During the last years the study of fatty acids belonging to omega 3 family in marine foods has be... more During the last years the study of fatty acids belonging to omega 3 family in marine foods has been emphasized due to their beneficial effects on cardiovascular diseases, which are the main cause of death in occidental countries, as described by literature. In order to obtain more information about the fatty acid composition of the main marine species fat constituent, usually consumed by Eastern Island population, seven fish species were analyzed: Maito (Acanthurus leucopareius), Matuko (Bodianus vulpinus), Marau (Myripristis tiki), Nanue (Kiphosus bigibus). Moki (Mori and Marari, Anampses caeruleopunctatus), Puia (Girellops nebulosus) and Raea (Cheilodactilus plessisi). Fatty acid profile and proximate analysis were determined for each species. According to its fat content, Nanue and Marari showed the highest lipid percentage, with values of 2.8 and 3.6% respectively. Fatty acid profile expressed as methyl esters percentage indicated that the most important group was that of the saturated fatty acids (SFA 35.1-54%), followed by the polyunsaturated fatty acids group (PUFA, 22-42.5%). Palmitic acid was the most important between saturated fatty acids, while oleic acid was the main fatty acid between the monounsaturated group. In omega-3 family fatty acids, eicosapentaenoic acid (EPA, C20:5w3) and docosahexaenoic acid (DHA, C22:6w3) were the most important, with values in a range between 2.0-12% and 1.8-18.3%, respectively. Omega-6 family showed a higher content in arachidonic acid (AA, C20:4w6) with values between 1.9 and 10%. Considering the fatty acid composition and the fat content, Marari was the highest in w-3 and w-6 fatty acid contribution, with values of 850 and 240 mg per one hundred grams of edible portion respectively.
Ischemia-reperfusion (IR) is a deleterious condition associated with liver transplantation or res... more Ischemia-reperfusion (IR) is a deleterious condition associated with liver transplantation or resection that involves pro-oxidant and pro-inflammatory mechanisms. Considering that Rosa Mosqueta (RM) oil composition is rich in protective components such as α-linolenic acid (ALA) and tocopherols, we studied the effects of RM oil supplementation given prior to an IR protocol. Male Sprague-Dawley rats receiving RM oil (0.4 mL d-1) for 21 days were subjected to 1 h of ischemia followed by 20 h reperfusion. Parameters of liver injury (serum transaminases, histology), oxidative stress [liver contents of protein carbonyls, thiobarbituric acid reactants, Nrf2 activity and its target mRNA expression of heme oxygenase-1 (HO-1) and NADPH-quinone oxidoreductase-1 (NQO-1)] and inflammation [nuclear factor-κB (NF-κB) and its target mRNA expression of tumor necrosis factor-α (TNF-α) and interleukine-1β (IL-1β)] were studied. RM oil increased liver ALA and its derived EPA and DHA fatty acids' contents, with enhancement in those of α- and γ-tocopherols. IR induced inflammatory liver injury, with enhancement in serum transaminases, oxidative stress-related parameters with reduced Nrf2 signaling, and higher pro-inflammatory cytokines, indexes that were attenuated or abrogated by RM oil pretreatment. It is concluded that RM oil supplementation represents a novel non-invasive preconditioning strategy against liver injury induced by IR that has potential clinical applications in metabolic stress conditions.
European Journal of Lipid Science and Technology, Jul 10, 2012
ABSTRACT Tara is a native species of Peru and is widely distributed in Latin America; its fruits ... more ABSTRACT Tara is a native species of Peru and is widely distributed in Latin America; its fruits (pods) have a high potential for medical, industrial and food uses. A supercritical tara polyphenol extract (STPE) was obtained from tara pods by supercritical fluid extraction (SFE) with CO2. The antioxidant activity of the STPE was studied in two oils, regular and high-oleic sunflower oil (SO, HOSO), with and without their natural antioxidants. Under accelerated conditions of oxidation, a linear relationship was observed in antioxidant-stripped oils between the polyphenol content of the STPE and the induction period. The antioxidant effect of STPE on the HOSO was studied at 60°C. The highest polyphenol concentration of STPE showed the greatest α-tocopherol degradation and the lowest hydroperoxide formation, which implies that α-tocopherol causes the regeneration of the polyphenols that protect the TAGs in HOSO. Tara pods combined with SFE method could be used as a source of antioxidants in oils.
In this thesis, the main concern has been to improve the reliability of different parts of the an... more In this thesis, the main concern has been to improve the reliability of different parts of the analytical workflow (Paper I, II, IV &V). Additionally, one of the resulting optimized methods was used in a real application (Paper III). Paper I-II concerned the extraction of acrylamide (AA) from foods. In Paper I different parameters such as sample particle size, extraction solvent, extraction time and extraction temperature were optimized, leading to a method that showed good agreement with the assigned AA levels of several proficiency test samples. Later, after the publication of the paper, the method showed good performance in a collaborative trial validation, in terms of trueness, repeatability and reproducibility figures. It was labeled “undoubtedly fit for the purpose”. In Paper II, it was shown that the ‘extra’ amounts of AA obtained during extraction of foods with an alkaline aqueous solution was not due to improved extractability of AA from the food matrix. Strongly alkaline conditions seemed to rather induce net formation of AA from water-soluble precursors formed during thermolysis. This phenomenon should therefore be regarded as an extraction artifact. Paper III was an application of the optimized method from Paper I, where it was used to study the reduction of AA in potato chips (crisps) by using pre-treatments and frying at reduced pressure. There were significant reductions in AA, down to below the limit of quantification (5 µg/kg) for the method. Paper IV-V concerned analysis of anthocyanins (AC) in red onion. In Paper IV, a new separation method using capillary electrophoresis was developed, and its rapidness combined with an acidic background electrolyte helped in preventing AC degradation. Furthermore, its alternative separation mechanism is a complement to that of the more commonly used liquid chromatography technique. In Paper V, simultaneous extraction and degradation of anthocyanins from red onion was studied in a static batch reactor at 110oC. The extraction and degradation kinetics were successfully separated, and an ideal theoretical extraction curve was constructed by compensating mathematically for degradation effects, showing that more anthocyanins, 21 to 36% depending on different species, could be extracted if no degradation occurred. The results give important information about the different kinetics competing during an extraction procedure, and also show that quantitative extraction is not to recommend in the batch system used in the study.
During the last years the study of fatty acids belonging to omega 3 family in marine foods has be... more During the last years the study of fatty acids belonging to omega 3 family in marine foods has been emphasized due to their beneficial effects on cardiovascular diseases, which are the main cause of death in occidental countries, as described by literature. In order to obtain more information about the fatty acid composition of the main marine species fat constituent, usually consumed by Eastern Island population, seven fish species were analyzed: Maito (Acanthurus leucopareius), Matuko (Bodianus vulpinus), Marau (Myripristis tiki), Nanue (Kiphosus bigibus). Moki (Mori and Marari, Anampses caeruleopunctatus), Puia (Girellops nebulosus) and Raea (Cheilodactilus plessisi). Fatty acid profile and proximate analysis were determined for each species. According to its fat content, Nanue and Marari showed the highest lipid percentage, with values of 2.8 and 3.6% respectively. Fatty acid profile expressed as methyl esters percentage indicated that the most important group was that of the saturated fatty acids (SFA 35.1-54%), followed by the polyunsaturated fatty acids group (PUFA, 22-42.5%). Palmitic acid was the most important between saturated fatty acids, while oleic acid was the main fatty acid between the monounsaturated group. In omega-3 family fatty acids, eicosapentaenoic acid (EPA, C20:5w3) and docosahexaenoic acid (DHA, C22:6w3) were the most important, with values in a range between 2.0-12% and 1.8-18.3%, respectively. Omega-6 family showed a higher content in arachidonic acid (AA, C20:4w6) with values between 1.9 and 10%. Considering the fatty acid composition and the fat content, Marari was the highest in w-3 and w-6 fatty acid contribution, with values of 850 and 240 mg per one hundred grams of edible portion respectively.
Ischemia-reperfusion (IR) is a deleterious condition associated with liver transplantation or res... more Ischemia-reperfusion (IR) is a deleterious condition associated with liver transplantation or resection that involves pro-oxidant and pro-inflammatory mechanisms. Considering that Rosa Mosqueta (RM) oil composition is rich in protective components such as α-linolenic acid (ALA) and tocopherols, we studied the effects of RM oil supplementation given prior to an IR protocol. Male Sprague-Dawley rats receiving RM oil (0.4 mL d-1) for 21 days were subjected to 1 h of ischemia followed by 20 h reperfusion. Parameters of liver injury (serum transaminases, histology), oxidative stress [liver contents of protein carbonyls, thiobarbituric acid reactants, Nrf2 activity and its target mRNA expression of heme oxygenase-1 (HO-1) and NADPH-quinone oxidoreductase-1 (NQO-1)] and inflammation [nuclear factor-κB (NF-κB) and its target mRNA expression of tumor necrosis factor-α (TNF-α) and interleukine-1β (IL-1β)] were studied. RM oil increased liver ALA and its derived EPA and DHA fatty acids' contents, with enhancement in those of α- and γ-tocopherols. IR induced inflammatory liver injury, with enhancement in serum transaminases, oxidative stress-related parameters with reduced Nrf2 signaling, and higher pro-inflammatory cytokines, indexes that were attenuated or abrogated by RM oil pretreatment. It is concluded that RM oil supplementation represents a novel non-invasive preconditioning strategy against liver injury induced by IR that has potential clinical applications in metabolic stress conditions.
European Journal of Lipid Science and Technology, Jul 10, 2012
ABSTRACT Tara is a native species of Peru and is widely distributed in Latin America; its fruits ... more ABSTRACT Tara is a native species of Peru and is widely distributed in Latin America; its fruits (pods) have a high potential for medical, industrial and food uses. A supercritical tara polyphenol extract (STPE) was obtained from tara pods by supercritical fluid extraction (SFE) with CO2. The antioxidant activity of the STPE was studied in two oils, regular and high-oleic sunflower oil (SO, HOSO), with and without their natural antioxidants. Under accelerated conditions of oxidation, a linear relationship was observed in antioxidant-stripped oils between the polyphenol content of the STPE and the induction period. The antioxidant effect of STPE on the HOSO was studied at 60°C. The highest polyphenol concentration of STPE showed the greatest α-tocopherol degradation and the lowest hydroperoxide formation, which implies that α-tocopherol causes the regeneration of the polyphenols that protect the TAGs in HOSO. Tara pods combined with SFE method could be used as a source of antioxidants in oils.
In this thesis, the main concern has been to improve the reliability of different parts of the an... more In this thesis, the main concern has been to improve the reliability of different parts of the analytical workflow (Paper I, II, IV &V). Additionally, one of the resulting optimized methods was used in a real application (Paper III). Paper I-II concerned the extraction of acrylamide (AA) from foods. In Paper I different parameters such as sample particle size, extraction solvent, extraction time and extraction temperature were optimized, leading to a method that showed good agreement with the assigned AA levels of several proficiency test samples. Later, after the publication of the paper, the method showed good performance in a collaborative trial validation, in terms of trueness, repeatability and reproducibility figures. It was labeled “undoubtedly fit for the purpose”. In Paper II, it was shown that the ‘extra’ amounts of AA obtained during extraction of foods with an alkaline aqueous solution was not due to improved extractability of AA from the food matrix. Strongly alkaline conditions seemed to rather induce net formation of AA from water-soluble precursors formed during thermolysis. This phenomenon should therefore be regarded as an extraction artifact. Paper III was an application of the optimized method from Paper I, where it was used to study the reduction of AA in potato chips (crisps) by using pre-treatments and frying at reduced pressure. There were significant reductions in AA, down to below the limit of quantification (5 µg/kg) for the method. Paper IV-V concerned analysis of anthocyanins (AC) in red onion. In Paper IV, a new separation method using capillary electrophoresis was developed, and its rapidness combined with an acidic background electrolyte helped in preventing AC degradation. Furthermore, its alternative separation mechanism is a complement to that of the more commonly used liquid chromatography technique. In Paper V, simultaneous extraction and degradation of anthocyanins from red onion was studied in a static batch reactor at 110oC. The extraction and degradation kinetics were successfully separated, and an ideal theoretical extraction curve was constructed by compensating mathematically for degradation effects, showing that more anthocyanins, 21 to 36% depending on different species, could be extracted if no degradation occurred. The results give important information about the different kinetics competing during an extraction procedure, and also show that quantitative extraction is not to recommend in the batch system used in the study.
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