969 resultados para TIRE CHIPS
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Mode of access: Internet.
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Mode of access: Internet.
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Mode of access: Internet.
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Mode of access: Internet.
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The objective of this study was to determine the antioxidant effect of essential oregano and alfavaca oil on the fatty acid profile of palm oil, used in industrial potato chips processing, aiming to reduce the oxidative state of palm oil. Essential oregano oil was obtained from industrial residues and commercial essential oregano oil was also acquired. The antioxidant activity of Oregano’s essential oil was taken by DPPH method. The DPPH analysis of the essential oil of oregano residue resulted in an IC50 of 797.04 mg.mL-1 and the essential oil of commercial oregano was 424.25 mg.mL-1. Regarding the content of total phenols, the essential oil of commercial oregano showed 0.167 ± 0.058 ug EAG.g-1. Based on these results, concentrations of 50, 100 e 150ug.g-1 of commercial oregano essential oil was added to palm oil and the fatty acid profile was determined by gas cromatography. Analysis were done with palm oil without being used in frying processes and without added essential oil, as well as with the different essential oil concentrations submitted at three frying processes at one single day. In the second part of the project, the effect of oreganos’s comercial essential oil compared to alfavacão essential oil, at the concentration of 100ug.g-1 in palm oil, and submitted to three frying processes during eleven cycles, was studied. The lipid profile was similar to that described in the literature, which an increase in the number of frying times caused a polyunsaturated fatty acids decrease and, therefore, a proportional increase in saturated fatty acids. It was noted an increase in the amounts of total saturated fatty acids from 43.36% (control) to 43.60% (palm oil with essential oil after 11 frying cycles at the concentration of 100ug.g-1). This fact proves that during the frying process, there is an increase in the rate of formation of saturated fatty acids. However, the addition of oregano essential oil did not provide significant change in the fatty acids of palm oil used in frying process of potato chips. The addition of oregano essential oil in a concentration of 100 ug./mL-1 until the third frying cycle showed a reduction effect of trans fatty acid formation. Although, during 11 frying cycles it was not noticed the essential oil effect under trans fatty acid formation. It can be suggested that this factor may be correlated to the frying time, which may not have been sufficient for significant formation of saturated and trans compounds.
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The aim of the project was to design in Solidworks and improve an existing Tire inspection machine. The project was developed in Gislotica - Mechanical Solutions, guided by ing. Rui Manuel Fazenda Silva who is a professor in ISEP. The designed device relates to the inspection of automobile tires for holes and weak places caused by punctures and usage. Such inspection includes careful examination of the inside surface of the tire which is difficult because of its cylindrical shape, stiff and resistant nature of the material out of which the tire is made. The whole idea is to provide a machine by which the walls of the tire may be spread and hold apart, presenting the inner surface for the worker to control. The device must also perform rotational and vertical movement of the tire. It is meant to provide inspection in hich there is no need for the controller to use force. It makes his work easier and more efficient.
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Deep-fat frying is susceptible to induce the formation of undesirable products as lipid oxidation products and acrylamide in fried foods. Plantain chips produced by small-scale producers are sold to consumers without any control. The objective of this study was to evaluate the quality of plantain chips from local producers in relation to production process parameters and oils, and to identify the limiting factors for the production of acrylamide in plantain chips. Samples of frying oils and plantain chips prepared with either palm olein or soybean oil were collected from 10 producers in Yaoundé. Quality parameters determined in this study were: fatty acid composition of the oils, determined by gas chromatography (GC) of free acid methyl ester; trans fatty acids, determined by Fourier transform infra-red spectroscopy; Tocopherols and tocotrienols as markers of nutritional quality were analyzed by High Performance Liquid Chromatography in isocratic mode. Free fatty acids and acylglycerols as markers of lipid hydrolysis were analyzed by GC of trimethylsilyl derivatives of glycerides. Conjugated dienes, Anisidine value and viscosity as markers of lipid oxidation and thermal decomposition of the oils; acrylamide which is formed through Maillard reaction and identified as a toxic compound in various fried products. Asparagine content of the raw fresh plantain powder was also determined. Fatty acid composition of palm oleins was stable within a day of intermittent frying. In soybean oils, about 57% and 62.5% of linoleic and linolenic acids were lost but trans fatty acids were not detected. Soybean oils were partly hydrolysed leading to the formation of free fatty acids, monoacylglycerols and diacylglycerols. In both oils, tocopherols and tocotrienols contents decreased significantly by about 50%. Anisidine value (AV) and polymers contents increased slightly in fried palm oleins while conjugated hydroperoxides, AV and polymers greatly increased in soybean oils. Acrylamide was not detected in the chips. This is explained by the absence of asparagine in the raw plantains, the other acrylamide precursors being present. This study shows that the plantain chips prepared at the small-scale level in Yaounde with palm olein are of good quality regarding oxidation and hydrolysis parameters and the absence of acrylamide. In contrast, oxidation developed with soybean oil whose usage for frying should be questioned. Considering that asparagine is the limiting factor for the formation of acrylamide in plantain chips, its content depending on several factors such as production parameters and maturity stage should be explored.
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Mestrado Vinifera Euromaster - Instituto Superior de Agronomia - UL
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The residual forest biomass (RFB) sector has been experiencing strong development at European level and particularly in Portugal mainly due to the increase of energy production from renewable sources. The aim of this study is to assess the environmental impacts of eucalyptus RFB chips production chain in Portugal. The environmental and economic impact comparison of the processes included in the production chain is presented as well. The environmental impacts were calculated by the life cycle assessment approach described in the ISO 14040 series of standards. The production chain assessed included all processes from eucalyptus forest until the delivery of RFB chips at the power plant. The main conclusion of this study is that eucalyptus wood production is the process that presents the greatest environmental impact through the product life cycle.