Identification of lard on grilled beef sausage product and steamed beef sausage product using fourier transform infrared (FTIR) spectroscopy with chemometric combination

Many issues are spreading about the use of lard in food, one of it is sausage. Sausage is one of the processed foods which are prone of containing pork. In Indonesia, grilled and steamed sausages are popular for children and adults. One of the method which is developed to analyze fat in grilled and steamed sausage products was FTIR spectrophotometry combined with chemometrics. This research aims to develop an analysis method using FTIR spectrophotometry combined with chemometrics to analyze lard content in grilled and steamed beef sausage. Reference sausage made from a mixture of pork and beef. This research was designed by making each 7 concentrations variants of pork and steamed sausage samples (100%, 75%, 65%, 50%, 35%, 25% and 0%). Five samples from market were taken from various beef sausage traders. The fat extraction used n-hexane solvent at the temperature of 70 °C for 5 hours. The extracted fat was analyzed by FTIR spectrophotometry combined with chemometrics. The results of spectrum were analyzed using Horizon MBTM to obtain optimum wave number of steamed sausages in the range of 1000 – 791 cm-1 and grilled sausages in the range of 1070 – 796 cm-1. The analysis of steamed sausage with Partial Least Square (PLS) is obtained the equation y = 0.9977x + 0.1166; and the value of R2 0.9977; RMSEC 1.22%; RMSEP 0.22%; and RMSECV 1.26%. The PLS analysis of grilled sausage is obtained the equation y = 0.9972x + 0.1379; and the value of R2 0.9972; RMSEC 1.27%; RMSEP 0.42%; and RMSECV 0.18%. The conclusion of this research is that the FTIR method combined with chemometrics is the proper method for analyzing fat in sausages. The analysis result using Principle Component Analysis (PCA) was obtained from 3 of 5 samples in the market which had the similar physicochemical properties of lard sausage.