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研究苦瓜皂甙的提取工艺和测定方法.以人参皂甙Rg1标准品为参照,采用分光光度法对苦瓜中皂甙进行定量分析;以料液比、浸提温度、乙醇的质量分数、提取时间为考察因素,采用二次回归正交旋转组合试验方法对苦瓜皂甙提取工艺条件进行优化.通过贡献率法分析表明,各因子对浸提率影响的相对大小依次为:提取时间>料液比>乙醇浓度>浸提温度;经频率分析得到苦瓜皂甙浸提率>2.18%的优化条件为:料液比10.190~11.016倍,浸提温度68.80~72.33℃,乙醇浓度71.32~74.32%,提取时间13.484~19.396h,且所建立的数学模型在此范围内能够较准确的预测皂甙的浸提率.料液比1:10,浸提温度70℃,乙醇浓度70%,提取时间为12h,这个条件比较贴近实际生产应用,且比较接近理论值. 相似文献
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利用响应面分析法对藜麦籽粒皂甙的提取条件进行探索,并研究萌芽对藜麦皂甙含量的影响。在单因素试验的基础上,选取乙醇提取分数、料液比和浸提温度进行三因素三水平的Box- Behnken试验设计,通过响应面分析法对提取条件进行了优化;同时在优化条件下测定萌芽144 h藜麦中的皂甙含量变化。结果表明,在560 nm波长下,最佳提取条件为乙醇体积分数65%,料液比1∶40,浸提温度60℃,皂甙提取量为5.56 mg/g。萌芽试验结果表明,萌芽初期(6 h内)皂甙含量迅速下降,在6~42 h期间含量保持平稳,42 h后逐渐升高直至96 h时达最高值7.80 mg/g,萌芽120 h后皂甙含量开始下降。 相似文献
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以栀子粉末为原料,运用微波辅助提取栀子中的皂甙,并对其抗氧化性进行研究。在单因素试验基础上,以微波时间、浸提时间、液固比和乙醇浓度为因素,皂甙得率为响应值,采用Box-Behnken试验设计进行响应面分析。并以抗坏血酸为对照,用铁氰化钾还原法和DPPH自由基的清除率考察栀子皂甙的抗氧化活性。实验结果表明,栀子皂甙微波辅助提取最优条件为微波功率450 W、微波时间40 s、浸提时间9.6 min、浸提温度50 ℃、液固比21:1 (mL/g)、乙醇浓度80%,所得最佳得率为13.92%±0.04%,与模型预测皂甙得率相对误差仅为2.05%。微波辅助法提取栀子皂甙简便、提取得率高,回归模型合理可靠,可用于实际预测。抗氧化活性研究表明,栀子皂甙对羟基自由基的还原能力和DPPH自由基清除能力均较好,但其总体抗氧化性低于抗坏血酸。 相似文献
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纸浆清洁漂白过程中非过程金属元素富集态的研究 总被引:1,自引:1,他引:1
采用外加非过程金属离子的方法模拟苇浆生产过程金属离子的富集,进行纸浆清洁漂白非过程金属元素在过程流中的富集状态研究.研究表明:约50%的过渡金属离子以游离态存在,易被洗涤除去;Mn2 、Ca2 和Fe3 为纤维素纤维化学吸附态>木素螯合态,Gu2 则相反;酸性条件下预处理对去除金属离子富集有良好效果,对Mn2 尤其有效;N助剂(pH值4)对消除不同富集态金属离子效果服从木素螯合>纤维素纤维化学吸附的关系.浆中残余富集的金属离子中,Mn2 、Fe3 和Ca2 以纤维素纤维化学吸附态居多;浆中金属离子的富集随浆中木素含量的提高而增加. 相似文献
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Effect of substituting pork backfat with rind on quality characteristics of pork sausage 总被引:1,自引:0,他引:1
A study was conducted in which pork backfat in pork sausage was replaced with rind at 0, 33, 66 and 100% levels. The high moisture and high protein content of rind consequently influenced the moisture and protein content of the final products. The fat level decreased with increase in the level of rind in the sausage. The lowest fat content of 7.99% was recorded on batch 4 sausage with 100% rind replacement level. Replacement of pork backfat with rind decreased refrigeration and cooking weight losses. The values obtained for sensory properties decreased with increase in the level of rind in the sausage. Up to 66% pork backfat can be replaced with rind in pork sausage without adverse effect on processing yield. 相似文献
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以苦荞为原料,将不同有效氯浓度(available chlorine concentration,ACC)的微酸性电解水(slightly acidic electrolyzed water,SAEW)应用于芽苗菜生产,研究其对苦荞芽活性成分及其抗氧化能力的影响。结果表明:SAEW处理组苦荞芽活性成分含量相比对照组有所增加,ACC为20 mg/L的SAEW处理的苦荞芽总酚、总黄酮及芦丁含量相比自来水对照组分别提升了28.69%、26.19%和29.08%。SAEW处理萌发的苦荞芽在生长7 d内苯丙氨酸解氨酶比活力均高于自来水对照组。苦荞芽的抗氧化活性物质含量与其抗氧化能力间呈显著正相关。 相似文献
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建立了高效液相色谱(HPLC)/示差折光检测器(RID)测定烟草和烟草制品中葡萄糖、果糖和蔗糖的方法。样品用0.01 mol/L 氢氧化钠溶液振荡提取60 min,以高度交联的铅型磺化苯乙烯-二乙烯苯(SDVB)树脂为填料的阳离子交换色谱柱为分离柱,用纯水作流动相进行等梯度洗脱,外标法定量。方法线性良好,相关系数均大于0.999。方法回收率98.9%~101.8%,精密度0.44%~0.90%。方法测定值与离子色谱法的检定结果一致。方法适用于各种烟草和烟草制品中葡萄糖、果糖和蔗糖的分析测定。 相似文献
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Dutch style fermented sausages were manufactured with a substitution of 10%, 15% and 20% of pork backfat by flaxseed oil and canola oil, pre-emulsified with soy protein isolate. The 15% and 20% substitution were also reached by adding encapsulated flaxseed oil and encapsulated fish oil and by adding flaxseed oil, pre-emulsified with sodium caseinate, respectively. The products were sliced, packaged in an oxygen-enriched atmosphere and stored in the dark for 12 weeks at 7°C. No differences were detected in moisture, protein and fat content between control and modified sausages, with the exception of the formulation with sodium caseinate. The PUFA/SFA ratio increased from 0.30 in the control to 0.42-0.48 in the sausages with canola oil and to 0.49-0.71 in the sausages with flaxseed oil. The n-6/n-3 ratio decreased from 11.20 in the control to 6.94-5.12 in the sausages with canola oil and to 1.93-1.05 in the sausages with flaxseed oil. The addition of canola oil and encapsulated flaxseed oil resulted in a comparable shelf life as the control in terms of lipid oxidation. In the samples with addition of pre-emulsified flaxseed oil, especially with sodium caseinate, lipid oxidation clearly increased during storage. Physical and sensory analysis showed that the sausages with encapsulated fish oil and flaxseed oil resembled the control most. 相似文献
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Quality of Sour Cream Packaged in Cups with Different Light Barrier Properties Measured by Fluorescence Spectroscopy and Sensory Analysis 总被引:1,自引:0,他引:1
Hanne Larsen Siri Birgitte Geiner Tellefsen Annette Veberg Dahl 《Journal of food science》2009,74(8):S345-S350
ABSTRACT: In this study, photooxidation of sour cream packaged in cups with different light barrier properties was investigated. The sour cream was light exposed for 36 h with a standard fluorescent light tube, simulating storage conditions in many Norwegian grocery stores. Three different cups were evaluated: a white cup, a cup with medium light barrier (LB), and a cup with high LB. The quality of the sour cream was evaluated by sensory analysis and front face fluorescence spectroscopy. The sour cream stored in white cups became very rancid during the light exposure, with a rancid flavor score of 7.8 on a scale from 1 to 9, where 9 is the highest intensity. Cups with high LB gave best protection against the light. The sensory assessors could not distinguish between sour cream stored in cups with high LB and sour cream stored in the dark. The rancid flavor intensity for the cups with medium LB was significantly different ( P < 0.05) from both the white cup and the cup with high LB. The sensory flavor intensities indicated that with 36 h of light exposure, only a cup with high LB will protect the sour cream sufficiently. The fluorescence measurements corresponded well with the sensory analysis as the photosensitizers were somewhat degraded for sour cream stored in cups with medium LB and most degraded in the white cups. For the cups with high LB, the fluorescence peaks that originated from the photosensitizers were all intact.
PRACTICAL APPLICATION: Dairy products such as sour cream will develop off-odor and taste faults ("sunlight taste") in a few hours if exposed to sufficient fluorescent lightning in the grocery stores. A light barrier can be incorporated in the packaging material to protect the dairy products from the light. Our experiment showed that the incorporation of a black pigment into 1 of the 3 plastic layers in the cup for packaging of sour cream protected the sour cream from degradation when exposed to light. 相似文献
PRACTICAL APPLICATION: Dairy products such as sour cream will develop off-odor and taste faults ("sunlight taste") in a few hours if exposed to sufficient fluorescent lightning in the grocery stores. A light barrier can be incorporated in the packaging material to protect the dairy products from the light. Our experiment showed that the incorporation of a black pigment into 1 of the 3 plastic layers in the cup for packaging of sour cream protected the sour cream from degradation when exposed to light. 相似文献
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目的观察肝素钠乳膏(海普林)联合皮质类固醇软膏治疗剥脱性唇炎的效果。方法治疗组联合用药,对照组单独用药,均外涂于患处。结果联合用药效果优于单独用药。结论肝素钠乳膏联合皮质类固醇软膏治疗剥脱性唇炎疗效满意。 相似文献
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A selective and sensitive method for the determination of trace amounts of cobalt has been developed by polymer-phase fluorophotometry
with thiamine as an emission reagent. The method is based on the fact that cobalt reacts with thiamine to form a strong fluorescent
compound in 0.65% sodium hydroxide medium. The fluorescence intensities show a good linearity with the concentration of cobalt
in the range of 2–56 μg/L. The fluorescence intensities were measured in 5-mm quartz cells with excitation and emission wavelengths
at 375 and 438 nm, respectively. The detection limit is 0.61 μg/L and the RSD is 1.70%. The sensitivity of the method is four
times the conventional fluorophotometry in solution. The fluorescent life of thiamine is longer in polymer than that in solution.
The general coexisting ions have no interference to the reaction of cobalt and thiamine except for copper and iron ions. The
proposed method was applied to the determination of trace amounts of cobalt in food samples with satisfactory results. 相似文献
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辅助材料设计参数对烤烟型卷烟烟气焦油、烟碱和CO释放量的影响 总被引:3,自引:0,他引:3
为探索辅助材料与卷烟烟气化学成分之间的关系,研究了卷烟纸定量、卷烟纸透气度、成形纸透气度、接装纸透气度和滤棒吸阻对卷烟主流烟气焦油、烟碱和CO释放量的影响,并通过辅材设计参数的组合设计,建立了辅材设计参数预测焦油、烟碱和CO释放量的数学模型.结果表明:①卷烟纸定量增加CO释放量增加;②卷烟纸透气度增加,焦油、烟碱和CO释放量降低;③滤棒吸阻增加,焦油和烟碱释放量降低;④接装纸透气度增加,焦油、烟碱和CO释放量显著降低;⑤成形纸透气度增加,焦油、烟碱和CO释放量降低,降低程度与配合使用的接装纸透气度有关;⑥焦油、烟碱和CO释放量预测模型的预测值与实测值基本吻合. 相似文献