共查询到20条相似文献,搜索用时 95 毫秒
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本文结合水热合成法和模板法,以氯化镁和硅胶球为前驱体制备多孔硅酸镁,用作糖汁清净剂。运用XRD、FTIR和SEM等多种表征手段对多孔硅酸镁进行了表征。以多孔硅酸镁作为吸附剂,以吸附量为指标,考察了吸附时间、初始浓度对多孔硅酸镁吸附没食子酸性能的影响。由表征结果可知,制备的硅酸镁为孔径为5和22 nm为主的介孔球形多孔硅酸镁;吸附实验结果表明,当没食子酸的初始浓度分别为25、50、75 mg/L时,多孔硅酸镁对没食子酸的吸附过程均可用准二级动力学方程描述(R2分别为0.9965、0.9941、0.9941),附等温曲线符合Freundlich模型(R2=0.9926)。方法可为制糖工艺吸附脱色提供理论研究基础。 相似文献
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目的:建立HPLC 色谱法测定罗汉果中VC 含量的方法。采用5g/L 草酶对罗汉果浸提15min,对提取液中VC 进行检测,具体方法:采用SinoChrom ODS-BP(250mm × 4.6mm,5μm)分离;流动相为体积分数0.05% 磷酸溶液- 甲醇(98:2,V/V);流速1.0mL/min;采用二极管阵列多波长检测器确定VC 的最大吸收波长为242nm;测定温度25℃;进样量10μL。结果表明:VC 溶液0.08~0.50mg/mL 范围线性关系良好,相关系数r=1;回收率为99.3%,RSD 为1.93%。结论:该方法操作简便快速,精密度和稳定性好,适用于罗汉果VC 含量的测定。 相似文献
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建立了一种利用高效液相色谱法(HPLC)测定绿茶提取物原料中表没食子儿茶素没食子酸酯(EGCG)含量的方法。通过对流动相组成、色谱柱、流速及温度等色谱条件的选择及优化,得到了适合EGCG检测的色谱条件:色谱柱TSK-GELODS-100V,流动相组成甲醇∶水∶乙酸=23∶75∶2的,流速1.0mL/min,检测波长276nm,柱温24℃。实验结果表明,EGCG在含有咖啡因及与EGCG类似物质的复杂体系中被快速、高效地检出。同时,该方法操作简单,检测效率高,重现性好,可以有效地节约实验成本,进一步证明了该方法可行性。在实际测定中,可以实现原料检测工作的快速、高效运行,适合企业对绿茶提取物原料中EGCG的质量控制。 相似文献
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建立了高效液相色谱法测定制备Lyocell纤维的N-甲基氧化吗啉/水(NMMO/H2O)溶液中没食子酸正丙酯含量的方法;讨论了影响检测准确性的主要因素。 相似文献
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建立了用高效液相色谱(HPLC)法测定金莲花中谷甾醇的含量的方法。其中色谱柱:HypersilODS2柱(4.6mm×150mm,5μm);流动相:甲醇;检测波长208nm;柱温40℃;流速为1.0mL/min。结果胆甾醇质量在1.835-18.35μg范围与峰面积值的线性关系良好(R2:0.9995),平均含量为99.65%,RSD=0.3%,(n=5)。结论该法准确性和重复性好,可用于金莲花的质量控制。 相似文献
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Fabiane Hamerski Vítor R. da Silva Marcos L. Corazza Papa M. Ndiaye Arislete D. de Aquino 《International Journal of Food Science & Technology》2012,47(2):422-428
This paper reports a study of sugar cane juice carbonation and the evaluation of variables effects such as pH, carbonation time and temperature on industrially relevant parameters for the quality of sugar cane juice. Three different batches of sugar cane juice were evaluated using a complete two‐level factorial design with central point performed in triplicate. From results in this work, it can be seen that the higher sucrose concentrations and lower percentage of total soluble solids and reducing sugars were obtained in clarified juices with the maximum values for pH, time and reaction temperature (9.5, 60 min and 80 °C). The temperature favoured the removal of starch, phosphate and turbidity. Colour removal reached a maximum of 88–93% among the batches. The optimum clarification condition using carbonation procedure can be achieved between 20 and 40 min, at pH values between 8.0 and 9.5 and temperature condition at 80 °C. 相似文献
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对食用仙人掌汁中蔗糖的测定方法进行了探讨,通过单因素和正交实验确定了食用仙人掌汁中测定蔗糖含量最佳条件为:样品水解时加入的浓盐酸量15ml,反应滴定温度80℃,反应液碱度(pH)5.0、水解时间30min. 相似文献
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为了研究取代SO2的新型糖用澄清剂,以壳聚糖(CTS)为原料、氯乙酸(CA)为改性剂,采用微波辐射技术制备羧甲基壳聚糖。以该产物对蔗汁澄清的脱色率和纯度差为评价指标,优化制备条件,使用扫描电镜(SEM)、红外光谱仪(FT-IR)及核磁共振(1H-NMR)分析产物性能及表征结构。结果表明,在mNa OH∶mCTS=5∶1,微波功率600W,辐射时间12min,mCA∶mCTS=6∶1条件下,所制备的羧甲基壳聚糖为N,O-羧甲基壳聚糖,水溶性得到改善、对蔗汁中带电胶体的吸附范围及电中和性能有所增加;其对蔗汁澄清的脱色率和纯度差分别达50.45%和1.63%,通过对比亚硫酸法澄清工艺的实际生产数据,认为羧甲基壳聚糖可以取代SO2作为糖用澄清剂应用于蔗汁澄清过程。 相似文献
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为得到澄清的甘蔗汁,提高甘蔗汁的利用价值。考查了反应时间、两性聚丙烯酰胺的用量、反应温度和甘蔗汁的p H对甘蔗汁透光率的影响,在单因素基础上,利用L16(45)正交实验研究了最优组合和因素的主次关系,比较了原甘蔗汁与澄清后甘蔗汁的主要理化指标,并利用红外光谱和紫外光谱进行了表征。结果表明甘蔗汁澄清的最优组合:反应时间为20 min、絮凝剂用量为8 m L、反应温度为60℃和p H为5,因素的主次关系依次为p H、絮凝剂用量、反应温度和反应时间。在此条件下澄清后甘蔗汁透光率可达到94.7%。经澄清后的甘蔗汁较原甘蔗汁的VC、可溶性固形物、总糖和蛋白质等的含量有所下降,并且还有一定量的两性聚丙烯胺残留在甘蔗汁中。 相似文献
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Katia Rezzadori Rodrigo R. Petrus Silvia Benedetti Claudimir A. Carminatti José C. C. Petrus 《International Journal of Food Science & Technology》2013,48(1):1-9
The aim of this study was to determine the physico‐chemical, microbiological, rheological and sensory characteristics of sugar cane juice with passion fruit pulp (5% w/w) added and which had been submitted to microfiltration and pasteurisation (90 °C/30 s; 95 °C/30 s) processes. The results showed that the juices obtained after the microfiltration and pasteurisation processes had low microbial counts. The microfiltered juice showed a reduction in the soluble solids, acidity and vitamin C content (P = 0.05), while the pasteurised juice showed no change in these parameters (P > 0.05) in relation to the natural sugar cane juice, with the exception of vitamin C, which was not detected after the thermal treatment. In relation to the rheological properties, Newtonian behaviour was observed for both microfiltered and pasteurised juices. The sensory tests on a hedonic scale showed good acceptance of both juices (microfiltered and pasteurised). 相似文献
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Maritza A. Sirven Marcos Negrete Stephen T. Talcott 《International Journal of Food Science & Technology》2019,54(5):1523-1529
The effect of tannase on gallic acid (GA) bioaccessibility and auto-oxidative browning of mango juice was investigated. After 2 h of simulated gastric digestion, the concentration of bioaccessible GA increased (P < 0.05) 94.3 ± 7.0% in juice treated with 0.5 U mL−1 tannase while juice not treated with tannase had only a 6.3 ± 3.4% increase in GA. During 2–10 h of simulated intestinal digestion, tannase treated juice continued to have a higher concentration (P < 0.05) of bioaccessible GA in comparison to juice that was not treated with tannase. The use of 167 U 100 mL−1 tannase while processing mango juice did not result in any differences (P < 0.05) in browning measured at 420 nm, yet there was significantly higher (P < 0.05) GA in mango juice post-storage. Processing mango juice with tannase can help improve the bioaccessibility of mango polyphenols without hindering the quality of juice during storage. 相似文献