Hair Mercury Levels in Pregnant Women: Fish Consumption as a Determinant of Exposure.

The consumption of fish in food may contain mercury, a harmful element and dangerous chemical detrimental to human health. The purpose of this study was to determine the mercury level in the hair of pregnant women with different fish intakes in their diets. The concentration of total mercury in hair was determined using an atomic absorption spectrometer. In this study, 98 pregnant women were invited to participate (aged from 18 to 48 years). The mean content of mercury in the hair of pregnant women in Northwestern Russia was 0.428 mg/kg (ranging from 0.018 to 3.1 mg/kg). As a result, 22% of women had mercury values above 0.58 mg/kg, which is considered dangerous for the fetus. The hair mercury concentration in a village area was higher than that in a city area (i.e., 0.548 mg/kg and 0.326 mg/kg). Moreover, the maximum level of mercury was noted for a group of pregnant women who consumed more than 5 kg/month of fish and fish products. Furthermore, the consumption of freshwater fish in the diet leads to a higher mercury content in the hair of pregnant women than the consumption of marine fish.

Comparison of four classification statistical methods for characterising virgin olive oil quality during storage up to 18 months.

This study examines the ability of fluorescence spectroscopy for monitoring the quality of 70 Moroccan virgin olive oils belonging to three varieties and originating from three regions of Morocco. By applying principal component analysis and factorial discriminant analysis to the emission spectra acquired after excitation wavelengths set at 270, 290, and 430 nm, a clear differentiation between samples according to their storage time was observed. The obtained results were confirmed following the application of four multivariate classification methods: partial least squares regression, principal component regression, support vector machine, and multiple linear regression on the emission spectra. The best prediction model of storage time was obtained by applying partial least squares regression since a coefficient of determination (R2) and a root mean square error of prediction (RMSEP) of 0.98 and 24.85 days were observed, respectively. The prediction of the chemical parameters allowed to obtain excellent validation models with R2 ranging between 0.98 and 0.99 for free acidity, peroxide value, chlorophyll level, k232, and k270.

Application of new emerging techniques in combination with classical methods for the determination of the quality and authenticity of olive oil: a review.

The determination of the quality and authenticity of olive oil becomes more and more required by producers, consumers, and authorities to thwarter falsification. Several analytical techniques including chemical, sensory, chromatography, and so on, are used for the determination of the quality and authenticity of olive oil. Although these methods are considered as the reference ones, they are cumbersome, time-consuming and destructive. Therefore, rapid analytical techniques such as fluorescence, ultraviolet-visible, near infrared, and mid infrared spectroscopies, electronic sensing, among others, are more and more used for the determination of the quality and authenticity of olive oils. This review will identify current gaps related to different analytical techniques in olive oil authentication and discuss the drawbacks of existing analytical methods concerning olive oil authenticity from 2010 up to now.

A preliminary study on the potential of front face fluorescence spectroscopy for the discrimination of Moroccan virgin olive oils and the prediction of their quality.

This study examines the feasibility of using front face fluorescence spectroscopy (FFFS) to authenticate 41 virgin olive oil (VOO) specimens collected from 5 regions in Morocco (Fez/Meknes, Eastern, Northern, Beni-Mellal/Khenifra, and Marrakech/Safi) during 2 consecutive crop seasons (2015-2016 and 2016-2017). By jointly applying factorial discriminant analysis (FDA) to the emission spectra acquired after excitation at 270, 290, and 430 nm, clear discrimination between VOOs according to their geographic origin (96.72% correct classification) and variety (95.12% correct classification) was observed. This trend was confirmed following the application of partial least squares regression (PLSR) to the fluorescence spectra, where excellent prediction of free acidity (R2 = 0.98) and peroxide (R2 = 0.96) values and good prediction of k232 (R2 = 0.88), k270 (R2 = 0.88), and chlorophyll content (R2 = 0.89) values were observed.

Preliminary study on the potential application of Fourier-transform mid-infrared for the evaluation of overall quality and authenticity of Moroccan virgin olive oil.

BACKGROUND: Olive oil provides a wide range of health-promoting compounds. The quality of olive oil is an even more complex concept as it is affected by several factors, such as variety, season, stage of maturation, extraction processing, and so on. The main objective of this study was to determine the potential of chemical and mid-infrared spectroscopy techniques to determine the quality and authenticity of virgin olive oil (VOO). For this, we studied 41 VOOs originating from five regions of Morocco (Fez/Meknes, Eastern, Northern, Beni-Mellal/Khenifra, and Marrakech/Safi) and produced using different agricultural and technological conditions during two successive crop seasons (2015-2016 and 2016-2017). RESULTS: By applying principal component analysis and factorial discriminant analysis with leave-one-out validation to the mid-infrared spectroscopy, clear discrimination between VOO samples according to their geographic origin and variety was observed, with correct classification rates of 91.87% and 91.87% being observed respectively. The application of partial least-squares regression to mid-infrared and chemical data sets allowed excellent prediction of free acidity, peroxide value, k270 , and chlorophyll level with R2 of 0.99, 0.97, 0.98, and 0.93 respectively, and good prediction of k232 (R2 = 0.84). CONCLUSION: The results demonstrate that mid-infrared spectroscopy coupled with chemometric tools could be used as a rapid screening tool for evaluating the overall quality and authenticity of VOO. © 2020 Society of Chemical Industry.