羊肉嫩度傅里叶变换近红外光谱偏最小二乘法定量分析研究

以从内蒙、宁夏、甘肃、新疆4个肉羊产区筛选的有代表性的98份羊肉样品为试材，应用傅里叶变换近红外光谱技术探讨了羊肉嫩度无损检测的方法。以模型决定系数(r2)、校正标准差(RMSECV)和预测标准差(RMSEP)为模型精度评价指标，采用偏最小二乘法(PLS)对近红外光谱信息与样品的质构仪剪切力值进行了拟合，确定了最佳的光谱预处理方法、主成分数和波段范围。结果表明：所选98个羊肉样品的剪切力值分布范围为1.673～6.631 kg，其中75%以上的样品剪切力值在2～5 kg，基本覆盖了我国现有的肉羊嫩度值分布；在11 995～5 446 cm-1和4 601～4 246 cm-1的波段范围内，最佳主成分数为10，光谱经矢量归一法处理后，建立的羊肉嫩度模型精度最高，r2达到86.2%，RMSECV为0.445；用此模型对预测集29个样品进行预测，预测值与实测值的相关系数r达到0.87，预测平均偏差为0.385，RMSEP为0.524。

The Quantified Analysis of Fresh Mutton Tenderness Using PLS Methods and Fourier Transform Near-Infrared Spectroscopy

Ninety eight representative fresh mutton samples from Neimeng,Ningxia,Gansu,Xinjiang province were selected for this study,the nondestructive measurement of the fresh mutton tenderness by Fourier transform near infrared(FT-NIR) spectroscopy was discussed.Partial least squares(PLS) algorithm was used to build the model between the shear force value of the fresh mutton tenderness measured by the texture machine 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) was studied.The result showed that the shear force value of ninety eight representative fresh mutton samples was 1.673-6.631 kg,and the shear force value above 75% samples was 2-5 kg,almost covering the fresh mutton tenderness of our country's sheep,the r2 of the calibration could reach 86.2% and the RMSECV was up to 0.445 in the wave number range 11 995-5 446 cm-1 and 4 601-4 246 cm-1 with vector normalization when the PLS factors was ten.The correlation coefficient(R),RMSEP and average bias between value measured by the texture machine and predicted value of model based on validation samples were 0.87,0.524 and 0.385 respectively.The result indicates that FT-NIR spectroscopy is capable of predicting tenderness value of fresh mutton.