氧化改性聚乙烯蜡微乳液的制备及应用

以高密度氧化改性聚乙烯蜡Hi-Wax 4051 E为原料,采用直接高温高压密闭乳化法制备氧化改性聚乙烯蜡微乳液。探讨了乳化剂配比和总用量、乳化时间及乳化温度等因素对乳液性能的影响。优化的乳化工艺为:乳化剂总用量30%(相对氧化聚乙烯蜡质量,其中异构脂肪醇聚氧乙烯醚A与脂肪醇聚氧乙烯醚B的质量比为1∶1),快速升温到130℃,以一定的速度恒温搅拌乳化30min。制备的微乳液与聚氨酯并用,可提高针织物的抗起毛起球性;单独使用,可提升针织物的顶破强力。     

氧化聚乙烯蜡乳液的制备及在皮革涂饰中的应用

采用相转变法对氧化聚乙烯蜡进行乳化制备氧化聚乙烯蜡乳液用于皮革涂饰。考查了乳化剂种类、用量、乳化温度及机械搅拌速度等主要因素对乳化效果的影响。结果表明:使用的乳化剂体系为OS-15与K-12或OS-15与1631,质量比分别为m(OS-15)∶m(K-12)=1∶3或m(OS-15)∶m(1631)=1∶1,其总用量分别为氧化聚乙烯蜡质量的10%和20%,乳化温度为90~95℃,机械搅拌速度为500~1000 r/min,可制备出均一稳定的氧化聚乙烯蜡乳液。皮革涂饰表明:使用氧化聚乙烯蜡乳液的涂层蜡感及润感较强,可增强皮革的真皮感效应,适用于软革的涂饰。     

氧化聚乙烯蜡微乳液的制备

氧化聚乙烯蜡在纺织行业有广阔的应用前景．考察了乳化剂的种类、用量、乳化时间、乳化温度、搅拌速度、助乳化剂等因素对乳液性能的影响．确定了采用高温高压直接乳化氧化聚乙烯蜡为微乳液的配方组成和乳化工艺条件。     

含氟阳离子丙烯酸酯聚合物的阳/非离子乳液合成

采用阳/非离子乳化体系制备阳离子型含氟丙烯酸酯聚合物乳液.结果显示,阳离子乳化剂1631、非离子乳化剂AEO-9和非离子含氟乳化剂FSA的最佳用量分别为1.75％、1.25％和0.08％,此条件下合成共聚物,转化率93.8％,乳液平均粒径139 nm,胶膜接触角为92.8°.无论是碳氢乳化剂,还是含氟乳化剂,用量增加时...     

聚乙烯乳液柔软剂应用实践

在免烫整理中,聚乙烯乳液柔软剂作为纤维强力保护剂,可增强织物的撕破强力和耐磨强度;在抗起毛起球整理中,聚乙烯乳液柔软剂可协助抗起毛起球剂提高织物的抗起毛起球效果.文中介绍了聚乙烯乳液柔软剂的特性及其在生产实践中的应用情况.     

反应型阳离子柔软剂的制备及应用

以硬脂酸和二乙烯三胺经酰化反应制得二硬脂酰化物,用环氧氯丙烷阳离子化后,再加入乳化剂乳化,可制得带有反应性基团环氧基的新型双酰胺阳离子乳液型纸张柔软剂.以草浆为原料抄纸,通过纸张应用实验表明,在配制乳液时加入10%十六烷基三甲基氯化铵作为乳化剂,所得柔软剂乳液分散均匀、稳定,有利于柔软剂与纸张纤维发生较好的吸附,当柔软剂的阳离子度为0.6,其用量为1%时,纸张的柔软度可达到575 mN.     

一种复配有机硅羊毛织物柔软剂

筛选了三种氨基硅油为柔软剂的主要成分,以异构十三脂肪醇醚和十二烷基三甲基氯化铵为主乳化剂.乙二醇单丁醚为助乳化剂,制得透明清晰的氨基硅油微乳液.重点考察了主乳化荆配比及用量、助乳化剂的优选及用量、复合氨基硅油配比和含量以及pH、搅拌强度等对氨基硅油微乳液状态的影响.根据微乳液的理化性能测定方法,对氨基硅油微乳液及多功能柔软剂的技术性能指标进行了测定.     

酰胺醚SME15在氧化聚乙烯蜡乳液制备中的应用

采用相转变法和复合乳化体系对氧化聚乙烯蜡进行乳化,制备了稳定的氧化聚乙烯蜡乳液。结果表明：乳化剂的种类、用量、乳化温度以及剪切搅拌速度等因素对乳液性能有很大的影响。实验优化的乳化条件是：SME15用量为氧化聚乙烯蜡质量的10%,复合的乳化剂体系为m（SME）∶m（1631）=1∶3,总用量为氧化聚乙烯蜡质量的10%;或复合乳化体系为m（SME）∶m（K-12）=1∶3,总用量为氧化聚乙烯蜡质量的10%,乳化温度为90-95℃,在500-800 r/min的转速下连续剪切分散40-60 min。     

氧化聚乙烯复合乳液的制备及其应用

以氧化聚乙烯为原料,用石蜡和液态萜烯树脂等材料复合改性,采用常压熔融逆转乳化工艺制备了一种O/W型氧化聚乙烯复合乳液,并探讨了其制备工艺条件和乳化剂的选用。制得的该乳液性能优良,适用于作纸品上光防潮涂料、造纸剥离剂和造纸施胶剂。     

酰胺醚SME15在氧化聚乙烯蜡乳液制备中的应用

采用相转变法和复合乳化体系对氧化聚乙烯蜡进行乳化,制备了稳定的氧化聚乙烯蜡乳液.结果表明:乳化剂的种类、用量、乳化温度以及剪切搅拌速度等因素对乳液性能有很大的影响.实验优化的乳化条件是:SME15用量为氧化聚乙烯蜡质量的10%,复合的乳化剂体系为m(SME)∶m(1631)=1∶3,总用量为氧化聚乙烯蜡质量的10%;或复合乳化体系为m(SME)∶m(K-12)=1∶3,总用量为氧化聚乙烯蜡质量的10%,乳化温度为90～95℃,在500～800r/min的转速下连续剪切分散40～60min.     

High pressure versus heat treatments for pasteurisation and sterilisation of model emulsions

Heat treatments can have considerable influence on the droplet size distribution of oil-in-water emulsions. In the present study, high-pressure (HP) pasteurisation and sterilisation were evaluated as alternatives for heat preservation of emulsions. HP conditions used were 600 MPa, 5 min, room temperature and 800 MPa, 5 min, 80 °C initial temperature, 115 °C maximum temperature for HP pasteurisation and HP sterilisation respectively. The effects on droplet size of these conditions were compared to heat treatments for whey protein isolate (WPI) and soy protein isolate (SPI) emulsions at two pH values and two ionic strengths. For WPI, also the effect of protein in the bulk phase was evaluated.Both HP and heat pasteurisation treatments resulted in similar or slightly decreased average droplet sizes compared to the untreated samples. For neutral SPI emulsions, heat sterilisation increased the average droplet size from 1.6 μm to 43.7 μm, while HP sterilisation resulted only in a small increase towards an average droplet size of 2.1 μm. The neutral WPI emulsions, except those with a high ionic strength, gave similar results with respect to the droplet size, showing that for neutral pH WPI or SPI emulsions HP sterilisation is preferable above heat sterilisation. Concerning the low pH WPI emulsions, the droplet sizes were unaffected after both heat and HP sterilisation.Industrial relevanceHeat pasteurisation and sterilisation are effective treatments to preserve food products that are based on emulsions with respect to microbial safety. However, heat treatments can negatively affect emulsion stability. Currently, in addition to high pressure at room temperature, high-pressure treatments at elevated temperature received a great deal of interest to achieve sterilised products. This study evaluated the effects of both heat and high-pressure pasteurisation and sterilisation on droplet size of whey protein isolate and soy protein isolate emulsions. It was shown that for pasteurisation treatments, both heat and high pressure have minor effects on the droplet size of the emulsion. However, for sterilisation purposes high-pressure treatment is preferable for emulsion at neutral pH. High-pressure sterilisation can therefore be interesting alternatives to heat treatments to preserve emulsion stability.     

Antioxidant effect of Majorana syriaca extract in bulk corn oil and o/w emulsion after applying high hydrostatic pressure

Bulk oils and oil-in-water emulsions were subjected to high hydrostatic pressure (HHP) (200, 650 MPa) treatment so as to estimate the effect of applied pressures on lipid oxidation. HHP-treated and non-treated samples were left to autoxidise under accelerated conditions (2 weeks, 70 °C) and their oxidative status was periodically estimated by measurement of conjugated dienes and peroxide value. Total changes of thiobarbituric acid-reactive substances were recorded as additional oxidative markers for emulsions. Results showed an increase in oxidation as pressure was increased especially at 650 MPa. Lipid oxidation rates that were more pronounced for HHP-treated samples can be correlated to measured dissolved oxygen that was also higher. HHP did not seem to have an effect on emulsion droplet size. The addition of Majorana syriaca (200 ppm) ethyl acetate extract led to protection against lipid oxidation under HHP and atmospheric conditions, 20.9–38.7% and 28.9–43.2%, respectively. It was observed that the antioxidant effect of M. syriaca extract under HHP was weaker.     

紫苏油多层乳液的制备及乳液油脂体外消化特性

针对紫苏油在贮藏过程中极易氧化的特点,以大豆分离蛋白、壳聚糖和海藻酸钠为乳化剂,采用静电层层自组装技术对紫苏油进行包封,使紫苏油保持良好的物理稳定性,并能达到油脂缓释的目的。分别对紫苏油单层乳液、双层乳液和三层乳液微观形态和稳定性进行考察,建立体外模拟消化模型,通过气相色谱测定3 种乳液消化前后的脂肪酸组成。结果表明：壁材质量分数为大豆分离蛋白1.0%、壳聚糖2.0%、海藻酸钠1.5%时制备的3 种乳液粒径较小、电位较高,具有良好的理化稳定性。在酸性条件下的多层乳液能够更好保护多不饱和脂肪酸,随着包埋层数的增加,紫苏油的氧化速率越慢。体外模拟消化结果表明三层乳液较单层和双层乳液具有更好的缓释效果,多层乳液可以保证油脂中脂肪酸有效释放。本实验阐明不同界面层对紫苏油消化和脂肪酸释放特性的影响,为指导油脂缓释体系加工提供一定的参考。     

蛋白质氧化影响乳液稳定性研究进展

乳液在食品工业中应用十分广泛,通常可以作为营养与风味物质的良好载体。作为乳液天然稳定剂的蛋白质在食品加工和贮藏过程中会不可避免地发生氧化,进而影响乳液稳定性。近年来,食品蛋白质氧化对乳液稳定性造成的影响已经受到了越来越多的关注。本文首先分析了蛋白质乳液的形成机制以及影响乳液稳定性的主要因素,随后重点探讨了蛋白质柔性对蛋白质乳液稳定性的影响,进而从蛋白质柔性的角度,阐述蛋白质氧化影响乳液稳定性的机理,可为蛋白质乳液的开发及其在食品体系中的应用提供一定的理论参考。     

Oxidative stability of fish oil‐in‐water emulsions under high‐pressure treatment

Over the last decade, high‐pressure treatment has been of considerable interest as an alternative to thermal treatment for food preservation and processing. The impact of high‐pressure treatment on lipid oxidation in fish oil‐in‐water emulsions stabilised by 0.5 wt% whey protein isolate or sodium caseinate was investigated by determining thiobarbituric acid (TBA), propanal values and hydroperoxide values (PVs). The TBA value and the PV of all emulsions increased with increasing pressure at low temperature, indicating that lipid oxidation was promoted by high‐pressure treatment. The impact of high‐pressure treatment on the oxidative stability of lipids was increased when the temperature was increased as the TBA and propanal values were markedly enhanced by high pressure at high temperature. However, high‐pressure treatment did not affect the antioxidant properties of whey protein isolate and sodium caseinate in the fish oil‐in‐water emulsions, which may suggest that high‐pressure treatment does not alter the lipid oxidation pathway in emulsion systems. The promotion of lipid oxidation by high pressure is due mainly to increasing the pressure on a gas reaction shifts the position of equilibrium towards the side with fewer gas molecules.     

Oxidation Stability of O/W Emulsion Prepared with Linolenic Acid Enriched Diacylglycerol

The sn‐1,3‐regiospecific Rhizomucor miehei lipase (Lipozyme RM IM) was employed to produce structured diacylglycerol (SL‐DAG), which contained 67.3 mol% DAG with 27.2 area% of C18:3. To investigate the oxidative stability of the SL‐DAG in emulsion form, 5% oil‐in‐water (O/W) emulsions were prepared with 200 and 400 ppm sinapic acid. It was shown that the hydroperoxide values of the control (without any antioxidant) was the highest (117.7 meq/L) on day 43 of storage and thereafter the value decreased. However, the emulsions with 200 and 400 ppm sinapic acid resulted in slow oxidation degree until day 64 of storage (30.3 and 7.3 meq/L, respectively). Aldehyde measurements for the 200 ppm sinapic acid emulsion (12.8 mmol/mol) and the 400 ppm sinapic acid emulsion (7.5 mmol/mol) also showed better oxidative stability than that for the 200 ppm catechin emulsion (27.4 mmol/mol) and the control (52.7 mmol/mol). Although the SL‐DAG in the emulsions contains high levels of polyunsaturated fatty acids, the degree of oxidation in the emulsions can be reduced when sinapic acid is used as an antioxidant.     

均质压力对亚麻籽油体乳液稳定性及体外消化的影响

本实验以亚麻籽油体为研究对象,通过对其进行均质处理,得到了稳定的富含α-亚麻酸的亚麻籽油体乳液,为居民在日常膳食中提高-3不饱和脂肪酸摄入量提供了新的途径。在保持均质时间相同的条件下(3 min),对亚麻籽油体进行不同均质压力(40、80、120 MPa)与均质次数(1～3次)处理,考察均质处理对亚麻籽油体乳液的性质、环境稳定性(pH、离子强度、热、氧化稳定性)、储藏稳定性和消化特性的影响。结果表明,FOB在120 MPa下均质处理3次,电位绝对值增加,粒径显著减小(P<0.05)。均质处理后的亚麻籽油体乳液在50～90℃下热处理30 min,粒径、电位稳定,且表现出更好的氧化稳定性和储藏稳定性(P<0.05)。均质处理亚麻籽油体并不影响其对pH4～5和离子强度不稳定(P>0.05)。消化结果表明,均质处理后的亚麻籽油体乳液具有更快的脂肪酸释放速率(FFA)。综上,均质处理显著了减小亚麻籽油体乳液的粒径,增强了亚麻籽油体的储藏稳定性和氧化稳定性,且加快了脂肪酸释放速率。     

紫苏油乳液的制备及其稳定性影响因素研究

本研究针对紫苏油不饱和脂肪酸含量高,在储存过程中易氧化等特点,采用高压均质法制备紫苏油乳液,通过激光粒度仪分析乳液粒径大小与分布,通过TURBISCAN浓缩体系稳定性分析仪监测乳液稳定性的变化趋势,探究乳化剂用量、油水比例、高压均质的压力和循环次数及HLB值对紫苏油乳液稳定性的影响,以提供一种紫苏油缓释方法,拓宽紫苏油在食品中的应用范围。试验结果表明,紫苏油乳液粒径主要分布在300~670nm;乳化剂浓度由0.2%增加至1.2%,乳液粒径下降,稳定性提高;浓度为1.2%时,乳液平均粒径(d=513nm)最小。随着油水比增加,紫苏油乳液稳定性下降;高压均质过程对乳液的稳定性有显著影响,压力越大,循环次数越高,乳液越稳定。与单一乳化剂(HLB=15)相比,复配乳化剂(HLB=8~14)可制得更为稳定的乳液,且当HLB值为11时,紫苏油乳液的平均粒径(d=374nm)最小,乳液稳定性最佳。     

大豆酸溶蛋白/大豆多糖纳米乳液的制备及表征

纳米乳液具有抗沉降和抗乳析动力学稳定性,是提高脂溶性物质的水溶性和生物利用度的有效手段。本论文探索了大豆酸溶蛋白(acid soluble soy protein,ASSP)/大豆多糖(soy soluble polysaccharides,SSP)纳米乳液的制备工艺,系统分析了p H条件、加油量、压力、质量比、热处理等因素对纳米乳液形成以及稳定性的影响。结果表明:在p H 3.0~4.0范围内,酸溶蛋白与大豆多糖质量比1:4,400 bar的压力下,可以很好地包埋5%~20%的油,此时制备的乳液粒径为269.33±2.26 nm,并且储存60天粒径无显著性变化(P0.05)。p H条件、高压以及热处理对乳液的稳定性具有显著影响(P0.05),ASSP/SSP纳米乳液适合食品工业中的酸性介质、高温以及高盐环境下的应用。通过果胶酶水解大豆多糖,对酸溶蛋白/大豆多糖纳米乳液的形态学进行了研究分析,结果表明酸溶蛋白/大豆多糖纳米乳液的微滴表面被多糖覆盖,大豆多糖能够很好地固定在微滴表面并使得纳米乳液微滴稳定和分散。     

Effect of α-lactalbumin and β-lactoglobulin on the oxidative stability of 10% fish oil-in-water emulsions depends on pH

The objective of this study was to investigate the influence of pH on lipid oxidation and protein partitioning in 10% fish oil-in-water emulsions prepared with different whey protein isolates with varying ratios of α-lactalbumin and β-lactoglobulin. Results showed that an increase in pH increased lipid oxidation irrespective of the emulsifier used. At pH 4, lipid oxidation was not affected by the type of whey protein emulsifier used or the partitioning of proteins between the interface and the water phase. However, at pH 7 the emulsifier with the highest concentration of β-lactoglobulin protected more effectively against oxidation during emulsion production, whereas the emulsions with the highest concentration of α-lactalbumin were most stable to oxidation during storage. These differences were explained by differences in the pressure and adsorption induced unfolding of the individual protein components.