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Fereidoon Shahidi - One of the best experts on this subject based on the ideXlab platform.
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Oxidative Stability of Cashew Oils from Raw and Roasted Nuts
Journal of the American Oil Chemists' Society, 2011Co-Authors: Neel Chandrasekara, Fereidoon ShahidiAbstract:Cashew nut oils, extracted from raw and roasted whole cashew nuts, were examined for their fatty acid composition, color change and Oxidative Stability. Fatty acids were analyzed using gas chromatography, and a spectrophotometric method was used to determine the color changes of the resultant oils. Oxidative Stability was determined under accelerated oxidation conditions by employing conjugated diene (CD) and thiobarbituric acid reactive substances (TBARS) assays. The contents of monounsaturated (MUFA), polyunsaturated (PUFA) and saturated (SAFA) fatty acids were 61, 17 and 21%, respectively. Oleic acid was the major MUFA whereas linoleic acid was the main PUFA present in cashew nut oils. Oxidative Stability of the oil as determined by CD values after 72 h of storage under Schall oven condition at 60 °C was 1.08 and 0.65 for the raw and high temperature roasted cashew nut, respectively. The TBARS values, expressed as malondialdehyde equivalents decreased with increasing roasting temperature. Thus roasting of whole cashew nuts improved the Oxidative Stability of the resultant nut oils.
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Lipid oxidation and improving the Oxidative Stability
Chemical Society Reviews, 2010Co-Authors: Fereidoon Shahidi, Ying ZhongAbstract:Lipids are a major component of food and important structural and functional constituents of cells in biological systems. However, this diverse group of substances is prone to oxidation through various pathways. Their Oxidative Stability depends on a number of intrinsic and extrinsic factors, including the unsaturation of their fatty acids, composition of minor components, environment conditions, delivery techniques and use of antioxidants, among others. Lipid oxidation has detrimental effects on both food quality and human health, and efforts must be made to minimize oxidation and improve Oxidative Stability of lipid products. Antioxidant strategy has been successfully employed in the food industry for quality preservation of the food products and in the medicinal industry for risk reduction of numerous Oxidative stress-mediated diseases. This tutorial review will provide important knowledge about lipid oxidation, including the mechanism and factors involved in oxidation, as well as strategies for improving Oxidative Stability of lipids.
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Oxidative Stability of Tree Nut Oils
Journal of Agricultural and Food Chemistry, 2008Co-Authors: Homan Miraliakbari, Fereidoon ShahidiAbstract:The Oxidative Stability of selected tree nut oils was examined. The oils of almond, Brazil nut, hazelnut, pecan, pine nut, pistachio, and walnut were extracted using two solvent extraction systems, namely, hexane and chloroform/methanol. The chloroform/methanol system afforded a higher oil yield for each tree nut type examined (pine nut had the highest oil content, whereas almond had the lowest). The fatty acid compositions of tree nut oils were analyzed using gas chromatography, showing that oleic acid was the predominant fatty acid in all samples except pine nut and walnut oils, which contained high amounts of linoleic acid. The tocopherol compositions were analyzed using high-performance liquid chromatography, showing that alpha- and gamma-tocopherols were the predominant tocopherol homologues present; however delta- and beta-tocopherols were also detected in some samples. The Oxidative Stability of nonstripped and stripped tree nut oils was examined under two conditions, namely, accelerated autoxidation and photooxidation. Progression of oxidation was monitored using tests for conjugated dienes, peroxide value, p-anisidine value, and headspace volatiles. Primary products of oxidation persisted in the earlier stages of oxidation, whereas secondary oxidation product levels increased dramatically during the later stages of oxidation. Hexanal was the major headspace aldehyde formed in all oxidized samples except walnut oil, which contained primarily propanal. Results showed that chloroform/methanol-extracted oils were more stable than hexane-extracted oils in both the accelerated autoxidation and photooxidation studies. Oils of pecan and pistachio were the most stable, whereas oils of pine nut and walnut were the least stable.
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Oxidative Stability of Algal Oils As Affected by Their Minor Components
Journal of agricultural and food chemistry, 2006Co-Authors: Reem Abuzaytoun, Fereidoon ShahidiAbstract:Algal oils, namely, arachidonic acid single-cell oil (ARASCO), docosahexaenoic acid single-cell oil (DHASCO), and a single-cell oil rich in both docosahexaenoic acid and docosapentaenoic acid (OMEGA-GOLD oil), were evaluated for their Oxidative Stability, as such and after stripping of their minor components, in the dark at 60 degrees C and under fluorescent light at 27 degrees C. Several analytical methods were used to assess the Oxidative Stability of these oils. Oil extracts were also investigated for their scavenging of 1,1-diphenyl-2-picrylhydrazyl radical by a spectrophotometric method and by measuring their total phenolic contents. The results indicated that minor oil constituents play a major role in their Oxidative Stability in the dark as well as under fluorescent light. The Stability of the oils was dictated by their fatty acid composition, total tocopherols, and the type of pigment present. DHASCO contained a significant level of natural radical scavengers and phenolic compounds that contributed to its higher Stability compared to the ARASCO and OMEGA-GOLD oils. Thus, the importance of minor components in the Stability of the oils examined was demonstrated.
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Oxidative Stability of flax and hemp oils
Journal of the American Oil Chemists' Society, 2006Co-Authors: Reem Abuzaytoun, Fereidoon ShahidiAbstract:Oxidative Stability of flax and hemp oils, and of flax and hemp oils stripped of their minor components, was evaluated in the dark at 60°C and under fluorescent light at 27°C. Several analytical methods were used to assess the Oxidative Stability of oils. Oil extracts were also investigated for their scavenging of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and for their total phenolic contents. The results indicate that bioactive constituents of these edible oils play a major role in their Oxidative Stability. However, the FA composition of the oils and their total content of tocopherols as well as the type of pigments present contribute to their Stability. Nonstripped flax and hemp oils were more stable than their corresponding stripped counterparts. Furthermore, nonstripped hemp oil had a higher Oxidative Stability than nonstripped flax oil as evidenced by scavenging of DPPH radical and consideration of total phenolic contents.
Selma E. Mazzetto - One of the best experts on this subject based on the ideXlab platform.
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Oxidative Stability of Acylated and Hydrogenated Ricinoleates Using Synthetic and Natural Antioxidants
Hindawi Limited, 2019Co-Authors: Murilo F. T. Luna, Davi Costa Salmin, Vanessa S. Santiago, Francisco J. N. Maia, Francisco O. N. Silva, Selma E. Mazzetto, Célio L. CavalcanteAbstract:As increasing environmental policies constrains are imposed, the demand for biodegradable products also increases. Although vegetable oils present some properties that favor its use for formulation of a bio-based lubricant, its poor resistance to oxidation hinders its application as such. In this study, the thermo-Oxidative Stability of bio-based products was compared to petroleum-based lubricants and vegetable oils through the PetroOXY method. Chemical modifications in the ricinoleic acids were carried out using long-chain alcohols in esterification reactions. Acetates were obtained from ricinoleates with and without hydrogenation steps. Additionally, commercial antioxidants and phenolic compounds (saturated and unsaturated cardanol) obtained from cashew nut shell liquid were added to the synthesized samples with higher induction times. The results show that the chemically modified bio-based products exhibited improved Oxidative Stability (up to 6 times) and depressed pour point (−42°C) when compared to pure castor oil. Overall, the addition of antioxidants increased from 6 to 20 times the Oxidative Stability of the bio-based products. Propyl gallate and saturated cardanol showed higher efficiency for retarding the Oxidative process of bio-based samples than the commercial antioxidants
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Evaluation of antioxidants on the thermo-Oxidative Stability of soybean biodiesel
Journal of Thermal Analysis and Calorimetry, 2013Co-Authors: Maria A. S. Rios, Francisco F. P. Santos, Francisco J. N. Maia, Selma E. MazzettoAbstract:This work shows the evaluation of three antioxidants (2,6-di- t -butyl-4-methylphenol (BHT)—synthetic antioxidant, hydrogenated cardanol (HC), and alkyl hydrogenated cardanol (AHC)—both derived from cashew nut shell liquid) on the thermo-Oxidative Stability of the soybean biodiesel. The antioxidants were added at concentrations of 200, 300, and 400 ppm, and the Oxidative Stability of the biofuel with and without antioxidants were investigated by thermogravimetric analysis (TG-DTG and IPDT) and Metrohm 743 Rancimat per the EN 14112 method. The results showed that all antioxidants contributed for the thermo-Oxidative Stability of the soybean biodiesel as follows: soybean biodiesel
Selma Elaine Mazzetto - One of the best experts on this subject based on the ideXlab platform.
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Evaluation of antioxidants on the thermo-Oxidative Stability of soybean biodiesel
Journal of Thermal Analysis and Calorimetry, 2012Co-Authors: Maria Alexsandra De Sousa Rios, Francisco Jonas Nogueira Maia, Francisco F. P. Santos, Selma Elaine MazzettoAbstract:This work shows the evaluation of three antioxidants (2,6-di-t-butyl-4-methylphenol (BHT)—synthetic antioxidant, hydrogenated cardanol (HC), and alkyl hydrogenated cardanol (AHC)—both derived from cashew nut shell liquid) on the thermo-Oxidative Stability of the soybean biodiesel. The antioxidants were added at concentrations of 200, 300, and 400 ppm, and the Oxidative Stability of the biofuel with and without antioxidants were investigated by thermogravimetric analysis (TG-DTG and IPDT) and Metrohm 743 Rancimat per the EN 14112 method. The results showed that all antioxidants contributed for the thermo-Oxidative Stability of the soybean biodiesel as follows: soybean biodiesel < soybean biodiesel + BHT < soybean biodiesel + HC < soybean biodiesel + AHC. In the Rancimat method, the results showed that the antioxidants influenced the biodiesel Stability with an increase of at least 71 %.
Francisco F. P. Santos - One of the best experts on this subject based on the ideXlab platform.
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Evaluation of antioxidants on the thermo-Oxidative Stability of soybean biodiesel
Journal of Thermal Analysis and Calorimetry, 2013Co-Authors: Maria A. S. Rios, Francisco F. P. Santos, Francisco J. N. Maia, Selma E. MazzettoAbstract:This work shows the evaluation of three antioxidants (2,6-di- t -butyl-4-methylphenol (BHT)—synthetic antioxidant, hydrogenated cardanol (HC), and alkyl hydrogenated cardanol (AHC)—both derived from cashew nut shell liquid) on the thermo-Oxidative Stability of the soybean biodiesel. The antioxidants were added at concentrations of 200, 300, and 400 ppm, and the Oxidative Stability of the biofuel with and without antioxidants were investigated by thermogravimetric analysis (TG-DTG and IPDT) and Metrohm 743 Rancimat per the EN 14112 method. The results showed that all antioxidants contributed for the thermo-Oxidative Stability of the soybean biodiesel as follows: soybean biodiesel
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Evaluation of antioxidants on the thermo-Oxidative Stability of soybean biodiesel
Journal of Thermal Analysis and Calorimetry, 2012Co-Authors: Maria Alexsandra De Sousa Rios, Francisco Jonas Nogueira Maia, Francisco F. P. Santos, Selma Elaine MazzettoAbstract:This work shows the evaluation of three antioxidants (2,6-di-t-butyl-4-methylphenol (BHT)—synthetic antioxidant, hydrogenated cardanol (HC), and alkyl hydrogenated cardanol (AHC)—both derived from cashew nut shell liquid) on the thermo-Oxidative Stability of the soybean biodiesel. The antioxidants were added at concentrations of 200, 300, and 400 ppm, and the Oxidative Stability of the biofuel with and without antioxidants were investigated by thermogravimetric analysis (TG-DTG and IPDT) and Metrohm 743 Rancimat per the EN 14112 method. The results showed that all antioxidants contributed for the thermo-Oxidative Stability of the soybean biodiesel as follows: soybean biodiesel < soybean biodiesel + BHT < soybean biodiesel + HC < soybean biodiesel + AHC. In the Rancimat method, the results showed that the antioxidants influenced the biodiesel Stability with an increase of at least 71 %.
Maria A. S. Rios - One of the best experts on this subject based on the ideXlab platform.
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Evaluation of antioxidants on the thermo-Oxidative Stability of soybean biodiesel
Journal of Thermal Analysis and Calorimetry, 2013Co-Authors: Maria A. S. Rios, Francisco F. P. Santos, Francisco J. N. Maia, Selma E. MazzettoAbstract:This work shows the evaluation of three antioxidants (2,6-di- t -butyl-4-methylphenol (BHT)—synthetic antioxidant, hydrogenated cardanol (HC), and alkyl hydrogenated cardanol (AHC)—both derived from cashew nut shell liquid) on the thermo-Oxidative Stability of the soybean biodiesel. The antioxidants were added at concentrations of 200, 300, and 400 ppm, and the Oxidative Stability of the biofuel with and without antioxidants were investigated by thermogravimetric analysis (TG-DTG and IPDT) and Metrohm 743 Rancimat per the EN 14112 method. The results showed that all antioxidants contributed for the thermo-Oxidative Stability of the soybean biodiesel as follows: soybean biodiesel
