Publications (75) View all
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Article: Use of Crude Glycerol from Biodiesel Producers and Fatty Materials to Prepare Allyl Esters
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ABSTRACT: Vegetable oils and fats are important renewable raw materials for use by the biodiesel industry. One drawback of this industry is the large amounts of glycerol produced as a by-product. Consequently, crude glycerol is moving from a by-product to a residue. New industrial applications for this substance are required. A conversion of this by-product to allyl esters using various fatty materials in a two-step process is reported: After a simultaneous alcoholysis–chlorination reaction of vegetable oils and fats without a solvent, allyl esters were synthesized in a high yield by a rearrangement–elimination reaction using n-butanol as a solvent. All the reactions could be carried out using conventional heating or microwave irradiation with comparable results. Microwave irradiation allows for an important reduction in the reaction time. KeywordsGlycerol–Biodiesel–Vegetable oils–Animal fats–Raw materials–Allyl estersWaste and Biomass Valorization 05/2012; 2(3):285-290. -
Article: Determination of carotenoids by liquid chromatography/mass spectrometry: effect of several dopants.
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ABSTRACT: Various carotenoids were analyzed by ultra-high-pressure liquid chromatography with tandem mass spectrometry detection (UHPLC-MS/MS). Three different techniques to ionize the carotenoids were compared: electrospray ionization (ESI), atmospheric pressure chemical ionization (APCI) and atmospheric pressure photoionization (APPI). For all of the carotenoids tested, it was possible to obtain characteristic transitions for their unequivocal identification using each ionization technique. APCI was shown to be a more powerful technique to ionize the carotenoids than ESI or APPI. Transitions to differentiate carotenoids that coelute were determined to distinguish antheraxanthin from astaxanthin and lutein from zeaxanthin. In addition, four dopants were evaluated to improve ionization and enhance the carotenoid signal strength in APPI. These dopants were acetone, toluene, anisole, and chlorobenzene. Carotenoids improved their response in almost all cases when a dopant was used. The use of dopants allowed the enhancement of the carotenoid signals strength up to 178-fold.Analytical and Bioanalytical Chemistry 03/2011; 400(5):1339-46. · 3.78 Impact Factor -
Article: Activity of several IGRs against Nezara viridula (L) (Hem., Pentatomidae) eggs
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ABSTRACT: Concentrations of 10, 1, 0.1, 0.05 and 0.01 μg/ml of fenoxycarb, and 10, 5 and 1 μg/ml of other IGR products were applied topically to eggs of Nezara viridula.The effects of the treatment and concentration on egg hatching were studied comparatively for each product. Whereas at 10 μg/ml all compounds almost presented 100% of mortality, at lower concentrations most of them lost their activity. Fenoxycarb among all the IGR tested was the most active compound producing 81% mortality of 0.1 μg/ml concentration.Journal of Applied Entomology 08/2009; 119(1‐5):699 - 701. · 1.31 Impact Factor -
Article: Influence of age on ergosterol content in mycelium of Aspergillus ochraceus
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ABSTRACT: Ergosterol has been suggested as a paramoter for studying the content and evolution of fungal infestation in different products. Important differences in this parameter have been described for different genera and species. A study of the relationship between ergosterol content and dry mass in a strain of Aspergillus ochraceus, which is able to produce an antifungal agent, has therefore been carried out in order to use this parameter to accurately evaluate the fungal mass of this strain. We report herein our research work to determine the ergosterol content of the mycelial mass of our mould and how it changes with the fungal age.Letters in Applied Microbiology 06/2008; 15(1):20 - 22. · 1.62 Impact Factor -
Article: Fumonisin B1 Production and Growth of Fusarium moniliforme and Fusarium proliferatum on Maize, Wheat, and Barley Grain
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ABSTRACT: Two isolates each of Fusarium moniliforme and Fusarium proliferatum isolated from maize were compared for growth and fumonisin B1 production on maize, wheat, and barley extract agars and on irradiated maize, wheat, and barley grain in relation to water availability and temperature. Growth rates of both Fusarium spp. were similar or higher on wheat and barley than on maize extract agar. Regardless of temperature, all isolates produced fumonisin B1 only on irradiated maize grain, but not on wheat or barley. This might be a reason for the low natural occurrence of fumonisins on those grains.Journal of Food Science 06/2008; 64(5):921 - 924. · 1.66 Impact Factor
