羊肉色泽傅立叶变换近红外光谱定量分析方法研究

以从北京市、山西大同市、宁夏吴忠市3个地区筛选的有代表性的227份羊肉样品为试材,应用傅里叶变换近红外光谱技术探讨羊肉色泽无损检测的方法。以决定系数(R2)、校正标准差(RMSECV)和预测标准差(RMSEP)为近红外光谱检测模型的评价指标,采用偏最小二乘法(PLS)对近红外光谱信息与样品的色差e值进行拟合,确定最佳的光谱预处理方法、主成分数和光谱区间范围。结果表明:所选227个羊肉样品的色差e值分布范围为1.556～9.879,其中80%以上的样品e值在1～5之间,具有显著的代表性;在11995.5～4597.6cm-1的波段范围内,最佳主成分数为6时,近红外光谱经最大最小归一法处理后,建立的羊肉色泽预测模型精度最高,R2达到0.776,RMSECV为0.451;用此模型对预测集48个样品进行预测,预测值与实测值的相关系数(R)为0.835,RMSEP为0.517,该研究表明利用近红外光谱技术检测羊肉色泽可行。

ESTABLISHMENT OF QUANTIFIED ANALYSIS METHOD OF FRESH MUTTON COLOR WITH FOURIER TRANSFORM NEAR-INFRARED SPECTROSCOPY

227 representative fresh mutton samples from Beijing,Datong City of Shanxi Province,Wuzhong City of Ningxia Province were selected,the nondestructive measurement of the fresh mutton color by Fourier transform near infrared (FT-NIR) spectroscopy was discussed.Partial least squares (PLS) algorithm was used to build the model between the e value of the fresh mutton color measured by the colorimeter and the FT-NIR spectra.The influence of different processing method of spectra,factors and wave regions on the determination coefficients (R2) ,root mean square error of cross validation (RMSECV) and root mean square error of prediction (RMSEP) were studied.The result showed that the color e value of 227 samples is 1.556～9.879,and the color e value of prediction samples is all in the range of the color e value of validation samples ;the R2 of the validation samples could reach 0.776 and the RMSECV was 0.451 in the wave number range 11995.5～4597.6cm-1 with min-max normalization when the PLS factors was 6.The correlation coefficient(R) ,RMSEP between value measured by the colorimeter and predicted value of model based on prediction samples were 0.835 and 0.517,respectively.The result indicates that FT-NIR spectroscopy is capable of predicting color e value of fresh mutton.