On the basis of the results obtained with pilot studies conducted in vitro on human low density lipoprotein (LDL) and on cell cultures (Caco-2), which had indicated the ability of certain molecules present in olive oil to inhibit prooxidative processes, an in vivo study was made of laboratory rabbits fed special diets. Three different diets were prepared: a standard diet for rabbits (diet A), a standard diet for rabbits modified by the addition of 10% (w/w) extra virgin olive oil (diet B), a modified standard diet for rabbits (diet C) differing from diet B only in the addition of 7 mg kg(-1) of oleuropein. A series of biochemical parameters was therefore identified, both in the rabbit plasma and the related isolated LDL, before and after Cu-induced oxidation. The following, in particular, were selected: (i) biophenols, vitamins E and C, uric acid, and total, free, and ester cholesterol in the plasma; (ii) proteins, triglycerides, phospholipids, and total, free, and ester cholesterol in the native LDL (for the latter, the dimensions were also measured); (iii) lipid hydroperoxides, aldehydes, conjugated dienes, and relative electrophoretic mobility (REM) in the oxidized LDL (ox-LDL). In an attempt to summarize the results obtained, it can be said that this investigation has not only verified the antioxidant efficacy of extra virgin olive oil biophenols and, in particular, of oleuropein, but has also revealed a series of thus far unknown effects of the latter on the plasmatic lipid situation. In fact, the addition of oleuropein in diet C increased the ability of LDL to resist oxidation (less conjugated diene formation) and, at the same time, reduced the plasmatic levels of total, free, and ester cholesterol (-15, -12, and -17%, respectively), giving rise to a redistribution of the lipidic components of LDL (greater phospholipid and cholesterol amounts) with an indirect effect on their dimensions (bigger by about 12%).

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Because of its high price, butter has always been the object of adulteration by addition of less expensive vegetable or animal fats. Although a number of methods have been proposed for the detection of butterfat adulteration, none has found widespread use. For this reason, a study was conducted to assess the use of differential scanning calorimetry (DSC) for detecting the presence of added animal fat, i.e., chicken fat, in butter. The results obtained show that DSC is an efficient method for characterizing pure animal fats as well as their mixtures. Furthermore, the accuracy with which data are obtained, in combination with the sensitivity of DSC to subtle changes in chemical composition of the sample, makes DSC an attractive possibility for development as a quality control procedure.

In recent years, erythromycin has received considerable attention for its therapeutic efficacy against some bacterial kidney diseases in aquaculture and, therefore, suitable and sensitive analytical methods to monitor erythromycin residues in fish are required. A fast sample treatment followed by an LC-ESI-MS/MS method is described for the purification, identification, and quantification of erythromycin A residues in fish. After two extractions with acetonitrile, samples were defatted with n-hexane, filtered, and analyzed by tandem mass spectrometry. Three characteristic transition reactions (m/z 734 --> 716, 734 --> 576, and 734 --> 558) in multiple reaction monitoring were tested for the determination and confirmation of erythromycin A. The method was in-house validated through the determination of precision, accuracy, specificity, stability, calibration curve, decision limit (CCalpha), and detection capability (CCbeta), in accordance with European Commission Decision 657/2002. The coefficients of variation ranged from 1.8 to 9.4% and from 7.5 to 10.9% for intra- and interday repeatability, respectively. Recovery data were also satisfactory, with values varying from 85 to 97%. The method was specific, stable, and robust enough for the required purposes. The calibration curve showed a good linearity in the whole range of the tested concentrations (0-1000 microg kg(-1)) with a correlation coefficient (r2) equal to 0.9956. CCalpha and CCbeta were found to be 220 and 238 microg kg(-1), respectively.