卵磷脂与山梨醇酐单硬脂酸酯复合对菜籽油凝胶凝胶特性的影响

为增强卵磷脂在食品领域的适用性,促进菜籽油凝胶的开发,以菜籽油为基料油,添加卵磷脂和山梨醇酐单硬脂酸酯（SMS）制备菜籽油凝胶,探究卵磷脂与SMS质量比（0∶10、1∶9、2∶8、3∶7和4∶6）对其理化性质、微观结构与氧化稳定性的影响。结果表明：卵磷脂与SMS质量比对菜籽油凝胶硬度和析油率具有显著影响（p<0.05),卵磷脂与SMS质量比为2∶8时菜籽油凝胶的硬度最高,析油率最低;菜籽油凝胶的弹性模量（G′）均大于黏性模量(G″),表明全部形成凝胶结构,卵磷脂与SMS质量比为2∶8时具有最高的弹性模量和黏性模量;XRD、氧化稳定性、FTIR和DSC分析表明,卵磷脂比例的增加有利于菜籽油凝胶结晶和氧化稳定性的提升,但热力学稳定性降低,菜籽油凝胶网络分子间作用力以氢键为主。综上,卵磷脂与SMS复合作为凝胶剂可有效固化菜籽油成功构建菜籽油凝胶体系,其中卵磷脂与SMS质量比为2∶8时形成的菜籽油凝胶的凝胶特性最好。     

Microstructure and Stability of Non-Protein Stabilized Oil-in-Water Food Emulsions Measured by Optical Methods

ABSTRACT: :
The microstructure and stability of oil-in-water emulsions, stabilized with non-protein emulsifiers (sor-bitan esters), were analyzed as a function of emulsification time, rotor speed, hydrophilic-lipophilic balance (HLB), and ionic strength. Sauter average dia (D[3,2]) were determined from micrographs. Back-scattered light data were analyzed and a method to determine creaming rates of the systems was proposed. Creaming rates showed that the relationship between emulsion stability and HLB was non-linear. Addition of NaCl raised creaming rates, resulting in decreased stability, while micrographs showed the presence of flocs. Results were discussed taking account of interactions present in the system.     

单甘酯及冷却温度对牛油样品特性的影响

目的:探讨牛油火锅底料生产过程中单甘脂(Glyceryl monostearate,GMS)及冷却温度对牛油样品结晶行为的影响。方法:以牛油火锅底料中的牛油样品为研究对象,通过测定牛油样品的硬度、固体脂肪含量(Solid Fat Content,SFC)、色度、等温结晶动力学参数探究牛油样品结晶行为。结果:当GMS添加量超过1.5%时,牛油样品硬度随GMS添加量升高而增大,但GMS添加量对牛油样品SFC无明显影响;随冷却温度的降低,牛油样品的硬度及SFC呈增大的趋势,0~-15℃温度范围内差异明显,-15~-25℃差异不明显;GMS及冷却温度对牛油样品的结晶性能有显著的影响。结论:通过添加GMS及降低冷却温度可一定程度优化牛油火锅底料硬度、色泽,并缩短冷却时间降低能耗。     

Studies on Surfactant–Ionic Liquid Interaction on Clouding Behaviour and Evaluation of Thermodynamic Parameters

The present study investigates the effect of tetraethyl ammonium tetrafluoroborate [TEA(BF₄)] ionic liquid (IL) on the cloud point (CP) of the following nonionic surfactants in aqueous solution: ter‐octylphenol ethoxylates with 9.5 and 4.5 ethylene oxide groups (abbreviated TOPEO9.5 and TOPEO4.5, respectively), cetyl alcohol ethoxylate with 10 ethylene oxide groups (C16EO10), and sorbitan monolaurate and monooleate both with 20 ethylene oxide groups (SMLEO20 and SMOEO20, respectively) in aqueous solutions. The thermodynamic parameters of these mixtures were calculated at different IL concentrations. The CP of most of the tested nonionic surfactants increased with the increment of IL concentrations with the exception of C16EO10 for which it decreased. The solubility of a nonionic surfactant containing polyoxyethylene (POE) hydrophilic chain was considered as maximum at the CP, hence the thermodynamic parameters were calculated at the same temperature. The results showed that the standard Gibbs free energy (?G_CP⁰), the enthalpy (?H_CP⁰) and the entropy (?S_CP⁰) of the clouding phenomenon were found to be positive for ethoxylated octylphenol and sorbitan esters, whereas ?H_CP⁰ and ?S_CP⁰ were found to be negative for C16EO10. It was found that the overall clouding process is endothermic for ethoxylated octylphenol and sorbitan esters and exothermic for C16EO10. For all the studied systems, ?H_CP⁰ > T?S_CP⁰ indicated that the process of clouding is guided by both enthalpy and entropy. The positive value of standard Gibbs free energy (?G_CP⁰) for the all mixed systems indicated that the process proceeds non‐spontaneously. The ?G_CP⁰ decreased with increasing IL concentration for all the nonionic surfactants; however, it decreased with increasing surfactant concentration for TOPEO9.5, C16EO10, and SMOEO20, and increased with increasing surfactant concentration for TOPEO9.5 and SMLEO20.     

Span系列乳化剂发展综述及其在乳化炸药中的应用

综述了Span系列表面活性剂的国内外研究现状及其在乳化炸药中的应用进展，对Span的合成工艺进行了重点综述，包括合成时的原料选择、催化剂及其浓度的选择、合成温度及时间、反应体系环境及产品的后期处理。对Span的组成、性能、表征及发展趋势也进行了综述。     

Span 60对3-甲基吡啶电氧化的影响

通过循环伏安曲线测定,考察了Span 60(山梨糖醇酐单硬脂酸酯)对3-甲基吡啶电氧化的影响。正交实验确定的最佳反应条件是:n(3-甲基吡啶)/n(硫酸)=0.4,添加高于或接近临界胶束浓度的Span 60,反应温度15℃,阳极电位1.9~2.0 V,电解电量为理论电量的10%;其选择性可达85.46%,电流效率为48.69%,电流密度提高300 mA/cm2,并根据最佳反应条件进行外循环放大实验,其结果与小试基本相同。在选定的实验范围内,Span 60对3-甲基吡啶电氧化有明显的促进作用,有应用前景。     

低表面能水性聚氨酯的研究

以聚醚210(N210),IPDI(异佛尔酮二异氰酸酯)为基本单体,用硬脂酸单甘油酯封端,合成了一种表面能达33mN/m的低表面能水性聚氨酯树脂,并研究了硬脂酸单甘油酯用量、n(-NCO)/n(-OH)对树脂表面能的影响。     

用传统催化剂提高失水山梨醇单油酸酯的质量

本文介绍了用传统催化剂提高失水山梨醇单油酸酯（Ｓｐａｎ－８０）质量的实践、所选定的醚化催化剂浓度、醚化温度和醚化时间与有关资料上介绍的有较大的差别。大生产中制得的Ｓｐａｎ－８０各项指标均符合国家行业标准，外观色泽及其它有关数据与国外产品相似。     

硼酸酯化法合成聚乙二醇(6000)单硬脂酸酯

采用硼酸酯化法合成了聚乙二醇(6000)单硬脂酸酯,试验考察了反应时间、反应温度、催化剂用量、物料比等对产物中聚乙二醇(6000)单硬脂酸酯含量的影响,确定了最佳合成条件。在此条件下,产物中聚乙二醇(6000)单硬脂酸酯的含量可达93％。     

Skin contact allergy to emulsifiers

Contact allergy to cetyl and stearyl alcohols has been reported for many years. About one per cent of eczema patients are allergic to either alcohol or a mixture of the two. In the present study, 11 of 1374 patients reacted to 20% cetylstearyl alcohol in patch tests. Results of a previous study, suggested that some impurities in commercial cetyl and stearyl alcohols might be responsiblefor the contact allergies. Sorbitan esters are also contact allergens in dermatological preparations. Sorbitan sesquioleate (20% in petrolatum) was patch-tested in 4469 eczema patients in the present study, with a positive result in 25 (0.56%) of them. Widespread dermatitis from moisturizing creams was seen in two patients, one of whom was treated with peroral corticosteroids and the other with a potent corticosteroid cream. Several other emulsifiers have also occasionally been found to cause contact allergy. Popular emulsifiers are thus potential allergens, especially in preparations commonly used as moisturizersfor dry or slightly eczematous skin. Les allergies cutanees aux emulsifiants Résumé Les allergies par contact aux alcools cetyliques et stéaryliques ont déjà fait l'objet de nombreux articles. Environ 1% des patients souffrant d'eczéma sont allergiques soit à l'un des deux alcools, soit à leur mélange. Dans cette étude, 11 patients sur 1374 ont réagi àdes patch tests à 20% d'alcool cetostearylique. Les résultats d'une étude précédente laissaient supposer que les impuretés présentes dans les alcools cétyliques et stéaryliques du commerce pourraient être responsables de ces allergies de contact. Les esters de sorbitan sont également des allergisants dans les préparations dermatologiques. Le sesquioleate de sorbitan (à 20% dans la vaseline) a été testé sur 4469 patients souffrant d'eczéma, avec un résultat positif pour 25 d'entre eux (0.56%). Des dermatoses importantes ont été observés chez deux patients utilisant des crèmes hydratantes; l'un d'entre euxa été traité par des corticosteroides par voie buccale et l'autre par une crème corticosteroide puissante. Il a également été démontré que de nombreux autres émulsifiants pouvaient causer des allergies de contact. Les émulsifiants courants sont des allergisants potentiels, spécialement dans les préparations hydratantes pour les peux sèches ou légèrement eczémateuses.