脂肪球在搅打乳状液中的部分聚结及其作用

综述了脂肪球在搅打乳状液中的部分聚结现象和搅打条件、脂肪种类、脂肪球吸附膜对部分聚结的影响。以冰淇淋和搅打奶油为例 ,说明脂肪球的部分聚结对于搅打乳状液最终形成充气的泡沫结构起关键作用 ,控制脂肪球的部分聚结程度对于改善搅打乳制品的质量、性能具有重要意义。联系控制脂肪球的部分聚结在冰淇淋生产中的实际应用 ,介绍了近来国际上有关脂肪球部分聚结的研究进展。     

稻谷脂肪酸值测定结果的影响因素探讨

在认真执行GB/T 20569—2006《稻谷储存品质判定规则》附录A《稻谷脂肪酸值测定方法》标准的基础上,结合实践经验,从试样接收、制备、样品准备、检测等各个方面,全面、系统地分析了对稻谷脂肪酸值测定结果的影响因素及影响的机理和规律,提出了准确测定稻谷脂肪酸值的措施和建议。     

光度滴定法同时测定酱油中游离酸和游离氨基氮的研究

本文设计了简便可行的光度滴定装置，探讨了光度滴定法同时测定酱油中游离酸和游离氨基氮的测定条件。结果表明，此法操作简便、快速，有良好的重现性和精密度。用该法不酱油中的游离酸和游离氨基氮，取得了回收率分别为９９．４％￣１０３％和９７．３％￣１０１％，变动系数分别为２．２％￣２．８％和０．３９％￣１．４％的良好效果。经ｔ经验，用本方法测定酱油中游离酸和游离氨基氮不引起系统误差，并且测定结果与我国国家标准     

红葡萄酒中合成色素的测定研究

建立了HPLC测定红葡萄酒中色素柠檬黄、苋菜红、日落黄、胭脂红含量的方法,采用色谱柱:THERMO C18(4.6 mm×250 mm,5μm),检测波长:254 nm,流量:1.0 mL/min,进样量:10μL,流动相:0.02 mol/L乙酸铵与甲醇。梯度条件为:甲醇20%~35%,3%/min;35%~98%,9%/min;98%继续6 min。结果表明:柠檬黄、苋菜红、胭脂红、日落黄在0~50μg/mL范围内呈现良好的线性关系,Y=30 264 440X+3 047.2(R=0.999 8)、Y=29 741 606.67X+607.03(R=0.999 8)、Y=28 790 266.67-6 523.42(R=0.999 8)、Y=25 122 776.67X+1 953.58(R=0.999 8)。色素在24 h内稳定。本方法简单,快速、准确、重现性好,可以用作葡萄酒中色素的含量测定。     

改进测定饮料中合成色素的方法

改进测定饮料中合成色素的方法四川省产品质量监督检验所周晓群随着科学，尤其是毒理学的发展，人们已发现某些合成色素有慢性毒性和致癌性，因此，各国都严格控制其使用范围和使用量，着色剂指标已成为饮料类产品质量检验的强制性必测项目之一。目前，对于色素的检测方法...     

食品中脂肪测定国家标准方法的改良应用

本文主要对《食品安全国家标准食品中脂肪的测定》（GB 5009.6—2016）第一法、第二法、第三法作出优化和改进。改良后的方法测定结果准确,还能简化操作步骤,缩短实验时长。     

索氏抽提法测定大豆粉中脂肪含量方法改进研究

本文对GB／T5009．6—2003《食品中脂肪的测定》索氏抽提法的实验技术进行试验和研究,提出了改进技术措施,并运用这些方法,在CNAL能力验证考核中对CNALT0186大豆粉样品进行测定,提高了测定准确度和重复性,｜Z｜≤2,为满意结果。表明改进后的方法实用性强,实验操作更为科学合理,确保获得高质量的检测结果。     

关于火腿肠脂肪含量测定的方法研究

基于采用GB/T 5009.6-2003第一法测定火腿肠脂肪含量时,由于火腿肠是一种淀粉含量较高、粘稠性较大、含有一定水分的肉制品,对测定结果产生较大的干扰,使测定结果严重偏低,提出一系列针对样品的预处理措施,从而解决测定结果偏低的问题。     

新疆紫花苜蓿中黄酮类色素提取过程中定量方法的研究

就新疆紫花苜蓿中黄酮类色素提取过程中的定量分析方法进行研究,比较不同定量方法,使用快速定量方法进行定性、定量,使用其他方法进行检验。     

HPLC测定棉籽粕中游离棉酚含量的前处理方法研究

研究了高效液相色谱法(HPLC)测定棉籽粕中游离棉酚含量的前处理方法.利用70％丙酮水溶液超声辅助提取棉籽粕中的游离棉酚,采用HPLC测定其含量,系统考察了提取条件对游离棉酚含量测定的影响.优化后的前处理条件为:液料比26∶1,超声60 min,提取1次.在此条件下,测定结果稳定性佳(RSD=2.06％),重复性好(RSD=1.62％),加标回收率在97.89％～101.17％之间.该方法可用于棉籽粕中游离棉酚含量的测定.     

Release rate profiles of magnesium from multiple W/O/W emulsions

Water-in-oil-in-water (W/O/W) emulsions were formulated based on rapeseed oil, olive oil, olein and miglyol. Polyglycerol polyricinoleate and sodium caseinate were used as lipophilic and hydrophilic emulsifiers, respectively. Magnesium was encapsulated in the inner aqueous droplets. Emulsion stability was assayed through particle sizing and magnesium release at two storage temperatures (4 and 25 °C) over 1 month. Irrespective of the oil nature, both the primary W/O and W/O/W emulsions were quite stable regarding the size parameters, with 10-μm fat globules and 1-μm internal water droplets. Magnesium leakage from W/O/W emulsions was influenced by the oil type used in the formulation: the higher leakage values were obtained for the oils characterized by the lower viscosity and the higher proportion of saturated fatty acids. Magnesium release was not due to droplet–globule coalescence but rather to diffusion and/or permeation mechanisms with a characteristic rate that varied over time. In addition, W/O/W emulsions were resistant to various thermal treatments that mimicked that used in pasteurization processes. Finally, when W/O/W emulsions were placed in the presence of pancreatic lipase, the emulsion triglycerides were hydrolysed by the enzyme. These results indicated a possible use of W/O/W emulsions loaded with magnesium ions in food applications.     

Structure and oxidative stability of oil in water emulsions as affected by rutin and homogenization procedure

The structural properties of oil-in-water (O/W) emulsions, as well as their oxidative stability upon storage at 50 °C, were studied. Eight different formulations were prepared, with the aim of studying the effect of three variables: the composition of the oil phase, the presence of the flavonoid rutin and the homogenization procedure on the structure and the oxidative stability. It was found that high pressure homogenization, through droplet size reduction, stabilized the emulsions both against creaming and oil oxidation. The interfacial protein was also partially replaced by rutin, further improving the stability of the emulsions, whereas purification of the oil phase had hardly any effect. Thus, the structural and oxidative stability of emulsions was controlled by the size of the droplets and improved by the addition of rutin.     

脂肪替代物在乳制品中的应用

乳制品为营养价值近乎完善的食品,是人类不可或缺的,而乳制品中较高的脂肪可能会对人体健康带来不利影响。随着健康意识的提升,人们开始热衷于低脂或减脂的生活方式。既能维持乳制品本身的美味口感及其质构特性、流变特性等功能特性,又能减少脂肪含量的脂肪代替物应运而生,并具有广阔的市场前景。本文综述脂肪替代物的分类和制备方法,其在乳制品中的应用,并展望其未来研究方向和前景。     

乳与乳制品中主要营养成分快速分离与测定

介绍一种适用于绝大多数食品乳液及也制品中主要营养成分的简便,快速分离测定方法,并与标准法对照进行实际样品分析。     

An imaging-based analysis of lipid deposits on contact lens surfaces

Purpose

To evaluate whether LipidTOX could stain lipid deposits on contact lens (CL) surfaces and compare lipid deposition patterns on various CL surfaces using an imaging method.

Influence of the emulsion components and preparation method on the laboratory‐scale preparation of o/w emulsions containing different types of dispersed phases and/or emulsifiers

Emulsification is a complex process, strongly influenced by emulsion composition as well as by preparation procedure, and the characterisation of emulsions with regard to their structure and stability can be carried out with many different methods. To evaluate the influences of emulsion composition and preparation procedure on the structure and properties, oil‐in‐water emulsions were prepared using the model dispersed phase dodecane and the surfactant Tween on the one hand and the real food components sunflower oil (dispersed phase) and casein (emulsifier) on the other hand. The emulsions were prepared in a small laboratory‐scale with a turbo‐mixer alone and in combination with ultrasonic treatment. The emulsion activity was measured by photometry, the emulsion stability was evaluated visually and the droplet size was determined by laser particle analysis. The results of the investigations made with the model substances agreed only partly with those made with the real food substances. For the model emulsions strong correlation were found between the emulsion activity and the particle sizer data because of the high purity and the defined structure of the model substances. On the contrary, for the emulsions made with the real food components sunflower oil and sodium caseinate the correlation were much weaker. Therefore, a proper characterisation of the structure and properties of food emulsions requires examinations with several methods which are independent from each other. Furthermore, for laboratory‐scale emulsification the combination of turbo‐mixer and ultrasonic treatment is suitable to obtain small droplets and a narrow droplet distribution also for very small emulsion volumes.     

Oil-soluble Surfactants Have Little Effect on Competitive Adsorption of α-Lactalbumin and β-Lactoglobulin in Emulsions

Protein surface concentrations in emulsions stabilized by α-lactalbu-min (α-la), β-lactoglobulin (β-lg) and their mixture were studied with various amounts of oil-soluble surfactant present during homogenization. Three different surfactants were considered: diethyl glycol n-dodecyl ether (C₁₂E₂), sorbitan monooleate (Span 80), and glycerol monostearate (GMS). In n-tetradecane-in-water emulsions, low con-centrations of C₁₂ E₂or Span 80 resulted in a smaller average droplet size and a greater total protein surface coverage; we found the opposite effect at high surfactant concentrations. The effect of GMS in soybean oil-in-water emulsions was slight. In emulsions containing α-la+β-Ig, separate surface coverages of the whey proteins did not differ significantly. The competitive adsorption of milk proteins in food emulsions is unlikely to be affected by surface-active impurities present in typical food oils.