Visible/NIR analysis of fat, protein and water in chilled pork

Fat, protein and water were determined by visible and NIR transmittance spectroscopy in chilled pork. After preprocessed by multiplicative scatter correction (MSC), the quantitative analysis models were developed based on the original, first derivative and second derivative spectra by using partial least squares (PLS) at the temperatures of 0-4°C and 20°C, respectively. By comparing the correlation coefficient (r), RMSEC, and SEP, we found that the first derivative model was the best, and the performance for 0-4 °C was better than that for 20°C. At 0-4 °C and 20°C, the correlation coefficients were 0.950 and 0.924 for fat, 0.713 and 0.455 for protein and 0.944 and 0.914 for water respectively, SEP values were 2.41 and 2.95 for fat, 5.44 and 4.25 for protein, and 2.37 and 2.38 for water respectively. The results showed that the visible and NIR analysis could measure the fat and water contents in chilled pork well, but was bad for protein, and this was caused by processing line of chilled pork. What's more, the spectrum offset was found in the original spectra at about 770 nm to be about 10 nm.