氢核磁共振结合支持向量机鉴别蜂蜜植物源

目的建立基于氢核磁共振(1H nuclear magnetic resonance,1H NMR)结合支持向量机分类模型鉴别蜂蜜植物源的方法。方法采集荆条蜜、油菜蜜、洋槐蜜、葵花蜜4种不同植物源的蜂蜜共计122例样品的谱图信息,分全谱(δ0.10~δ9.50)、脂肪区(δ0.10~δ3.00)、糖类化合物区(δ3.00~δ6.00)、芳香区(δ6.00~δ9.50)4个不同积分区间建立分类模型,结合主成分权值系数筛选特征变量,进一步优化判别模型。结果基于主成分权值系数筛选变量范围δ3.40~δ3.90和δ4.60~δ4.70内共计267个积分变量,以该区域积分变量为输入变量建立的支持向量机分类模型,对训练集的判别正确率为97.53%,对测试集的判别正确率为100%。结论通过主成分权值系数能有效筛选特征变量,减少输入变量的同时提高模型稳健性与准确性,基于氢核磁共振结合支持向量机分类模型能有效鉴别不同植物源蜂蜜。     

基于氨基酸特征的荞麦Fisher判别

根据甜荞和苦荞氨基酸的特点,筛选有效判别指标,建立判别准则。分别以氨基酸质量分数和相对含量为指标,采用逐步法构建Fisher判别模型,并进行试验验证。采用质量分数法建立的判别模型,以组氨酸、谷氨酸、丝氨酸、甘氨酸、苏氨酸和酪氨酸为变量,回判正确率为94.71%,交互验证正确率为93.27%;采用相对含量法建立的判别模型,以组氨酸、谷氨酸、甘氨酸、丝氨酸、苏氨酸和丙氨酸的相对含量为变量,回判和交互验证正确率均为95.19%;采用12份荞麦材料对模型进行试验验证正确率为100%。组氨酸、谷氨酸、甘氨酸、丝氨酸、苏氨酸的质量分数和相对含量在荞麦判别中均发挥重要作用,氨基酸指标与判别分析技术相结合,可作为荞麦种类鉴别和质量控制的一种有效、可行的方法。     

高光谱成像技术检测油茶果成熟度

为解决油茶果采摘期判断不准确可能导致的茶油产量降低问题,应用高光谱成像技术结合化学计量法对油茶果成熟度进行定性判别。完成了高光谱图像的曲率校正,分析不同成熟阶段油茶果的光谱特征和理化特征的变化情况。使用4 种不同的分类算法建立基于全波段光谱数据的油茶果成熟度判别模型,发现支持向量机（support vector machine,SVM）模型的分类正确率最高为97%。结合5 种特征变量选择方法对全波段光谱数据进行降维,发现经过竞争性自适应重加权算法（competitive adaptive reweighted sampling,CARS）选择的特征波长建立的模型正确率最高为82%。提取高光谱图像中的颜色特征和纹理特征建立SVM模型后发现,融合颜色特征和光谱特征建立的SVM模型的正确率高于使用单一的光谱特征（经CARS降维）建立的模型正确率：训练集分类正确率为95%,测试集正确率为93%。结果表明,利用高光谱成像技术能够对不同成熟度的油茶果进行较准确的分类,为茶农对油茶果最佳采摘期的判断提供科学依据,在保障茶籽产量最大化、油质最优化等方面具有重要意义。     

基于外观特征识别的花生品种与品质检测方法

花生的品种和品质检测是花生育种实践和质量检验的重要内容.为了评价通过外观特征进行大数目花生种子检验可行性,采用图像识别的方法通过数码相机拍得了48个品种和同一品种6种不同品质的花生群体图像,基于主分量分析和人工神经网络的方法建立和检验了由形态类、纹理类、颜色类共49个种子外观特征构建的识别模型并进行了模型组合优化.结果表明:模型优化后品种识别率和品质识别率分别达到91.2%和93.0%;颜色类特征在品种品质检测上效果优势明显;外观特征对品质的区分度较对品种的区分度大.采用机器视觉检测具有成本和速度上的优势,能够用于花生品种和品质的真伪鉴定.     

二氯甲烷提取物致香成分GC/MS指纹图谱在烤烟香型鉴别中的应用

以3种香型90份烤烟烟叶样品为研究对象,通过感官评吸确定烤烟香型。用二氯甲烷提取样品,采用VIP结合PLS-DA法分析GC/MS指纹图谱的特征信息,解析影响烤烟不同香型的致香成分,分别构建指纹图谱和致香成分的分类模型。进而分析特征致香成分与烤烟主体香韵的相关关系,探析影响烤烟主体香韵的致香成分。结果表明:1筛选出1 533个特征指纹图谱信息,建立的GC/MS指纹图谱判别模型的验证准确率、R2、RMSECV和RMSEP分别为96.67%、0.926、0.190和0.250;2解析出对烤烟不同香型分类具有较大贡献的52个致香成分,建立的致香成分分类模型的验证准确率、R2、RMSECV和RMSEP分别为86.67%、0.817、0.301和0.396;3通过逐步回归分析引入16项致香成分指标,建立烤烟香型(浓香、清香和中间香)的判别方程,其回代验证判别正确率分别为100%、91.7%和97.2%;4优选的16个特征致香成分与烤烟主体香韵均显著相关。上述判别模型均可有效鉴别不同香型烤烟,尤其是特征指纹图谱判别模型及烤烟香型逐步回归判别方程均较基于52个致香成分建立的分类模型具有更高的识别准确率。     

基于LDA_SVM的小麦质地检测方法研究

研究基于透射光图像的小麦质地检测方法,使用工业相机采集14种小麦种子的透射光图像,通过图像处理技术获取整粒小麦、胚乳和种胚代表性区域,并提取对应区域的颜色特征数据。分别运用PCA和LDA进行数据降维,并将降维前后的数据与支持向量机(SVM)、K近邻算法(KNN)和决策树模型(DT)3种分类器相结合建立分类模型,对不同品种小麦质地进行分类识别研究。结果表明：利用图像处理技术提取透射光全部特征,建立的LDA＿SVM模型分类正确率可以达到97%以上,证明透射光图像下通过机器学习对不同质地小麦快速分类鉴别是可行的。     

利用模式识别技术鉴别中国葡萄酒的产地和品种

通过测定样品的物理化学指标来辨别中国葡萄洒的品种和产地.本实验借助葡萄洒分析仪和紫外可见分光光度计,共测了20项物理化学指标.33个样品来自3个不同的产地,34个样品来自3个不同品种.方差分析破用来鉴别具有显著差异的变量.主成分分析和逐步判别分析被用来对数据进行进一步的分类分析.最终,通过典则判别分析分别建立了有效的产地鉴别和品种鉴别的判别模型,并且交义检验被用来对该模型的预测能力进行估计,正确率分别为93.94%和100%.     

基于高光谱成像技术的酿酒高粱品种分类

针对不同品种酿酒高粱分类难、分类精度有待提高等问题,提出了一种结合光谱和图像信息的高光谱成像技术从而对酿酒高粱进行分类的方法。通过采集11类共550个高粱样本的高光谱数据,运用连续投影算法从多元散射校正预处理后光谱中筛选出48个特征波长,再提取图像的灰度共生矩阵作为图像特征,利用纹理特征、全光谱、特征光谱及其结合图像特征分别建立支持向量机、偏最小二乘判别和极限学习机分类模型,最后再采集220个未参与建模样本对所建模型进行外部验证。结果表明,基于特征光谱结合纹理特征建立的支持向量机模型效果最佳,训练集和测试集的识别率分别为96%和95.3%,验证集的识别率达到91.8%,高于单一光谱数据建模效果,说明光谱和图像信息结合可以提高酿酒高粱的分类识别率。该方法为高粱品种的高精度分类和不同酿酒原料的快速无损检测提供了可行的方法。     

基于高效液相色谱-高分辨质谱法的非靶标代谢组学方法分析鉴别不同产地番茄

目的 分析不同产地来源番茄内源成分的差异及建立产地来源判别方法。方法 采用液相色谱-高分辨质谱（liquid chromatography - high resolution mass spectrometry,HPLC-HRMS）分析来源于全国5个地区105个番茄样品的乙醇-水提取物化合物组成,结合主成分分析(principal component analysis PCA)、正交偏最小二乘法判别分析(orthogonal partial least squares analysis discriminant analysis OPLS-DA)、双向正交偏最小二乘法判别分析(two-way orthogonal PLS-DA,O2PLS-DA)方法,对采集的HPLC-HRMS数据进行标志成分筛选和产地溯源模型构建。结果 以全部875个化合物为变量构建O2PLS-DA模型,筛选出其中99个对模型判别贡献较大的特征成分,重新构建了番茄产地的OPLS-DA判别模型,判别正确率达到99.05%。对特征成分进行了化合物结构分析,确定了其中18个有机酸、黄酮类特征化合物。结论 本研究建立的基于液相色谱-高分辨质谱的非靶标代谢组学方法能够科学、准确地用于番茄产地溯源,该研究为番茄产地溯源提供了一种新的策略。     

基于近红外漫反射光谱技术判别柿子品种和贮藏期的研究

目的通过近红外漫反射光谱技术建立了柿子不同品种和贮藏期的快速判别方法。方法实验对贮藏冷库(0±0.5℃)20 d、40 d、60 d的磨盘柿和阳丰甜柿的近红外光谱(400~2500 nm)进行平滑、一阶倒数和标准正常化处理(SNV)处理,采用主成分分析法(PCA)建立判别模型。结果在全波长范围内,不同品种定标模型的正确分类率达到100%;阳丰甜柿不同贮藏期的正确分类率达到97.78%;磨盘柿不同贮藏期的正确分类率达到98.89%。3个预测模型的累积准确率达到96.67%。结论通过近红外漫反射光谱技术,判别不同品种的柿子并预测其贮藏期具有应用价值。     

盐胁迫对苦荞萌发及其总黄酮含量的影响

研究了在一定浓度的铝、锌、铜盐溶液浸种后,苦荞种子萌发7d内发芽势、发芽率、粗蛋白含量的变化,并采用正交试验法设计,用吸光光度法测定样品中的总黄酮含量.结果表明,铝、锌、铜盐溶液浸种萌发对种子的芽苗生长和粗蛋白含量增加有促进的作用,而对发芽势和发芽率影响并不显著;正交试验发现对总黄酮含量影响因素显著性依次为萌发温度＞萌发时间＞金属盐种类,最佳萌发工艺条件为:金属盐种类为1000mg/L硫酸铝溶液,萌发时间为84h,萌发温度25℃,在此工艺条件下,苦荞种子中总黄酮含量可以达到1347.1mg/100gDW.     

In‐gel detection and study of the role of flavonol 3‐glucosidase in the bitter taste generation in tartary buckwheat

The present study demonstrated that flavonol 3‐glucosidase (f3g) is an important cause of bitter taste generation in tartary buckwheat (Fagopyrum tataricum) flour using the f3g complement test. To screen the f3g deletion line, which must have little bitter taste, an in‐gel method to detect individual f3g isozymes in tartary buckwheat seeds was developed. The f3g isozymes in tartary buckwheat seed were stained using a rutin–copper complex on the native–PAGE gel. This method was able to clearly detect as little as 1.4 ng of individual f3g isozymes within 20 min following electrophoresis. With this method, screening of the f3g deletion line can be conducted efficiently and will result in a better taste in tartary buckwheat flour. Copyright © 2004 Society of Chemical Industry     

贵州不同品种苦荞品质及其对荞麦面条加工的影响

通过对贵州地区不同品种苦荞的灰分、水分、粗蛋白、粗脂肪、淀粉、直链淀粉、总糖、粗纤维、总黄酮、出粉率等指标进行测定,并结合不同品种苦荞粉对苦荞面条感官品质、蒸煮损失、拉伸特性、质构特性的影响,筛选出适宜加工苦荞面条的苦荞品种。结果表明:10个品种总黄酮含量均值可达2.07 g/100 g,黔苦7号中总黄酮含量(2.95±0.11)g/100 g显著多于其他品种(P<0.05),粗蛋白含量均值为10.91 g/100 g,黔苦7号粗蛋白含量最高(12.09±0.77)g/100 g,直链淀粉含量均值达到22.85 g/100 g,出粉率均值达到70.32%。在苦荞粉添加量40%,小麦粉添加量60%,面团含水量35%的条件下制作苦荞面条,黔苦7号感官评分最高,拉伸阻力最大,弹性较好,更适用于苦荞面条加工。     

萌发对苦荞籽粒品质的影响及工艺优化

以苦荞籽粒为原料,分析了浸种和萌发温度及时间对苦荞籽粒总黄酮含量、γ-氨基丁酸(GABA)含量、DPPH自由基清除率、发芽率及芽长的影响,并优化了其萌发工艺条件。结果表明,苦荞籽粒的最佳萌发条件为:浸种温度20℃、浸种时间8h、萌发温度26℃、萌发时间98h。该条件下,萌发苦荞的总黄酮含量为10.34mg/g,是对照组的2.27倍;GABA含量为2.86mg/g,是对照组的1.17倍。制茶后,萌发苦荞茶总黄酮质量浓度为7.678mg/100mL,是对照组的3.71倍;GABA质量浓度为13.142mg/100mL,是对照组的1.63倍;茶汤的颜色、透明度、香气、滋味、总分等感官评分均优于对照组。萌发处理可以提高苦荞茶的总黄酮含量、GABA含量及感官品质。     

苦荞品种对苦荞配制酒品质的影响

目的:寻找配制酒品质最佳的苦荞品种。方法:考察以3种不同苦荞浸泡出的酒(A、B、C)中的总黄酮、可溶性固形物、总酚含量,抗氧化特性,色差以及透光率,探究不同品种苦荞对酒品质特性的影响。结果:苦荞B的总黄酮、总酚、可溶性固形物含量及DPPH自由基、ABTS自由基清除率均为最佳。色差值表明总黄酮、总酚含量与酒样颜色有一定的显著相关性。浸泡40 d的B1样品中共有49种挥发性物质,相对含量为79.488%,其中酯类16种(相对含量为49.916%),是主要挥发性物质。结论:品种对酒品质影响很大,酒中总黄酮、总酚含量与酒样颜色有一定的显著相关性,浸泡苦荞酒宜选择黑苦荞B。     

不同种类荞麦中各种存在形式多酚含量的研究

从全国5个荞麦种植区域中各选取一种甜荞和苦荞,采用反向液相色谱法(RP-HPLC)分析甜荞和苦荞麸皮中8种酚酸、3种黄酮的含量差异。结果表明：同一种植区域不同种类和同一种类不同种植区域的荞麦麸中酚类物质含量存在显著差异。其中,苦荞的自由态酚酸、总酚酸、自由态黄酮和总黄酮含量均高于同一种植区域的甜荞。此外,甜、苦荞中均含有没食子酸、原儿茶酸、香草酸、咖啡酸、p-香豆酸、阿魏酸、儿茶素、芦丁及槲皮素,其中苦荞中对羟基苯甲酸含量丰富。     

苦荞营养、功能和香气成分的研究进展

苦荞麦是我国传统的杂粮品种之一,有丰富的可开发功能性成分,可加工成多种保健食品和药品,市场发展前景十分广阔。该文对苦荞的营养、功能性成分和挥发性香气成分的研究进展进行综述,并对苦荞食品的深加工进行总结,为今后高营养附加值、优质风味苦荞食品的综合开发利用提供参考。     

Identifying Potato Varieties Using Machine Vision and Artificial Neural Networks

The objective of this study is to develop a method for identifying and discriminating 10 potato varieties by combining machine vision and artificial neural network methods. The potato varieties include Agria, Savalan, Florida, Fontaneh, Natasha, Verona, Karso, Elody, Satina, and Emrad. A total number of 72 characteristic parameters specifying color, textural, and morphological features are found among these varieties. By using principal component analysis, 16 principal features are selected for identifying and discriminating potato varieties. The data obtained from image processing were classified using linear discriminant analysis and non-linear artificial neural network method. The accuracy of discriminant analysis were 73.3, 93.3, 73.3, 40, 73.3, 73.3, 66.7, 80, 40, and 53.3%, respectively, for the varieties used in this study. The classification accuracy was improved by 100% for all the varieties using neural network analysis and the correct classification ratio was 100% using this method. It is revealed from the results that machine vision technique and neural network analysis could identify potato varieties with acceptable accuracy.     

Comparison of phenolic compositions between common and tartary buckwheat (Fagopyrum) sprouts

The phenolic compositions of non-germinated/germinated seeds and seed sprouts (at 6–10 day-old) of common (Fagopyrum esculentum Möench) and tartary (Fagopyrum tataricum Gaertn.) buckwheats were investigated. Phenolic compounds, including chlorogenic acid, four C-glycosylflavones (orientin, isoorientin vitexin, isovitexin), rutin and quercetin, were determined in the seed sprouts by high-performance liquid chromatography (HPLC). In the edible parts of common buckwheat sprouts, individual phenolics significantly increased during sprout growth from 6 to 10 days after sowing (DAS), whereas in tartary buckwheat sprouts they did not. While the sum contents of phenolic compounds in the edible part (mean 24.4 mg/g DW at 6–10 DAS) of tartary buckwheat sprouts were similar to those of common buckwheat sprouts, rutin contents in the non-germinated/germinated seeds (mean 14.7 mg/g DW) and edible parts (mean 21.8 mg/g DW) of tartary buckwheat were 49- and 5-fold, respectively, higher than those of common buckwheat. Extracts of the edible parts of both species showed very similar free radical-scavenging activities (mean 1.7 μmol trolox eq/g DW), suggesting that the overall antioxidative activity might be affected by the combination of identified phenolics and unidentified (minor) components. Therefore, buckwheat seed sprouts are recommended for their high antioxidative activity, as well as being an excellent dietary source of phenolic compounds, particularly tartary buckwheat sprouts, being rich in rutin.     

Identification and quantification of aroma compounds of tartary buckwheat (Fagopyrum tataricum Gaertn.) and some of its milling fractions

Tartary buckwheat (Fagopyrum tataricum) seeds have a strong aroma that characteristically differs from the aroma of common buckwheat (Fagopyrum esculentum). Its phytochemical background has only been recently investigated. The aim of this study was to identify and quantify individual compounds responsible for tartary buckwheat aroma. Volatiles from different samples (whole seed, flour, and husks) were extracted with simultaneous extraction and distillation by Likens-Nickerson apparatus and analyzed by GC-MS. A total of 48 compounds were quantified and their odor activity values (OAV) were calculated. OAV of 26 compounds was higher than 10; therefore, they significantly contribute to the overall tartary buckwheat aroma. The compounds with OAV > 500 were: (E,E)-2,4-decadienal, (E)-2-nonenal, 2-phenylethanol, (E,E)-2,4-nonadienal, hexanal, decanal, and nonanal. The most important difference from the aroma of common buckwheat is the absence of salicylaldehyde and presence of naphthalene. Salicylaldehyde could be proposed as a marker to detect contamination/adulteration of tartary buckwheat with common buckwheat. PRACTICAL APPLICATION: Buckwheat is becoming one of important alternative crops. Its products which are rich in proteins, fiber, vitamins, and antioxidants have been associated with healthy nutrition. Although tartary buckwheat is similar to more familiar common buckwheat, their characteristic aromas differ notably. This study expands recent research on aroma of tartary buckwheat tea to seed, flour, and husks, and suggests how products from different species of buckwheat can be distinguished by analysis of aroma compounds.