The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform
Fereidoon Shahidi - One of the best experts on this subject based on the ideXlab platform.
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Importance of non-triacylglycerols to flavor quality of edible Oils
2020Co-Authors: Fereidoon Shahidi, Fayez Hamam, M. Ahmad KhanAbstract:Edible Oils from vegetable and animal sources are composed primarily of triacylglycerols and to a lesser extent minor components referred to as unsaponifiable matter. During processing of Oils and as a result of reactionsin production of structured and other novel lipids many of these components are removed and hence the relative stability of the preparation is compromised. Presence of chlorophyll in the Oils, both endogenous and in the additives, resulted in enhanced production of odor-active aldehydes under fluorescent light. However, simultaneous removal of non-triacylglycerol components reduced the stability of Oils under Schaal oven conditions. In enzymic acidolysis of Algal Oils with capric acid we found that the resultant Oils were much less stable than their unaltered counterparts despite a decrease in the degree of unsaturation of the products. Experiments carried out in the absence of any enzyme showed that removal of endogenous antioxidants was indeed responsible for this phenomenon.
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Marine Oils and other Marine Nutraceuticals
Handbook of Seafood Quality, Safety and Health Applications, 2010Co-Authors: Fereidoon Shahidi, Cesarettin AlasalvarAbstract:marine Oils and other marine nutraceuticals;seafoods and marine products - providing wide range of flavourful products;health benefits of long-chain omega-3 polyunsaturated fatty acids (PUFA) - in seafoods and marine organisms;nutraceuticals and bioactive ingredients - from marine resources;marine Oils, with n-3 fatty acids - foods used within short period of time;major fatty acids of omega-3 rich marine and Algal Oils;bioactive peptides and proteins - from marine resources;chitin, recovered from processing - discards of shrimp, crab, lobster, and crayfish following deproteinization and demineralization;shark cartilage, extracted from fins and heads of sharks - flexible connective tissue in animal's skeletal system;marine resources, rich reservoir of nutraceuticals and functional food ingredients Summary
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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 °C and under fluorescent light at 27 °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 high...
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lipase catalyzed acidolysis of Algal Oils with capric acid optimization of reaction conditions using response surface methodolgy
Journal of Food Lipids, 2004Co-Authors: Fayez Hamam, Fereidoon ShahidiAbstract:Lipase-assisted acidolysis of Algal Oils, arachidoinc acid single cell oil (ARASCO), docosahexaenoic acid single cell oil (DHASCO) and a single cell oil rich in both docosahexaenoic acid (DHA) and docosapentaenoic acid (DPA, n-6) known as OMEGA-GOLD, with a medium-chain fatty acid (capric acid) was studied. Response surface methodology was used to obtain a maximum incorporation of CA into Algal Oils. The process variables studied were the amount of enzyme (2–6%), reaction temperature (35–55C) and incubation time (12–36 h). The amount of water added and mole ratio of substrate (Algal oil to CA) were kept at 2% and 1:3, respectively. All experiments were conducted according to a face-centered cube design. Under optimum conditions (12.3% of enzyme; 45C; 29.4 h), the incorporation of CA was 20.0% into ARASCO, 22.6% into DHASCO (4.2% enzyme; 43.3C; 27.I h) and 20.7% into the OMEGA-GOLD oil (2.5% enzyme, 46.6C; 25.2 h).
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production and stability of structured lipids from Algal Oils and capric acid
Biofactors, 2004Co-Authors: Fayez Hamam, Fereidoon ShahidiAbstract:This study aimed to incorporate capric acid (CA) into selected Algal Oils, namely arachidoinc acid single cell oil (ARASCO), docosahexaenoic acid single cell oil (DHASCO) and the OMEGA-GOLD oil rich in dcosahexaenoic acid (DHA) and dosapentaenoic acid (n-6 DPA). Response surface methodology indicated that under optimum conditions (12.3% enzyme, 45°C, and 29.4 h) CA incorporation was 20.0% into ARASCO; (4.2% enzyme, 43.3°C, and 27.1 h) 22.6% into DHASCO and (2.5% enzyme, 46.6°C and 25.2 h) 20.7% into the OMEGA-GOLD oil. Stereospecific analysis indicated that in all Oils examined CA was mainly located at the sn-1 and sn-3 positions of the resultant TAG molecules while the highly unsaturated fatty acids being primarily esterified to the sn-2 positions of the three Oils. In all cases, enzymatically modified Oils were more susceptible to oxidation than their unmodified counterparts.
Gerhard Knothe - One of the best experts on this subject based on the ideXlab platform.
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Encyclopedia of Analytical Chemistry - Analysis of Biodiesel
Encyclopedia of Analytical Chemistry, 2017Co-Authors: Gerhard KnotheAbstract:Biodiesel is a biogenic alternative to diesel fuel derived from petroleum. It is produced by a transesterification reaction from materials consisting largely of triacylglycerols such as vegetable and other plant Oils, animal fats, used cooking Oils, and ‘alternative’ feedstocks such as Algal Oils. The variety of feedstocks that biodiesel can be derived from entails that biodiesel from different sources can have different properties depending on its composition, especially the fatty acid profile, and that the composition of the feedstock, in this case, especially the presence of extraneous materials, can influence the production process. Moreover, biodiesel is miscible with petrodiesel in all ratios, and blends of these two fuels can also be used to power diesel engines. Consequently, analysis of biodiesel has to deal with a variety of issues including the nature and quality of the feedstock, monitoring the production process, analyzing the biodiesel product for specifications in quality standards, assessing the properties of the biodiesel, and biodiesel–petrodiesel blend level determination. This chapter provides a brief synopsis of these issues and the methods used to analyze them. Keywords: analytical methods; biodiesel; biodiesel blends; biodiesel standards; cold flow; fatty acid methyl esters; fatty acid profile; fuel properties; gas chromatography; infrared spectroscopy; liquid chromatography; nuclear magnetic resonance; oxidation stability; reaction monitoring; transesterification
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Fuel properties of methyl esters of borage and black currant Oils containing methyl γ-linolenate.
European Journal of Lipid Science and Technology, 2013Co-Authors: Gerhard KnotheAbstract:In this work, the methyl esters of two Oils enriched in γ-linolenic acid (6Z,9Z,12Z-octadecatrienoic acid) were prepared under the aspect of evaluating their properties, including potential fuel properties. One oil is black currant oil in which γ-linolenic and α-linolenic (9Z,12Z,15Z-octadecatrienoic acid) are relatively evenly distributed, and the other oil is borage oil which mainly contains γ-linolenic acid as C18:3 species. The fatty acid profiles of both Oils confirm literature results. The cetane number (CN) of neat methyl γ-linolenate was also determined for the first time as 29.2, which is slightly higher than that of the more common methyl α-linolenate. The methyl esters (biodiesel) from such Oils meet most property specifications in biodiesel standards with the exception of feedstock restrictions on highly unsaturated fatty acid chains, although CNs are lower and antioxidants are required for oxidation stability. Although, due to their nutritional value and limited occurrence, these Oils are unlikely biodiesel feedstocks themselves, their methyl esters may be seen as models for similar derivatives from other feedstocks with elevated levels of unsaturation, including Algal Oils. The 1H and 13C NMR spectra of black currant and borage methyl esters are also reported.
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production and properties of biodiesel from Algal Oils
2013Co-Authors: Gerhard KnotheAbstract:Biodiesel is defined as the mono-alkyl esters of vegetable Oils or animal fats or other materials composed of triacylglycerols. This chapter discusses the potential fuel properties of biodiesel derived from Algal Oils. Since little to no experimental data are available, the potential properties need to be estimated from existing data for neat biodiesel components and biodiesel fuels derived from other feedstocks. This approach shows that many Algal biodiesel fuels would likely possess problematic cold flow and/or oxidative stability properties due to the relatively high content of polyunsaturated fatty acids and/ or saturated fatty acids in Algal Oils, although there are some exceptions.
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Fuel Properties of Highly Polyunsaturated Fatty Acid Methyl Esters. Prediction of Fuel Properties of Algal Biodiesel
Energy & Fuels, 2012Co-Authors: Gerhard KnotheAbstract:Biodiesel, defined as the monoalkyl esters of vegetable Oils and animal fats, can be derived from other triacylglycerol-containing feedstocks. Algae are being considered for this purpose due to their claimed high production potential. However, there are no comprehensive reports regarding the fuel properties of biodiesel obtained from Algal Oils. Algal Oils, with examples of some exceptions also mentioned here, often contain significant amounts of saturated and highly polyunsaturated (≥4 double bonds) fatty acid chains which influence fuel properties of the resulting biodiesel. In this connection, the relevant fuel properties of biodiesel from Algal Oils and the important fuel properties of highly polyunsaturated fatty acid methyl esters as they would occur in many biodiesel fuels obtained from Algal Oils, have not yet been reported. To fill this gap, in the present work for the first time two neat highly polyunsaturated fatty acid methyl esters with more than three double bonds, methyl 5(Z),8(Z),11(Z),14(...
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will biodiesel derived from Algal Oils live up to its promise a fuel property assessment
Lipid Technology, 2011Co-Authors: Gerhard KnotheAbstract:Algae have been attracting considerable attention as a source of biodiesel recently. This is largely due to the claimed high production potential of Algal Oils while circumventing the food vs. fuel issue. However, the properties of biodiesel fuels derived from Algal Oils have only been sparsely documented or discussed. This article discusses the expected properties of biodiesel derived from Algal Oils based on known fatty acid profiles.
Fayez Hamam - One of the best experts on this subject based on the ideXlab platform.
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Importance of non-triacylglycerols to flavor quality of edible Oils
2020Co-Authors: Fereidoon Shahidi, Fayez Hamam, M. Ahmad KhanAbstract:Edible Oils from vegetable and animal sources are composed primarily of triacylglycerols and to a lesser extent minor components referred to as unsaponifiable matter. During processing of Oils and as a result of reactionsin production of structured and other novel lipids many of these components are removed and hence the relative stability of the preparation is compromised. Presence of chlorophyll in the Oils, both endogenous and in the additives, resulted in enhanced production of odor-active aldehydes under fluorescent light. However, simultaneous removal of non-triacylglycerol components reduced the stability of Oils under Schaal oven conditions. In enzymic acidolysis of Algal Oils with capric acid we found that the resultant Oils were much less stable than their unaltered counterparts despite a decrease in the degree of unsaturation of the products. Experiments carried out in the absence of any enzyme showed that removal of endogenous antioxidants was indeed responsible for this phenomenon.
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lipase catalyzed acidolysis of Algal Oils with capric acid optimization of reaction conditions using response surface methodolgy
Journal of Food Lipids, 2004Co-Authors: Fayez Hamam, Fereidoon ShahidiAbstract:Lipase-assisted acidolysis of Algal Oils, arachidoinc acid single cell oil (ARASCO), docosahexaenoic acid single cell oil (DHASCO) and a single cell oil rich in both docosahexaenoic acid (DHA) and docosapentaenoic acid (DPA, n-6) known as OMEGA-GOLD, with a medium-chain fatty acid (capric acid) was studied. Response surface methodology was used to obtain a maximum incorporation of CA into Algal Oils. The process variables studied were the amount of enzyme (2–6%), reaction temperature (35–55C) and incubation time (12–36 h). The amount of water added and mole ratio of substrate (Algal oil to CA) were kept at 2% and 1:3, respectively. All experiments were conducted according to a face-centered cube design. Under optimum conditions (12.3% of enzyme; 45C; 29.4 h), the incorporation of CA was 20.0% into ARASCO, 22.6% into DHASCO (4.2% enzyme; 43.3C; 27.I h) and 20.7% into the OMEGA-GOLD oil (2.5% enzyme, 46.6C; 25.2 h).
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production and stability of structured lipids from Algal Oils and capric acid
Biofactors, 2004Co-Authors: Fayez Hamam, Fereidoon ShahidiAbstract:This study aimed to incorporate capric acid (CA) into selected Algal Oils, namely arachidoinc acid single cell oil (ARASCO), docosahexaenoic acid single cell oil (DHASCO) and the OMEGA-GOLD oil rich in dcosahexaenoic acid (DHA) and dosapentaenoic acid (n-6 DPA). Response surface methodology indicated that under optimum conditions (12.3% enzyme, 45°C, and 29.4 h) CA incorporation was 20.0% into ARASCO; (4.2% enzyme, 43.3°C, and 27.1 h) 22.6% into DHASCO and (2.5% enzyme, 46.6°C and 25.2 h) 20.7% into the OMEGA-GOLD oil. Stereospecific analysis indicated that in all Oils examined CA was mainly located at the sn-1 and sn-3 positions of the resultant TAG molecules while the highly unsaturated fatty acids being primarily esterified to the sn-2 positions of the three Oils. In all cases, enzymatically modified Oils were more susceptible to oxidation than their unmodified counterparts.
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lipase catalyzed acidolysis of Algal Oils with a medium chain fatty acid capric acid
2003Co-Authors: Fayez HamamAbstract:Lipase-assisted acidolysis of Algal Oils with a medium-chain fatty acid (capric acid) was studied. Five commercially available lipase preparations from Candida antarctica, Mucor miehei, Pseudomonas sp., Aspergillus niger and Candida rugosa were initially used as biocatalysts for the incorporation of capric acid (CA) into selected Algal Oils. The Algal Oils of interest were arachidoinc acid single cell oil (ARASCO), docosahexaenoic acid single cell oil (DHASCO) and single cell oil rich in docosahexaenoic acid (DHA) and docosapentaenoic acid (DP A) (OMEGA-GOLD). Among the lipases examined, Pseudomonas sp. was the most efficient. -- Effects of various reaction variables, namely the mole ratio of substrates, enzyme amount, time course, temperature and the amount of added water were examined for Pseudomonas sp. Response surface methodology was used to obtain a maximum incorporation of CA into Algal Oils. The process variables studied were the amount of enzyme (2-12 %), reaction temperature (25-55°C) and incubation time (12-48h). All experiments were conducted according to a face-centred cube design. Under optimum conditions (12.3 % of enzyme; 45°C; 29.4 h), the incorporation of CA was 20.0 % into ARASCO. Optimization of acidolysis of DHASCO with CA gave rise to a maximum of 22.6 % at 4.2 % enzyme amount, and a reaction temperature of 43.3°C and reaction time of 27.1 h. Similarly, the maximum incorporation of CA into the OMEGA-GOLD oil was obtained when enzyme amounts, reaction temperature and time were 2.5 %, 46.6°C and 25.2 h, respectively. -- Stereospecific analysis was performed to establish positional distribution of fatty acids on the glycerol backbone of modified ARASCO, DHASCO and the OMEGA-GOLD oil. In all Oils examined CA was mainly located at the sn-1 and sn-3 positions of the triacylglycerol (TAG) molecules. In ARASCO-based SL, arachidonic acid (ARA) was mostly esterified at the sn-2 position of the glycerol backbone. In DHASCO-based SL, DHA was concentrated in the sn-2 position, but also present in the sn-1,3 positions. DHA or DP A were preferentially esterified at the sn-2 position of the modified OMEGA-GOLD oil. -- The oxidative stabilities of enzymatically modified Oils as well as their unmodified counterparts were assessed under Schaal oven conditions at 60°C over a 72 h storage period. Conjugated dienes (CD), and 2-thiobarbituric acid reactive substances (TBARS) were used to follow the primary and secondary products of oxidation, respectively. Among the Oils tested, the structured lipids (SL) of ARASCO, DHASCO, and the OMEGA-GOLD oil had higher conjugated dienes than those of their unmodified counterparts. TBARS values of modified DHASCO were significantly higher than their origin oil at all times. TBARS values of both modified and unmodified ARASCO increased gradually over the entire storage period. TBARS values of the OMEGA-GOLD-based SL increased steadily with increasing storage time. The results presented in this study suggest that enzymatically modified Oils are more susceptible to oxidation than their unmodified counterparts. However, when the three Oils (ARASCO, DHASCO and the OMEGA-GOLD) were subjected to the same procedure steps, the stabilities of the Oils were adversely affected to a large extent. This observation might possibly be due to the loss of natural antioxidants during the reaction work up.
Yao Wang - One of the best experts on this subject based on the ideXlab platform.
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highly efficient enzymatic conversion of crude Algal Oils into biodiesel
Bioresource Technology, 2014Co-Authors: Yao Wang, Henri Gerken, Chengwu Zhang, Qiang Hu, Yantao LiAbstract:Energy-intensive chemical conversion of crude Algal Oils into biodiesel is a major barrier for cost-effective Algal biofuel production. To overcome this problem, we developed an enzyme-based platform for conversion of crude Algal Oils into fatty acid methyl esters. Crude Algal Oils were extracted from the oleaginous microalga Nannochloropsis oceanica IMET1 and converted by an immobilized lipase from Candida antarctica. The effects of different acyl acceptors, t-butanol as a co-solvent, oil to t-butanol ratio, oil to methanol ratio, temperature and reaction time on biodiesel conversion efficiency were studied. The conversion efficiency reached 99.1% when the conversion conditions were optimized, i.e., an oil to t-butanol weight ratio of 1:1, an oil to methanol molar ratio of 1:12, and a reaction time of 4 h at 25 degrees C. The enzymatic conversion process developed in this study may hold a promise for low energy consumption, low wastewater-discharge biochemical conversion of Algal feedstocks into biofuels. Published by Elsevier Ltd.
Yantao Li - One of the best experts on this subject based on the ideXlab platform.
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highly efficient enzymatic conversion of crude Algal Oils into biodiesel
Bioresource Technology, 2014Co-Authors: Yao Wang, Henri Gerken, Chengwu Zhang, Qiang Hu, Yantao LiAbstract:Energy-intensive chemical conversion of crude Algal Oils into biodiesel is a major barrier for cost-effective Algal biofuel production. To overcome this problem, we developed an enzyme-based platform for conversion of crude Algal Oils into fatty acid methyl esters. Crude Algal Oils were extracted from the oleaginous microalga Nannochloropsis oceanica IMET1 and converted by an immobilized lipase from Candida antarctica. The effects of different acyl acceptors, t-butanol as a co-solvent, oil to t-butanol ratio, oil to methanol ratio, temperature and reaction time on biodiesel conversion efficiency were studied. The conversion efficiency reached 99.1% when the conversion conditions were optimized, i.e., an oil to t-butanol weight ratio of 1:1, an oil to methanol molar ratio of 1:12, and a reaction time of 4 h at 25 degrees C. The enzymatic conversion process developed in this study may hold a promise for low energy consumption, low wastewater-discharge biochemical conversion of Algal feedstocks into biofuels. Published by Elsevier Ltd.
