Preliminary Discrimination of Cheese Adulteration by FT-IR Spectroscopy
The present work describes a preliminary study to compare some traditional Romanian cheeses and adulterated cheeses using Attenuated Total Reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). For PLS model calibration (6 concentration levels) and validation (5 concentration levels) sets&l...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
AcademicPres
2014-11-01
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| Series: | Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca: Food Science and Technology |
| Subjects: | |
| Online Access: | http://journals.usamvcluj.ro/index.php/fst/article/view/10795 |
| Summary: | The present work describes a preliminary study to compare some traditional Romanian cheeses and adulterated cheeses using Attenuated Total Reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). For PLS model calibration (6 concentration levels) and validation (5 concentration levels) sets<strong> </strong>were prepared from commercial Dalia Cheese from different manufacturers by spiking it with palm oil at concentrations ranging 2-50 % and 5-40 %, respectively. Fifteen Dalia Cheese were evaluated as external set. The spectra of each sample, after homogenization, were acquired in triplicate using a FTIR Shimatsu Prestige 21 Spectrophotometer, with a horizontal diamond ATR accessory in the MIR region 4000-600 cm<sup>-1</sup>. Statistical methods as PLS were applied using MVC1 routines written for Matlab R2010a. As first step the optimal condition for PLS model were obtained using cross-validation on the Calibration set. Spectral region in 3873-652 cm<sup>-1</sup>, and 3 PLS-factors were stated as the best conditions and showed an R<sup>2 </sup>value of 0.9338 and a relative error in the calibration of 17.2%. Then validation set was evaluated, obtaining good recovery rates (108%) and acceptable dispersion of the data (20%). The curve of actual vs. predicted values shows slope near to 1 and origin close to 0, with an R<sup>2 </sup>of 0.9695. When the external sample set was evaluated, samples F19, F21, F22 and F24, showed detectable levels of palm fats. The results proved that FTIR-PLS is a reliable non-destructive technique for a rapid quantification the level of adulteration in cheese. The spectroscopic methods could assist the quality control authority, traders and the producers to discriminate the adulterated cheeses with palm oil. |
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| ISSN: | 2344-2344 2344-5300 |