The study on the near infrared spectrum technology of sauce component analysis

The author, Shangyu Li, engages in supervising and inspecting the quality of products. In soy sauce manufacturing, quality control of intermediate and final products by many components such as total nitrogen, saltless soluble solids, nitrogen of amino acids and total acid is demanded. Wet chemistry analytical methods need much labor and time for these analyses. In order to compensate for this problem, we used near infrared spectroscopy technology to measure the chemical-composition of soy sauce. In the course of the work, a certain amount of soy sauce was collected and was analyzed by wet chemistry analytical methods. The soy sauce was scanned by two kinds of the spectrometer, the Fourier Transform near infrared spectrometer (FT-NIR spectrometer) and the filter near infrared spectroscopy analyzer. The near infrared spectroscopy of soy sauce was calibrated with the components of wet chemistry methods by partial least squares regression and stepwise multiple linear regression. The contents of saltless soluble solids, total nitrogen, total acid and nitrogen of amino acids were predicted by cross validation. The results are compared with the wet chemistry analytical methods. The correlation coefficient and root-mean-square error of prediction (RMSEP) in the better prediction run were found to be 0.961 and 0.206 for total nitrogen, 0.913 and 1.215 for saltless soluble solids, 0.855 and 0.199 nitrogen of amino acids, 0.966 and 0.231 for total acid, respectively. The results presented here demonstrate that the NIR spectroscopy technology is promising for fast and reliable determination of major components of soy sauce.