Butter is the product of milk fat, sometimes adulterations occurs with low-cost animal fat, which affects food safety and quality. The aim of this study was to evaluate the authenticity of butter in combination with bovine tallow (0-15% w/w) using FTIR and NMR methods. These studies have shown that by adding bovine tallow fat, there was a significant difference on peaks height in FTIR and value of NMR peaks. According to the statistical analysis obtained, L_Pseudo equations showed that in the FTIR spectra of 3473-3470, 723-720, 590-587 and 458-455 cm-1, by increase in bovine tallow percentage, the height of these spectra was decreased. L_Pseudo equations for each 1H NMR and 13C NMR peak indicated that value (ppm) of these peaks decreased by increase percentage of tallow. Given value of R2, it was found that none of the spectra were capable of estimating the presence of foreign fat. تفاصيل المقالة