近红外高光谱快速无接触评估冷鲜猪肉脂质氧化

Rapid and non-contact evaluation of lipid oxidation in fresh chilled pork by near-infrared hyperspectral imaging

基于近红外高光谱成像技术对不同贮藏期的猪肉脂肪氧化程度进行快速无接触评估研究。采集冷鲜猪肉样品的900~1700 nm反射光谱信息,经高斯滤波平滑(GFS)、移动平均值平滑(MAS)、卷积平滑(SGCS)、中值滤波平滑(MFS)、多元散射校正(MSC)、标准正态变量变换(SNV)和基线校正(BC)7种预处理后,利用偏最小二乘回归(PLSR)算法挖掘光谱信息与2-硫代巴比妥酸(TBA)参考值之间的定量关系。结果显示,经GFS预处理的全波段光谱(486个波长)构建的GFS-PLSR模型预测TBA效果较好(R P=0.919,RMSEP=0.036 mg/100 g)。采用回归系数法(RC),逐步回归法(Stepwise)和连续投影算法(SPA)筛选最优波长优化GFS-PLSR模型。结果显示,使用RC法从GFS光谱中筛选的29个最优波长构建的RC-GFS-PLSR模型预测TBA效果较好(R P=0.924,RMSEP=0.034 mg/100 g),且和GFS-PLSR模型预测精度相近。试验表明,利用近红外高光谱成像技术结合RC法预测猪肉中TBA值可实现猪肉脂肪氧化程度的间接快速评估。

The lipid oxidation of fresh chilled pork was evaluated rapidly and contactlessly by near-infrared hyperspectral imaging during different storage periods.The Gaussian filter smoothing(GFS),moving average smoothing(MAS),Savitzky-Golay convolution smoothing(SGCS),median filtering smoothing(MFS),multiplicative scatter correction(MSC),standard normal variable(SNV)correction and baseline correction(BC)were used to preprocess the reflectance spectra of the pork samples at 900~1700 nm.After the seven kinds of pretreatments mentioned above,Partial least squares regression(PLSR)model was established to explore the quantitative relationship between spectral data and the 2-thiobarbituric acid(TBA)value.As a result,the GFS-PLSR model based on full 486 wavelengths of GFS spectra showed better performance in prediction(R P=0.919,RMSEP=0.036 mg/100 g).Regression coefficients(RC)method,stepwise and successive projections algorithm(SPA)were used to select optimal wavelengths to simplify the GFS-PLSR model and improve the efficiency of prediction.It was indicated that the RC-GFS-PLSR model established with the 29 optimal wavelengths selected from GFS spectra by RC showed better performance in prediction(R P=0.924,RMSEP=0.034 mg/100 g),similar to GFS-PLSR model.The overall results showed that the TBA value could be quantitatively predicted by using near-infrared hyperspectral imaging technology combined with RC method,and this could be applied to realize the rapid and contactless evaluation of lipid oxidation in pork.