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1.
采用白金板法对Surfactin的表面活性进行研究,并用浊度法和离心法对其乳化性进行研究。结果表明:Surfactin的临界胶束浓度为9.03×10-5 mol/L,可将水的表面张力由73.98 mN/m降至最低27.48 mN/m。在浓度为1×10-3~1.2×10-2 mol/L的NaCl溶液中,Surfactin溶液的表面张力随盐浓度升高逐渐降低并最终稳定在34 mN/m;Surfactin在121 ℃处理20 min后,其表面张力仍能保持在37.10 mN/m;在pH值为2~12范围内,其表面活性稳定并良好;表明Surfactin具有较强的NaCl浓度、温度、pH值的耐受性。浊度法测得Surfactin亲水亲油平衡(hydrophilelipophilic balance,HLB)值为14,对所需HLB值为12~16的油相乳化性能良好。  相似文献   

2.
反丁烯二酸蔗糖甲酯的功能特性研究   总被引:7,自引:0,他引:7  
基于防腐防霉剂的构效关系和乳化剂的分子结构特点,合成了反丁烯二酸蔗糖甲酯。抑菌实验表明:对几种常见微生物,酯化度为5.5的反丁烯二酸蔗糖甲酯的最低抑菌浓度比山梨酸的低而接近于富马酸二甲酯,说明其具有较高的抗菌活性;反丁烯二酸蔗糖甲酯的抗菌半衰期要长于山梨酸和富马酸二甲酯,说明其抗代谢性能好,具有一定的开发应用价值。乳化实验表明:酯化度为5.5的反丁烯二酸蔗糖甲酯的HLB值为6.8、临界胶束浓度为0.7g,L、浓度为0.3%溶液的表面张力为28.5mN/m,都接近于span-80,说明反丁烯二酸蔗糖甲酯具有一定的表面活性。有关反丁烯二酸蔗糖甲酯的抗菌特性及乳化特性在食品、日化及涂料等工业领域的应用有待于进一步研究。  相似文献   

3.
先由食用葵花籽油和甲醇在碱性催化剂条件下酯交换反应制得脂肪酸甲酯,然后脂肪酸甲酯与蔗糖通过水溶剂法,以逆相转移催化剂DMAP催化制备蔗糖脂肪酸酯.通过对酯糖摩尔比、催化剂用量、反应温度、反应时间进行考察,确定最佳合成条件为:酯糖摩尔比2.5∶1,催化剂用量4%,反应温度 85℃,反应时间7h.在最佳合成条件下,葵花籽油脂肪酸甲酯的转化率高达65.32%,所得产品具有良好的表面活性,其临界胶束质量浓度(CMC)为6.5 g/L,表面张力为27.41 mN/m,乳化力为79 s,浊点指数为7.2 mL,HLB值为10.1,碘值(Ⅰ)为126.9 g/100 g.  相似文献   

4.
采用大孔树脂分离纯化山茶甙,并研究了山茶甙表面性能及对废报纸的脱墨活性.结果表明,山茶甙的临界胶束浓度为0.022%,最低表面张力为38.6mN/m,最大乳化力为122s,发泡参数为73.5%,稳泡参数为350s,均显著优于十二烷基硫酸钠.山茶甙与脂肪酶有协同作用,可显著提高脂肪酶脱墨的纸浆白度,减少其有效残余油墨浓度.山茶甙是一种性能优良的表面活性剂,用于脂防酶脱墨是可行的.  相似文献   

5.
In this work, four surfactant-like humic acids (HAs) obtained from garden lignocellulose wastes and kitchen food wastes mixed with garden-lignocellulose wastes, both before and after composting, were tested for surfactant properties and the ability to solubilize tetrachloroethene (PCE). The waste-derived HAs showed good surfactant properties, lowering the water surface tension from 74 mN m(-1) to 45.4 +/- 4.4 mN m(-1), with a critical micelle concentration (CMC) of 1.54 +/- 1.68 g L(-1), which is lower than many synthetic ionic surfactants. CMC was affected by both waste origin and composting processes. The addition of food waste and composting reduced CMC by adding alkyl-C (measured by CP MAS 13C NMR) and N- and S-HA contents (amide molecules), so that a multistep regression was found [CMC = 24.6 - 0.189 alkyl C - 2.64 (N + S); R2 = 0.77, P < 0.10, n = 6]. The four HAs solubilized PCE at the rate of 0.18-0.47 g PCE/g aqueous biosurfactant. These results were much higher than those reported in the literature for a commercial HA (0.026 g/g), but they were in line with those measured in this work for nonionic surfactants such as Tween-80 (0.69 g/g) and Triton X-100 (1.08 g/g).  相似文献   

6.
氨基葡萄糖盐酸盐与三乙胺在乙醇-水相条件下生成氨基葡萄糖(GA),GA再与癸酸反应,合成了一种氨基葡萄糖为反离子的脂肪羧酸盐表面活性剂——氨基葡萄糖癸酸盐(GAD)。采用红外光谱和N元素含量分析对GAD进行了结构表征,并测试了其表面性能。结果表明:25℃下,GAD的临界胶束浓度(CMC)为8.51×10-4mol/L,临界胶束浓度所对应的表面张力(γCMC)为30.1 mN/m,饱和吸附量(Γmax)为4.33×10-10mol/cm2,饱和吸附分子面积(Amin)为0.38 nm2;GAD具有一定的泡沫性能,并对液体石蜡具有较好的乳化能力;与Tween 80、十二烷基二甲基甜菜碱(BS-12)和十六烷基三甲基氯化铵(1631)等助剂配伍良好,无分层现象。  相似文献   

7.
以漆脂为原料,经过硫酸催化水解,生成漆脂脂肪酸,再与氯化亚砜反应生成漆脂脂肪酰氯,然后采用肖顿-鲍曼(Schotten-Baumann)缩合法,在弱碱性条件下,漆脂脂肪酰氯与肌氨酸钠盐进行缩合反应,再经过酸化、萃取等过程,制得漆脂酰肌氨酸。采用红外光谱和核磁共振碳氢谱对其结构进行表征,并对产物钠盐的表面性能进行分析。结果表明,合成产物为漆脂酰肌氨酸,漆脂酰肌氨酸钠盐的临界胶束浓度为6. 733×10~(-4)mol/L,表面张力为22. 845 m N/m,具有较好的表面活性。当漆脂酰肌氨酸钠盐浓度为0. 01 mol/L时,从乳化的液体石蜡中分出10 m L水的时间为90 s,对低极性溶剂的乳化效果较差,但漆脂酰肌氨酸钠盐的起泡和稳泡性能较好,起泡高度为130 mm,5 min后降至115 mm。  相似文献   

8.
[目的]为解决水溶性香精爆珠的稳定成型问题,通过反滴法制备毫米级中空海藻酸钙载水胶囊(水润珠),研究液滴的表面张力对水润珠成型的影响.[方法]采用Tween 80、Poloxamer 407和APG 0810三种非离子表面活性剂调控氯化钙/羧甲基纤维素钠(CaCl2/CMC)液滴的表面张力,考察液滴表面张力对水润珠形貌...  相似文献   

9.
扁桃仁蛋白质(Almond protein isolate,API)营养丰富,是一种重要的植物蛋白质资源,而乳化性差是一直困扰其开发应用的一个重要问题,为提高其乳化特性,本试验以扁桃仁分离蛋白质为研究对象,探讨了黄原胶(Xanthan gum,XG)对其乳化特性的影响。结果表明:XG的添加可使其复合乳液液滴直径更小且分布更均匀,即在XG添加量为0%~0.25%时,其乳液黏度从5.9 mPa·s增加至77.5 mPa·s,表面张力由13.1 mN/m降低至5.6 mN/m,界面吸附能力增强,乳液电位绝对值由29.0 mV增加到54.4 mV。尤其是XG添加量为0.2%时,API-XG乳液不仅具有较好的热稳定性和耐盐性,而且其储藏及冻融循环稳定性优良。实验研究有效提升了API的乳化性,为其在食品、化工等领域的应用提供了良好的技术支撑。  相似文献   

10.
大豆多糖是从豆渣中提取出来的酸性水溶性多糖,具有乳化稳定性、抗黏结性、成膜性等特性,可广泛应用在食品加工中。该文使用红外光谱、紫外-可见光谱和高效液相色谱(HPLC)等仪器,测定国内外不同大豆多糖的分子键类型、紫外-可见光特征吸收、糖组分等理化特性。结果表明,国产1#样品的灰分、黏度、表面张力小,乳化性一般,蛋白、二糖、葡萄糖和果糖的含量相对较高,溶液吸光度值最大;国产2#样品的红外光谱和3#样品相近,但乳化性较差,呈碎片状,与1#、3#样品的近球状差别较大;国外3#样品的表观黏度为90.0~204.3 mPa·s,表面张力介于31.2~51.6 mN/m2,在同等条件下较1#、3#样品高;其乳化性能较好,综合颜色等因素,3#大豆多糖样品的性能最好。  相似文献   

11.
Emulsifying Properties of Whey Protein-Carboxymethylcellulose Complexes   总被引:2,自引:0,他引:2  
ABSTRACT: Proteins/polysaccharides complexes could improve emulsifying properties of proteins by thickening the layer at the interface of the oil droplets. Emulsifying properties of whey protein-carboxymethylcellulose complexes (WPI/CMC) were compared with those of a whey protein isolate (WPI). Ingredients were incorporated into oilinwater emulsions with various protein and oil contents. Visual observations, protein load, protein distribution and rheological measurements were used to evaluate emulsion stability. Protein load up to 26.1 and 48.9 mg protein/g oil were obtained for WPI and WPI/CMC emulsions, respectively. The higher protein load of WPI/CMC emulsions and visual observations indicated that WPI/CMC complexes had greater emulsifying properties against coalescence than whey proteins. However, complexes enhanced flocculation of oil droplets.  相似文献   

12.
对四种类型麦芽糊精:木薯麦芽糊精(CMD)、木薯交联麦芽糊精(CCMD)、木薯酯化麦芽糊精(COMD)、木薯交联酯化麦芽糊精(CCOMD)的吸湿性及表面活性进行了研究。四种糊精的吸湿性随着DE值和相对湿度的升高而升高,但受温度的影响并不显著。交联和酯化作用都可以降低CMD的吸湿性,降幅分别为26.5%和12.1%,两者协同作用降幅为33.7%。四种麦芽糊精的表面活性通过表面张力的测定进行了评估。当浓度为5%时,CMD、CCMD、COMD、CCOMD溶液的表面张力分别为67.24mN/m、64.61mN/m、52.93mN/m和52.21mN/m。酯化作用比交联作用更能有效降低木薯麦芽糊精的表面张力。  相似文献   

13.
Cuttlefish skin gelatins modified with oxidized linoleic acid (OLA) and oxidized tannic acid (OTA) were characterized and determined for emulsifying properties and antioxidative activity. Modification of gelatin with 5% OTA increased the total phenolic content and 1,1-diphenyl-2-picrylhydrazyl, 2,2′-azinobis(3-ethylbenzothiazoline-6-sulphonic acid) radical scavenging activity and ferric reducing antioxidant power of gelatin–OTA. Incorporation of OLA into gelatin (OLA-to-free amino group molar ratio of 10:1) increased surface hydrophobicity of gelatin from 17.39 to 32.38 and reduce surface tension at air/water interface of gelatin solution from 53 to 32 mN/m. Gelatin–OLA had the increase in emulsion activity index, compared with gelatin without modification and was capable of producing a fine emulsion (d 32?=?0.79 μm, d 43?=?0.82 μm). Modification of gelatin–OLA complex with OTA at different concentrations (2.5%, 5%, and 10%) increased antioxidative activity but decrease emulsifying properties. However, gelatin–OLA modified with 5% OTA had higher emulsifying properties than the commercial gelatin (bovine gelatin). The presence of an alkyl group and a hydroxyl group in gelatin after modification with OLA and OTA, respectively, was revealed by Fourier transform infrared study. Coincidental decrease in free amino group was also noticeable in modified gelatin. Menhaden oil-in-water emulsion stabilized by gelatin modified with OLA and 5% OTA was more resistant to lipid oxidation and phase separation as evidenced by the lower thiobarbituric acid reactive substances value and smaller oil droplet size, compared with that stabilized by commercial bovine gelatin. Thus, the modification of gelatin by both OLA and OTA was able to improve antioxidative and emulsifying properties of cuttlefish skin gelatin.  相似文献   

14.
Whey protein nanoparticles (NPs) were prepared by heat‐induced method. The influences of whey protein isolates (WPIs) and concentrates (WPCs) on the formation of NPs were first investigated. Then Pickering emulsions were produced by protein NPs and their properties were evaluated. After heat treatment, WPC NPs showed larger particle size, higher stability against NaCl, lower negative charge and contact angle between air and water. Dispersions of WPC NPs appeared as higher turbidity and viscosity than those of WPI NPs. The interfacial tension of WPC NPs (~7.9 mN/m at 3 wt% NPs) was greatly lower than that of WPI NPs (~12.1 mN/m at 3 wt% NPs). WPC NPs‐stabilised emulsions had smaller particle size and were more homogeneous than WPI NPs‐stabilised emulsions. WPC NPs‐stabilised emulsions had higher stability against NaCl, pH and coalescence during storage.  相似文献   

15.
以羧甲基淀粉为原料,溴代十六烷为醚化剂,NaOH为催化剂,利用双螺杆挤压机在干法挤压条件下制备了一种高碳疏水基团的十六烷基羧甲基淀粉醚。探讨了醚化剂用量、螺杆转速、机筒温度、物料水分及碱用量对产品乳化性的影响,利用紫外分光光度计、红外光谱分析仪、粒度仪等对不同取代度(0、0.025 6、0.049 5、0.058 0、0.0701)的十六烷基羧甲基淀粉醚的结构和表面活性、乳液粒径等进行了表征比较。红外光谱图在2 960~2 850 cm~(-1)处产生了吸收峰,-OH的伸缩振动变得弱而平缓,这是因为淀粉中羟基基团进一步被取代所导致,说明溴代十六烷的长碳链已接入淀粉分子;与原淀粉相比,产物的表面张力减小,且随着产物溶液质量分数的增大表面活性越大;随着醚化取代度的增加,乳状液的平均粒度逐渐减小,从粒径分布可以证明羧甲基淀粉疏水化后乳化性明显得以改善;当淀粉接入长碳链疏水基团后,十六烷基羧甲基淀粉醚的水溶性降低。  相似文献   

16.
Food foams such as marshmallow, Chantilly and mousses have behavior and stability directly connected with their microstructure, bubble size distribution and interfacial properties. A high interfacial tension inherent to air/liquid foams interfaces affects its stability, and thus it has a direct impact on processing, storage and product handling. In this work, the interactions of egg albumin with various types of polysaccharides were investigated by drop tensiometry, interfacial rheology and foam stability. The progressive addition of egg albumin and polysaccharide in water induced a drop of the air–water surface tension which was dependent on the pH and polysaccharide type. At pH 4, that is below the isoeletric point of egg albumen (pI = 4.5) the surface tension was decreased from 70 mN/m to 42 mN/m by the presence of the protein, and from 70 mN/m to 43 mN/m, 40 mN/m and 38 mN/m by subsequent addition of xanthan, guar gum and κ-carrageenan, respectively. At pH 7.5 the surface tension was decreased from 70 mN/m to 43 mN/m by the simultaneous presence of the protein and κ-carrageenan. However, a higher surface tension of 48 and 50 mN/m was found when xanthan and guar gum were added, respectively, when compared with carrageenan addition. The main role on the stabilization of protein–polysaccharide stabilized interfaces was identified on the elasticity of the interface. Foam stability experiments confirmed that egg-albumin/κ-carrageenan at pH below the protein isoeletric point are the most efficient systems to stabilize air/water interfaces. These results clearly indicate that protein–polysaccharide coacervation at the air/water interface is an efficient process to increase foam stability.  相似文献   

17.
选用甲氧基封端的烯丙基聚醚进行接枝,在高效铂络合物催化剂作用下,通过无溶剂界面聚合,在氮气保护下进行硅氢加成反应制备聚醚接枝硅氧烷类表面活性剂。对催化剂用量、反应物配比、反应温度、反应时间对产物的表面张力影响进行了深入考察。结果表明,在m(聚醚)/m(硅)为2.5,催化剂用量为20滴(HMX-8用量的1%)、140℃下反应5 h所得聚醚改性硅氧烷表面活性剂性能最佳,其0.5%的水溶液的表面张力低至18.83 mN/m。  相似文献   

18.
从来源不同的土样和污水中,分离得到1株酵母菌Y_(2A)。摇瓶发酵培养,发现该菌发酵液具有很好的排油活性,并且能将发酵液的表面张力从72mN/m降为37.4mN/m。薄层层析、紫外光谱、红外光谱分析以及菌种鉴定,表明该菌是1株未见报道的糖脂产生菌拟成克酵母(Wickerhamiella domercqiae)Y_(2A)。该糖脂在pH 2~8,12%盐浓度和120℃下仍然保持良好的表面活性,并且对原油有较好的乳化能力。  相似文献   

19.
The emulsifying properties and interfacial behaviour of conventional arabic gum (Acacia Senegal, control gum) and after thermal maturation (EM1 and EM2) were studied. All gums presented good oil in water emulsifying capacities. However, after 20–60 high-pressure homogenization passes, matured gums formed more homogenous emulsions with smaller mean oil droplets (0.4 μm) than the control gum (0.65 μm). Modification of pH from 4.5 to 7.0 did not affect sample characteristics. The film-forming capability of all samples at air–water interface was studied using adsorbed and spread techniques. The greater the amount and molecular mass of the arabinogalactan protein (AGP) component in the gum, the better the interfacial properties (tension drop kinetic and interfacial tension final values). Good dilatational elasticity was found for all three gums samples, corresponding to highly elastic interfacial films. The spread films of matured gum EM2 rearranged during compression, passing through liquid expanded, liquid condensed into solid states. Conversely, control and EM1 gums only formed liquid expanded films and smaller surface coverage than EM2. Analytical interfacial results confirm the improved emulsifying properties of matured gums. The properties of the AGP molecules in the gums could be responsible for these differences.  相似文献   

20.
改性菠萝皮渣纤维素染料吸附剂的性质研究   总被引:1,自引:1,他引:0  
对菠萝皮渣中纤维素进彳醚化和胺化改性得到的染料吸附剂,对其进行染料吸附、结构表征和性质等方面研究.结果表明:改性菠萝皮渣纤维素对染料具有显著的吸附作用;红外图谱的相关吸收峰的变化说明菠萝皮渣纤维素发生了醚化和胺化的改性反应,X射线衍射分析表明在改性前后纤维素的晶型和结晶度上未发生显著变化;差示热量扫描分析显示改性后的菠...  相似文献   

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