Deep‐fat frying under moderate vacuum of potato cylinders

This study evaluates parameters relating to the mass transfer during the frying of potato cylinders at different temperatures (100, 120 and 140 °C) and moderate vacuum (around 25 kPa). In all cases, there is a linear relation between water loss and fat uptake. The parameters relating to the textural and structural modifications show less marked changes in vacuum fried products compared to those fried under atmospheric pressure. The maximum penetration force reaches 30%–40% of the initial hardness in vacuum frying and 10% for atmospheric pressure frying; starch gelatinization and pectin methylesterase enzyme activity reduce more quickly under atmospheric pressure, although after 240 s both values are negligible. The scanning electron microscopy images verify that the surface of potato cylinders fried under vacuum or atmospheric pressure are completely different as a result of the steam being released at different temperatures.     

The role of vehicle interactions on permeation of an active through model membranes and human skin

Previous work from this group has focused on the molecular mechanism of alcohol interaction with model membranes, by conducting thermodynamic and kinetic analyses of alcohol uptake, membrane partitioning and transport studies of a model compound (i.e. methyl paraben) in silicone membranes. In this article, similar membrane transport and partitioning studies were conducted in silicone membranes to further extend the proposed model of alcohol interactions with silicone membranes to include other vehicles more commonly used in dermal formulations, that is, isopropyl myristate (IPM), dimethyl isosorbide (DMI), polyethylene glycol (PEG) 200, PEG 400 and Transcutol P^® (TC). More importantly, membrane partitioning studies were conducted using human SC to evaluate the application of the proposed model of solvent‐enhanced permeation in simple model membranes for the more complex biological tissue. The findings support a model of vehicle interactions with model membranes and skin where high solvent uptake promotes drug partitioning (i.e. K) by enabling the solute to exist within the solvent fraction/solvent‐rich areas inside the membrane or skin in a concentration equivalent to that in the bulk solvent/vehicle. High solvent sorption may also ultimately impact on the membrane diffusional characteristics, and thus the diffusion coefficient of the solute across the membrane. The implications for skin transport are that increased partitioning of a drug into the SC may be achieved by (i) selecting vehicles that are highly taken up by the skin and also (ii) by having a relatively high concentration (i.e. molar fraction) of the drug in the vehicle. It follows that, in cases where significant co‐transport of the solvent into and across the skin may occur, its depletion from the formulation and ultimately from the skin may lead to drug crystallization, thus affecting dermal absorption.     

羟乙基甲基纤维素改性对棉和锦纶织物表面性质的差异性影响

棉纤维和锦纶表面性质的巨大差异使喷墨印花墨水在棉/锦交织织物2种纤维上的铺展与渗化行为不同,为棉/锦交织织物喷墨印花获得清晰图案带来了巨大困难。针对这一问题,选取了多种水溶性聚合物分别对棉/锦交织织物进行表面改性,对比研究了改性后的棉纤维和锦纶表面性质的变化。结果表明：当使用羟乙基甲基纤维素对棉/锦交织织物改性后,棉纤维表面亲水性减弱,锦纶表面亲水性增强;在羟乙基甲基纤维素改性后的棉/锦交织织物上喷墨打印青色、品红、黄色和黑色色块的染色深度值较使用海藻酸钠改性分别提升34.6%、45.0%、40.0%和31.5%;羟乙基甲基纤维素改性有利于棉/锦交织织物喷墨印花色深和图案清晰度提升。     

乳品中5种脂肪酸的测定

建立了气相色谱法同时测定奶粉中亚油酸、α-亚麻酸、花生四烯酸、二十碳五烯酸(EPA)、二十二碳六烯酸(DHA)的高通量分析方法。简化奶粉中提取脂肪的方法,改进脂肪酸甲酯化方法。采用三氟化硼甲醇法衍生,5种脂肪酸的线性范围为25～5 000 mg/L,样品的亚油酸在0.05,0.1和0.2 g/g(脂肪)3个水平的添加回收率为84.9%～109.0%之间,相对标准偏差为2.0%～11.0%;α-亚麻酸在10,20和30 mg/g(脂肪)3个水平的添加回收率为81.5%～122.3%之间,相对标准偏差为3.9%～9.2%;花生四烯酸、二十碳五烯酸(EPA)、二十二碳六烯酸(DHA)在1,2和3 mg/g(脂肪)3个水平的添加回收率为61%～119%之间,相对标准偏差为2.0%～9.5%;方法的定量限为25μg/g脂肪。方法简便、快速、准确,适用于奶粉中5种脂肪酸的测定。     

高压液相色谱法检测酸性乳饮料及酸奶中对羟基苯甲酸酯类

目的 建立酸性乳饮料及酸奶中对羟基苯甲酸甲、乙、丙、丁酯含量的高压液相色谱分析方法。方法 样品去蛋白后, 用甲醇提取, 提取液用高压液相色谱仪进行检测。结果 对羟基苯甲酸甲酯、对羟基苯甲酸乙酯、对羟基苯甲酸丙酯、对羟基苯甲酸丁酯在 0～10 μg/kg 范围内, 相关系数大于 0.999, 检出限分别为 0.48、0.45、0.47、0.49 mg/kg; 在 1、2、5 mg/kg 3 个加标水平下,样品中对羟基苯甲酸甲酯、对羟基苯甲 酸乙酯、对羟基苯甲酸丙酯、对羟基苯甲酸丁酯的加标平均回收率分别为 95.59%~104.52%、93.21%~108.05%、 97.75%~107.98%、97.48%~103.67%, 相对标准偏差均小于 10%。结论 本方法适用于乳与乳制品中对羟基苯 甲酸(尼泊金)甲、乙、丙、丁酯含量的测定需要。     

新型防腐剂富马酸纤维二糖甲酯的合成及抗菌特性研究

茂名学院化学与生命科学学院(茂名525000)摘要基于食品防腐防霉剂的结构-活性关系研究结果,合成了具有α,β-不饱和羰基功能基团的新型食品防腐剂——富马酸纤维二糖甲酯。抑菌活性试验结果表明:富马酸纤维二糖甲酯对牛奶酸败混合菌的生长具有良好的抑菌能力,抑菌效果优于富马酸单甲酯,接近苯甲酸。     

麻疯树籽油制备生物柴油及应用研究

采用压榨法提取了麻疯树籽油,用GC/MS法分析了不同产地麻疯树籽油中的脂肪酸成分及含量。检测了麻疯树籽油甲酯的理化性质,并将其与石化柴油按一定比例混合后,检测了16项质量指标。结果显示,麻疯树籽出油率为39.8%,其脂肪酸主要成分是月桂酸、棕榈酸、硬脂酸、花生酸、油酸、亚油酸、亚麻酸,其中含油酸46.833%,亚油酸为28.500%,棕榈酸为19.767%,合计为95.1%。麻疯树籽油甲酯密度为0.885g/cm3,十六烷值为44.81,与柴油混配后,大部分指标均在标准范围内。     

高温气相色谱分析油脂转酯反应

建立了高温气相色谱分析油脂转酯反应样品中各种脂肪酸甲酯和脂肪酸甘油酯的方法。样品经硅烷化处理后分流进样,使用VF-5HT高温毛细柱,优化后的程序升温使各种脂肪酸甲酯和甘油酯得到良好分离,同时缩短了分析时间;十三酸甲酯和辛酸三甘油酯双内标分别对脂肪酸甲酯和脂肪酸甘油酯定量,提高了分析的准确度。该方法为油脂转酯反应制备生物柴油提供了分析依据。     

植物甾醇共轭亚油酸的制备及其血脂调节作用的研究

植物甾醇与共轭亚油酸甲酯通过酯交换反应合成植物甾醇共轭亚油酸脂,反应产率达94%,该法适合工业化生产。首次研究了植物甾醇共轭亚油酸酯对大鼠血脂的调节作用,实验表明植物甾醇共轭亚油酸酯具有调节血脂作用。