Autenticação de óleos comestíveis empregando espectroscopia UV-Vis e quimiometria

Abstract

The search for practical and quickly results increase the importance of methodologies that can ponder if the quantitative results are really needed. The qualitative methods are used as a prior screening to quantification and allows a reduction of time and costs. These methods have increasingly its importance and the instrumental employ provided new perspectives and ensuring greater reliability and applicability. The development of qualitative methods combining instrumental and chemometric can be appropriate for authentication samples. Thus, coupled with spectroscopy in the ultraviolet and visible region (UV-Vis) the supervised pattern recognition method of partial least squares with discriminant analysis (PLS-DA), showed be a tool to authenticate transgenic and non-transgenic soybean oil samples, as well, extra virgin olive oil according to the acidity percentage. Furthermore, the proposed method promote a rapid and non-destructive analysis of the samples. Authentication studies of transgenic and non transgenic soybeans oils can be attributed to the bathochromic shift, due to differences in the chromophore group present in the transgenic and non transgenic samples, while in the extra virgin olive oils with different acidity percentages the authentication can be attributed to the occurrence of hyperchromic and hypochromic effects. UV-Vis spectroscopy allowed the geographic authentication of extra virgin olive oils from the Mediterranean region through the chemometric method of independent component analysis (ICA). Due the ICA be a method based on statistical independence, differences between samples from different countries around the Mediterranean Sea were authenticated, as well the samples from the same country.