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基于近红外高光谱成像技术的干制红枣品种鉴别 总被引:4,自引:0,他引:4
为实现干制红枣的快速鉴别,提出了一种基于近红外高光谱成像技术的鉴别方法。采集四个品种共240个样本干制红枣的近红外高光谱图像(1 000~1 600 nm)。通过主成分分析法(principal component analysis,PCA)、载荷系数法(x-Loading Weights,x-LW)和连续投影算法(successive projections algorithm,SPA)分别提取7个、8个和10个特征波长;基于灰度共生矩阵(gray level co-occurrence matrix, GLCM)提取第一主成分图像的纹理特征。分别以光谱特征、纹理特征、光谱和纹理融合特征作为输入,建立偏最小二乘判别分析(partial least squares-discriminant analysis,PLS-DA)、反向传播神经网络(back-propagation neural network,BPNN)和最小二乘支持向量机(least squares support vector machines,LS-SVM)模型。结果显示,基于融合特征的模型鉴别率高于分别基于光谱特征或纹理特征的模型鉴别率;基于融合特征的BPNN模型的结果最优,对预测集样本鉴别正确率为100%。说明近红外高光谱成像技术可用于干制红枣品种的快速鉴别。 相似文献
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建立了UV-Vis分光光度测定红枣中多糖含量的方法.考察了乙醇体积、超声温度、超声时间、料液比4因素对多糖含量测定的影响.在单因素试验结果的基础上,进行正交试验设计,试验结果表明:最佳测定条件为A2B2C3D2,即超声温度为50℃,超声时间为60min,料液比为1∶30(g/mL),乙醇用量为30mL.方法平均回收率为96.87%,RSD为1.11%(n=5).该法快速、灵敏、准确,可用于红枣多糖的提取及含量测定. 相似文献
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采用火焰原子吸收光谱法,测定了6种红枣中6种微量元素的含量.测定结果表明,红枣中微量元素含量丰富,其含量顺序由高到低为Ca、Mg、Fe、Zn、Mn和Cu.并对6种红枣作了聚类分析,比较分析了6种红枣之间的相关性,这对于发挥红枣的药用价值具有重要意义. 相似文献
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南疆红枣品质近红外光谱在线模型参数的实验研究 总被引:1,自引:0,他引:1
为建立南疆红枣品质近红外光谱在线校正模型,分析了在线检测结果的主要影响因素,对相应的参数进行了实验研究。设置红枣不同的光谱采集条件,如测量状态、波段谱区、仪器参数等,利用近红外光谱仪和自行设计的红枣批量采集附件,获取南疆红枣品质光谱,通过光谱预处理和检测精度相结合的办法选择条件参数。通过不同建模参数进行PLS光谱校正和二维相关光谱分析,选择糖度特征光谱参数。结果表明:红枣糖度中心波长9 116,9 418和10 500cm-1,采集分辨率16cm-1,扫描次数8次,糖度相对误差8%~10%,单粒红枣光谱数据量减少为原来的1/10,采集时间减少了3s左右。通过实验参数,压缩了数据量,建立了初级在线校正模型,基本实现南疆红枣品质近红外光谱在线检测。 相似文献
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近红外拓扑方法在南疆红枣品质分析中的应用 总被引:2,自引:0,他引:2
从南疆红枣的物理和光谱特征两方面,通过反复调整和逐步细分相结合的方法,给出红枣品质细分和特征因子分析框图。实际应用中可依据不同需要设置最佳光谱参数来提高光谱重复性和质量。实验分离出南疆红枣常见的裂口褐变、色泽和成分等光谱特征因子,如褐变特征因子明显尖峰特征谱线位置10 170cm-1。通过光谱图的特征分析,初步建立了红枣近红外光谱和部分品质之间的对应关系,为下一步红枣品质编码奠定了基础。该方法可节省大量重复建模费用,在建立红枣近红外品质分析标准和模型库共享方面有较好的应用前景。 相似文献
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FAAS测定新疆哈密红枣中的微量元素 总被引:1,自引:0,他引:1
用硝酸-高氯酸溶解试样,盐酸溶出,利用空气-乙炔火焰原子吸收光谱法测定哈密红枣中Ca、Mg、Fe、Zn、Cu、Mn微量元素的含量,该方法的加标回收率在97.10%—100.20%之间,相对标准偏差(RSD)在0.18%—2.33%之间,具有较好的准确度和精密度。实验发现哈密红枣中微量元素含量丰富,这为哈密红枣的合理食用及进一步开发利用提供了可靠的依据。 相似文献
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红枣中微量元素含量的测定 总被引:5,自引:0,他引:5
用火焰原子吸收光谱法(FAAS)测定了红枣中K、Ca、Mg、Cu、Mn、Zn、Fe等7种微量元素的含量.实验方法加入标准样回收率在99.4%-105.2%之间,RSD在0.4%-1.3%之间,分析结果令人满意.红枣中含有丰富的微量元素,其含量由高到低的排列顺序为:Fe、K、Ca、Mg、Zn、Mn、Cu,说明红枣具有很高的营养价值. 相似文献
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不同品种红枣中微量元素的分析 总被引:2,自引:1,他引:1
微波消解-原子吸收光谱法测定红枣中微量元素含量,发挥不同品种红枣的药用和食用贾?红枣中6种微量元素含量分别是:铁21.01-31.09mg/kg,钙607.40-787.80mg/kg,铜1.97-3.58mg/kg,锌6.46-14.91mg/kg,锰2.64-3.67mg/kg,镁358.60-431.40mg/kg.红枣中微量元素的含量丰富,尤其是钙、镁、铁的含量较高. 相似文献
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优化了舒胸片处方中红花与川芎超声提取工艺.以红花中羟基红花黄色素A (Hydroxysafflor yellow A.HsYA)、川芎中阿魏酸(Ferulic acid,FA)的提取率为考察指标,应用正交试验,考察乙醇浓度、物料比、超声时间和超声次数对提取效果的影响.最终得到川芎和红花药材提取工艺如下,加入12倍50%乙醇超声提取2次,每次30min,能最大限度的提取红花与川芎药材中的有效成分.建立的优化工艺能有效克服川芎、红花药材有效成分热不稳定的缺点,提取转移率较高,可为工业生产提供参考. 相似文献
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It is reported that salvianolic acid B, a bioactive phenolic compound contained in the root of Salvia miltiorrhiza, exhibits a much stronger activity in free radical scavenging and antioxidance than those of vitamin E. When a conventional refluxing method is adopted to extract salvianolic acid B from the root, in which the materials are subjected to higher temperature and longer time, the yield of this phenolic compound is lower due to the possibility of its hydrolysis to tanshinol. However, a higher extraction yield can be achieved over a shorter time period and lower temperature when an ultrasound-assisted extraction method is used. This paper investigated the parameters influencing the extraction of salvianolic acid B. Factors such as extraction time, frequency of the ultrasound, the ratio of solvent to material, and types of extraction solvent were examined. A comparison was also conducted between conventional refluxing and ultrasound-assisted extraction. Results showed that the optimal parameters to extract salvianolic acid B from the root of S. miltiorrhiza were as follows: ultrasonic frequency: 45 Hz; solvent: 60% aqueous ethanol; extraction temperature: 30 °C; extraction time duration: 25 min.; ratio of solvent to material: 20:1 (v/w, ml/g). Under these conditions, the yield of salvianolic acid B was 5.17 mg/g (33.93 mg/g) higher than those with conventional refluxing method (28.76 mg/g), indicating that the efficiency and the yield of ultrasound-assisted extraction method are higher than reflux method, and the hydrolysis of salvianolic acid B to tanshinol is effectively avoided. 相似文献
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Ultrasound-assisted extraction of ginseng saponins from ginseng roots and cultured ginseng cells 总被引:11,自引:0,他引:11
Ultrasound-assisted extraction was evaluated as a simpler and more effective alternative to conventional extraction methods for the isolation of ginsenosides (saponins) from various types of ginseng. The ginseng samples were extracted with different solvents, under either direct sonication by an ultrasound probe horn or indirect sonication in an ultrasound cleaning bath. The ultrasonic extraction was compared with the conventional method of refluxing boiling solvents in a soxhlet extractor, on the yields of both the total saponin isolated by thin-layer chromatography and the individual ginsenosides by high performance liquid chromatography. It was found that the sonication-assisted extraction of ginseng saponins was about three times faster than the traditional extraction method. The ultrasonic extraction was not only more efficient but also convenient for the recovery and purification of the active ingredients of plant materials. In addition, the sonication-assisted extraction can be carried out at lower temperatures which are favorable for the thermally unstable compounds. 相似文献
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Improved extraction of vegetable oils under high-intensity ultrasound and/or microwaves 总被引:3,自引:0,他引:3
Cravotto G Boffa L Mantegna S Perego P Avogadro M Cintas P 《Ultrasonics sonochemistry》2008,15(5):898-902
Ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE) techniques have been employed as complementary techniques to extract oils from vegetable sources, viz, soybean germ and a cultivated marine microalga rich in docosahexaenoic acid (DHA). Ultrasound (US) devices developed by ourselves, working at several frequencies (19, 25, 40 and 300 kHz), were used for US-based protocols, while a multimode microwave (MW) oven (operating with both open and closed vessels) was used for MAE. Combined treatments were also studied, such as simultaneous double sonication (at 19 and 25 kHz) and simultaneous US/MW irradiation, achieved by inserting a non-metallic horn in a MW oven. Extraction times and yields were compared with those resulting from conventional procedures. With soybean germ the best yield was obtained with a ‘cavitating tube’ prototype (19 kHz, 80 W), featuring a thin titanium cylinder instead of a conventional horn. Double sonication, carried out by inserting an immersion horn (25 kHz) in the same tube, improved the yield only slightly but halved the extraction time. Almost comparable yields were achieved by closed-vessel MAE and simultaneous US/MW irradiation. Compared with conventional methods, extraction times were reduced by up to 10-fold and yields increased by 50–500%. In the case of marine microalgae, UAE worked best, as the disruption by US of the tough algal cell wall considerably improved the extraction yield from 4.8% in soxhlet to 25.9%. Our results indicate that US and MW, either alone or combined, can greatly improve the extraction of bioactive substances, achieving higher efficiency and shorter reaction times at low or moderate costs, with minimal added toxicity. 相似文献