共查询到20条相似文献,搜索用时 234 毫秒
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为提高腈纶活性染料的染色性能,采用三乙烯四胺对腈纶纤维进行接枝改性,探究了氯化钠、染料和碳酸钠用量,染色p H值、温度和时间对改性腈纶活性红B-3BF染色性能的影响,测试了染色腈纶的上染百分率和表观色深K/S值。研究结果表明,活性红B-3BF对改性腈纶的上染百分率和K/S值随染色p H值的降低而增加,随染色温度的升高或时间的延长而增加,氯化钠对染料的染色影响不大,染料用量超过2%(owf)后提升性能较差;当染料活性红B-3BF为2%(owf)时,最佳染色工艺为:p H值5,升温至100℃加入碳酸钠0~2 g/L,保温染色40 min,该工艺条件下改性腈纶活性红B-3BF染色的上染百分率可达到80%以上。 相似文献
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涤锦超细纤维无纺布分散染料低温染色 总被引:1,自引:1,他引:0
选用托拉斯分散染料对涤锦超细纤维无纺布进行低温染色,研究了入染温度、染色温度、保温时间及染料用量等因素对染色性能的影响。结果表明,涤锦超细纤维无纺布分散染料低温染色优化工艺为:入染温度30℃,染色温度100℃,保温时间60 min,染料用量不大于4%。该工艺条件下,锦纶组分损伤小,染料上染率高,得色深。 相似文献
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为开发植物多酚保健功能纺织品,通过单因素分析法,探讨pH值、温度、处理时间对茶多酚在棉织物上吸尽率的影响;对棉织物进行阳离子改性,分析改性剂浓度、碱剂用量、改性温度和改性时间对吸尽率的影响;测试茶多酚整理后棉织物的抗菌消臭性能。结果表明:茶多酚对棉织物的浸渍优化工艺为茶多酚6%(o. w.f),温度40℃,时间60min,浴比1:30,应用此工艺,茶多酚对棉织物的吸尽率为14.6%;棉织物的阳离子改性优化工艺为:改性剂质量浓度25 g/L,碱剂质量浓度6 g/L,温度70°C,时间90 min,浴比1:30,茶多酚应用此改性工艺处理的棉织物的吸尽率为48.8%。经阳离子改性和茶多酚二步法处理后,棉织物的抑菌率(金黄色葡萄球菌)和消(氨)臭率分别为92.2% 和90%,再经铜后媒处理,棉织物的抑菌率(金黄色葡萄球菌)和消(氨)臭率分别达100% 和99.9%。 相似文献
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Yongfeng Liu Qingqing Bai Yi Liu Duolong Di Mei Guo Lei Zhao Jintian Li 《European Food Research and Technology》2014,238(1):59-69
To separate and purify tea polyphenols and caffeine from discarded green tea crude extract with macroporous adsorption resins (MARs), the adsorption properties of twenty kinds of MARs are systematically evaluated. The results show that GS-18 has higher separation efficiency than other MARs, and the experimental data fit best to the pseudo-second-order kinetic model. And adsorption isotherms and thermodynamics of tea polyphenols and caffeine on GS-18 are investigated. The separation parameters of tea polyphenols and caffeine from discarded green tea crude extract are optimized according to dynamic adsorption/desorption experiments with the column packed with GS-18. Through only one cycle treatment, the content of tea polyphenols increases 3.0-fold from 20 to 60 % with a recovery yield of 91 % and that of caffeine increases 3.1-fold from 7 to 22 % with a recovery yield of 98 %. The results demonstrate that the method of MARs will provide useful help for the development of large-scale separation of tea polyphenols and caffeine from discarded green tea in industry. 相似文献
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Aurlie Couzinet-Mossion Stphane Balayssac Vronique Gilard Myriam Malet-Martino Martine Potin-Gautier Philippe Behra 《Food chemistry》2010,119(1):107-181
Black tea infusions of Camellia sinensis leaves were studied for the influence of water composition, especially calcium content, on the amount of extracted organic matter and on the interactions between caffeine and polyphenols. The higher the calcium content, the lower the extraction of caffeine and polyphenols in acidic media. In alkaline media, besides the calcium effect, polyphenols are oxidized. Caffeine NMR chemical shifts varied depending on the water used showing modified interactions. Using model solutions, polyphenols seem to be responsible for these changes in the case of ultra pure water, but in the case of alkaline solutions, the data in model solutions are different from tea infusions implying that other compounds should interact. Moreover, epigallocatechin gallate (EGCg) and epigallocatechin are the polyphenols interacting most strongly with caffeine in infusions and not EGCg and epicatechin gallate as thought before. 相似文献
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:目的 研究3个不同等级烘青绿茶的生化成分、感官品质及抗氧化活性。方法 使用分光光度计测定3种茶样中总黄酮、茶多酚、氨基酸和咖啡碱的含量,利用清除二苯代苦味酰基自由基(1,1-dipheny-2-picryhydrazyl free radical, DPPH)法测定了其抗氧化活性,并进行感官评价。结果 3个等级绿茶总黄酮、茶多酚、氨基酸和咖啡碱含量差异显著(P<0.05),茶多酚随着茶样等级的降低而升高,咖啡碱的含量则相反,而氨基酸和黄酮是波动变化;不同等级绿茶的半抑制浓度(half maximal inhibitory concentration, IC50)差异显著(P<0.05),且IC50随着等级的降低而下降;感官评价得分随着等级的降低而降低;3种茶的抗氧化活性与其茶多酚含量成极显著正相关P<0.01),与咖啡碱的含量和感官审评得分呈极显著负相关(P<0.01)。结论 3个等级的炒青绿茶抗氧化性随着等级的降低而升高,且与其主要生化成分呈显著相关。 相似文献
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选用‘陕茶1号’春季一芽二叶新梢为原料,分别按照扁形茶、卷曲形茶、针形茶、兰花形茶和炒青工艺加工成绿茶,所制茶样通过感官审评、内含成分分析、香气组分分析和抗氧化能力分析,以确定‘陕茶1号’春季鲜叶原料加工绿茶的最佳工艺。结果表明:兰花形茶各内含成分适中协调,水浸出物含量为46.24%,氨基酸含量最高达4.22%,咖啡碱含量为4.54%,茶多酚含量为21.52%,酚氨比最低,叶绿素含量最高达2.15 mg/g,绿茶主要香气物质含量最高达21.69%,感官品质最佳,其加工工艺是加工‘陕茶1号’春季一芽二叶新梢的最佳工艺;扁形茶感官品质及其主要香气物质含量仅次于兰花形茶,多酚类保留量最高,各内含成分也较协调,且抗氧化能力最强,其加工工艺也适合‘陕茶1号’春季一芽二叶新梢的加工。 相似文献
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试验测定了不同焙火程度武夷水仙(毛茶、轻火、中轻火、中火、足火)的主要生化成分及其清除DPPH自由基的能力。结果表明,中火处理的武夷水仙感官评价得分最高,滋味醇厚顺滑,花香馥郁持久,清亮度较高。随着焙火程度的增加,水浸出物含量呈上升趋势;茶多酚和氨基酸的含量焙至轻火时含量升至最高,而后随着焙火程度增加而减少;黄酮焙至轻火时含量降低,然后又随着焙火呈现先升后降的倒Z型曲线变化;咖啡碱含量总体呈下降趋势;抗氧化能力随着焙火程度的升高而下降,其清除能力依次为毛茶>轻火>中轻火>中火>足火。相关性分析表明,茶多酚含量与DPPH·清除率呈显著相关(p<0.05),氨基酸、咖啡碱含量与DPPH·清除率呈极显著相关性(p<0.01)。结合武夷水仙感官评定和抗氧化能力,中火和中轻火可以作为最佳焙火选择。 相似文献
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Geoffrey V. Stagg David J. Millin 《Journal of the science of food and agriculture》1975,26(10):1439-1459
The nutritional significance of tea is confined to certain vitamins and minerals. Tea is able to contribute riboflavin, folic acid, β-carotene, α-tocopherol and phylloquinone, and is also one of the more significant sources of fluoride in the UK diet. The pharmacological action of caffeine in tea is so modified, probably by its interaction with polyphenols, that the beneficial properties of the alkaloid may be enjoyed without harmful side effects. Beneficial effects attributed to tea polyphenols acting synergistically with ascorbic acid include the strengthening of capillary blood vessels and an anti-atherosclerosis action. The potential value of tea has been well recognised in Russia but has received scant attention in the West. 相似文献