DETECTION OF TOTAL VOLATILE BASIC NITROGEN (TVB-N) IN PORK USING FOURIER TRANSFORM NEAR-INFRARED (FT-NIR) SPECTROSCOPY AND CLUSTER ANALYSIS FOR QUALITY ASSURANCE

摘要

Fourier transform near-infrared (FT-NIR) spectroscopy was applied to rapidly detect the TVB-N content in raw pork that was stored at room temperature (20 degrees C) and refrigeration temperature (4 degrees C). The NIR spectra of pork samples were collected before chemical analysis of TVB-N content was conducted. Cluster analysis of average spectra was used to judge and classify the freshness of the pork samples. According to pork freshness, the threshold value of the TVB-N content was confirmed For pork stored at room temperature, it is fresh when the TVB-N content is 4.0 to 5.0 mg per 100 g, it is less fresh but can still be eaten when the TVB-N content is 5.0 to 15.0 mg per 100 g, and it is putrid and not edible when the TVB-N content is 15.0 to 29.0 mg per 100 g. For pork stored at refrigeration temperature, it is fresh when the TVB-N content is 2.0 to 6.0 mg per 100 g, it is less fresh but can still be eaten when the TVB-N content is 6.0 to 10.0 mg per 100 g, and it is putrid and not edible when the TVB-N content is 10.0 to 17.0 mg per 100g. FT-NIR spectroscopy could be applied to effectively determine the freshness of pork. A partial least squares model coupled with optimal spectral processing gave good predictions of the measured TVB-N content, with R-2 of 0.91. The cluster analysis of principal components for the NIR spectra can classify pork into different freshness categories and define the threshold value of the TVB-N content for each freshness category.