The metabolic and vascular protective effects of olive (Olea europaea L.) leaf extract in diet-induced obesity in mice are related to the amelioration of gut microbiota dysbiosis and to its immunomodulatory properties.

INTRODUCTION: Many studies have showed the beneficial effects of the olive (Olea europaea) leaf extract (OLE) in experimental models of metabolic syndrome, which have been ascribed to the presence of phenolic compounds, like oleuropeoside. This study evaluated the effects of a chemically characterized OLE in high fat diet (HFD)-induced obesity in mice, describing the underlying mechanisms involved in the beneficial effects, with special attention to vascular dysfunction and gut microbiota composition. METHODS: C57BL/6J mice were distributed in different groups: control, control-treated, obese and obese-treated with OLE (1, 10 and 25 mg/kg/day). Control mice received a standard diet, whereas obese mice were fed HFD. The treatment was followed for 5 weeks, and animal body weight periodically assessed. At the end of the treatment, metabolic plasma analysis (including lipid profile) as well as glucose and insulin levels were performed. The HFD-induced inflammatory status was studied in liver and fat, by determining the RNA expression of different inflammatory mediators by qPCR; also, different markers of intestinal epithelial barrier function were determined in colonic tissue by qPCR. Additionally, flow cytometry of immune cells from adipose tissue, endothelial dysfunction in aortic rings as well as gut microbiota composition were evaluated. Faecal microbiota transplantation (FMT) to antibiotic-treated mice fed with HFD was performed. RESULTS: OLE administration reduced body weight gain, basal glycaemia and insulin resistance, and showed improvement in plasma lipid profile when compared with HFD-fed mice. The extract significantly ameliorated the HFD-induced altered expression of key adipogenic genes, like PPARs, adiponectin and leptin receptor, in adipose tissue. Furthermore, the extract reduced the RNA expression of Tnf-α, Il-1ß, Il-6 in liver and adipose tissue, thus improving the tissue inflammatory status associated to obesity. The flow cytometry analysis in adipose tissue corroborated these observations. Additionally, the characterization of the colonic microbiota by sequencing showed that OLE administration was able to counteract the dysbiosis associated to obesity. The extract reversed the endothelial dysfunction observed in the aortic rings of obese mice. FMT from donors HFD-OLE to recipient mice fed an HFD prevented the development of obesity, glucose intolerance, insulin resistance and endothelial dysfunction. CONCLUSION: OLE exerts beneficial effects in HFD-induced obesity in mice, which was associated to an improvement in plasma and tissue metabolic profile, inflammatory status, gut microbiota composition and vascular dysfunction.

Evolution of bioactive compounds of three mango cultivars (Mangifera indica L.) at different maturation stages analyzed by HPLC-DAD-q-TOF-MS.

Mango is an important natural source of bioactive compounds with functional properties. However, factors such as variety and maturation stage can have a great influence on the bioactive composition. In this sense, a comprehensive study of chemical composition of three spanish mango varieties (Keitt, Kent and Osteen) at five ripening stages was conducted. The analysis by HPLC-DAD-q-TOF-MS revealed the presence of more than seventy compounds from different chemical families. Subsequently, PCA evidenced that ripening process entailed an important decrease on phenolic compounds which was being more accentuated in Keitt variety. On the other hand, Osteen was revealed as the poorest variety on phenolic compounds meanwhile mangoes from Keitt variety exhibited the major quantities of gallotannins and mono and di-galloyl species at the earliest maturation stages. Therefore, from a functional point of view, unripe mango from Keitt variety seems to be an excellent natural source of bioactive compounds.

Use of HPLC- and GC-QTOF to determine hydrophilic and lipophilic phenols in mango fruit (Mangifera indica L.) and its by-products.

Mango industry processing generates high quantities of mango by-products such as peels and seeds (35%-60% of the fruit). Indeed, it is known that mango and its by-products contain different families of bioactive compounds that possess several health benefits. Thus, the aim of this study has been the determination of different families of phenolic derivatives (free and bound phenolic compounds and alk(en)ylresorcinols (ARs)) in mango edible part and its by-products (peel, seed and seed husk) from three different cultivars. This is the first study that evaluates the phenolic compounds and ARs in the four fractions of mango of three different cultivars. Special attention has been paid to the determination of anthocyanins and ARs, because these families of compounds had not been studied in depth in mango. In fact, petunidin rutinoside-(p-coumaric acid) gallate was found in mango pulp, peel, seed and seed husk of the three cultivars and, it had never been described in mango before. It is also important to highlight that this is the first time that the identification and quantification of ARs have been performed in mango seed and seed husk; besides, four and five out of eleven alk(en)ylresorcinols detected in peel and pulp, respectively, were identified for the first time in these mango fractions. Furthermore, antioxidant activity was measured by ABTS and FRAP assays. Seed free and bound phenolic extracts showed the highest antioxidant capacity.

Chemometric applications to assess quality and critical parameters of virgin and extra-virgin olive oil. A review.

Today virgin and extra-virgin olive oil (VOO and EVOO) are food with a large number of analytical tests planned to ensure its quality and genuineness. Almost all official methods demand high use of reagents and manpower. Because of that, analytical development in this area is continuously evolving. Therefore, this review focuses on analytical methods for EVOO/VOO which use fast and smart approaches based on chemometric techniques in order to reduce time of analysis, reagent consumption, high cost equipment and manpower. Experimental approaches of chemometrics coupled with fast analytical techniques such as UV-Vis spectroscopy, fluorescence, vibrational spectroscopies (NIR, MIR and Raman fluorescence), NMR spectroscopy, and other more complex techniques like chromatography, calorimetry and electrochemical techniques applied to EVOO/VOO production and analysis have been discussed throughout this work. The advantages and drawbacks of this association have also been highlighted. Chemometrics has been evidenced as a powerful tool for the oil industry. In fact, it has been shown how chemometrics can be implemented all along the different steps of EVOO/VOO production: raw material input control, monitoring during process and quality control of final product.

Bioactive lipids in the butter production chain from Parmigiano Reggiano cheese area.

BACKGROUND: Bovine milk contains hundreds of diverse components, including proteins, peptides, amino acids, lipids, lactose, vitamins and minerals. Specifically, the lipid composition is influenced by different variables such as breed, feed and technological process. In this study the fatty acid and phospholipid compositions of different samples of butter and its by-products from the Parmigiano Reggiano cheese area, produced by industrial and traditional churning processes, were determined. RESULTS: The fatty acid composition of samples manufactured by the traditional method showed higher levels of monounsaturated and polyunsaturated fatty acids compared with industrial samples. In particular, the contents of n-3 fatty acids and conjugated linoleic acids were higher in samples produced by the traditional method than in samples produced industrially. Sample phospholipid composition also varied between the two technological processes. Phosphatidylethanolamine was the major phospholipid in cream, butter and buttermilk samples obtained by the industrial process as well as in cream and buttermilk samples from the traditional process, while phosphatidylcholine was the major phospholipid in traditionally produced butter. This result may be explained by the different churning processes causing different types of membrane disruption. Generally, samples produced traditionally had higher contents of total phospholipids; in particular, butter produced by the traditional method had a total phospholipid content 33% higher than that of industrially produced butter. CONCLUSION: The samples studied represent the two types of products present in the Parmigiano Reggiano cheese area, where the industrial churning process is widespread compared with the traditional processing of Reggiana cow's milk. This is because Reggiana cow's milk production is lower than that of other breeds and the traditional churning process is time-consuming and economically disadvantageous. However, its products have been demonstrated to contain more bioactive lipids compared with products obtained from other breeds and by the industrial process.

Development of a rapid method to determine phenolic and other polar compounds in walnut by capillary electrophoresis-electrospray ionization time-of-flight mass spectrometry.

The aim of this work was to develop a capillary electrophoresis-mass spectrometry (CE-MS) method to identify and quantify phenolic and other related polar compounds in walnut samples. The extraction capacity of several solvent mixtures of phenolic compounds from walnut by conventional solid-liquid extractions was tested, and CE and electrospray ionization MS parameters were optimized. The finalized procedure is able to determine many well-known phenolic compounds present in walnuts and provide relevant information about the presence of minor polar compounds. A new compound in walnut ((2E,4E)-8-hydroxy-2,7-dimethyl-2,4-decadiene-1,10-dioic acid 6-O-beta-d-glucopiranosyl ester, [M-H](-) 403.161m/z) with a structure similar to glansreginins was also identified. Phenolic compounds correspond to 14-28% of total polar compounds quantified. Aglycone and glycosylated ellagic acid represent the principal components and account for 64-75% of total phenols in walnuts. However, the sum of glansreginins A, B and (2E,4E)-8-hydroxy-2,7-dimethyl-2,4-decadiene-1,10-dioic acid 6'-O-beta-d-glucopiranosyl ester was in the range of 72-86% of total quantified compounds. In addition, this is the first time that separation by CE with detection by electrospray ionization time-of-flight MS has been applied to the analysis of phenolic and other polar compounds in walnut samples, providing results in less than 15min.