共查询到17条相似文献,搜索用时 78 毫秒
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共轭亚油酸(CLA)是亚油酸的位置和几何异构体。其中9c,11t-CLA和10t,12c-CLA是目前发现生理活性比较强的两种共轭结构。作者使用氢氧化钾甲醇溶液对油脂中的共轭亚油酸甘三酯进行水解和甲酯化,利用毛细管气相色谱进行分离后外标法定量。作者得到共轭亚油酸9c,11t-CLA回收率在97.66%~103.51%之间,10t,12c-CLA回收率在96.12%~102.48%之间,检出限2.4 mg/kg,定量限8 mg/kg。 相似文献
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气相色谱法分析共轭亚油酸异构体 总被引:17,自引:0,他引:17
有许多种测定共轭亚油酸各异构体相对含量的方法 ,如气相色谱法、银离子高效液相色谱法、气质联用和核磁共振法等 ,其中气相色谱法最为简便快速。本研究选择气相色谱法用于共轭亚油酸各异构体的分析。结果表明 ,气相色谱法可用于共轭亚油酸中主要异构体的相对含量的测定 相似文献
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毛细管柱气相色谱法测定乳制品中的甜蜜素 总被引:1,自引:1,他引:0
采用Rtx-1非极性毛细管柱对乳制品中的甜蜜素的检测方法进行了探讨,改进了样品处理方法,建立了应用Carrez试剂沉淀蛋白,毛细管柱分离检测乳制品中甜蜜素的方法.经方法验证,方法检出限为5.16μg,定量下限为15.48μf,在0.0~1.0μg浓度范围内线性关系良好,相关系数R2为0.9999,回收率在94.2%~1... 相似文献
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研究了牛乳中共轭亚油酸含量的紫外分光光度测定方法。利用紫外分光光度计,先建立标准曲线与回归公式,再将牛奶样品提取、甲酯化后,进行紫外检测。结果表明,共轭亚油酸甲酯的最大吸收波长是234nm;共轭亚油酸浓度的有效测定范围是0.00856-0.0428mg/mL;吸光度与共轭亚油酸浓度间的回归公式为Y=52.602X+0.0917(R2=0.9862);得出共轭亚油酸浓度与吸光度之间的经验公式为:共轭亚油酸浓度C(mg/mL)=0.019×吸光度(ABS);并且推出了利用紫外分光光度法测定牛奶中共轭亚油酸含量的计算公式。同时,检验了几种市售牛奶中共轭亚油酸,其平均含量为1.64mg/g。 相似文献
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Ethylbenzene and styrene were determined by an automated dynamic headspace system with a purge-and-trap injector. Hydrocarbons were purged with He into a cold trap and separated by GC. The procedure. was applied to dairy products without sample preparation. Preliminary He treatment, temperature of condenser, and of the analytical cell were important. Results of styrene migration from the package into dairy products, including yogurts, cream and chocolate desserts, were well below 5μg/kg. 相似文献
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Samples were taken at 9 stages of processing, from raw milk to cheese aged for 6 mo. Fatty acid distributions, conjugated linoleic acid (CLA), moisture, protein, lipid contents, and titratable acidity were determined. CLA contents were highest after 3 mo, with one type of Cheddar (3.76 mg/g lipid) higher than the other two (3.44 and 3.47 mg/g lipid). Multiple linear regression showed all composition parameters were directly related to CLA content (mg/100 g sample). The content of oleic acid isomer C18:1ω7 was also directly related to CLA content (mg/g lipid). Thus, content of CLA in Cheddar-type cheeses might be controlled by stage and conditions of processing. An understanding of the effects of processing on CLA formation in Cheddar-type cheeses will be beneficial in designing processing methods to enhance CLA contents. 相似文献
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高效液相色谱法测定乳制品中的低聚果糖的含量 总被引:8,自引:3,他引:5
HPLC法能准确,快速地对低聚果糖进行定性,定量分析,本研究对添加了低聚果乐的酸奶,测定各糖组分如下:乳糖约30%,葡萄糖15%,FOS40%。此外还含有少量的果糖和蔗糖。 相似文献