黄原胶在低浓度时的流变特性及影响因素研究

以低浓度黄原胶溶液为研究对象,考察了其流变特性及浓度、温度、ｐＨ值和搅拌作用对溶液粘度的影响。结果表明当浓度≤１．１０８时,黄原胶溶液呈牛顿流体,浓度〉０．１０％时为假塑性流体;不同温度和浓度的黄原胶溶液粘度符合指数律流变方程ｒ＝ＫＤ＾ｎ;低浓度的黄原胶溶液在ｐＨ５．０～９．５范围,粘度不受ｐＨ值变化的影响,搅拌作用使黄原胶溶液的粘度提高。     

浅析影响尾气总管压力的各种因素

尾气总管压力的连续稳定控制,标志着整个纯碱生产线运行是否连续稳定,尾气压力频繁波动,不仅影响碳化反应,而且对设备也存在一定的破坏性,通过分析各类影响尾气总管压力的因素,得出有针对性的措施,从而提高碳化转化率,降低能耗,保证设备的连续稳定运行。     

帘式涂布幕帘稳定性影响因素研究

研究了帘式涂布中导杆、增稠剂、涂料固含量、颜料配比对幕帘稳定性的影响。结果表明,增加幕帘与导杆的结合力,可提高幕帘的稳定性;对于没有加入表面活性剂的涂料来说,未加聚乙烯醇(PVA)时的可操作最小流量为1.64 cm~2/s,PVA用量为1.5份时的可操作最小流量为3.07 cm~2/s;对于加入了表面活性剂的涂料来说,PVA用量为0.5份时的可操作最小流量为1.95 cm~2/s,PVA用量为1.5份时的可操作最小流量为1.55 cm~2/s;涂料固含量对幕帘稳定性影响有限;高岭土用量为20份时的可操作最小流量为1.92 cm~2/s,高岭土用量为40份时的可操作最小流量为2.24 cm~2/s。     

纸张涂料的流平过程分析和影响因素

本文从流变学上分析了涂料在纸面上的流平过程，计算出流平时间。计算表明不可能达到完全流平状态，并指出影响流平性的因素及流平性能测量和评价。     

影响钢帘线与橡胶粘合力的因素分析

影响钢帘线与橡胶粘合力的主要因素一是钢帘线的结构、镀层合金的组分和厚度、表面状态等；二是子午线轮胎生产的橡胶配方、结构设计和制造工艺。建议国家子午线轮胎及钢帘线技术主管部门和有关科研院所重视此课题的研究，制订钢帘线与橡胶粘合力的标准配方和试验方法，确定权威的仲裁机构。     

Factors Affecting the Protein Quality of Yogurt and Acidophilus Milk

The apparent protein digestibility in vivo, the protein digestibility in vitro, the net protein ratio, and computed protein efficiency ratio were used to assess the protein quality of yogurt and acidophilus milk as affected by heat treatment, direct acidification, addition of culture, or fermentation. Rats fed diets containing either heated mix or yogurt tended to eat more and gain more weight than rats fed diets containing either unheated mix or the acidified yogurt. Feed efficiency was also significantly higher for rats fed heated mix and yogurt. The apparent protein digestibility in vivo was significantly higher in yogurt diet than in the unheated yogurt mix diet. The net protein ratio of the yogurt diet was significantly higher than that of either the unheated mix or the acidified yogurt but not significantly different from the heated mix. The computed protein efficiency ratio values were also increased with both heating and fermentation. The direct acidified yogurt had a significantly lower net protein ratio and lower computed protein efficiency ratio than the fermented yogurt. Rats fed either sweet acidophilus (unfermented) or acidophilus milk exhibited a significantly higher protein digestibility than rats fed heated milk, indicating that the lactic culture may have a direct effect on protein digestibility. Despite their increased protein digestibilities, the acidophilus products did not display any significant increase in net protein ratio or computed protein efficiency ratio.     

Production of Soy Isolates by Ultrafiltration: Factors Affecting Yield and Composition

Water extracts of defatted soy flour were prepared by multiple extraction and centrifugation. Ultrafiltration of extracts in hollowfiber units showed significant deviation from ideal behavior for removal of nonprotein components, probably due to solute-solute and solute-membrane interactions. These interactions affected the retentate composition as well as the yield of protein. Membrane adsorption losses increased with feed concentration and were higher for the XM than for the PM series of membranes. A retentate washing step, such as the continuous diafiltration mode of operation, was necessary to produce a true protein isolate. Overall yield of protein was 86% of that in the defatted soy flour.     

多酚-蛋白质络合反应的影响因素研究

本实验根据游离蛋白质含量的变化，以其在595nm的波长下的吸光度为指标，研究多酚物质与蛋白质的络合起混反应。在研究影响多酚－蛋白质反应的各种因素中，发现温度，体系的pH值，有机溶剂乙醇，反应中多酚－蛋白质的比例等都对多酚－蛋白质络合物的生成量有一定的影响。在40℃，pH值为．5，乙醇浓度为6％，明胶与单宁酸的质量比例为5：1时，产生的多酚－蛋白质络合物的量最大。     

Factors Affecting the Functional Properties of Whey Protein Products: A Review

Numerous why protein products (WPP) have been developed as excellent food ingredients with unique functional properties. However, the functional properties of WPP are affected by several compositional and processing factors. Recently, novel processing technologies such as high hydrostatic pressure, ultrasound, extrusion and tribomechanical activation have been used to modify the functional properties of WPP. Also, WPP have been used as delivery systems for functional ingredients and in edible films. The present paper reviews the latest developments in the role of different factors on the functional properties of WPP with emphasis on novel processing technologies, and interaction with other food ingredients     

大豆蛋白凝胶制备及其影响因素的研究进展

大豆作为我国重要的粮食作物之一,具有较高的营养价值。凝胶性作为大豆分离蛋白重要的功能特性备受关注。大豆蛋白在产品中多用作多种配合物如水分子、糖类、脂质以及不稳定小分子活性物质的包埋载体,但大豆蛋白天然凝胶制品存在结构松散、成品率低等问题,极大地限制了其凝胶制品的应用与发展。本文从大豆分离蛋白凝胶形成机理进行解析,并对大豆蛋白构象及组成、多糖、脂质间的相互作用、离子强度等内在影响因素,以及物理、化学、生物等外部因素对凝胶形成产生的影响进行了深入探讨和系统分析,以期对今后大豆蛋白凝胶制品加工与利用提供理论依据。     

大豆分离蛋白功能性质及其影响因素

作为一种食品添加剂,大豆分离蛋白广泛应用于各种各样的食品体系中。大豆分离蛋白的成功应用在于它具有多种多样的功能性质,功能性质是大豆分离蛋白最为重要的理化性质,如凝胶性、乳化性、起泡性、粘度等。本文主要综述大豆分离蛋白功能性质,并简要概述影响大豆分离蛋白功能性质的主要因素。     

肉品中的蛋白质氧化机制及其影响因素

随着肉品加工技术的进步和人们生活方式的改变,丰富多样的加工肉制品越来越受到广大消费者青睐。但 加工肉制品的理化性质、营养成分和食用安全性易受各种加工及贮藏环境因素的作用而产生变化,如蛋白质氧化与 冷冻变性、脂质氧化、生物自身代谢、病原菌的滋生及致癌物产生等。其中蛋白质氧化对肉制品品质影响极大,它 被定义为一种共价键修饰作用,该作用对蛋白质分子结构造成破坏,引起蛋白质氨基酸侧链被修饰、蛋白质多肽 链的断裂、蛋白质分子间的交联聚合等,从而改变了蛋白质的凝胶、持水、消化、营养等特性,最终影响肉品的品 质。本文从蛋白质氧化机理、评估指标、影响因素等3 个方面出发,综述有关肉品蛋白质氧化的国内外最新研究进 展,归纳总结肉品中蛋白质氧化规律及其实际生产中的影响因素。     

黄铜镀层成份梯度对钢帘线与橡胶粘结力的影响

应用ＡＥＳ法对两步法镇黄铜工艺所得镀层成份进行了分析，并通过试验研究了不同镀层成份对钢帘线与橡胶的粘结规律。结果表明，在一定范围内，镀层成份梯度（变化）对钢帘线与橡胶粘结力有显著影响。     

盐法提取豌豆分离蛋白凝胶特性及影响因素

采用一种低变性的提取方法--盐法提取豌豆分离蛋白并使用流变仪测定其流变特性,结果表明：盐法豌豆分离蛋白最低凝胶形成质量浓度是5.5 g/100 mL,豌豆分离蛋白凝胶点与蛋白质量浓度无相关性。豌豆分离蛋白凝胶点随加热速率增加呈上升趋势。较高的加热和冷却速率能够增加反应终点储能模量（G’）和耗能模量（G”）值,因而降低凝胶强度。盐法豌豆分离蛋白凝胶韧性随蛋白质量浓度的增加而增大,且蛋白质量浓度与G’、G”值之间存在乘幂规律。tanδ值随蛋白质量浓度升高而降低,当蛋白质量浓度高于5 g/100 mL时,弱凝胶开始形成;当蛋白质量浓度高于7 g/100 mL时,tanδ值几乎保持恒定,表明凝胶弹性在此范围内基本恒定。比较盐法和商业豌豆分离蛋白凝胶性质后发现：盐法豌豆分离蛋白具有更好的凝胶性。     

Effects of Environmental Factors and Milk Protein Polymorphism on Composition of Casein Fraction in Bovine Milk

Test-day samples were collected from individual Holstein cows in 62 herds enrolled in the Quebec Dairy Herd Analysis Service. Samples were analyzed for protein, fat, casein, and serum protein content, somatic cell count, and relative percentages of α-, β-, and κ-casein and a-lactalbumin. Cows included in the study were phenotyped for the genetic variants of α_s1-, β-, and κ-casein. Unadjusted means for relative percentages of α_s-, β-, and κ-casein were 59.85, 31.23, and 8.93%, respectively. Least-squares analyses showed that month of test, stage of lactation, age of the cow, somatic cell count, and phenotype of the cow for β-casein contributed to variations in the relative percentages of α_s- and β-casein. Month of test, somatic cell count, and phenotype of the cow for κ-casein also had a significant effect on the relative percentage of κ-casein. When test-day milk yield; percentages of fat, protein, casein, and serum protein; casein to protein ratio; and relative percentage of α-lactalbumin were included in the model as covariates, only casein percentage did not have a significant effect on the relative percentages of α_s- and β- casein. For κ-casein, only fat percent was significant.     

不同黏度多糖阿拉伯胶和瓜尔胶对肌原纤维蛋白乳化性质的影响

选取两种分子质量相近、黏度相差较大的天然高分子多糖阿拉伯胶（arabic gum,AG）和瓜尔胶（guar gum,GG）分别与肌原纤维蛋白（myofibrillarprotein,MP）进行复合,研究不同多糖添加量（0.1%～0.5%）对MP-多糖复合物乳液性质的影响规律。结果表明,AG和GG均可以显著改善MP的乳化性质,其中AG对乳化活性的改善效果较好,而GG更有利于乳液的稳定性。随着多糖质量分数增加,乳化活性指数和稳定性指数均呈先升高后降低趋势,AG和GG添加量分别为0.3%和0.2%时,乳化活性指数和稳定性指数达到最大值。界面蛋白含量测定结果显示,AG和GG均会导致界面蛋白含量下降,尤其是GG的作用更明显。随着AG和GG添加量增加,乳液粒径逐渐减小,且尺寸分布更加均一,添加量超过0.3%后,GG组乳液出现少量絮凝现象。同一添加量下,GG组乳液粒径明显小于AG组。流变学分析证实,所有乳液均为假塑性流体,表现出弱凝胶性质。AG添加量较少（≤0.3%）时会降低乳液黏度,并明显提高乳液的储能模量,而GG的添加使乳液表观黏度和储能模量均显著提高,与AG相比,高黏度GG制备的乳液拥有更高的...     

Role of Fimbriae and Flagella in the Attachment of Salmonella typhimurium to Poultry Skin

The role of fimbriae and flagella in the mechanism of attachment of S. typhimurium to poultry skin was examined by using cells with (1) type 1 fimbriae (flagella present), (2) cells from which fimbriae and flagella were removed by physical means, (3) cells grown at 18°C which produced relatively thick, mannose-sensitive type 1 fimbriae only, and (4) cells grown in the presence of D-mannose which produced thin, mannose-resistent fimbriae. When broiler skin was immersed in the above cell suspensions, S. typhimurium cells adhered firmly and equally well in all instances except that fewer cells attached when grown in the presence of D-mannose. When fimbriated and nonfimbriated cells were spread on broiler skin, thus avoiding effects of water uptake, cells attached, but in lower numbers than when skin was immersed in a cell suspension. It was concluded that bacterial attachment to poultry skin is a complex phenomenon which involves mechanisms other than fimbriae, flagella or water uptake, though a combination of these and other factors may be involved.     

亚麻籽胶、黄原胶与大豆分离蛋白对肉制品出品率和质构特性的影响

利用三因素中心复合旋转试验设计的原理,研究亚麻籽胶、黄原胶、大豆分离蛋白添加对肉制品出品率和质构特性的影响。结果表明:亚麻籽胶、黄原胶、大豆分离蛋白的添加均能显著性提高猪肉肠出品率(P0.01),亚麻籽胶和大豆分离蛋白对出品率和黏着性有显著性交互作用(P0.05);大豆分离蛋白的添加使得产品的硬度显著性增加(P0.05);随着黄原胶和大豆分离蛋白的添加,猪肉肠的弹性不断下降,且二者之间有显著性交互作用(P0.05);随着亚麻籽胶的添加,猪肉肠的凝聚性呈极显著性下降趋势(P0.01),但是,随着黄原胶和大豆分离蛋白的添加,凝聚性不断增加,且二者之间有显著性交互作用(P0.05);亚麻籽胶、黄原胶、大豆分离蛋白对猪肉肠的咀嚼性没有显著性影响。     

鸡蛋蛋白质凝胶特性影响因素的研究进展

为了进一步了解不同因素对鸡蛋蛋白质凝胶特性的影响,国内外研究者已经针对性的进行了大量的研究工作.本文综合论述了鸡蛋中蛋白质的组成和凝胶的形成机理,分析了温度、压力、pH、酶、盐、蛋白质浓度、处理时间等因素对鸡蛋蛋白质凝胶特性的影响,其中温度、压力、pH、盐、处理时间几个因素对鸡蛋蛋白质凝胶特性的影响研究已较为全面,但生...     

Xanthan Gum Effects on Solubility and Emulsification Properties of Soy Protein Isolate

The effect of xanthan gum (XG) on solubility and emulsifying properties of soy protein isolate (SPI) was evaluated. The solubility of SPI was increased by addition of XG (p < 0.05). The emulsifying activity of SPI-XG was 4 times higher than that of SPI or XG alone (p < 0.05) and similar to that of bovine serum albumin (BSA) (P > 0.05). The emulsifying stability of SPI-XG dispersions was respectively 3 and 2 times higher than that of SPI and BSA (p < 0.05). The solubility and emulsifying properties of SPI-XG dispersions were stable over a wide range of pH (3.0 to 9.0), ionic strength (0.1 to 1.0M NaCl), and heat (85°C, 1 hr).