Detection of beef adulteration in mutton by fourier transform-near infrared spectroscopy with chemometrics

A study was conducted for detection of beef adulteration in mutton by using Fourier transformnear infrared spectroscopy (FT-NIR).A total of 22 trials containing seven classes with different ratios of mutton and beef (100:0, 0:100, 90:10, 80:20, 70:30, 60:40 and 50:50) were conducted. Each sample was scanned six times and a total of 924 spectra (132 for each class) were collected over 12500-4000 cm⁻¹ at room temperature (25±1°C). Coefficient of determination (R²) and ratio of prediction to deviation (RPD) for different % of beef adulteration were 0.75 to 0.99 and 2.78 to 8.54, respectively. Increased root mean square error of cross validation (RMSECV) from 1.20 to 1.60 indicated that outliers have great impact on PLSR model building. These outliers are excluded by using Mahalanobis distance method. The absorbance of spectral values were 10056.47to 10284.84 cm⁻¹ for moisture(O-H) band, 8424.63 to 8463.77 cm⁻¹ for fat(C-H) band and 6002.68 to 6034.25 cm⁻¹ for protein (N-H) band in different ratios of beef adulterated mutton. Fat content (C-H)was significantly different among the classes of adulteration in beef adulterated mutton. The study indicated that near infrared spectroscopy technology has great potential to identify beef adulteration in mutton.