Microencapsulation of dodecyl acetate by complex coacervation of whey protein with acacia gum and its release behavior

Complex coacervation of whey protein（WP） with acacia gum（AG） was carried out in water with the presence of dodecyl acetate （DA）,a component of insect sex pheromones,in order to obtain microcapsules with DA as the core material and WP-AG coacervate as the wall materials.Through variations in wall/core ratios,concentrations of the wall materials in capsule preparations,DA encapsulation was optimized,which showed a high DA encapsulation was achieved when coacervation was conducted at pH 3.5 with wall/core mass ratio at 3 combined with concentration of wall materials at 1.0 wt%.Morphology and the structure of DA loaded microcapsules were examined by scanning electron microscope,which showed the microcapsules were of core/shell structure with DA encapsulated in the inner of the microcapsules.DA release was examined and the behavior of the release was discussed.

The Effect of Gum Acacia on Post-Prandial Glucose and Insulin Levels in Healthy Subjects

This double-blind, controlled, randomized, three-way cross-over study evaluates the effect of 40 g (D1 group) and 20 g (D2 group) of acacia gum (AG) versus no treatment (NT group) on post-prandial glucose (PPG) levels in normal-weight and overweight subjects. Additionally, post-prandial insulin (PPI) levels as well as the safety and tolerability of gum acacia were assessed. 35 healthy subjects aged 25 - 60 years, body mass index 18.5 kg/m2 - 29.9 kg/m2, received one treatment of 20 g, 40 g, or 0 g of AG each. Glucose and insulin values were determined at -15 min and prior to the intake (time “0”) as well as 15, 30, 45, 60, 90 120, and 180 min after the “0 min” blood draw. The mean PPG levels were lower (34% in D1 group, p = 0.003;35% in D2 group, p = 0.005) than in the NT group. PPI concentration was statistically significantly lower at all time points except baseline in both treatment groups compared to NT groups. Global benefit and tolerability were rated as “very good” or “good” by 100% of subjects in the treatment groups. This study provides robust evidence of the significant benefits of AG consumption on PPG and PPI levels in healthy subjects. Moreover, very good tolerability was demonstrated.

Effect of tapping tools and date of tapping on Acacia polyacantha gum yield in South Kordofan State, Sudan

A study was conducted in South Kordofan, Sudan to determine the effect of tapping, tapping tools and date of tapping on the gum yield of Acacia polyacantha. A two-factor experiment was conducted for two seasons in 2008-2009. One location was used for two seasons and two locations for one season. The first factor （4 levels） was the tools of tapping： Makmak, Farrar, and Sonki, and the control which was not tapped. The second factor （2 levels） was the date of tapping that comprises mid October and mid November. These treatments were arranged in Randomaized Complete Block Design and replicated three times. Gum yield （g/tree and g/ picking） was recorded for five pickings. Economic analysis was done using the partial budget technique. The results showed highly significant （p 〈 0.01） differences on gum yield （g/picking and g/tree）. The results indicated that the process of tapping increases gum production by 88.4% and 79.8% compared with un-tapped trees, respectively. The date of tapping has no significant effect on gum yield （g/tree and g/picking） of A. polyacantha. Tapping of the tree with Makmak in mid- November was found to be economically beneficial compared to using the other tools and the control. These results could identify a new source of income for the poor farmers in South Kordofan mainly because of the wild occurrence of Kakamut as a potential gum producing tree species grown naturally in the area.

Effect of grass density and date of tapping on Acacia senegal gum yield in north kordofan state, Sudan

We conducted a two-factor experiment in randomized complete block design with four replications during 2004 in El Demokeya Forest Reserve and El Himaira Natural Forest, North Kordofan State, Sudan. The objective was to develop an understanding of the ecological effects of under-story vegetation and tapping date on the productivity of gum arabic from Acacia senegal as over story cover. The first factor was grass cover which was tested in four levels （100% and 50% grass cover in addition to bare and burnt）. The second factor, date of tapping was tested in three levels namely （1st Oct, 15th Oct and 1st Nov）. The first picking was done after 45 days from tapping and the gum yield up to seven pickings was collected at intervals of 15 days. Gum yield from each picking was collected and weighed using sensitive balance. Analysis of variance was carried out using MSTAT-C statistical package, and the Tukey test was applied for mean comparisons. The results showed highly significant differences （p 〈 0.01） of grass cover on gum arabic yield in the two sites for most of the first consecutive pickings （1st–4th out of seven） in addition to total yield （kg/ha）. With exception to the 4th pickings, the interaction effect between the grass densities and tapping date was not significantly different. The total gum yield was significantly （p 〈 0.05） increased in only two pickings （third and fourth） in El Demokeya Forest Reserve and two pickings （1st and 2nd） at El Himaira Natural Forest. The density of grass cover significantly （p 〈 0.05） affected the number of pickings at both sites; the number of gum pickings was directly proportional to grass density. The number of gum pickings was found to be significantly （p 〈 0.05） increased at the early date of tapping.

Diversity, regeneration status and population structure of gum-and resin-bearing woody species in south Omo zone, southern Ethiopia

South Omo Administrative Zone in Ethiopia is home to 18 indigenous ethnic groups whose livelihood is vulnerable due to recurrent drought and degradation. Despite the preliminary observation showing the rich dry-forest resource base that, if sustainably managed could enhance livelihoods and biodiversity conservation, there is lack of empirical data on its current status. We conducted a study aiming at quantifying the population status of gum- and resin-bearing species in two randomly selected districts, Hamer and Bena-Tsemay. Seventy-five quadrats （35 at Hamer and 40 at Bena-Tsemay） each measuring 400 m2 were established along line transects to assess species diversity and equitability, density, frequency, dominance, importance value and population structure. We recorded a total of 27 woody species of 12 families and 14 genera. Fifteen species （9 at Hamer and 14 at Bena-Tsemay） of the genera Acacia, Boswellia, Commiphora and Sterculia, were identified as either major sources of commercial gums and resins or their adulterants. Gum- and resin-bearing species comprised 56% and 57% of species richness, 48% and 50% of total density per ha, 95% and 98% of basal area, and 64% and 56% of importance values at Hamer and Bena-Tsemay, respectively. Diversity of the entire woody species assemblage and of the gum- and resin-bearing species was slightly higher at Bena-Tsemay （H= 2.61, 1.4） than at Hamer （H＇= 2.48, 1.28）, respectively. The diversity and abundance of the resource base suggest potential for development of value-added commercialization of gum and resins to enhance livelihoods and encourage sustainable management of the forest at these study areas. We recorded, however, declining natural regeneration of most gum- and resin-bearing species, and this calls for integrated and participatory species management and landscape rehabilitation.

阿拉伯胶在黄铜矿滑石浮选分离中的作用及机理

通过浮选试验、吸附量分析和Zeta电位测试,研究阿拉伯胶在黄铜矿与滑石浮选分离中的作用,并考察其作用机理。结果表明,在本研究设定的pH范围内,黄铜矿及滑石在丁基黄药作用下具有较好的可浮性,难以实现浮选分离。阿拉伯胶在黄铜矿及滑石表面发生了吸附,但在滑石表面的吸附量显著高于在黄铜矿表面,对滑石表面电位的影响也比对黄铜矿电位的影响大。阿拉伯胶对黄铜矿及滑石均产生了抑制作用,但在pH为5~7的区间内,阿拉伯胶对黄铜矿的抑制作用较弱,对滑石的抑制作用较强。在混合矿分选中使用阿拉伯胶作抑制剂,在混合矿中铜质量分数为15.21%时,可以获得铜质量分数为29.36%,铜回收率81.82%的精矿。

阿拉伯胶-大豆分离蛋白接枝工艺优化及产物理化特性的研究

以自制大豆分离蛋白(SPI)为原料,与阿拉伯胶混合制备接枝改性大豆分离蛋白,并对其乳化性进行了研究。结果表明:在阿拉伯胶与SPI质量比1∶2,反应时间16h的条件下,大豆分离蛋白-阿拉伯胶接枝物的乳化性显著提高。在此基础上,利用电泳、紫外吸收、氨基酸分析、扫描电镜对接枝物的结构进行初步研究,接枝改性的SPI亚基随着反应的进行逐渐消失,其中7S以及11S的酸性亚基更容易参与反应;紫外吸收光谱在265nm附近出现一个新的特征吸收峰;精氨酸和赖氨酸含量显著降低;接枝物形成分散均一的小分子物质。

酯水解行为与其烷基极化效应指数关系和酯与阿拉伯胶缔合行为的研究和应用

本文运用电导法测定了不同浓度的乙醇溶液中脂肪酸酯的水解速率常数(k),并对脂肪酸乙酯类化合物的分子结构、水解条件与k的关系进行了相关分析,并推导得出酯类化合物k与烷基极化效应指数PEI(R)及体系介电常数(ε)间的关系表达式:lgk=a+blgPEI(R)+clgε,为研究酯水解机理主要影响因素、预测其k和判断酯的结构提供了一定的理论依据。同时研究了38%(V/V)乙醇溶液中阿拉伯胶(简称GA)与脂肪酸酯之间的缔合行为,并建立了定量确定缔合常数(A)的方法,推导并验证了定量表达酯水解速率常数k与GA浓度(M)关系的数学表达式:k’=k/(1+AM),得出了GA对脂肪酸酯水解起禁阻作用的结论。其研究结果用于38°清香型汾酒稳定性的提高取得了令人满意的效果。

阿拉伯胶的种类及性质与功能的研究

不同种类的阿拉伯胶,具有不同的理化参数,其多糖的组成及结构也有明显的区别,从而导致功能应用方面的差异。

应用红外光谱结合化学计量学方法检测阿拉伯胶产地和蛋白质含量（英文）

研究利用傅里叶红外光谱结合化学计量学方法来实现对苏丹阿拉伯胶的产地和蛋白质含量的快速无损检测的可行性。采集自6个不同的产地,每个产地12个,总计72个阿拉伯胶样本,作为研究对象,运用线性判别分析(linear discriminant analysis,LDA)和反向区间偏最小二乘(backward interval partial least squares,Bi-PLS)法分别实现对苏丹阿拉伯胶的产地区分和蛋白质含量检测。结果表明,当主成分数为6时,LDA对样本的训练集(48个样本)和预测集(24个样本)的识别率都为100%。Bi-PLS法回归联合20个光谱子区间中的4个子区间得到最佳的蛋白质预测模型,其预测集相关系数为0.937 3,均方根误差为0.173%。因此,利用傅里叶红外光谱结合化学计量学方法可实现对苏丹阿拉伯胶的产地以及蛋白质的含量的快速无损检测。

镉超高灵敏显色反应的研究

本文研究了高灵敏测定镉的光度法,在阿拉伯胶存在下,在0.02—0.16mol/L硫酸介质中,镉与碘化物和罗丹明6G生成离子缔合物。该缔合物最大吸收波长为525mn,表观摩尔吸收系数ε_(525)为1.6×10~6L·mo1^(-1)·cm^(-1),镉浓度在0—2μg/25ml符合比耳定律。考察了共存离子的干扰影响,该法可用于测定水中痕量镉。

刺绣抗起毛整理工艺研究

刺绣作为高档元素在服饰等家纺场景中的应用广泛,但是刺绣容易起毛的问题成为消费痛点。文章用毛笔蘸取水溶性聚合物整理剂,沿着刺绣图案纹路进行少量多次浸润,油膜纸覆盖刺绣表面,用熨斗熨烫进行固化处理。使用一段时间后的刺绣产品,可以采用皂荚胶等天然整理剂进行二次补强。结果表明,水溶性聚合物整理剂质量分数为0.6%时,绣品纤维表面形成包裹性状和透明度较好的膜,起毛程度降低。整理后的绣品手感良好、色差较小,底料无明显水渍污染。随洗涤次数增加,整理后绣品的抗起毛性能降低,可以采用0.2%的皂荚胶等进行二次加固整理,使得绣品抗起毛性得到一定程度恢复。

纳米硒的制备及表征

报道了一种用阿拉伯胶作为分散体系制备纳米硒的方法,研究了反应时间、反应物浓度、反应温度、超声等对产物粒度大小、形貌的影响,并采用光谱法、透射电镜、扫描电镜等手段对产物进行了表征.

5-氟尿嘧啶阿拉伯胶-白蛋白毫微粒的制备

采用乳液固化法制备了阿拉伯胶牛血清白蛋白毫微粒， 透射电子显微镜测定微粒的平均粒径为 （２２８±６１）ｎｍ （ｎ＝ ３００）。以５－氟尿嘧啶为模型药物， 将５－氟尿嘧啶阿拉伯胶－白蛋白毫微粒在酸性条件下１００ ℃水解２０ ｈ， 测得５－氟尿嘧啶的平均包封率为３０．１１％ 。体外试验结果表明， ５－氟尿嘧啶毫微粒在３７ ℃０．１ ｍ ｏｌ／Ｌ盐酸液中３６ ｈ 累计释药达８８．２％

松节油微胶囊化的研究

论文采用松节油为芯材、明胶和阿拉伯胶为壁材，运用复合凝聚法制备了一种具有核-壳结构的皮革防霉剂。在论文中，笔者研究了pH值对明胶和阿拉伯胶复合凝聚的影响，绘制了明胶和阿拉伯胶的pH值凝聚区间图；讨论了温度、时间、转速和表面活性剂的用量等对乳液稳定性和粒径的影响，确定了乳化的最佳条件：50℃；15min转速为900r／min；表面活性剂为4％；分析了产品的显微形态，产品具有核-壳结构，粒径在10～30微米左右。

壳聚糖/阿拉伯胶复凝聚鱼油微胶囊的制备及性质研究

研究以壳聚糖(chitosan,CS)和阿拉伯胶(acacia gum,GA)作为包裹鱼油的壁材,通过复凝聚反应制备CS/GA复凝聚鱼油微胶囊。首先通过单因素分析法,对复凝聚行为的影响因素进行研究。结果表明,当m(CS)∶m(GA)为1∶6,1∶7,壁材总浓度为3%,4%,5%,pH值为4.0,4.5,5.0,反应温度为20℃,反应时间为30min时,CS与GA具有较好的复凝聚效果。以此为基础,在保证较好的复凝聚效果的前提下,确定了CS/GA复凝聚鱼油微胶囊的最佳制备工艺:CS/GA壁材总浓度为5%,m(CS)∶m(GA)为1∶7,芯壁比为1∶2,pH值为4.5,反应温度为20℃,复凝聚反应时间为30min。在最佳制备工艺下制备的CS/GA复凝聚鱼油微胶囊呈规整的球形,分散性良好;粒径分布均匀,平均粒径为16.3μm;对鱼油的包埋率和壁材的利用率分别为75.33%和81.01%。

相变储能微囊的制备及性能研究

通过复相凝聚法制备了价格低、性能高的相变储能微囊;微囊的壁材为明胶、阿拉伯胶复凝聚产物,芯材为十二醇。对不同干燥方式得到的微囊的储热性能和形貌进行比较,烘箱干燥和喷雾干燥所得微囊的储热密度分别为122.18J/g、100.15J/g,微囊的芯材包覆效率分别为56.7%(wt)、46.5%(wt);其中喷雾干燥得到的微囊成球性较好,得到近球形微囊,适于应用推广。

厚膜金导体浆料用类球形金粉制备研究

分别以抗坏血酸(VC)、草酸、对苯二酚、亚硫酸钠和硫酸亚铁为还原剂,以阿拉伯树胶为分散剂还原雷酸金制备金粉。利用SEM对所制金粉进行了表征,分析了还原剂种类对金粉形貌和粒径的影响。并且以弱还原性的VC作为还原剂,分别探究了分散剂种类、用量及反应体系p H值、加入速度和温度对金粉粒径的影响。经过优化工艺,在金溶液浓度为20 g/L,p H值为4,质量比ζ(阿拉伯树胶:Au)=5:2,反应温度为50℃,金溶液加入速度为110 m L/min时,制备出呈类球形形貌和约2μm粒径的金粉。

一种抗菌水凝胶的制备及性能研究

以阿拉伯树胶、聚乙烯醇等为原料,通过戊二醛交联成功制备了具有pH和温度敏感的水凝胶,通过溶液吸附法制备了负载水杨酸的水凝胶。分别研究了pH和温度对水凝胶溶胀性能的影响,以及pH和温度对负载水凝胶的缓释性能。实验结果表明,水凝胶对pH和温度有敏感性;负载水杨酸的水凝胶在中性介质下的缓释性能要好于酸性和碱性介质,水凝胶缓释性能受温度影响,随着温度升高,缓释性能提高,凝胶的缓释性与溶胀行为一致。

维药阿拉伯胶重金属含量测定及安全性评价

目的测定阿拉伯胶中常见重金属铅、镉、铜、砷、汞的含量,评价其安全性,为建立阿拉伯胶重金属检测限值提供参考。方法用原子吸收法测定铅、镉、铜、砷、汞的含量,以《药用植物及制剂外经贸绿色行业标准》为标准评价阿拉伯胶的安全性。结果所测各批次样品铅、镉、铜、砷、汞的含量相差较小,符合《药用植物及制剂外经贸绿色行业标准》。结论可安全用于临床,为保障临床用药安全提供依据。