Examination of Starch-Water and Cellulose-Water Interactions With Near Infrared (NIR) Diffuse Reflectance Spectroscopy

Starch-water and cellulose-water interactions were examined with NIR diffuse reflectance spectroscopy. Samples of native potato, wheat, and corn starches and microcrystalline cellulose (MCC) were equilibrated to water activities (a_w) ranging from 0.11 to 0.94 a_w. A modified B.E.T. model was applied to the water vapor sorption isotherm (T=25°C) data. NIR spectra (1000 to 2640 nm) revealed no abrupt changes in molecular structure. However, as has been suggested in the literature, there appear to be two species of non-freezable water whose relative quantities change as a_w varies. It is hypothesized that the first species represents water within the monolayer, and the second species represents multilayer water. NIR spectra of starch suggests that some multilayer water is present before the monolayer is completed. Spectra of MCC corroborate the existence of two species of highly associated water. The isotherm model was highly successful in describing sorption behavior over the a_w range examined.     

普通公牛肉和淘汰母牛肉的近红外光谱鉴别方法

选取来自内蒙同一品种普通公牛和淘汰母牛各部位肉各224个肉样,新疆同一品种普通公牛和淘汰母牛各部位肉130个肉样,分别经冷冻解冻和冷鲜状态下,应用便携式近红外光谱仪在1000～1799nm波长内对绞碎后的肉糜进行光谱扫描,并且测定了内蒙肉样的蛋白质、脂肪、水分和剪切力值(WBSF)。从中分别选择来自两个产地的154和91个肉样作为建模集,采用偏最小二乘判别分析法(PLS-DA)建立了两个产地普通公牛肉和淘汰母牛肉的鉴别模型。所建的两个模型对校正集和验证集样本的鉴别准确率均达100%,对剩余预测集的70和39个肉样进行鉴别分析的鉴别准确率分别为96%和90%。     

Potential of Near Infrared Reflectance Spectroscopy for Analysis of Silage Composition, ,

A wide range of ensiling conditions were simulated to test the capability of near infrared reflectance spectroscopy to determine the chemical composition of undried silages. Fifty-seven different grass and legume silages were produced by adding varying amounts of water, sucrose, and formate to hays differing in species, maturity, cutting, or location. The material was ensiled for 21 d in airtight, evacuated plastic bags prior to analysis. Standard errors of calibration (as received basis) and coefficients of determination were, respectively: DM (1.80, .98); total N (.070, .98); insoluble N (.035, .98); acetate (.064, .78); butyrate (.078, .70); lactate (.328, .82); pH (.208, .77). The results indicate that near infrared reflectance has the potential to measure true DM, total N, and insoluble N in ensiled forages.     

油菜籽芥酸和硫甙含量近红外反射光谱测定技术的优化设置

以完整甘蓝型油菜籽为样品,研究了不同光谱预处理和回归统计方法在用近红外反射光谱（NIRS）分析油菜籽中芥酸和硫甙的含量时,对建立回归方程的影响。结果表明,光谱预处理对校正结果影响较大,不同光谱数学处理以2阶导数处理较好,在各阶导数处理中存在着交叉现象,对于芥酸和硫甙都可找到一些较好的处理组合。对于芥酸,除趋势变换法（De-trending）散射处理外,其余各处理均有明显效果。但散射处理对硫甙分析效果不如芥酸明显。回归统计方法对建立芥酸和硫甙的回归方程影响最为有效,两者表现一致,其中以改良偏最小二乘法（MPLS）效果最好。对于芥酸和硫甙,采用“标准正态变量转换（SNV） 趋势变换法（De-trending）/2,4,4,1/MPLS”的组合建立回归方程效果较好,检验平均偏差（Bias）分别小至-0.405和0.315,而检验决定系数（RSQ）分别高至0.982和0.972。本研究采用整粒小样品（3g）来分析,效果较好,可直接用于育种早世代选择。     

不同小麦品种营养组分含量的近红外光谱分析

为探讨快速评价小麦营养品质性状的方法,利用近红外品质测定仪检测14个小麦品种全麦粉的营养组分。通过对蛋白、淀粉、纤维、脂肪、水分、氨基酸等15个营养组分比较分析发现不同品种间变异均达到极显著水平,脂肪含量变异系数最大为13.05%,淀粉含量变异系数最小为2.20%。不同品种方差分析发现强筋小麦品种小冰麦33和云南57的蛋白质、氨基酸含量显著高于其他品种。对这些品种的营养成分聚类分析可以分成2大类,并且很好的将强筋品种与其他筋力的品种区分开。     

Examination of Starch-Water and Cellulose-Water Interactions With Near Infrared (NIR) Diffuse Reflectance Spectrospocy

Starch-water and cellulose-water interactions were examined with NIR diffuse reflectance spectroscopy. Samples of native potato, wheat, and corn starches and microcrystalline cellulose (MCC) were equilibrated to water activities (a_w) ranging from 0.11 to 0.94 a_w. A modified B.E.T. model was applied to the water vapor sorption isotherm (T=25°C) data. NIR spectra (1000 to 2640 nm) revealed no abrupt changes in molecular structure. However, as has been suggested in the literature, there appear to be two species of non-freezable water whose relative quantities change as a_w varies. It is hypothesized that the first species represents water within the monolayer, and the second species represents multilayer water. NIR spectra of starch suggests that some multilayer water is present before the monolayer is completed. Spectra of MCC corroborate the existence of two species of higly associated water. The isotherm model was highly successful in describing sorption behavior over the a_w range examined.     

Use of Near Infrared Reflectance Spectroscopy in Forage Testing

Near infrared reflectance spectroscopy analysis of forages for CP, ADF, NDF, and minerals was compared with wet chemistry results. Infrared analysis was conducted with a NEO-Tech 51A where spectral equations had been transferred by the vendor from master calibrations. These calibrations were based upon microwave drying of feed samples and grinding through a cyclone mill. Our forage testing laboratory routinely tests by oven drying at 60°C and grinding with a Wiley mill through a 2-mm screen. Protein and ADF analyses were conducted on 66 corn silage, hay crop silage, and hay samples. Coefficients of determination for oven drying-wet chemistry and microwave-infrared, oven drying-wet chemistry and oven drying-infrared, and microwave-infrared and oven drying-infrared analysis were: .90, .93, and .98 for crude protein and .92, .94, and .96 for ADF. Infrared results were compared with wet chemistry CP and ADF for 265 corn silage, hay, and hay crop silage samples. Coefficients of determination were .97 for CP and .95 for ADF with standard errors of prediction of .92 and 1.98. The respective correlation coefficients for corn silage, hay crop silage, and hay were .94 and .73; .95 and .92; and .73 and .74. Although standard errors of prediction were low for all minerals, coefficients of determination were above .80 for Ca and K.     

近红外光谱检测技术在肉类工业中的应用

近年来,近红外光谱技术(near infrared reflectance spectroscopy,NIRS)已经成为肉和肉产品品质检测中最为有效、先进的方法之一。本文回顾了应用NIRS技术对食品化学成分、物理性质和感官指标的检测,说明了NIRS技术在肉品分级制度中的应用,并讨论了NIRS在肉品工业上的应用前景。     

甘薯蛋白质含量近红外反射光谱分析模型应用研究

以71份薯叶和170份薯块根样品为材料,应用近红外光谱技术(NIRS)和偏最小二阶乘法(PLs),建立甘薯蛋白质含量近红外反射光谱分析数学模型,并对模型预测结果的准确性进行了评价.结果显示.甘薯叶和块根的蛋白质含量的近红外光谱预测模型校正决定系数(R2cal)分别为O.996和0.993,校正均方差(RMSEE)分别为O.255和O.126,内部交叉验证决定系数(R2cv)分别为0.984和O.986,均方差(RMSECV)分别为0.448和O.178.模型对样品NIR的预测值与其相应的化学值有较好的相关性,此模型可用来预测甘薯蛋白含量.在甘薯优质育种和品质分析中具有广泛的应用价值.     

近红外光谱法预测干辣椒辣度的影响因素分析

采用近红外光谱分析技术,对干辣椒辣度的校正模型的影响因素进行比较研究.高效液相色谱测定干辣椒样品中的辣椒碱和二氢辣椒碱含量,计算得到辣度,并用近红外光谱仪采集试样的近红外漫反射光谱,研究样品粒度、光谱波段和预处理方法及主成分数选择对校正模型的影响,采用偏最小二乘法(PLS)建立干辣椒样品的辣度评价的校正模型,并对模型进行预测.结果表明,样品粒度为0.1～0.4 mm,筛选出建模光谱波段为9000～4000 cm-1,预处理方法为移动平均平滑、归一化处理和多元散射校正处理,最适主成分数为8;在优化条件下所建立的近红外光谱预测模型效果最好.     

近红外反射光谱法在烟草育种中的运用

为选育新的烟草品种,在育种过程中需尽早对候选品系能否产出具有理想化学特性原烟的能力做出评定。大量的候选品系要求采用快速测定工具以代替化学分析。因近红外反射光谱法(NIRS)可以直接通过对研磨得到的烤烟烟末的测定获得一系列化学参数以及更为复杂的特征数据,该项技术目前已成为Bergerac烟草研究所的常规方法。对每一种烟草类型,如:深色晾烟,白肋烟和烤烟等,首先应建立校正PLS(Partial Least Squares)预测模型,将NIR光谱数据与生物碱,氮,还原糖和灰分含量建立数学关系。所建模型基于超过1600份烟末样本的测定数据(1995~2000农事…     

Compositional Analysis of Powdered Cocoa Products by Near Infrared Reflectance Spectroscopy

Near infrared reflectance (NIR) spectroscopy was used to measure moisture, fat, and sucrose in powdered cocoa products. Spectra of a series of known samples were recorded and multiple linear regression techniques were used to relate the concentrations of each parameter to reflectance measurements at selected wavelengths. Precision and accuracy were estimated to evaluate the potential application of the NIR spectroscopy in the quality control of powdered cocoa products. Results showed that moisture, fat, and sucrose could be analyzed in powdered cocoa products by near infrared reflectance spectroscopy because good correlation coefficients and low standard errors were achieved in prediction study.     

Compositional Analysis of Whey Powders Using Near Infrared Diffuse Reflectance Spectroscopy

Compositional analysis data for 47 whey powders (including sweet whey, acid whey, demineralized delactosed whey and whey protein concentrates) were correlated with near infrared reflectance (NIR) measurements. The most useful wavelengths for determining constituent concentrations were chosen from 19 pre-selected wavelengths by using linear regression analysis. Results indicate that samples to be used for NIR calibrations should be similar in composition and should represent a limited range of constituent concentrations. Individual NIR calibrations need to be developed for each type of whey powder to be analyzed.     

近红外漫反射光谱法测定纸浆卡伯值

介绍了近红外漫反射技术在纸浆卡伯值定量分析测定中的应用.用近红外光谱仪对竹浆、蔗渣浆、松木浆样品的卡伯值进行了分析测定.研究结果表明,用近红外方法对纸浆卡伯值的测定是可行和有效的,样品不需预处理,分析快速、简便、环保,结果准确.     

近红外光谱分析技术在糜子品质检测中的应用

为寻找一种简便易行的糜子籽粒水分、淀粉、粗蛋白、粗脂肪含量测定方法,以120个普通糜子品种为材料,采用近红外漫反射光谱(NIRS)法测定糜子籽粒水分、淀粉、粗蛋白、粗脂肪含量进行了研究。结果表明,采用一阶导数+减去一条直线、矢量归一化光谱预处理,分别建立水分、淀粉、粗蛋白、粗脂肪含量的校正模型,校正和预测效果最佳。模型的校正决定系数(R~2cal)分别为0.921 0、0.905 8,0.926 3和0.904 5,交叉验证决定系数(R~2cv)分别为0.921 0、0.900 2、0.940 0和0.881 2;外部验证决定系数(R~2val)分别为0.912、0.801、0.890和0.786。结果表明该模型代替化学分析法鉴定糜子品质是完全可行的。     

近红外分析仪在玉米质量检测中的应用

将近红外分析仪应用于玉米质量检测,开发了对玉米淀粉含量和水分测定的工厂校准,并对该校准进行了测试,实验证明该校准测定结果符合国家标准要求.通过实验找到测定玉米原始水分及潮粮二次水分和淀粉的快速测定方法,与常规方法比较快速、准确.     

近红外漫反射光谱技术对小米产地溯源的研究

为建立小米产地溯源的快速检测技术,更好的维护地方名优小米品牌效益,试验利用近红外漫反射光谱技术对不同状态小米进行产地溯源鉴别,试验分别选取来自肇源和肇州两个小米主产区的144份小米样品,应用近红外漫反射光谱技术结合化学计量学对不同状态下的小米进行产地溯源研究,结果表明:在全波长范围内采用因子化法建立的定性分析模型和在特征波段范围内采用偏最小二乘法(PLS)建立的定量分析模型,对肇源、肇州两个小米主产区的小米籽粒和小米粉末的正确鉴别率均在90%以上,其中小米粉末的模型正确预测率要高于小米籽粒。因此,应用近红外漫反射光谱技术对不同状态小米产地溯源的鉴别具有一定的可行性。