College of Animal Science and Veterinary Medicine, Henan Institute of Science and Technology, Xinxiang 453003, China.
Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan 430070, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2025 Jan 5;324:124969. doi: 10.1016/j.saa.2024.124969. Epub 2024 Aug 12.
The fraudulent adulteration of goat milk with cheaper and more available milk of other species such as cow milk is occurrence. The aims of the present study were to investigate the effect of goat milk adulteration with cow milk on the mid-infrared (MIR) spectrum and further evaluate the potential of MIR spectroscopy to identify and quantify the goat milk adulterated. Goat milk was adulterated with cow milk at 5 different levels including 10%, 20%, 30%, 40%, and 50%. Statistical analysis showed that the adulteration had significant effect on the majority of the spectral wavenumbers. Then, the spectrum was preprocessed with standard normal variate (SNV), multiplicative scattering correction (MSC), Savitzky-Golay smoothing (SG), SG plus SNV, and SG plus MSC, and partial least squares discriminant analysis (PLS-DA) and partial least squares regression (PLSR) were used to establish classification and regression models, respectively. PLS-DA models obtained good results with all the sensitivity and specificity over 0.96 in the cross-validation set. Regression models using raw spectrum obtained the best result, with coefficient of determination (R), root mean square error (RMSE), and the ratio of performance to deviation (RPD) of cross-validation set were 0.98, 2.01, and 8.49, respectively. The results preliminarily indicate that the MIR spectroscopy is an effective technique to detect the goat milk adulteration with cow milk. In future, milk samples from different origins and different breeds of goats and cows should be collected, and more sophisticated adulteration at low levels should be further studied to explore the potential and effectiveness of milk mid-infrared spectroscopy and chemometrics.
山羊奶与更便宜、更易得的牛奶（如牛奶）掺假的欺诈性掺假时有发生。本研究的目的是研究山羊奶与牛奶掺假对中红外（MIR）光谱的影响，并进一步评估 MIR 光谱法识别和定量掺假山羊奶的潜力。山羊奶在 5 个不同水平（包括 10%、20%、30%、40%和 50%）与牛奶掺假。统计分析表明，掺假对大多数光谱波数有显著影响。然后，用标准正态变量（SNV）、乘法散射校正（MSC）、Savitzky-Golay 平滑（SG）、SG 加 SNV 和 SG 加 MSC 对光谱进行预处理，分别使用偏最小二乘判别分析（PLS-DA）和偏最小二乘回归（PLSR）建立分类和回归模型。PLS-DA 模型在交叉验证集中的灵敏度和特异性均超过 0.96，得到了较好的结果。使用原始光谱的回归模型获得了最佳结果，交叉验证集的决定系数（R）、均方根误差（RMSE）和偏差比（RPD）分别为 0.98、2.01 和 8.49。结果初步表明，MIR 光谱是检测山羊奶与牛奶掺假的有效技术。未来应收集不同来源和不同品种的牛奶样本，并进一步研究更低水平的更复杂掺假，以探索牛奶中红外光谱和化学计量学的潜力和有效性。
