A Method for the Quantitative Evaluation of Emulsion Stability in Coffee Whiteners

A method is described for quantitatively measuring the extent of emulsion destabilization (feathering) when liquid coffee whiteners are added to hot coffee. Coffee whitener is added to standard hot coffee solution (pH 4.9, 90°C) in a 0.5% fat Babcock bottle. Feathering is observed on the surface of the whitened coffee in the wide portion of the bottle. Dense corn syrup solution is layered beneath to raise the level of the surface so that the coagulated material is concentrated into the graduated capillary tube. After standing to allow compaction, the length of the column of coagulated material is measured.     

透射光浊度法对食品油脂乳状液稳定性的快速测定

采用透射光浊度法研究食品油脂乳状液的粒径大小、分布与其稳定性的关系,并且与激光粒度仪法、离心分析法等方法进行比较分析。结果表明：透射光浊度法与激光粒度仪法测定结果基本一致,可见,透射光浊度法是一种简便、可靠的预测乳状液稳定性的方法。     

二十二碳六烯酸微藻油乳状液稳定性的测定方法和影响因素

以二十二碳六烯酸（docosahexaenoic acid,DHA）微藻油微胶囊化过程中形成的乳状液为研究对象,探究乳状液稳定性的测定方法和影响因素。通过比较3 种不同乳状液稳定性测定方法以及显微镜观察发现：采用0.1 g/100 mL十二烷基硫酸钠溶液对乳状液进行稀释,检测乳状液形成24 h在600 nm波长处透光率的变化可以方便、准确地衡量其稳定性。壁材组成、芯材比例和总固形物质量分数都能够明显影响乳状液稳定性,从而影响微胶囊产品品质。当壁材中辛烯基琥珀酸酯化淀粉与麦芽糊精的质量比在2∶3、DHA微藻油质量分数在20%、总固形物质量分数在33%以下时,制备得到的DHA微胶囊产品的品质较高,且能够满足SC/T 3505—2006《鱼油微胶囊》规定。微胶囊化后DHA微藻油的贮存稳定期得到明显延长。     

Evaluation of Emulsion Stability by Centrifugation with Conductivity Measurements

An industry problem when evaluating stability of emulsions is lack of a method reproducing, in a short time, aging of the emulsion. A method that combines centrifugation and conductivity measurements could be used for this purpose. Centrifugation accelerates destabilization of the product and thus simulates aging. Conductivity measurement of the aqueous phase, a function of the oil concentration, evaluates destabilization. Our method was compared with a creaming-measurement method based on fat content. The increase in conductivity was representative of the creaming rate, with correlation higher than 0.93. The combined method, applied to different oil-in-water (O/W) emulsions, enables following stability during aging and assures the need of industry for a fast, easy method to evaluate emulsion stability.     

A Rapid Method for the Analysis of Starch

A rapid enzymic method for starch analysis, especially in cereal products, is presented. One person can analyze 30 samples per day. The method includes a 15 min gelatinization step in a boiling water bath in the presence of a thermostable α-amylase, a 30 min amyloglucosidase incubation of a subsample, and subsequent determination of glucose with a glucose oxidase/peroxidase reagent. The method was evaluated by analysis of the starch content in various raw and industrially processed wheat samples. The method showed high precision (CV=0.6–1.0%) and accuracy. Some factors which might affect the enzymic availability of starch and thus its recovery in the analysis are evaluated and discussed.     

总黄酮含量分析法快速评价蜂胶原料质量

采用亚硝酸钠—硝酸铝分光光度法测定蜂胶原料中的总黄酮,检测结果(Y)与重量法测得的蜂胶含量(X)之间存在显著的相关关系,相关系数r=0.9134,回归方程:Y=1.2109X 5.0418蜂胶的检出限为0.762μg/mL,在黄酮含量30％及6％的加标水平下,回收率分别为97.7％及99.6％。从而为蜂胶原料的质量评定建立了一种快速、灵敏、准确的检验方法。     

壳聚糖W/O型乳状液的超声辅助制备及其稳定性

以非牛顿假塑性大分子壳聚糖溶液为水相,棕榈油为油相,Span-80为乳化剂,采用单因素试验及响应面试验优化超声协助制备W/O型乳液工艺,并考察优化条件下制备的乳液稳定性.结果表明:内水相含量是影响乳液粒度大小的关键因素,且超声功率对乳液的粒度及其分布存在过处理现象.优化工艺为超声功率300 W、超声时间15 min、内...     

香料乳状液的稳定性研究

香料在乳状液中因明胶(成膜材料)所形成的保护性包膜而增强稳定性.影响乳状液稳定的因素有乳化剂浓度、乳化温度以及明胶浓度等.正交试验结果表明,香料乳状液稳定的优化条件是乳化剂浓度0.3%～0.4%、乳化温度60℃、明胶(成膜材料)浓度4.0%～5.0%.     

加脂剂乳化稳定性的探讨

本文从表面化学的角度讨论了维持及影响加脂剂乳液稳定性的因素。界面张力、油水之间的界面有蓦 及乳液颗粒所速 电荷是维持加脂剂乳液稳定性的主要因素;而加脂剂的乳化成分及其复配、水的硬度、pH值、中性盐和温度则会影响乳液的稳定.     

一种快速鉴定细菌的方法

16S rDNA基因同源性分析是一种常用的细菌分子鉴定方法,16S rDNA基因的扩增需要细菌染色体DNA作为模板。传统的细菌染色体DNA提取方法费时费力,限制了细菌分子鉴定的规模化。文中建立了1种新的快速高效的细菌染色体DNA提取方法,整个提取过程仅耗时20min,从而使得细菌的快速鉴定成为可能。用该方法制备的染色体DNA无需任何处理即可作为模板用于PCR扩增细菌的16S rDNA基因,并获得了良好的扩增结果以及扩增产物的测序结果。     

高乳化稳定性小米淀粉Pickering乳液的制备

淀粉基Pickering乳液在食品、医药、化妆品等领域的研究日益广泛。为获得高乳化稳定性淀粉基Pickering乳液,作者采用超声辅助辛烯基琥珀酸化、球磨处理改性小米淀粉,通过测定取代度、水解度、特征官能团、结晶结构、微观形貌、粒径及乳化指数等指标,研究了小米淀粉乳化能力及影响其稳定性的因素。结果表明,超声处理提高了小米淀粉酯化反应效率和取代度,OSA基团主要接枝在小米淀粉无定形区,少量进入了结晶区;球磨破坏了OSA小米淀粉的颗粒形态和晶体结构;随着球磨时间和OSA小米淀粉添加量的增加,OSA小米淀粉形成Pickering乳液的能力和乳化稳定性显著增加。超声辅助辛烯基琥珀酸化结合球磨处理是一种制备高乳化稳定性淀粉基Pickering乳液的有效方法,有助于拓展淀粉资源在Pickering乳液领域的开发利用。     

小议AKD乳液的稳定性

ＡＫＤ（ＡｌｋｙｌＫｅｔｅｎｅＤｉｍｅｒ,烷基烯酮二聚体）是近年得到迅速发展的一种高效中碱性造纸施胶剂,由于其性能优异与高的反应活性而在造纸行业倍受青睐。但同时也因为它的活性太高而造成了应用上的许多问题,如贮存时间不能太长,贮存与使用温度也不能太高,其中,最受关注的是ＡＫＤ乳液的稳定性。本文就乳化剂的选择与影响ＡＫＤ乳液的稳定性有关内容作简单介绍。１ＡＫＤ的施胶机理众所周知,ＡＫＤ可与纤维表面的纤维素链上的ＯＨ反应:再异构化为酮式结构,称为β酮酸纤维素酯,Ｒ和Ｒ′两个疏水基均朝外,从而达到使纸页抗水的目的…     

一种酵母快速批量分子鉴定方法

26S rDNA D1/D2区域序列同源性分析是一种常用的酵母分子鉴定方法。D1/D2区域序列的扩增需要酵母染色体DNA作为模板,目前常用的酵母染色体DNA提取方法繁琐耗时且难以进行批量操作,限制了酵母分子鉴定的规模化。研究中建立了一种快速高效的批量酵母染色体DNA提取方法,整个提取过程仅耗时20min,从而使得酵母大规模快速分子鉴定成为可能。用该方法制备的染色体DNA不需要任何后续处理即可作为模板用于扩增酵母的26S rDNA D1/D2区域序列,获得了良好的扩增结果以及扩增产物的测序结果。     

鱼油乳液的稳定性

报道了一种鱼油乳液的制取工艺 ,采用混合乳化剂和乳粉可制得乳化稳定性较好的鱼油乳液 .考察了β CD和茶多酚对抑制鱼油腥味及提高鱼油乳化液氧化稳定性的效果     

纸浆白度的快速测定方法

基于浆料水分、湿压片、定量和玻璃片等因素对纸浆白度测定值的影响,提出了一种纸浆白度的快速测定方法。结果表明,当浆料水分含量超过60%时,水分含量对湿浆片的白度测定值产生较大影响;湿浆压片处理使湿浆白度测定值略有下降,但是可显著提高湿浆白度测定的重现性;定量对纸浆白度的测定值没有影响;玻璃片对湿浆白度测定值产生的影响是恒定的。通过对白度在30%～90%范围内不同种类浆料的湿浆白度与其风干浆片和纸片白度测定值进行测定比较,发现它们之间存在很好的线性相关,可分别由校正模型y=98.1x-101(R2=0.9798)和y=89.1x-82.5(R2=0.9889)来描述和计算。该方法简单、重现性和准确性好,适用于生产过程中对纸浆白度的快速测定。     

A Simplified and Rapid Method to Uniformly Size Rib Steak Pieces for Taste Panel Evaluation

SUMMARY: Uniformity of size and preparation of steak samples are important prerequisites for accurate taste panel analysis. A system is described to utilize a Broiling and Sectioning Apparatus (BSA) to obtain this uniformity. Frozen beef rib steaks are uniformly sized before broiling and then sectioned into bite-size pieces for presentation to a taste panel.     

Evaluation of Process Parameters in the O/W/O Multiple Emulsion Method for Flavor Encapsulation

ABSTRACT: The multiple emulsion/cold dehydration method was developed for the flavor encapsulation. The effects of various process parameters on the emulsion stability and flavor retention were investigated. Microfluidizer (at 68 MPa) produced more stable emulsion with small uniform droplets than pressure-homogenizer. Increasing the gum arabic content created a highly viscous emulsion, which resulted in a stable O/W emulsion. The stability of an O/W/O multiple emulsion was highly affected by the type of emulsifiers and the most stable emulsion was prepared using the blend of Span 80 and PGPR. Well-formed microcapsules having high flavor retention (71%) was obtained when ethanol/water mixture solution of 9:1 was used as a dehydrating agent.     

A Method for the Measurement of Foam Formation and Stability

A whipping method for the measurement of overrun and foam stability was developed. Using this method the characteristic foams formed by the following proteins were studied: sodium caseinate, milk protein isolate and whey protein. The method was able to detect differences between foams produced by different proteins. The effects of copper sulfate and proteose-peptone on egg white foams were studied to show the reliability of the method. It was demonstrated that the addition of ImM copper sulfate stabilized (p < 0.05) foams made from both fresh and powdered egg white. Addition of proteose-peptone (0.05% and 0.1%) reduced the overrun and destabilized egg white foams.