Estimation of freshness of beef using near-infrared spectroscopy

As adenosine 5′-triphosphate (ATP) is automatically degraded during storage of beef, K _i-value increases. From an experimental result showing that K _i-value was highly proportional to the volatile basic nitrogen (VBN) of beef, it was confirmed in this study that K _i-value could be a useful index for the freshness of beef. Therefore, a calibration model for estimating K _i-value was developed using near-infrared spectroscopy (NIRS) and principal component regression (PCR), and validated. The coefficient of determination (R ²), standard error of calibration (SEC), and standard error of prediction (SEP) of the calibration model developed using the absorption spectra were 0.53, 8.7%, and 9.3%, respectively. To improve the prediction of the calibration model, the second-order derivative spectra were calculated and used to develop a calibration model. The NIR wavelength range of 1200 to 1300 nm produced the best calibration model, of which the R ², SEC, and SEP were 0.93, 8.3%, and 7.7%, respectively. It was concluded that it was feasible to estimate the freshness of beef through measurement of K _i-value with NIRS.