The Experts below are selected from a list of 129 Experts worldwide ranked by ideXlab platform
Matteo Scampicchio - One of the best experts on this subject based on the ideXlab platform.
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Hyphenation of proton transfer reaction mass spectrometry with thermal analysis for monitoring the thermal degradation of Retinyl Acetate.
Rapid communications in mass spectrometry : RCM, 2017Co-Authors: I. Peinado, Marco Mason, Franco Biasioli, Matteo ScampicchioAbstract:RATIONALE The processing of Retinyl Acetate, a vitamin and biomarker, at high temperatures causes significant decomposition of the compound and thus loss of its activity. The rate of mass loss can be conveniently studied by thermogravimetry (TG). However, this technique generally fails to reveal which compounds have been evolved from the compound. In this work we propose a new hyphenation approach to continuously monitor the thermal decomposition of Retinyl Acetate and follow the evolution of specific volatile organic compounds (VOCs). METHODS Thermal degradation of Retinyl Acetate was followed by TG coupled to a direct injection mass spectrometer based on proton transfer mass spectrometry (PTR-MS) to follow continuously the thermal decomposition of Retinyl Acetate. The results were also compared with those obtained by a second evolved gas analysis system based on the coupling of TG with FTIR. RESULTS The TG results showed two main mass losses, at 180°C and 350°C. When the PTR-MS instrument was connected to the outlet of the TG instrument, specific fragment ions (m/z 43, 61, 75, 85 and 97) showed characteristic evolution profiles. The first mass loss was mainly associated with the release of acetic acid (m/z 43 and 61), whereas the second mass loss was connected with the degradation of the molecule backbone (m/z 43, 61, 75, 85 and 97). These results were substantially correlated with those achieved by TG coupled with FTIR, although PTR-MS showed superior performance in terms of the qualitative identification of specific fragments and better sensitivity toward complex organic VOCs. CONCLUSION The proposed TG-PTR-MS technique shows a great potential for following in real time the thermal degradation of ingredients such as Retinyl Acetate and identifying compounds evolved at specific temperatures.
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Controlled Release of Retinyl Acetate from β-Cyclodextrin Functionalized Poly(vinyl alcohol) Electrospun Nanofibers
Journal of agricultural and food chemistry, 2015Co-Authors: Solomon M Lemma, Matteo Scampicchio, Peter J. Mahon, Igor Sbarski, James Wang, Peter KingshottAbstract:Retinyl Acetate (RA) was effectively incorporated into electrospun nanofibers of poly(vinyl alcohol) (PVA) containing β-cyclodextrin (β-CD) in order to form inclusion complexes for encapsulation to prolong shelf life and thermal stability. The physical and thermal properties of encapsulated RA were determined by scanning electron microscopy (SEM), X-ray diffraction (XRD), and differential scanning calorimetry (DSC). The nanofibers of PVA/RA and PVA/RA/β-CD exhibited bead free average fiber diameters of 264 ± 61 and 223 ± 49 nm, respectively. The surface chemistry of the functional nanofibers was investigated by X-ray photoelectron spectroscopy (XPS). Thermogravimetric analysis (TGA) demonstrated different thermal stabilities between the bioactive and the polymer, with and without β-CD. Square-wave voltammogram peak current changes were used to follow the release kinetics of RA from the nanofibers. Results indicate that RA coated inside PVA/β-CD nanofibers was protected against oxidation much better than RA in PVA nanofibers and should extend the shelf life. In addition, RA encapsulated in the PVA/β-CD had better thermal stability than PVA nanofibers.
P. P. Favero - One of the best experts on this subject based on the ideXlab platform.
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In vivo confocal Raman spectroscopy and molecular dynamics analysis of penetration of Retinyl Acetate into stratum corneum
Spectrochimica acta. Part A Molecular and biomolecular spectroscopy, 2016Co-Authors: Laurita Dos Santos, Claudio A. Téllez S, Mariane P.j. Sousa, Nuno G. Azoia, Artur Cavaco-paulo, Airton Abrahão Martin, P. P. FaveroAbstract:Abstract Objective The purpose of this study is to elucidate the behavior of Retinyl Acetate in penetrating human skin without the presence of enhancers by using confocal Raman spectroscopy and molecular dynamics simulation. Methods In this study, in vivo confocal Raman spectroscopy was combined with molecular dynamics simulation to investigate the transdermal permeation of the aqueous suspension of Retinyl Acetate. Results Permeation was measured after 30 min, and Retinyl Acetate was found up to 20 μm deep inside the stratum corneum. The delivery of Retinyl Acetate inside a skin membrane model was studied by molecular dynamics. The membrane model that was used represented normal young skin containing a lipid bilayer with 25% ceramide, 36% fatty acid, 30% cholesterol, and 6% cholesterol sulfate. Conclusion Spectroscopy data indicate that Retinyl Acetate permeates into the stratum corneum. Molecular dynamics data showed that Retinyl Acetate permeates in the membrane model and that their final location is deep inside the lipid bilayer. We showed, for the first time, a correlation between Raman permeation data and computational data.
Laurita Dos Santos - One of the best experts on this subject based on the ideXlab platform.
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In vivo confocal Raman spectroscopy and molecular dynamics analysis of penetration of Retinyl Acetate into stratum corneum
Spectrochimica acta. Part A Molecular and biomolecular spectroscopy, 2016Co-Authors: Laurita Dos Santos, Claudio A. Téllez S, Mariane P.j. Sousa, Nuno G. Azoia, Artur Cavaco-paulo, Airton Abrahão Martin, P. P. FaveroAbstract:Abstract Objective The purpose of this study is to elucidate the behavior of Retinyl Acetate in penetrating human skin without the presence of enhancers by using confocal Raman spectroscopy and molecular dynamics simulation. Methods In this study, in vivo confocal Raman spectroscopy was combined with molecular dynamics simulation to investigate the transdermal permeation of the aqueous suspension of Retinyl Acetate. Results Permeation was measured after 30 min, and Retinyl Acetate was found up to 20 μm deep inside the stratum corneum. The delivery of Retinyl Acetate inside a skin membrane model was studied by molecular dynamics. The membrane model that was used represented normal young skin containing a lipid bilayer with 25% ceramide, 36% fatty acid, 30% cholesterol, and 6% cholesterol sulfate. Conclusion Spectroscopy data indicate that Retinyl Acetate permeates into the stratum corneum. Molecular dynamics data showed that Retinyl Acetate permeates in the membrane model and that their final location is deep inside the lipid bilayer. We showed, for the first time, a correlation between Raman permeation data and computational data.
I. Peinado - One of the best experts on this subject based on the ideXlab platform.
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Hyphenation of proton transfer reaction mass spectrometry with thermal analysis for monitoring the thermal degradation of Retinyl Acetate.
Rapid communications in mass spectrometry : RCM, 2017Co-Authors: I. Peinado, Marco Mason, Franco Biasioli, Matteo ScampicchioAbstract:RATIONALE The processing of Retinyl Acetate, a vitamin and biomarker, at high temperatures causes significant decomposition of the compound and thus loss of its activity. The rate of mass loss can be conveniently studied by thermogravimetry (TG). However, this technique generally fails to reveal which compounds have been evolved from the compound. In this work we propose a new hyphenation approach to continuously monitor the thermal decomposition of Retinyl Acetate and follow the evolution of specific volatile organic compounds (VOCs). METHODS Thermal degradation of Retinyl Acetate was followed by TG coupled to a direct injection mass spectrometer based on proton transfer mass spectrometry (PTR-MS) to follow continuously the thermal decomposition of Retinyl Acetate. The results were also compared with those obtained by a second evolved gas analysis system based on the coupling of TG with FTIR. RESULTS The TG results showed two main mass losses, at 180°C and 350°C. When the PTR-MS instrument was connected to the outlet of the TG instrument, specific fragment ions (m/z 43, 61, 75, 85 and 97) showed characteristic evolution profiles. The first mass loss was mainly associated with the release of acetic acid (m/z 43 and 61), whereas the second mass loss was connected with the degradation of the molecule backbone (m/z 43, 61, 75, 85 and 97). These results were substantially correlated with those achieved by TG coupled with FTIR, although PTR-MS showed superior performance in terms of the qualitative identification of specific fragments and better sensitivity toward complex organic VOCs. CONCLUSION The proposed TG-PTR-MS technique shows a great potential for following in real time the thermal degradation of ingredients such as Retinyl Acetate and identifying compounds evolved at specific temperatures.
Muhammad Tahir Nadeem - One of the best experts on this subject based on the ideXlab platform.
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Bioavailability and storage stability of vitamin A fortificant (Retinyl Acetate) in fortified cookies
Food Research International, 2007Co-Authors: Masood Sadiq Butt, Muhammad Umair Arshad, Muhammad Shahzad Alam, Muhammad Tahir NadeemAbstract:Abstract Vitamin A deficiency is one of the major nutritional deficiencies affecting population in developing regions. In Pakistan, 60% of the child deaths are due to diarrhea and respiratory infection, which are associated with vitamin A deficiency. This study was to assess the bioavailability and stability of vitamin A fortificant in cookies fortified with Retinyl Acetate. Cookies fortified with Vitamin A (Retinyl Acetate) were manufactured and physically, chemically and sensorial analyzed. Efficacy studies were carried and Serum retinol concentrations were measured to assess the bioavailability of Vitamin A (Retinyl Acetate), different organ weights were also measured to check the effects of Vitamin A (Retinyl Acetate) on organ weights and body growth. The treatment T4 containing (257.85 μg) 45% RDA fortification level of Retinyl Acetate was judged best considering, physical, chemical and sensory characteristics. Baking losses were lowest in T4. Efficacy study revealed that Serum retinol concentrations were 125.19 μg/dl in control group and it was raised to 148.64 μg/dl in T4. Liver, lungs, left kidney, right kidney, heart, spleen, brain, left testicles and right testicles increased in their weights when fed with vitamin A fortified diet as compared to control. Exceptions were only brain and spleen, in spleen it remained stable and brain weight reduced as compared to control. Fortification of cookies with 257.85 μg (45% RDA) of retinol Acetate improved nearly all quality attributes and through efficacy studies it was concluded that vitamin A significantly affects growth and body functioning of rats. Concludingly cookies fortified with 257.85 μg of retinol Acetate can be used effectively to overcome vitamin A deficiency in the children.
