联合冲击破碎、浮选和酸处理禽蛋壳膜提取方法的研究

以蛋膜的最大提取得率为目的,采用冲击破碎、浮选和低浓度酸处理的联合处理方法分离蛋壳与蛋膜来获得纯蛋壳膜。在蛋壳含水量为6.5%时用万能粉碎机粉碎10s后,通过80目筛面的细粉直接按纯蛋壳粉收集,筛上物经水中浮选分离,最终蛋膜的得率达到2.20%(折合蛋白膜回收率为90.5%),此时钙残留率为3.30%。再选择低浓度盐酸脱除蛋膜中的残留蛋壳。通过正交实验确定最佳脱钙条件为:盐酸浓度为0.4mol/L,料液比为1:20,反应时间为15min,在该条件下脱钙率达到94.51%。该法操作简单,成本低廉,且提取的蛋膜纯度较高。     

一种禽蛋壳膜高效分离新方法

一种机械辗压 酸处理联合高效分离蛋壳壳膜的新方法.利用禽蛋石灰壳脆性好、蛋壳膜韧性强的特点,在合适的水分下,通过机械碾压、水中筛选,初步分离壳膜;再经稀酸处理,分离黏附在粗级蛋壳膜上的少量石灰壳,实现壳膜完全分离.结果表明,相对于现有方法,机械碾压 酸处理联合分选法最大程度保留了石灰壳及蛋壳膜原有的结构、成分与性质,酸用量大大减少,蛋壳膜回收率大大提高,达 79.0%,膜中钙残存量小于 0.29%.石灰壳回收率达 93%.石灰壳中膜残存量小于0.48%.该法可望用于大规模分离蛋壳膜和处理石灰壳.     

多孔辊筒紧密纺三维流场的数值模拟

通过建立流体动力学模型,对多孔辊筒紧密纺纱系统集聚区流场进行模拟,分析槽宽、内胆负压、导流块对集聚区流场运动的影响。研究表明：多孔辊筒紧密纺纱系统是利用负压效应来产生集聚气流;内胆空气负压小时,抽气管出口速度大;吸风斜槽不同宽度和不同负压对气流集聚产生不同的集聚效果;紧密纺纱装置有导流块比无导流块的集聚效果好。经对比,数值模拟和实验结果得到了比较一致的结论,为气流聚集型纺纱装置的应用提供了可靠的理论依据。     

络筒机筒纱吸嘴吸头成功率的研究

从纺纱品种、络筒工艺、机械结构、动作逻辑等方面对影响络筒机筒纱吸嘴吸头成功率的问题进行分析与探讨,提出了加大风机负压、增大支臂平衡气压、筒纱吸嘴点动吸纱、减少启动切纱并优化启动切纱吸头逻辑、优化钢梳齿形、磨砂处理钢梳背面和优化槽筒正反转程序等提高一次吸头成功率的有效措施,以提高棉纺厂的生产效率、提高筒纱质量、大幅降低挡车工的劳动强度。     

食疗健康广场

红蛋染料染鸡蛋,害处多多？很多地方都有喜事吃红蛋的习俗。然而,从卫生保健的角度来看,用化学染料染鸡蛋是有很多害处的目前市售的红色染料,几乎都是芳香族硝基、氨基化合物或其衍生物,其中含有未、萘、苯胺等有毒有害物质。用此类红色染料来染蛋,会危害人体健康：蛋壳上有缝隙,染料中的有毒物质就会渗入蛋内;双手在剥蛋壳和蛋膜时,也极易污染;即使蛋壳不破,煮蛋时水沸腾了,蛋壳和蛋膜的通透性增加,有毒物质也会渗入蛋内;老将蛋煮熟后出锅染红,由于蛋的温度很高,其壳、膜的通透性与在锅内并无多大的差异,污染同样不可避免…     

蛋壳膜的分离及应用初探

蛋壳膜中含有与人皮肤弹性有关的角蛋白及构成胶原蛋白的羟脯氨酸。加入蛋壳膜水解液的化妆品,可以使肌肤显得细腻光滑,有弹性。以废弃的鸡蛋壳为原料,利用12m ol/L浓盐酸进行壳膜分离,得到的蛋壳膜在碱溶液中水解为15%的蛋壳膜水解液,将其脱色、脱味后在化妆品的生产上进行应用初探。     

用声学相位法检测裂纹蛋

裂纹蛋俗称哑子蛋,当食用蛋的蛋壳上存在裂纹时,蛋壳声音发哑,同时外界污染能透过裂隙侵入、使得蛋品不易保存。因此蛋品加工厂在提供市销、出口以及制作松花蛋和咸蛋之前,都需要把裂纹蛋剔除。我国至今一直是靠人工倾听蛋壳互相撞击的声音,来判别是否     

鸡蛋壳暗斑成因

通过对正常鸡蛋壳及暗斑鸡蛋壳中暗斑部、无斑部石灰质硬蛋壳的硬度、厚度、水分和蛋白质含量,以及壳下膜厚度、蛋白质含量进行测定,并结合其超微结构比较分析,对鸡蛋壳暗斑的产生原因进行初步探索。结果表明:与无斑组、正常组相比较,暗斑组的石灰质硬蛋壳硬度最小,含水量最大,差异极显著(P0.01),而无斑组和正常组无差别;3组之间石灰质硬蛋壳厚度没有差异,但暗斑组壳下膜厚度极显著低于无斑组和正常组(P0.01),无斑组壳下膜厚度显著低于正常组(P0.05);石灰质硬蛋壳的蛋白质含量无显著差异(P0.05),而暗斑蛋壳下膜蛋白质含量极显著低于正常蛋(P0.01)。经扫描电镜对石灰质硬蛋壳的断面、内外表面及壳下膜的内外表面观察发现,与无斑组及正常组相比较,暗斑组的石灰质硬蛋壳及壳下膜整体表现出明显的质地疏松,且孔隙较多。通过对检测指标及超微结构图像的综合分析,初步判断鸡蛋壳暗斑的形成是由于壳下膜在暗斑位置厚度较薄,网孔较大,致使蛋内水分更易通过该膜渗透进入石灰质硬蛋壳,进而被石灰质硬蛋壳中该部分较多的缝隙所容纳,从而在宏观上形成暗斑。     

导流筒对搅拌槽流场的影响

为研究导流筒对搅拌槽内流场的影响,应用数值计算方法,对搅拌槽内流场进行数值模拟。通过对有、无导流筒的搅拌槽内流场和速度的对比分析表明：导流筒强化了搅拌槽内上下液体的整体轴向流动,在近浆区域改善了液体的跟转,有强烈的混合效果,并且,在较为理想的流场分布下,有导流筒的搅拌槽功率消耗比无导流筒搅拌槽节省12％,其结果将为搅拌槽的整体结构优化提供有效途径。     

基于CFD的喷气织机辅助喷嘴流场分析

 为了研究辅助喷嘴的流场性质,本文建立了喷气织机辅助喷嘴流场的三维模型,利用计算流体动力学(CFD)分析软件Fluent对辅助喷嘴流场的三维模型进行了数值模拟,得到了供气压力为0.28MPa条件下辅助喷嘴出口实际流速中心线上的速度分布曲线、压力分布曲线以及不同供气压力条件下辅助喷嘴出口的速度分布曲线。计算结果表明：供气压力为0.28MPa时,辅助喷嘴出口最大风速高达404m/s,在辅助喷嘴出口出现了负压区;随着供气压力的增加,辅助喷嘴出口风速逐渐增大,供气压力每增加0.1MPa,出口风速约增加50m/s。最后,通过与相关文献实验值的比较,证明了数值模拟方法和实验方法分析辅助喷嘴流场的一致性。     

鸡蛋壳、壳下膜分离工艺优化

为了开发利用鸡蛋壳和蛋壳膜,首先必须使二者分离。本文采用机械粉碎、水浮选和稀酸处理相结合的方法进行壳膜分离,筛选了鸡蛋壳、壳下膜分离的条件;通过单因素实验考察盐酸体积、反应时间、盐酸浓度对蛋壳膜脱钙率的影响,并采用响应面分析方法,对稀盐酸除蛋壳膜中残留蛋壳的工艺条件进行优化。结果表明：鸡蛋壳在粉碎机运行5 s/次、粉碎3次的条件下壳膜分离效果最佳,出粉率58.72%,脱膜率87.91%,综合得分72.91;用盐酸去除蛋壳膜中残留蛋壳的最佳工艺条件为粗蛋壳膜1 g时,使用盐酸体积20 mL、反应时间19 min、盐酸浓度0.5 mol/L,此时脱钙率可达89.21%。该工艺为鸡蛋壳的精深加工提供技术支撑。     

对蛋壳膜中角蛋白与胶原蛋白的提取分离技术及功能多肽的概述

中国是世界第一禽蛋生产和消费大国。随着人们对鸡蛋消费量的增加以及鸡蛋的集中加工使得大量蛋壳堆积与丢弃,这不仅对环境造成了严重的污染,也是资源上的极度浪费,对蛋壳的资源化利用具有极其重要的意义。国内外对蛋壳的资源化利用甚多,而对蛋壳膜的利用则相对较少。事实上,蛋壳膜是蛋白和多肽等的潜在资源,具有十分可观的应用价值。为此本文概述了蛋壳膜这一具有高附加值的生物膜,并对其内在的角蛋白与胶原蛋白及其生物活性肽进行了相应的介绍,着重强调了其提取分离的方法。旨在为开发利用鸡蛋壳膜这一丰富的资源提供科学的理论依据。     

扁杏仁水解蛋白的喷雾干燥及其抗氧化活性

通过响应面设计方法探讨减压浓缩脱水比例、进风温度和进料速度等喷雾干燥工艺参数对扁杏仁水解蛋白溶液干燥效果及水解蛋白粉抗氧化活性的影响,获得表征相关指标的数学模型,在实践过程中可以对相关指标进行预测。扁杏仁水解蛋白粉具有一定的抗氧化活性,但受到喷雾干燥工艺参数的影响,通过SAS统计分析软件对相关指标进行优化,并进行验证实验,总体而言,脱水比例在0.5～0.6之间,进风温度200℃左右,进料速度在270～320mL/h,可以获得较好的综合效果。     

Eggshell factors influencing eggshell penetration and whole egg contamination by different bacteria, including Salmonella enteritidis

Trans-shell infection routes and whole egg contamination of 7 selected bacterial strains; Staphylococcus warneri, Acinetobacter baumannii, Alcaligenes sp., Serratia marcescens, Carnobacterium sp., Pseudomonas sp. and Salmonella enteritidis, recovered from egg contents, were studied. The first objective was to correlate bacterial eggshell penetration with various eggshell characteristics and bacterial strains. An agar approach was used to assess the eggshell penetration. The second objective was to assess the contamination of whole eggs with the bacterial strains; whole intact eggs were used in this case. The intact shells of agar-filled and whole eggs were inoculated with 10(3) -10(4) cfu of the selected strains. During 3 weeks storage at 20 degrees C and 60% relative humidity, the bacterial eggshell penetration was regularly monitored. The whole egg contamination was only analyzed after 3 weeks. The eggshell characteristics such as area eggshell, shell thickness and number of pores did not influence the bacterial eggshell penetration. For each individual bacterial strain the mean cuticle deposition was lower for penetrated compared to non-penetrated eggshells. For the individual strain Carnobacterium sp. and for the global results of all strains this difference was statistical significantly. The whole egg contamination was not influenced by neither the area of the eggshell nor the porosity of the eggshell. The results of the agar approach indicate that the Gram-negative, motile and non-clustering bacteria penetrated the eggshell most frequently; Pseudomonas sp. (60%) and Alcaligenes sp. (58%) were primary invaders followed by S. enteritidis (43%). All selected strains were able to penetrate; penetration was observed most frequently after ca. 4-5 days. Particularly S. enteritidis was a primary invader of whole eggs: the membranes and/or the content of 32% of the whole eggs was contaminated. The remaining bacterial eggshell contamination with the selected strain was determined after 3 weeks storage. Penetrated eggshells and contaminated whole eggs showed a significantly higher bacterial contamination on the eggshell compared to non-penetrated eggshells and non-contaminated whole eggs respectively (global results of all strains). The influence of hen age on bacterial eggshell penetration and egg content contamination was not significant. While the agar approach is suitable to study the influence of the eggshell characteristics on the bacterial eggshell penetration, the intact egg approach gives an estimation of the penetration of the shell followed by the probability of survival and migration in whole eggs.     

超声波法制备蛋壳柠檬酸钙的工艺研究

为充分利用鸡蛋壳丰富的钙资源,通过单因素与三元正交多项式回归设计相结合的研究方法,构建出超声波法高效制备蛋壳柠檬酸钙的三元正交多项式回归模型,并优化出最佳工艺条件为：蛋壳粉颗粒细度180 目、料液比1:60、超声功率700W、超声时间25min、柠檬酸与蛋壳粉的质量比2:1、柠檬酸钙得率可达90.83%。超声波法与传统方法相比,不但提高了蛋壳柠檬酸钙产品得率,而且还克服了柠檬酸钙在制备过程中的凝聚沉淀现象。     

禽蛋表面细菌污染及影响因素的调查分析

目的检测养殖场的禽蛋受细菌污染的情况,调查分析禽蛋表面细菌污染的主要影响因素。方法根据GB 4789.2-2010食品安全国家标准食品微生物学检验菌落总数测定对饲养场的蛋壳表面、饲料、垫草中的细菌菌落总数进行测定,采用沉降法测定饲养场空气中的细菌数,并进行统计分析。结果饲养场鸡蛋和鸭蛋表面的细菌菌落总数分别达到4~6和6~7个数量级,且饲养场的空气、饲料以及垫草中的细菌数越多,从蛋壳表面检测出来的细菌数也越多。结论养殖场的禽蛋均受到不同程度的细菌污染,且饲养场的空气、饲料、垫草是造成禽蛋表面细菌污染的主要原因,禽蛋生产过程中卫生管理非常重要。     

枯草芽孢杆菌Prob1822喷雾干燥制备益生菌粉工艺优化

为优化枯草芽孢杆菌喷雾干燥工艺参数,以菌体存活率为评价指标,利用单因素实验研究了保护剂用量、入口温度、进料速率、进风量和出口温度对菌体存活率的影响。结果表明,进料速率、进风量和出口温度为重要因素;采用中心复合响应面优化技术研究了进料速率(X₁)、进风量(X₂)、出口温度(X₃)对菌体存活率的影响并构建了多元非线性回归方程;方差与回归分析表明,进料速率(X₁)与进风量(X₂)影响不显著(P>0.05),出口温度(X₃)影响极显著(P<0.01)。喷雾干燥最优参数为进料速率600 mL/h,进风量80 m3/h和出口温度52℃,优化条件下验证试验结果为96.64%±1.43%,与模型预测值基本一致。试验结果表明,热诱激预处理和复合抗热保护剂的使用可提高菌体热耐受性,显著提高喷雾干燥后菌体存活率,研究结果可为枯草芽孢杆菌的喷雾干燥提供理论支持。     

Automatic Identification of Defects on Eggshell Through a Multispectral Vision System

The objective of this research was to develop an off-line artificial vision system to automatically detect defective eggshells, i.e., dirty or cracked eggshells, by employing multispectral images with the final purpose of adapting the system to an on-line grading machine. In particular, this work was focused on studying the feasibility of identifying organic stains on brown eggshells (dirty eggshell) caused by blood, feathers, feces, etc., from natural stains caused by deposits of pigments on the outer layer of clean eggshells. During the analysis, a total of 384 eggs were evaluated (clean, 148; dirty, 236). Dirty samples were evaluated visually in order to classify them according to the kind of defect (blood, feathers, and white, clear or dark feces), and clean eggshells were classified on the basis of the color of the natural stains (clear or dark). For each sample, digital images were acquired by employing a charged coupled device camera endowed with 15 monochromatic filters (440?C940?nm). A Matlab? function was developed in order to automate the process and analyze images with the aim to classify samples as clean or dirty. The program was constituted by three major steps: first, the research of an opportune combination of monochromatic images in order to isolate the eggshell from the background; second, the detection of the dirt stains; third, the classification of the image samples into the dirty or clean group on the basis of the geometric characteristics of the stains (area in pixel). The proposed classification algorithm was able to correctly classify nearly 98% of the samples with a very low processing time (0.05?s). The robustness of the proposed classification was observed applying an external validation to a second set of samples (n?=?178), obtaining a similar percentage of correctly classified samples (97%).     

自吸式管道泵研发和应用

介绍自吸式管道泵的设计并给出结构图。设计中应注意:(1)贮水箱顶部距蓄水槽液面高度不大于10m。(2)贮水箱内贮存的液体至少是启动前入水管道内空腔体积的6倍。(3)吸水管上口应与贮水箱的上面板连接,管头插入不要超出面板。(4)必须保证吸水液面至管道泵的出水口空腔的气密性。(5)管道泵的出水口必须高于贮水箱的上面板。(6)在贮水箱上面板加装进水管,水满后关闭阀门才能启动管道泵。(7)通过改变出口管道上的调节阀门开口调节管道泵电机的电流。实际运行表明:自吸式管道泵启动时不会出现气缚现象,使用故障少,适用于各行业的液体提升。