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Olive oil is one of the main vegetable sources of squalene, substance with several interesting properties and applications. This work aims to present and validate a rapid method to quantify squalene in olive oil by gas chromatography (GC) coupled with flame ionization detector and to apply the method to extra virgin olive oils (EVOOs) and olive oils (OOs) from large scale distribution retail, and to some EVOOs from little companies productions (Italian monovarietal Leccino and Frantoio EVOOs, and niche blend Italian EVOOs). A transmethylation of the oil sample is exploited to allow the direct GC analysis avoiding the separation from saponifiable fraction. The optimized conditions provide high sensitivity, short time (total GC run time is 5 min and about 10 min are needed for sample preparation) and require instruments and materials usually available in most of the laboratories. The method was validated by determining linearity, intraday and interday repeatability, recovery, limit of detection and limit of quantification. Within EVOOs investigated, the niche blend EVOO contained significantly higher amount (P

The quality of olive oil depends, among other factors, on the quality of the olives used. Ergosterol is proposed as a marker for olives degraded by yeast or mold, since yeast as well as mold produce ergosterol, whereas olives do not. Ergosterol was determined in olive oil by on-line HPLC-GC-MS, using the high efficiency of HPLC to separate ergosterol from the sterols that are present at far higher concentrations. The detection limit was around 0.1 mg kg−1 oil. Among 50 extra virgin olive oils, 5 contained less than 0.1 mg kg−1 ergosterol, 18 were in the range 0.1–2 mg kg−1 and the highest concentration was 39 mg kg−1. Oil extracted from degraded olives contained ergosterol in a range of 21–289 mg kg−1, with higher values in the samples with a high number of yeast and mold cells. Being a marker for degraded olives, the ergosterol concentration should be related to fatty acid ethyl esters, formed by ethanol from fermentation by yeast, but the ergosterol concentration is considered more pertinent, since the ethyl esters only detect activity of yeast and their concentration depends on the conversion of the ethanol to fatty acid ethyl esters by transesterification in the olives.

The effects of deep-fat frying performed using different culinary fats (extra virgin olive oil, conventional sunflower oil and high-oleic sunflower oil) and different frying temperatures (160 and 180 °C) on the composition of the preponderant fish phospholipid classes, phosphatidylethanolamine (PE) and phosphatidylcholine (PC), were investigated on Sardina pilchardus. The total fish lipid fraction was injected into the HPLC system coupled on line with a second order mass spectrometer (MS–MS) by means of electronebulization interface (ESI), without a prior clean-up of the phospholipid fraction. The deep-fat frying process caused significant changes on PE and PC molecular species composition of the fish fillet. In all cases, the deep-fat frying process caused a significant (P Both PE and PC compositions were not influenced by the frying temperature, whereas the nature of the culinary fat had an effect on the PC composition. Particularly, the frying tests with conventional sunflower oil produced a statistically significant increase of PC species containing saturated/polyunsaturated fatty acids and a significant decrease of PC species formed by the combination of two polyunsaturated fatty acids.