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Abstract: A Fourier transform infrared spectroscopy–Partial Least Squares (FTIR–PLS) strategy for the determination of the quality of olive fruits and the respective virgin olive oil (VOO) has been developed. This methodology has been demonstrated as able to correlate the level of fly attack in olive oils with their FTIR spectra. A multivariate calibration model was built by the PLS algorithm using the 4000–700 cm−1 spectral range on pretreated data and an evaluation of some of the usual quality parameters of VOO (free acidity, fatty acids composition, oxidative stability by OSI time and phenolic compounds obtained by capillary electrophoresis) and was performed to corroborate the real influence of fly attack on the quality of the oils. Furthermore, the evaluation of the FTIR data showed some differences in the regions of the fatty acids and phenolic compounds depending on the percentage of fly attack on the olives. This non-destructive method easily allows a non-destructive measure and, at the same time, establishes the level of Bactrocera oleae attack in olive fruit thus analysing directly the olive oil obtained without any previous treatment. [Copyright &y& Elsevier]

study on the characterization of Tunisian extra-virgin olive oil varieties produced in their place of origin has been carried out. Due to the influence of the genotype and environmental, agronomic and technological factors on the chemical composition of olive oil and its quality, all the olives studied were collected on the same season, and the oil was obtained under the same processing technique. Several analyses were performed to characterize the different olive oils: free acidity, peroxide value, fatty acid composition, radical scavenging activity, Rancimat assay, pigments content and phenolic compounds by HPLC-MS. In order to evaluate all the results obtained (36 parameters for each variety), different statistical analyses were used to discriminate the extra-virgin olive oil varieties: one-way analysis of variance was performed to check significant differences among cultivars ( p ≤ 0.05); PCA was applied to the data showing that variables such as oleic, linoleic, quinic and vanillic acids, apigenin, luteolin, taxifolin, oleuropein aglycon, pinoresinol acetate, elenolic acid and oxidative stability allowed discriminating among the different varieties of extra-virgin olive oil studied. Besides, LDA model was able to classify the samples depending on their geographical origin in Tunisia (North, Centre and South). [ABSTRACT FROM AUTHOR]

Abstract: The phenolic compounds present in seven samples of olive fruits were analysed by a rapid and resolutive LC–ESI-TOF MS method. All samples were collected during the normal picking period for olive oil production, in central and south Tunisia, and were obtained from the Oueslati variety cultivated in different olive growing areas. In the Tunisian samples, 22 compounds have been characterised by LC–ESI-TOF MS analysis. Results showed no qualitative differences in the phenolic fractions between virgin olive oils from different geographical region. However, significant quantitative differences were observed in a wide number of phenolic compounds. These results permit to use the phenolic fractions as an indicator of each region. [Copyright &y& Elsevier]

The present study aimed to examine how different oils (extra virgin olive oil (EVOO), refined olive oil, high oleic sunflower oil (HOSO), and refined sunflower oil (RSO)) and intermittent deep-frying could influence the levels of glycidols (GD), monochloropropanediols (MCPDs) and acrylamide (AA) in pre-fried French fries. Time and type of oil affected the content of MCPDs, GD, and AA. The migration of MCPDs and glycidols in French fries during the frying was confirmed, but a new formation was also noticed. Extra virgin olive oil showed the lowest MCPDs and GD content (3-MCPD: 0.016–0.27 mg/kg, 2-MCPD < limit of detection (LOD)-0.04 mg/kg, and GD: 0.05–0.14 mg/kg). The 22% of the samples analyzed showed an AA content higher than 500 μg/kg (the limit recommended by the EFSA), 18% corresponded to samples deep-fried with EVOO, and 4% to samples deep-fried with RSO. Moreover, the lowest AA level was found when using HOSO (121.2–250.8 mg/kg). The overall analysis of these results suggests that HOSO could be used as a deep-frying oil, furnishing a good compromise between MCPD accumulation and AA formation. • Intermittent frying contributes to improve the formation of AA, GD and MCPDs. • MCPD and glycidols were transferred from oil to fried potatoes. • High oleic sunflower oil showed the best performance. [ABSTRACT FROM AUTHOR]