畜禽肉化学成分近红外光谱检测技术研究进展

和传统的肉品化学成分检测方法相比,近红外光谱分析是一种能够快速、简单、安全和可同时测定多种化学成分的肉品检测方法。论述了近年来猪、鸡、牛、羊四种动物肉中粗蛋白质、肌间脂肪、脂肪酸、水分、灰分、肌红蛋白和胶原蛋白七种化学成分的近红外光谱分析检测研究进展,并探讨了目前研究中存在的问题及其原因。从已发表的研究结果可以看出,近红外光谱分析具有替代耗时成本高的现有肉品化学检测方法的巨大潜力,特别是用于商业上同步检测多种化学成分。研究大多采用主成分分析法进行特征光谱筛选,偏最小二乘和修正偏最小二乘法建立校正模型,交互验证进行预测结果评价。目前研究热点集中在肉中脂肪酸含量预测模型和应用近红外高光谱图像和多元回归预测肉中化学成分。近红外光谱预测结果差异性较大,这与样品集选择、光谱预处理和建模方法都有很密切的关系。样品选择对近红外预测精度具有重要的意义,非均质肉样影响了近红外化学成分预测精度。总的来说,肌间脂肪、脂肪酸与水分指标预测效果较好,粗蛋白质和肌红蛋白指标预测效果次之,灰分和胶原蛋白指标预测结果较差。     

近红外光谱法田间快速估测新鲜紫花苜蓿品质

田间快速估测苜蓿品质对于适时刈割具有重要意义。试验共采集来自不同地域、不同品种、不同生育期和不同茬次的新鲜紫花苜蓿样170份,经便携式近红外光谱仪(1 100～1 800 nm)扫描得到近红外光谱,利用偏最小二乘法(PLS)在国内首次建立基于紫花苜蓿新鲜样品的干物质(DM)、粗蛋白(CP)、中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)化学分析值的近红外校正模型,探讨利用近红外漫反射光谱技术(NIRS)在田间快速估测紫花苜蓿品质的可行性,摸索设备选择和制样方法。四项指标所建模型的交互验证决定系数(R2CV)分别为0.831 4,0.597 9,0.803 6和0.786 1;交互验证均方根误差(RMSECV)为1.241 1,0.261 4,0.990 3和0.830 6;外部验证决定系数(R2_V)为0.815 0,0.401 1,0.784 9和0.752 1,外部预测均方根误差(RMSEP)分别为1.06, 0.31, 0.95和0.80。对于苜蓿鲜样来说,DM,NDF和ADF的近红外模型可以进行粗略的定量分析,CP的建模效果较差,但因苜蓿中的粗蛋白含量一般都能满足家畜需求,DM,NDF和ADF是在适时刈割中最关键的估测指标,DM,NDF和ADF模型可以满足田间快速估测苜蓿品质的要求。     

近红外反射分析法测定水稻可能再转流物质的研究

为了探讨应用近红外反射分析法测定水稻可能再转流物质的可行性,以种植于海南儋州的7个水稻品种为试验材料,在淀粉酶处理结合中性洗涤纤维法分析的基础上,应用近红外反射分析法建立预测水稻茎叶部和穗部可能再转流物质含量的校正模型。结果表明：采用偏最小二乘法回归(PLS1)建立的校正模型的预测效果较好,光谱预处理对改进校正模型没有显著效果;采用不做预处理+PLS1建立的茎叶部和穗部校正模型都具有较高的预测准确度,校正模型的外部验证结果茎叶部的决定系数为0.991 2、均方根误差为0.008 1,穗部的决定系数为0.961 1、均方根误差为0.022 6。     

近红外光谱分析技术的一些数据处理方法的讨论

介绍了近红外光谱分析的技术原理,常用的几种建模方法以及各自的特点。同时,阐述了光谱的预处理,其中的小波变换方法是一种新的数学工具,有着广泛的应用前景。     

Assessing corn stover composition and sources of variability via NIRS

Corn stover, the above-ground, non-grain portion of the crop, is a large, currently available source of biomass that potentially could be collected as a biofuels feedstock. Biomass conversion process economics are directly affected by the overall biochemical conversion yield, which is assumed to be proportional to the carbohydrate content of the feedstock materials used in the process. Variability in the feedstock carbohydrate levels affects the maximum theoretical biofuels yield and may influence the optimum pretreatment or saccharification conditions. The aim of this study is to assess the extent to which commercial hybrid corn stover composition varies and begin to partition the variation among genetic, environmental, or annual influences. A rapid compositional analysis method using near-infrared spectroscopy/partial least squares multivariate modeling (NIR/PLS) was used to evaluate compositional variation among 508 commercial hybrid corn stover samples collected from 47 sites in eight Corn Belt states after the 2001, 2002, and 2003 harvests. The major components of the corn stover, reported as average (standard deviation) % dry weight, whole biomass basis, were glucan 31.9 (2.0), xylan 18.9 (1.3), solubles composite 17.9 (4.1), and lignin (corrected for protein) 13.3 (1.1). We observed wide variability in the major corn stover components. Much of the variation observed in the structural components (on a whole biomass basis) is due to the large variation found in the soluble components. Analysis of variance (ANOVA) showed that the harvest year had the strongest effect on corn stover compositional variation, followed by location and then variety. The NIR/PLS rapid analysis method used here is well suited to testing large numbers of samples, as tested in this study, and will support feedstock improvement and biofuels process research.     

An enrichment device of silica-based monolithic material and its application to determine micro-carbaryl by NIRS

Silica-based monolithic column material was synthesized and an enrichment device was fabricated with the material by assembling the material inside a glass column.The enrichment device was applied for the determination of micro-carbaryl with near-infrared spectroscopy(NIRS).The aqueous solutions of carbaryl passed through the device and the carbaryl was enriched on the surface of the material where diffuse reflection NIR spectra were measured.These procedures of enrichment and measurement ensured to conc...     

基于光谱技术和连续投影算法的润滑油品牌快速鉴别研究

为了实现润滑油品牌的快速无损检测,提出了一种基于可见/近红外光谱透射技术与连续投影算法相结合的润滑油品牌快速鉴别新方法。采用连续投影算法对6种润滑油的可见/近红外光谱数据进行波长变量的筛选,再结合偏最小二乘法建立润滑油品牌的鉴别模型。结果表明,鉴别模型的相关系数r为0.9721,预测均方根误差RMSEP为0.4055,鉴别正确率为91.7%。说明提出的连续投影算法结合偏最小二乘算法具有很好的预测效果。     

近红外光谱丸剂关键辅料炼蜜水分的快速测定

用近红外光谱法实现嫩,中,老三种炼蜜含水量的快速测定及不同炼制程度蜂蜜的快速分级。过程化控制是中药质量稳定的关键因素,但由于检测手段的滞后而无法实现,因而影响中药质量。蜜丸是具广阔应用市场的剂型;炼蜜工艺是影响蜜丸质量的关键工序;在炼蜜过程中,蜂蜜从嫩蜜炼制到中蜜仅需几至几十秒,变化迅速,传统检测手段不能对蜂蜜炼制过程进行实时监测,进而无法保证炼蜜质量的均一性。力求采用近红外光谱法（NIRS）对炼蜜过程进行实时检测,准确控制嫩蜜、中蜜的炼制程度,并对其含水量进行定量测定。实验通过Rudolph折光仪测定不同炼蜜的含水量,并快速测定样品的近红外光谱,结合偏最小二乘法（PLS）建立并优化88批炼蜜水分的定量模型,利用校正模型决定系数（R2）、校正模型均方根误差（RMSEE）;内部交叉验证决定系数（R2）,内部交叉验证均方根误差（RMSECV）;预测模型的相关系数（r）、预测均方根误差(RMSEP)对校正模型进行评价,其中RMSECV主要用来筛选建立模型的最佳主成分数,RMSEE和RMSEP分别对所建立校正集和验证集进行误差分析。同时采用鉴别分析法建立定性模型用来区分炼蜜等级。经不断优化,图谱经矢量归一化法（SNV）预处理后,在7 201.2~5 446.2 cm-1波段内选取9个主成分建立水分模型。建立的最佳模型中,校正集R2, RMSEE分别为99.43,0.299,内部交叉验证R2,RMSECV分别为99.05,0.348;预测集R2,RMSEP分别为98.19,0.347;定量模型显示,NIRS可快速、准确、无损的对炼蜜含水量进行测定。同时按照含水量测定结果对炼蜜嫩、中、老3个等级进行划分,进而采用鉴别分析法对炼蜜进行定性分析,结果显示嫩、中、老3种炼蜜有明显的聚类现象,表明因子化法是鉴别炼蜜程度的一种有效方法;综上所述,NIRS可望实现对炼蜜过程实时监测,准确控制嫩蜜,中蜜的炼蜜程度并对炼蜜含水量进行快速实时定量测定,为不同炼蜜等级划分提供参考,保证炼蜜质量的均一性,最终保证蜜丸质量的稳定性。     

Discrimination of Chili Powder Origin Using Inductively Coupled Plasma–Mass Spectrometry (ICP-MS), Inductively Coupled Plasma–Optical Emission Spectroscopy (ICP-OES), and Near Infrared (NIR) Spectroscopy

This study investigated the content of macronutrients (Ca, K, Mg, Na, P, and S), trace elements (Ba, Be, Co, Cr, Cu, Fe, Ga, Li, Mn, Ni, Rb, Se, Sr, V, and Zn), and trace toxic elements (As, Cd, In, Pb, and Tl) in chili powder from Korea, China, and Vietnam. For the analyses, inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma-optical emission spectroscopy (ICP-OES) were used. In addition, near-infrared (NIR) spectroscopy was used to differentiate functional groups based on the chemical constituents. For the validation of the applied analytical methods, good linearity (coefficients of determination, 0.9443–0.99997), and relative standard deviations below 4% were obtained. The contents of the toxic elements were below the provisional tolerable weekly intake values. Linear discriminant analysis using elemental contents and NIR data was performed to establish and authenticate the geographical origin of chili powder, which confirmed the reliability of the obtained results.     

基于FTIR指纹光谱的牛肉产地溯源技术研究

在中国牛肉4个产区吉林省榆树市、贵州省安顺市、宁夏自治区同心县、河北省张北县屠宰场采集了58个肉牛牛肉样品,进行脱脂、干燥、粉碎。利用近红外光谱分析技术,对牛肉样品的近红外光谱进行主成分分析、聚类分析、判别分析,建立了判别牛肉产地来源的傅里叶变换红外光谱定性分析模型。分析结果显示4个产区的牛肉的平均近红外光谱存在有差异,牛肉样品的主成分空间分布也位于不同的区域。根据光谱距离,对样品进行聚类分析,初步判定了牛肉的产区,其中贵州的牛肉光谱比较复杂,与河北牛肉样品的光谱距离很近,存在一定交叉。利用来源于4个产区的18个独立样品对模型进行了验证,正确识别率为100％。说明应用近红外光谱分析技术可准确、快速、低廉地追溯牛肉的产地来源。