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Fabrice Vaillant - One of the best experts on this subject based on the ideXlab platform.
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identification and quantification of Carotenoids by hplc dad during the process of peach palm bactris gasipaes h b k flour
Food Research International, 2011Co-Authors: Carolina Rojasgarbanzo, Ana Mercedes Pérez, Jairol Bustoscarmona, Fabrice VaillantAbstract:Abstract The identification and quantification of Carotenoids has been carried out on tropical and non tropical fruits because of two important carotenoid's properties: as antioxidant compounds having a prevention role in some diseases, and as a source of provitamin A needed for a good human nutrition. This study aimed to identify Carotenoids present during different steps for producing flour from Costa Rican peach-palm fruit ( Bactris gasipaes H.B.K). Nine Carotenoids were tentatively identified and quantified by HPLC-DAD in raw pulp, and 14 were detected in cooked pulp, the additional five being products of isomerization and hydroxylation of Carotenoids in the raw pulp. The flour contained 13 Carotenoids, one less (all- trans -α-criptoxanthin) than in cooked pulp, with the main one being all -trans β-carotene. This carotenoid was also present in raw pulp at a concentration of 96.0 ± 1.7 μg equiv. of β-carotene g −1 dw. The concentration decreased significantly ( P −1 dw in the flour. Flour production reduced ( P −1 dw, with a final retention rate of 63.7% by the end of the process. Moreover, 9 of the 14 Carotenoids account for high levels of provitamin A, which, even so, had decreased from 2723 retinol equivalents (RE) 100 g −1 in raw pulp to 1614 RE 100 g −1 in cooked pulp and 1289 RE 100 g −1 in flour. Provitamin A level is still high when compared to other common provitamin A sources. Our study shows that while there is a change in the levels and profile of Carotenoids during the peach-palm flour process, and a reduction of provitamin A value, peach-palm fruit is a great source of bioactive compounds.
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identification and quantification of Carotenoids by hplc dad during the process of peach palm bactris gasipaes h b k flour
Food Research International, 2011Co-Authors: Carolina Rojasgarbanzo, Ana Mercedes Pérez, Jairol Bustoscarmona, Fabrice VaillantAbstract:The identification and quantification of Carotenoids has been carried out on tropical and non tropical fruits because of two important carotenoid's properties: as antioxidant compounds having a prevention role in some diseases, and as a source of provitamin A needed for a good human nutrition. This study aimed to identify Carotenoids present during different steps for producing flour fromCosta Rican peach-palmfruit (Bactris gasipaes H.B.K). Nine Carotenoids were tentatively identified and quantified by HPLC-DAD in raw pulp, and 14 were detected in cooked pulp, the additional five being products of isomerization and hydroxylation of Carotenoids in the raw pulp. The flour contained 13 Carotenoids, one less (all-trans-?-criptoxanthin) than in cooked pulp, with themain one being all-trans ?-carotene. This carotenoidwas also present in rawpulp at a concentration of 96.0± 1.7 ?g equiv. of ?-carotene g?1 dw. The concentration decreased significantly (Pb0.05) during cooking and drying to reach a final concentration of 33.3±1.0 ?g equiv. ?-carotene g?1 dw in the flour. Flour production reduced (Pb0.05) the total carotenoid content from373.4 to 237.7 ?gof ?-carotene g?1dw,with a final retention rate of 63.7% by the end of the process. Moreover, 9 of the 14 Carotenoids account for high levels of provitamin A, which, even so, had decreased from 2723 retinol equivalents (RE) 100 g?1 in raw pulp to 1614 RE 100 g?1 in cooked pulp and 1289 RE 100 g?1 in flour. Provitamin A level is still high when compared to other common provitamin A sources. Our study shows that while there is a change in the levels and profile of Carotenoids during the peach-palm flour process, and a reduction of provitamin A value, peach-palm fruit is a great source of bioactive compounds. (Resume d'auteur)
Dariusz M. Niedzwiedzki - One of the best experts on this subject based on the ideXlab platform.
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Evaluating the Nature of So-Called S*-State Feature in Transient Absorption of Carotenoids in Light-Harvesting Complex 2 (LH2) from Purple Photosynthetic Bacteria
2016Co-Authors: Dariusz M. Niedzwiedzki, Neil C. Hunter, Robert E. BlankenshipAbstract:Carotenoids are a class of natural pigments present in all phototrophic organisms, mainly in their light-harvesting proteins in which they play roles of accessory light absorbers and photoprotectors. Extensive time-resolved spectroscopic studies of these pigments have revealed unexpectedly complex photophysical properties, particularly for Carotenoids in light-harvesting LH2 complexes from purple bacteria. An ambiguous, optically forbidden electronic excited state designated as S* has been postulated to be involved in carotenoid excitation relaxation and in an alternative carotenoid-to-bacteriochlorophyll energy transfer pathway, as well as being a precursor of the carotenoid triplet state. However, no definitive and satisfactory origin of the carotenoid S* state in these complexes has been established, despite a wide-ranging series of studies. Here, we resolve the ambiguous origin of the carotenoid S* state in LH2 complex from Rba. sphaeroides by showing that the S* feature can be seen as a combination of ground state absorption bleaching of the carotenoid pool converted to cations and the Stark spectrum of neighbor neutral Carotenoids, induced by temporal electric field brought by the carotenoid cation–bacteriochlorophyll anion pair. These findings remove the need to assign an S* state, and thereby significantly simplify the photochemistry of Carotenoids in these photosynthetic antenna complexes
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Triplet excited state spectra and dynamics of Carotenoids from the thermophilic purple photosynthetic bacterium Thermochromatium tepidum
Photosynthesis Research, 2011Co-Authors: Dariusz M. Niedzwiedzki, Masayuki Kobayashi, Robert E. BlankenshipAbstract:Light-harvesting complex 2 from the anoxygenic phototrophic purple bacterium Thermochromatium tepidum was purified and studied by steady-state absorption, fluorescence and flash photolysis spectroscopy. Steady-state absorption and fluorescence measurements show that Carotenoids play a negligible role as supportive energy donors and transfer excitation to bacteriochlorophyll- a with low energy transfer efficiency of ~30%. HPLC analysis determined that the dominant Carotenoids in the complex are rhodopin and spirilloxanthin. Carotenoid excited triplet state formation upon direct (carotenoid) or indirect (bacteriochlorophyll- a Q_x band) excitation shows that carotenoid triplets are mostly localized on spirilloxanthin. In addition, no triplet excitation transfer between Carotenoids was observed. Such specific carotenoid composition and spectroscopic results strongly suggest that this organism optimized carotenoid composition in the light-harvesting complex 2 in order to maximize photoprotective capabilities of Carotenoids but subsequently drastically suppressed their supporting role in light-harvesting process.
Robert E. Blankenship - One of the best experts on this subject based on the ideXlab platform.
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Triplet excited state spectra and dynamics of Carotenoids from the thermophilic purple photosynthetic bacterium Thermochromatium tepidum
Photosynthesis Research, 2011Co-Authors: Dariusz M. Niedzwiedzki, Masayuki Kobayashi, Robert E. BlankenshipAbstract:Light-harvesting complex 2 from the anoxygenic phototrophic purple bacterium Thermochromatium tepidum was purified and studied by steady-state absorption, fluorescence and flash photolysis spectroscopy. Steady-state absorption and fluorescence measurements show that Carotenoids play a negligible role as supportive energy donors and transfer excitation to bacteriochlorophyll- a with low energy transfer efficiency of ~30%. HPLC analysis determined that the dominant Carotenoids in the complex are rhodopin and spirilloxanthin. Carotenoid excited triplet state formation upon direct (carotenoid) or indirect (bacteriochlorophyll- a Q_x band) excitation shows that carotenoid triplets are mostly localized on spirilloxanthin. In addition, no triplet excitation transfer between Carotenoids was observed. Such specific carotenoid composition and spectroscopic results strongly suggest that this organism optimized carotenoid composition in the light-harvesting complex 2 in order to maximize photoprotective capabilities of Carotenoids but subsequently drastically suppressed their supporting role in light-harvesting process.
Carolina Rojasgarbanzo - One of the best experts on this subject based on the ideXlab platform.
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identification and quantification of Carotenoids by hplc dad during the process of peach palm bactris gasipaes h b k flour
Food Research International, 2011Co-Authors: Carolina Rojasgarbanzo, Ana Mercedes Pérez, Jairol Bustoscarmona, Fabrice VaillantAbstract:Abstract The identification and quantification of Carotenoids has been carried out on tropical and non tropical fruits because of two important carotenoid's properties: as antioxidant compounds having a prevention role in some diseases, and as a source of provitamin A needed for a good human nutrition. This study aimed to identify Carotenoids present during different steps for producing flour from Costa Rican peach-palm fruit ( Bactris gasipaes H.B.K). Nine Carotenoids were tentatively identified and quantified by HPLC-DAD in raw pulp, and 14 were detected in cooked pulp, the additional five being products of isomerization and hydroxylation of Carotenoids in the raw pulp. The flour contained 13 Carotenoids, one less (all- trans -α-criptoxanthin) than in cooked pulp, with the main one being all -trans β-carotene. This carotenoid was also present in raw pulp at a concentration of 96.0 ± 1.7 μg equiv. of β-carotene g −1 dw. The concentration decreased significantly ( P −1 dw in the flour. Flour production reduced ( P −1 dw, with a final retention rate of 63.7% by the end of the process. Moreover, 9 of the 14 Carotenoids account for high levels of provitamin A, which, even so, had decreased from 2723 retinol equivalents (RE) 100 g −1 in raw pulp to 1614 RE 100 g −1 in cooked pulp and 1289 RE 100 g −1 in flour. Provitamin A level is still high when compared to other common provitamin A sources. Our study shows that while there is a change in the levels and profile of Carotenoids during the peach-palm flour process, and a reduction of provitamin A value, peach-palm fruit is a great source of bioactive compounds.
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identification and quantification of Carotenoids by hplc dad during the process of peach palm bactris gasipaes h b k flour
Food Research International, 2011Co-Authors: Carolina Rojasgarbanzo, Ana Mercedes Pérez, Jairol Bustoscarmona, Fabrice VaillantAbstract:The identification and quantification of Carotenoids has been carried out on tropical and non tropical fruits because of two important carotenoid's properties: as antioxidant compounds having a prevention role in some diseases, and as a source of provitamin A needed for a good human nutrition. This study aimed to identify Carotenoids present during different steps for producing flour fromCosta Rican peach-palmfruit (Bactris gasipaes H.B.K). Nine Carotenoids were tentatively identified and quantified by HPLC-DAD in raw pulp, and 14 were detected in cooked pulp, the additional five being products of isomerization and hydroxylation of Carotenoids in the raw pulp. The flour contained 13 Carotenoids, one less (all-trans-?-criptoxanthin) than in cooked pulp, with themain one being all-trans ?-carotene. This carotenoidwas also present in rawpulp at a concentration of 96.0± 1.7 ?g equiv. of ?-carotene g?1 dw. The concentration decreased significantly (Pb0.05) during cooking and drying to reach a final concentration of 33.3±1.0 ?g equiv. ?-carotene g?1 dw in the flour. Flour production reduced (Pb0.05) the total carotenoid content from373.4 to 237.7 ?gof ?-carotene g?1dw,with a final retention rate of 63.7% by the end of the process. Moreover, 9 of the 14 Carotenoids account for high levels of provitamin A, which, even so, had decreased from 2723 retinol equivalents (RE) 100 g?1 in raw pulp to 1614 RE 100 g?1 in cooked pulp and 1289 RE 100 g?1 in flour. Provitamin A level is still high when compared to other common provitamin A sources. Our study shows that while there is a change in the levels and profile of Carotenoids during the peach-palm flour process, and a reduction of provitamin A value, peach-palm fruit is a great source of bioactive compounds. (Resume d'auteur)
Juan A. Amat - One of the best experts on this subject based on the ideXlab platform.
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Carotenoids, immune response and the expression of sexual ornaments in male greenfinches (Carduelis chloris)
Naturwissenschaften, 2007Co-Authors: Eduardo Aguilera, Juan A. AmatAbstract:Allocation trade-offs of Carotenoids between their use in the immune system and production of sexual ornaments have been suggested as a proximate mechanism maintaining honesty of sexual signals. To test this idea, we experimentally examined whether carotenoid availability in the diet was related to variation in antibody response to novel antigens in male greenfinches ( Carduelis chloris aurantiiventris ), a species with extensive carotenoid-dependent plumage colouration. We also measured the cost of mounting a humoral response in terms of circulating Carotenoids. Finally, we examined the relationship between plumage colour, immune response and circulating Carotenoids. We found that males with carotenoid-supplemented diets showed stronger antibody response than non-supplemented birds. We also found that activation of the immune system significantly reduced circulating Carotenoids (24.9% lower in immune-challenged birds than in control birds). Finally, intensity (chroma) of ventral plumage colouration of males, a character directly related to concentration of total Carotenoids in feathers, was negatively correlated with the immune response and circulating Carotenoids in winter. These results support the idea that Carotenoids are a limiting resource and that males trade ornamental colouration against immune response.