不饱和脂肪酸单甘油酯对大豆蛋白饮料稳定性的影响

不饱和脂肪酸单甘油酯具有优良的乳化分散性,兼具保健功能。以硬脂酸单甘油酯作为对照,采用分光光度法测定了油酸单甘油酯、亚油酸单甘油酯的乳化性能。脂肪酸单甘油酯作为乳化剂应用于大豆蛋白饮料配方,采用多重光散射法和离心分析法研究了乳化剂对大豆蛋白饮料分散体系稳定性的影响。结果表明:不饱和脂肪酸单甘油酯的乳化性能优于硬脂酸单甘油酯;添加单一乳化剂时,油酸单甘油酯及亚油酸单甘油酯的乳化稳定效果优于硬脂酸单甘油酯,不饱和脂肪酸单甘油酯的添加量对大豆蛋白饮料的稳定性影响不明显;油酸单甘油酯与蔗糖酯复配使用,质量比为1∶1和2∶1时,大豆蛋白饮料分散体系的稳定性较佳,且优于单独添加油酸单甘油酯时的稳定性。     

甲基丙烯酸甲酯相变微胶囊的制备及表征

以固液混合石蜡作为芯材,使用复配乳化剂乳化混合石蜡;以甲基丙烯酸甲酯单体(MMA)作为壁材,采用原位聚合法制备石蜡相变微胶囊。考察乳化剂种类、用量以及配比、乳化聚合温度和转速对产物结构和性能的影响。结果表明:将Tween-80、Span-80以11∶9的比例复配作为乳化剂使用,乳化时间30 min,6 000 r/min搅拌5 min,乳化效果达到最佳;制得的微胶囊粒径约为507 nm,相变潜热值为37.8 J/g。     

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.     

燕麦β-葡聚糖/大豆分离蛋白混合体系的乳化性能研究

为了扩大燕麦β-葡聚糖(OG)在食品中的应用,以粉末状的燕麦β-葡聚糖(OG)和大豆分离蛋白(SPI)为原料,研究了溶液状态下两者混合体系的质量分数、OG/SPI配比、温度和pH值对溶液乳化性能的影响,通过单因素及正交试验优化组合.结果表明,在质量分数为4%,OG/SPI配比为3:1,pH=8.5,温度为60℃时混合体系具有较好的乳化性能;两者的混合能提高乳化性能.     

聚丙烯非织造布/无机材料粘接用胶黏剂的制备

基于物理混合法制备了氯化聚丙烯乳液型胶黏剂。通过正交试验研究了乳化剂用量、乳化温度、乳化时间对胶黏剂的粒径、黏度、剥离强度与稳定性的影响。试验发现:乳化剂用量是影响胶黏剂粒径、黏度和稳定性的最主要因素,而乳化温度和乳化剂含量对剥离强度有较大影响,只有当胶黏剂的粒径和黏度合适分散时,剥离强度最大。当氯化聚丙烯∶离子型表面活性剂(乳化剂1)∶非离子型表面活性剂(乳化剂2)的质量比为50∶2∶1,乳化温度60℃,乳化时间3 h时,所得胶黏剂的综合性能最佳。     

乳化条件对大豆卵磷脂乳化作用的影响

本文研究了乳化条件对用大豆卵磷脂配制的乳液稳定性、微滴的直径(粒度)和乳液粘性的影响。将卵磷脂用(A)Hansen分散器、(B)加热和(C)超声处理三种方法分散在水中制成乳液,比较了乳液的稳定性,结果表明,A的稳定性最好,C最差。微滴的直径髓卵磷脂添加量的增加而降低。将乳化剂分散在油里制成的乳液,其粒度小于将乳化剂分散在水中制成的乳液。乳化温度和乳化后的存放温度升高时,乳液变得不稳定,乳液的粘性随卵磷脂含量的升高而上升,将卵磷脂分散在油里制成的乳液,其粘性高于将卵磷脂分散在水中制成的乳液。存放温度升高,乳液的粘性降低,粘性取决于乳化方法和卵磷脂的含量。试验结果表明,由较小的微滴构成的乳液粘性大,稳定性好。     

海水淡化浓盐水石灰法制备氢氧化镁的研究

以海水淡化获得的浓盐水为原料,进行石灰法制备氢氧化镁的实验研究。通过单因素实验和正交实验,考察了反应陈化时间、Ca(OH)2与Mg2+摩尔比、Ca(OH)2加料速率和反应器搅拌速率对氢氧化镁纯度及钙含量的影响,优化了反应条件。实验结果表明,影响氢氧化镁纯度及钙含量的各因素大小依次为:Ca(OH)2与Mg2+摩尔比、Ca(OH)2加料速率、反应陈化时间。并确定了氢氧化镁制备的优化条件为:Ca(OH)2与Mg2+摩尔比0.9、Ca(OH)2的加料速率10 mmol/min,反应陈化时间120 min。     

基于界面聚合法的橄榄油-聚氨酯微胶囊制备

为了应用微胶囊技术赋予纺织品护肤功能,采用界面聚合法,以甲苯-2,4-二异氰酸酯(TDI)和聚乙二醇(PEG)为反应单体,非离子表面活性剂为乳化剂,制备了以橄榄油为芯材、聚氨酯为壁材的护肤微胶囊.探讨乳化剂种类、界面聚合温度、搅拌转速和聚乙二醇分子质量等因素对微胶囊形成的影响.用粒度仪和生物显微镜分析不同乳化剂对橄榄油的乳化效果.结果表明,由吐温80和聚乙烯醇混合所乳化而成的橄榄油乳化体系受温度变化影响小,稳定性好.扫描电镜分析表明,以混合乳化剂制备的微胶囊平均粒径在3～5μm左右,粒径分布范围窄,颗粒大小较均匀,形状较规整;以聚乙二醇600制备的微胶囊较以聚乙二醇800制备的微胶囊多孔性好,囊芯橄榄油较易释出.     

非离子型皮革手感蜡乳液的制备及应用

采用相转变法对由石蜡和蜂蜡组成的混合蜡进行乳化,制备皮革涂饰用手感蜡乳液。考察了乳化剂种类、用量、乳化温度及搅拌速度等因素对乳液性能的影响。结果表明:使用乳化体系为Span60、Tween80与平平加O-20组成的复合乳化剂,总用量为20%,乳化温度为75℃,搅拌速度为500~700r/min,得到了稳定的非离子型手感蜡乳液。皮革涂饰结果表明:最优工艺下制得产品的综合性能与进口样品相近。     

乳液型二甲基硅油/气相SiO2/双酰胺复配消泡剂的制备及其性能研究

以牛油、二乙烯三胺（DETA）为主要原料合成了一种新型双酰胺表面活性剂,采用Span-Tween复配乳化剂将二甲基硅油／气相SiO2／双酰胺的混合体系进行乳化,制备出一系列乳液型的复配消泡剂,考察了物料配比、乳化剂用量、乳化剂配比对产品性能的影响,确定了最佳的制备工艺条件。实验表明：该消泡剂具有稳定性能好、分散性能优良、消泡力强的特点。     

五种常用硬脂酸盐食品添加剂的鉴定

采用加热实验、金属离子鉴定、气相色谱测定和红外光谱图等实验,建立硬脂酸钙、硬脂酸镁、硬脂酸钠、硬脂酸钾和硬脂酸等5 种常用硬脂酸(盐)类食品添加剂的鉴定方法。结果表明,加热实验特征现象、脂肪酸的气相色谱测定色谱图和红外光谱图是鉴定脂肪酸盐的有效指标;金属离子鉴定实验阳性明显,可作为鉴别实验中各种脂肪酸盐的有效指标。     

MODIFICATION OF COMPRESSIVE BEHAVIOUR OF CHIOS MASTICHE GUM

Reduction of Chios mastiche hardness by additions of beeswax, lecithin or calcium stearate was studied by compression tests using an Instron machine. Beeswax and lecithin brought about a marked decrease of mastiche's resistance to compression while calcium stearate had the opposite effect. Esterification of the hard and brittle monomeric fraction of mastiche with ethanol caused a drastic modification of its texture yielding a plastic material. Its addition to mastiche at various percentages brought about a considerable decrease in the product's resistance to compression.     

Effects of anticaking agents and relative humidity on the physical and chemical stability of powdered vitamin C

Vitamin C is an essential nutrient that is widely used by the food industry in the powder form for both its nutritional and functional properties. However, vitamin C is deliquescent, and deliquescence has been linked to physical and chemical instabilities. Anticaking agents are often added to powder systems to delay or prevent caking, but little is known about their effect on the chemical stability of powders. In this study, various anticaking agents (calcium phosphate, calcium silicate, calcium stearate, corn starch, and silicon dioxide) were combined with sodium ascorbate at 2% and 50% w/w ratios and stored at various relative humidities (23%, 43%, 64%, 75%, 85%, and 98% RHs). Chemical and physical stability and moisture sorption were monitored over time. Additionally, saturated solution samples were stored at various pHs to determine the effect of surface pH and dissolution on the vitamin degradation rate. Storage RH, time, and anticaking agent type and ratio all significantly affected (P < 0.05) moisture sorption and vitamin C stability. Silicon dioxide and calcium silicate (50% w/w) and calcium stearate (at both ratios) were the only anticaking agents to improve the physical stability of powdered sodium ascorbate while none of the anticaking agents improved its chemical stability. However, corn starch and calcium stearate had the least adverse effect on chemical stability. Dissolution rate and pH were also important factors affecting the chemical and physical stability of the powders. Therefore, monitoring storage environmental conditions and anticaking agent usage are important for understanding the stability of vitamin C. PRACTICAL APPLICATION: Anticaking agent type and ratio significantly affected the physical and chemical stability of vitamin C over time and over a range of RHs. No anticaking agent improved the chemical stability of the vitamin, and most caused an increase in chemical degradation even if physical stability was improved. It is possible that anticaking agents would greatly affect other chemically labile deliquescent ingredients, and therefore, anticaking agent usage and storage conditions should be monitored in blended powder systems.     

Study of commodity properties of food emulsions Part 1. The effect of dispersion medium composition on kinetic stability of O/W emulsions containing proteins,acidic polysaccharides and calcium salts

The effect of concentrations of acidic polysaccharide and calcium ions on the kinetic stability, viscosity and dispersity of protein-containing O/W emulsions is studied. Variation of kinetic stability of the emulsions studied is independent of dispersion composition. In a wide range of calcium acetate concentrations a correlation is observed between kinetic stability and viscosity of emulsions at sodium alginate concentration in the dispersion medium ≤ 0.3%. The transition zone between liquid solution and gel is widened in the presence of sodium caseinate. Maximum kinetic stability is reached at calcium acetate: sodium alginate concentrations of 1.0-1.2 and ～ 6.0, corresponding to optimum conditions for formation of homogeneous crosslinked structures of calcium alginate and calcium caseinate.     

Effects of anticaking agents and storage conditions on the moisture sorption,caking, and flowability of deliquescent ingredients

Deliquescent highly soluble crystalline ingredients are prone to caking and dissolution when they are stored above a certain relative humidity (RH) but exhibit minimal moisture adsorption below this RH. Anticaking agents are added to improve the flowability of powders and to prevent or reduce caking. The objective of this study was to determine the effects of anticaking agents on the moisture sorption behavior, flowability, and caking characteristics of deliquescent ingredients and blends thereof. Single deliquescent food ingredients (sodium chloride, sucrose, fructose, and citric acid) and binary systems (sodium chloride blended with sucrose, fructose, or citric acid) were used as the host powders, and silicon dioxide, calcium silicate, and calcium stearate were the three anticaking agents studied. Moisture sorption isotherms were generated to investigate the water–solid interactions of the anticaking and host powders. Following controlled RH storage treatments, caking was assessed by the sieve test and flowability by avalanche power and avalanche angle measurements. Formulation had variable effects on deliquescence behavior and moisture sorption, while formulation, storage RH, length of storage, and RH cycling all significantly affected the physical stability of the powder blends. Calcium stearate was the most effective anticaking agent at reducing moisture sorption and delaying the onset of deliquescence, as well as maintaining the flowability properties of all powders tested. In particular, calcium stearate was able to substantially alter the moisture sorption behavior of blends of deliquescent ingredients, which are inherently more susceptible to the deleterious effects of moisture due to deliquescence lowering. The results are of great significance because they show that the effectiveness of an anticaking agent in preventing moisture-induced caking depends on the complexity of the host powders as well as on the interaction with environmental moisture. Thus, the type of anticaking agent added to a deliquescent ingredient must be tailored to the host powder to enhance product quality and stability.     

百合涂膜保鲜的试验研究

以壳聚糖、亚硫酸氨钠，柠檬酸等主要组分复配而制成的保鲜液膜进行百合保鲜效果试验，测定了百合失重率，呼吸强度，颜色变化及20d内好果率等影响百合保鲜效果的指标参数值，试验结果确定壳聚糖4％，柠檬酸2％，硬脂酸钙5％, 亚硫酸氢钠1．5％，作为百合室温保鲜贮藏的处理方法。     

VC硬脂酸酯和异VC硬脂酸酯乙醇溶液的稳定性研究

将VC硬脂酸酯和异VC硬脂酸酯溶解到乙醇中,利用碘量法测定不同时间、不同条件下它们的浓度。通过比较残留率,考察了光照、温度、金属离子、金属离子络合剂和蔗糖等因素对他们稳定性的影响。实验所表现出的总体规律是:在相同条件下,VC硬脂酸酯比异VC硬脂酸酯更稳定。     

纳米CaCO3的表面改性及在水中的分散性能

利用阳离子表面活性剂十六烷基三甲基溴化铵改性纳米CaCO3.对改性前后的纳米CaC03进行了FT-IR光谱分析和透射电镜观察,测定了沉降体积、表观黏度、浊度和颗粒粒度分布,对其在水中的分散性能进行了评价.结果表明,经表面改性后,纳米CaCO3在水中的润湿性及分散稳定性有很大改善.     

改性扇贝壳粉与壳聚糖复合膜的制备及性质研究

以扇贝壳为原料,硬脂酸钠为改性剂,通过湿法改性制备了改性扇贝壳粉。采用单因素和响应面试验探讨改性温度、改性剂用量、改性时间对扇贝壳粉改性效果的影响,利用傅里叶红外光谱仪、电子扫描电镜和X射线衍射仪对扇贝壳粉进行表征。将制成的改性扇贝壳粉与壳聚糖制成复合膜,考察改性扇贝壳粉质量分数对复合膜性质的影响。结果表明,扇贝壳粉最佳改性条件为:硬脂酸钠添加量2.53%,改性温度80.70 ℃,改性时间43.19 min,在此条件下制得的扇贝壳粉活化度最高可达到76.41%,结合表征图谱分析,硬脂酸钠成功结合到壳粉表面,壳粉粉体粒子间团聚作用减弱,制得的改性扇贝壳粉具有良好的分散性。添加改性扇贝壳粉可以有效提高壳聚糖膜的机械性能、透光性和水蒸气阻隔性能。当改性扇贝壳粉的质量分数为1%时,改性扇贝壳粉与壳聚糖复合膜的性能最佳,此时膜拉伸强度为30.19 MPa,断裂伸长率为10.2%,水蒸气透过量为35.1 g·h?1·m?2,透光性为2.9 mm·%。     

硬脂酸淀粉酯的性质

对硬脂酸淀粉酯的流变学性质和乳化稳定性进行了研究.结果表明:硬脂酸淀粉酯的粘度明显低于原淀粉,其粘度随温度的升高和剪切速率的增加而下降,取代度的增加对硬脂酸淀粉酯的粘度没有显著影响;硬脂酸淀粉酯的乳化稳定性随取代度、硬脂酸淀粉酯用量以及油水比的增加而增加,随温度的升高而降低.