸡和景德黄鸡也表现出较密切的亲缘关系,这与RAPD分析结果及广丰白耳黄鸡是景德黄鸡的原始亲本之一的育种历史相一致。     

不同类型保水剂性能及其对玉米生长效应的比较

为了比较各类保水剂在同等条件下的性能和应用效果差异,促进保水剂在抗旱节水中的合理应用。本文对国内聚丙烯酸钠、淀粉接枝丙烯酸钠、凹凸棒（无机）/聚丙烯酸钠（有机）、腐殖酸/聚丙烯酸钾4种主要类型农用保水剂进行性能测定,比较其吸水倍率、吸水速率、抗离子特性、pH值、反复吸水性等性能的差异。结果表明,不同类型保水剂的性能差异较大,单一性保水剂聚丙烯酸盐在吸水倍率、吸水速率和保水性等方面表现最好,但反复吸水时吸水率降低较快;淀粉接枝丙烯酸钠第7次吸水时已丧失吸水性;复合型保水剂凹凸棒/聚丙烯酸钠、腐殖酸/聚丙烯酸钾抗二价（Ca^2＋,Mg^2＋）和三价（Fe^3＋）离子特性明显,反复吸水性能好;盆栽玉米实验证明,复合型保水剂及其与菌根配比使用能显著促进玉米生长。     

辐射技术制备固定化蛋白酶

本文探讨了在低温条件下,~(60)Co-γ射线诱导亲水性单体丙烯酸羟乙酯、疏水性的聚乙二醇二甲基丙烯酸酯系列单体聚合固定化蛋白酶的方法,研究了单体的分子结构,单体性质对固定化蛋白酶活性和热稳定性的影响。实验结果表明,采用单官能团单体(HEA)制备的固定化蛋白酶相对活性高于双官能团单体,固定化酶相对活性随疏水性单体聚乙二醇二甲基丙烯酸酯中乙二醇数的增加而增加。对于亲水性单体HEA固定化蛋白酶的相对活性则随单体的冷却速率的增加而增加。固定化蛋白酶的热稳定性随单体的亲水性而变化。     

用核酸探针检测鸡脏器及羽毛囊中禽呼肠孤病毒

摘要：用地高辛标记禽呼肠孤病毒（ARV）S1基因中编码σ3蛋白的基因片段作为核酸探针，在斑点分子杂交中可检测到1.6pg的ARV RNA。利用该核酸探针，通过检测鸡羽毛囊及体内病毒繁殖情况，比较研究了 ARV感染后在鸡体内及鸡群中的传播动态。结果显示，ARV感染后在24小时时就可侵染大部分器官，并且很快传播到同群未攻毒的鸡中。羽毛囊中的病毒检出率与鸡内脏器官中病毒的检出率一致。该研究证明用核酸探针检测鸡羽毛囊中ARV的方法检测ARV的感染与流行情况，具有灵敏、特异性高，操作方便的特点，尤其适用于大量样品的同时检测。     

Partially carboxymethylated feather keratins. 2. Thermal and mechanical properties of films

Free cysteine thiol groups of keratin extracted from chicken feathers were partially carboxymethylated with iodoacetic acid (25-76% cysteine modification). Stable dispersions were used for the preparation of films by solution casting. Glycerol was used as a plasticizer (0.05-0.47 g/g of keratin), and films were stored at a constant relative humidity (20, 30, 50, 70, or 90%). The degree of crystallinity in the films was higher when more cysteine residues were carboxymethylated. The films displayed an optimum in mechanical properties at approximately 50% cysteine carboxymethylation. The tensile strength at this optimum was 25 MPa, the E modulus, 350 MPa, and the elongation at break, 50%. Probably, this optimum was the result of both a decreasing amount of disulfide bonds and an increasing degree of crystallinity for higher degrees of cysteine modification. The influences of a higher amount of glycerol and of different storage conditions on the mechanical properties of films from keratin with a defined degree of cysteine modification were also investigated.     

Control of lipid oxidation by nonmigratory active packaging films prepared by photoinitiated graft polymerization

Transition metal-promoted oxidation impacts the quality, shelf life, and nutrition of many packaged foods. Metal-chelating active packaging therefore offers a means to protect foods against oxidation. Herein, we report the development and characterization of nonmigratory metal-chelating active packaging. To prepare the films, carboxylic acids were grafted onto the surfaces of polypropylene films by photoinitiated graft polymerization of acrylic acid. Attenuated total reflectance/Fourier transform infrared spectroscopy, contact angle, scanning electron microscopy, and iron-chelating assay were used to characterize film properties. Graft polymerization yielded a carboxylic acid density of 68.67 ± 9.99 nmol per cm(2) film, with ferrous iron-chelating activity of 71.07 ± 12.95 nmol per cm(2). The functionalized films extended the lag phase of lipid oxidation in a soybean oil-in-water emulsion system from 2 to 9 days. The application of such nonmigratory active packaging films represents a promising approach to reduce additive use while maintaining food quality.     

原料鸡类型对鸡汤煲品质的影响

为探索不同生长速度的黄羽肉鸡品种差异对鸡汤风味的影响,筛选更适合煲汤的黄羽肉鸡,本研究以快速型三黄鸡、中速型三黄鸡和慢速型三黄鸡为原料,通过测定3种黄羽鸡肉的水分、灰分、蛋白含量及所熬制鸡汤的游离氨基酸含量、粘度、滋味和挥发性风味物质等指标,探究不同生长速度的黄羽肉鸡所熬制鸡汤的品质差异。结果表明,慢速型三黄鸡鸡肉中水分含量低、蛋白含量显著高于快速型和中速型三黄鸡(P<0.05);慢速型三黄鸡熬制鸡汤中的游离氨基酸含量和感官评定分值显著高于其他2种鸡汤(P<0.05)。综上,慢速型三黄鸡最适合加工成汤煲类产品。本研究结果为鸡汤的实际生产提供了理论基础和科学依据。     

Lead concentrations in bones and feathers of the globally threatened Spanish imperial eagle

Raptors that consume game species may ingest lead fragments or shot embedded in their prey’s flesh. Threatened Spanish imperial eagles Aquila adalberti feed on greylag geese in southern Spain in winter, and often ingest lead shot. We analysed bone and feather samples from 65 Spanish imperial eagle museum specimens collected between 1980 and 1999, to investigate the prevalence of elevated lead concentrations. Four of 34 birds (12%) had very elevated bone lead concentrations. All four birds were young and the concentrations were outliers to the distribution, suggesting probable exposure to lead gunshot. Excluding these elevated lead outliers, bone lead concentrations were correlated with the bird’s age at death. Three of 41 feathers (7%) had elevated lead concentrations, indicative of high exposure during feather formation. When these outliers were omitted, feather lead concentration was correlated with the age of museum specimens, suggesting that a high proportion of feather lead was exogenous, deposited after specimen collection. Therefore, careful interpretation of feather lead concentrations is required to separate endogenous and exogenous lead. We discuss the potential significance of lead poisoning in Spanish imperial eagles and other raptors, and recommend measures for its reduction.     

Removal of Hexavalent Chromium from Water by Polyurethane�CKeratin Hybrid Membranes

The feasibility of employing a porous polyurethane?Ckeratin hybrid membrane for the removal of hexavalent chromium was investigated. Keratin was extracted from chicken feathers and incorporated onto a synthetic polyurethane polymer to synthesize a hybrid membrane. Keratin supply active sites to bioadsorb Cr(VI) and polyurethane play an important role as the support to protein. Also, polyurethane?Ckeratin biofiber membranes were synthesized. Biofibers obtained from chicken feathers were modified to activate their surface. The effective pore in membranes is less than 50 nm, which places these materials in the mesopore range. Scanning electron microscopy (SEM) was used to study the morphology of membranes, and mechanical dynamical analysis (DMA) was used to evaluate the viscoelastic properties. NH, C=O, S?CS and C?CS were determined via Fourier-transform infrared (FTIR) analysis as functional groups of keratin, which participate in the linking sorption of hexavalent chromium. Adsorption of Cr(VI) was carried out in a filtering system at low contact time in continuous flux; the maximum removal reached was 38% at neutral pH of chromium solution. Results indicate that the isoelectric point of keratin is relevant in the adsorption process. pH of keratin solution above the isoelectric point brings about higher adsorption of heavy metals, whereas lower pH causes minor adsorptions, due to the functional groups?? ion charges. Based on the results, keratin extracted from feathers is a natural biosorbent that can be incorporated onto synthetic polymers to develop novel membranes and improve its applications in the heavy metal separation process.     

丙烯酸酯木塑复合材料增容剂的性能及应用

该文以含有双键官能团的硅氧烷和丙烯酸酯类为原料,通过自由基聚合方法,制备了丙烯酸酯类木塑增容剂,采用模压成型工艺制备了甘蔗渣/聚乙烯木塑复合材料,利用万能电子试验和冲击试验机测试其拉伸及冲击性能,结果表明,采用硅烷偶联剂KH-570和甲基丙烯酸缩水甘油酯等丙烯酸酯类的共聚物是较好的木塑复合材料增容剂,其共聚单体中引入的环氧基团可以和氨基硅烷偶联剂的氨基或纤维素中的羟基进行开环交联反应,使木粉纤维和丙烯酸酯类共聚物之间形成交联互贯网络,在甘蔗渣、增容剂和塑料之间形成均匀稳定的微观分散体系,降低了纤维素极性,     

Solid phase microextraction-gas chromatography for quantifying headspace hexanal above freeze-dried chicken myofibrils

A method using solid phase microextraction (SPME) combined with gas chromatography/mass spectrometry (GC/MS) was developed and used to determine the oxidation of freeze-dried chicken myofibrils spiked with methyl linoleate. Freeze-dried chicken myofibrils were found to act as a significant reservoir for hexanal. Recovery of hexanal emissions from the headspace above spiked myofibrils was 95% using a 5 min sampling time, with a total analysis time of approximately 12 min/sample. The SPME-GC/MS working linear response was from 0.01 to 10 mg hexanal/L (r( 2) = 0.995). Freeze-dried chicken myofibrils with added methyl linoleate (0.6 mmol/g of protein) were stored at 50 degrees C at water activities of 0.30 and 0.75 for 0, 12, 27, and 50 h. Lipid oxidation was determined using SPME-GC/MS to measure headspace hexanal concentration, the thiobarbituric acid reactive substances assay (TBARS) to quantify malonaldehyde, and a conjugated diene assay. Lipid oxidation was influenced by storage time and water activity. A strong correlation (r = 0.938) existed between SPME-GC/MS and TBARS. The use of SPME-GC/MS was a sensitive and rapid method for detecting hexanal as an indicator of lipid oxidation in chicken myofibrils.     

利用小麦秸秆制备的保水剂性能研究

[目的]以小麦秸秆纤维素接枝丙烯酸制备保水剂,并检测各因素对保水剂吸水性能的影响,探索制备保水剂的最佳反应条件,以期制备出成本低,降解性好,保水性高的新型保水剂。[方法]采用水溶液聚合法制备保水剂,并通过单因素试验和正交试验来确定最佳反应条件,对合成产物的吸液倍率、保水性能和表观形态进行测定与表征。[结果]温度为70℃,去离子水用量为160ml,2.0%N,N’-亚甲基双丙烯酰胺(MBAM)用量为9ml,引发剂(过硫酸钾:硫代硫酸钠=3∶1)与丙烯酸单体比为2.0%,丙烯酸中和度为70%,反应时间为1h,合成的保水剂具有较高的吸水或盐水倍率,1g保水剂吸0.9%NaCl溶液41.2g/g,吸去离子水430.9g/g。红外光谱分析和电镜扫描结果表明,保水剂胶体接枝聚合成功,胶体具有良好的表面形态。[结论]制备的保水剂吸液速率快、重复吸水效果较好。保水剂在氯化铁溶液中吸水倍率最高,达到113g/g。复合离子溶液中,在离子浓度为1g/L时吸水倍率最高达57g/g。     

纤维素-N-乙烯基吡咯烷酮辐射接枝共聚物的制备及其溶胀性研究

采用共辐射法制备了纤维素-N-乙烯基吡咯烷酮接枝共聚物Cell-g-NVP。考察了辐照剂量、去离子水用量和NVP/纤维素质量比对接枝率的影响。结果表明,在去离子水用量及NVP/纤维素质量比一定的情况下,接枝率随辐照剂量的增加而增加,并逐步达到平衡;在辐照剂量和NVP/纤维素质量比一定时,接枝率在去离子水用量为2ml时达到最大;在辐照剂量和去离子水用量一定时,接枝率随着NVP/纤维素质量比增加而增加,并逐步达到平衡;通过正交试验,得到制备接枝共聚物的最佳工艺条件为:辐照剂量8kGy,去离子水用量4ml,NVP/纤维素质量比4∶1,此时得到的接枝共聚物接枝率为354.8%。正交试验结果也表明NVP/纤维素质量比对接枝率影响最大,其次是辐照剂量。红外光谱表明接枝反应发生在NVP乙烯基部位,接枝共聚物保留了NVP的内酰胺结构;热重分析表明其热稳定性得到了增强;通过溶胀性研究表明接枝共聚物的溶胀性得到增强,且持水性较好。     

Modified arabinoxylan-based films. Part B. Grafting of omega-3 fatty acids by oxygen plasma and electron beam irradiation

Arabinoxylans (AXs) are byproducts of the cereal milling industry. To obtain high-value products, AXs have been used as a film-forming agent. Hence, AX-based films are poor water vapor barriers. The objectives of this study were to graft omega-3 (omega3) fatty acids onto AX polymeric chains by using two new technologies: cold plasma and electron beam (EB) irradiation. Results show that the surface hydrophobicity of the modified films is higher than that of a waxy coating or a low-density polyethylene (LDPE) film. In addition, FTIR spectroscopy analysis reveals vibration bands attributed to new chemical functions. Finally, a decrease in water vapor permeability (WVP) is obtained for the film treated with the alpha-linolenic acid-rich oil. This result could be explained by a better diffusion of this shorter polyunsaturated fatty acid into the AX network. Linseed oils provide better barrier properties and a higher surface hydrophobicity than oils extract from marine oils. Edible oils were chosen for edible application of these films to retard moisture transfers in stuffed biscuits.     

134Cs在鸡体内累积与代谢

本试验以鸡为研究对象,探明134Cs在鸡体内的累积与代谢情况,为减少放射性同位素污染及安全提供参考依据。结果表明：134Cs引入后能很快被鸡体吸收,并迅速转移到各内脏器官和组织中,6h放射性比活度在肝、肠、胰、心中积累较高,达到3210780±1560Bq～4568580±1860Bq ,血、肉、骨、毛中累积较少,在198480±360～198480±360Bq之间, 之后随着时间的延长,而逐渐降低。在24h时,组织中放射性比活度下降到6h时的30%左右。到第69d时除毛和肉中以外,其余器官和组织中均未能检测到放射性134Cs的存在。喂饲NaCl能减轻134Cs在鸡体内的积累。清水浸洗对鸡肉中134Cs清除效果明显。     

Degradation of Oestrogen and an Oestrogen-like Compound in Chicken Faeces by Bacteria

Oestrogen-like compounds with biological activities are commonly chemical additives, which have been added into chicken feed for years. Large amount of oestrogen and oestrogen-like compounds were also found in chicken faeces. We believe that such compounds are incorporated into agricultural products as faeces are used in food production process as fertilizer, and they will influence human health. Biodegradation is an environment-friendly, economical way to reduce environmental disruption by oestrogen. In order to degrade oestrogen, we chose 11 bacterial strains that could exhibit high degradation activity against steroid compounds. Oestradiol (E2) and ethynyloestradiol (an artificial oestradiol-like compound; EE2) in chicken faeces were degraded by the bacteria and were detected by high-performance liquid chromatography (HPLC). The results show that a mixture of oestrogen-degrading bacteria exhibited higher rate of degradation than each of the 11 bacteria did individually. Therefore, we cultured the mixture of 11 bacteria with chicken faeces. An oestrogen-like compound found in chicken feed and faeces could be also degraded by the bacteria.