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Carotenoids are organic pigments naturally synthesized by microorganisms and plants. Several techniques are available for the nanoencapsulation of organic compounds: self-assembly, high pressure homogenization, nanoemulsification, supercritical fluids, etc. The objective of this paper is to review some nanoencapsulation techniques that are compatible with labile compounds, such as β-carotene. Strategies for testing the safety of nanoencapsulated β-carotene are also discussed.

β-Carotene is a carotenoid usually applied in the food industry as a precursor of vitamin A or as a colourant. β-Carotene is a labile compound easily degraded by light, heat and oxygen. Casein micelles were used as nanostructures to encapsulate, stabilise and protect β-carotene from degradation during processing in the food industry. Self-assembly method was applied to re-assemble nanomicelles containing β-carotene. The protective effect of the nanostructures against degradation during the most common industrial treatments (sterilisation, pasteurisation, high hydrostatic pressure and baking) was proven. Casein micelles protected β-carotene from degradation during heat stabilisation, high pressure processing and the processes most commonly used in the food industry including baking. This opens new possibilities for introducing thermolabile ingredients in bakery products.

The objective of this work was to obtain and stabilize natural vitamins from red pepper by-products. The method of obtainment was supercritical carbon dioxide extraction, studying different parameters that affect the yield. The highest extraction yield was found at 60 °C, 24 MPa extraction, with no modifier added and 0.2–0.5 mm particle size. The recovered extract was a red-coloured oil. The extract was subsequently microencapsulated by spray-drying using gum arabic as wall material to avoid the degradation of vitamin over the storage time. The thermal stability of microcapsules was analysed by thermal gravimetric analysis (TGA), while size, shape and morphology of microcapsules were studied by scanning electron microscopy (SEM). The microcapsules containing pepper extract were particles of spherical shape with dents on the surface, the average size of these particles was 5.46 μm.

The objective of this work is to determine whether there are differences between cardoon varieties in the content of bioactive substances. Different varieties of cardoon were selected from the collection owned by the ITGA of Navarre. The varieties used in this study were: 'Blanco de Peralta', 'El Cortijo', 'Lleno de Espana', 'Rojo de Agreda', 'Blanco de Valencia', 'Verde de Peralta', 'Bianco Inerme', 'Blanco Plain Inerme'. Harvesting was done on 7 April 2008. Samples of these varieties were analyzed to determine the major biochemical compounds. For each variety, various parameters have been determined: vitamins (C, E and B9), carotenoids (lutein, zeaxanthin, lycopene, α-carotene and β-carotene), polyphenols (quercetin, rutin, resveratrol, myricetin, catechin, epicatechin, caffeic acid and gallic acid) and simple sugars (glucose, fructose, sucrose, maltose and lactose) quantified by high performance liquid chromatography. Other parameters were analyzed such as total antioxidant capacity (TAC) by the diphenyl-picryl hydrazyl test (DPPH), and free and total polyphenols by Folin-Ciocalteu assay. Finally, the dietary fibre content of the samples was determined by enzymatic digestion. The results show that the compounds allowing the distinction between cardoon varieties analyzed, are gallic acid, glucose, fructose, TAC, free polyphenols, polyphenols and dietary fibre. The maximum concentration for each of these parameters was observed in different varieties. 'Inerme Bianco' presents greater concentration of gallic acid and polyphenols, 'Blanco de Peralta' contains higher sugar content, 'Verde de Peralta' has the greatest antioxidant capacity and 'Rojo de Agreda' presents greater concentration of free polyphenols. Finally, 'Lleno de Espana' has the highest percentage of dietary fibre. Therefore, we can’t conclude which cardoon variety is better than another from the standpoint of the content in bioactive compounds; we should particularly investigate the bioactive compound in which we are interested.

Near infrared spectroscopy combined with several chemometrical techniques has been used to control the aging process in vinegar and the changes produced during storage. Several considerations regarding NIR instrument changes, which can add noise to the determinations, were made and a strategy based on the correction of the spectra was used to eliminate the differences between spectra due to instrument variation, in particular to lamp change. Ninety-five different vinegars were measured using a near-infrared spectrometer. The spectrum of each vinegar sample was collected twice: the first time as soon as the bottle was opened and the vinegar had not undergone any oxidation process and the second measurement was taken after a certain period of time. Then, in order to quantify the discrimination between the two groups of spectra recorded in the two occasions and so to estimate the aging effect in the vinegar samples, Linear Discriminant Analysis was used as a classification method. To improve the results, bearing in mind that many of the measured variables could be useless and that the elimination of these wavelengths can help in interpretation, a feature selection technique was applied. For chemical interpretation of the retained wavelengths, the spectral zones correlated with the aging process were isolated and the species and compounds that can absorb in these NIR spectra bands were studied.