Fourier transform mid-infrared spectroscopy evaluation of early stages of virgin olive oil autoxidation

摘要: The applicability of FT-MIR/ATR spectroscopy (4000–400 cm−1) for the evaluation early stages autoxidation was examined extra virgin olive oil samples (EVOO), which even after 12-month storage (dark, 23 ± 3°C) satisfied official limits acidity, peroxide, K232 and K270 values. Changes in intensity values at 3470 cm−1 (hydroperoxide formation) various ratios, namely A3006/2924, A3006/2853, A3006/1746, A3006/1465, A3006/1163, A1118/1097, A2853/1746, A2853/1417, A2853/1163, A2853/1118, A2853/1097, A2853/723 (relevant to degree unsaturation) did not offer more information than physicochemical criteria when one by one. Principal component – discriminant analysis 2924, 2853, 1746, 1465, 1163, 1118, 1097, 723 cm−1 led a 100, 91, 54.5% correct classification 12, 6, 0 months stored ones, respectively. Improvement latter (73–91%) obtained second derivatives spectral ranges were treated same statistical approach. Frequencies assigned stretching and/or bending CO CH2 groups (1020–1260 cm−1) produced best discrimination among samples. Findings are discussed with reference literature reports about FT-MIR under oxidation conditions (VOO). A systematic inter-laboratory study is suggested order be used as robust tool VOO quality control. Practical applications: There an increasing awareness consumers producers distributors freshness discussions on way updating relevant EU regulations its characteristics. Modernization methods introduction additional can achieved employment powerful techniques that provide solid, multiple type little sample manipulation. requires no preparation, spectra related all chemical components lipid matrix recorded over broad region few minutes. Chemometric numerous peaks extracts valuable enhance claims or disputes oxidative status (e.g., loss freshness). Moreover, apparatus has uses industry (authenticity, origin) so investment such green technique advisable.