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Registro Completo |
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Biblioteca(s): |
Embrapa Instrumentação. |
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Data corrente: |
19/03/2025 |
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Data da última atualização: |
19/03/2025 |
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Tipo da produção científica: |
Artigo em Periódico Indexado |
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Autoria: |
TOBIAS, T. J.; MORAES, T. B.; COLNAGO, L. A. |
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Afiliação: |
UNIVERSITY OF SAO PAULO (USP); UNIVERSITY OF SAO PAULO (USP); LUIZ ALBERTO COLNAGO, CNPDIA. |
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Título: |
Establishing optimal parameters to mitigate the heating effects caused by CPMAS sequence in 13C solid-state NMR studies of cocoa butter and other fat samples. |
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Ano de publicação: |
2025 |
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Fonte/Imprenta: |
Food Research International, v. 204,115944, 2025. |
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Páginas: |
9 p. |
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ISSN: |
0963-9969 |
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DOI: |
https://doi.org/10.1016/j.foodres.2025.115944 |
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Idioma: |
Inglês |
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Conteúdo: |
The physical and chemical properties of solid triacylglycerols (fats) have been investigated through the use of 13C solid-state nuclear magnetic resonance (SS-NMR). However, the 13C SS-NMR experiments performed with crosspolarization (CP), magic angle sample spinning (MAS) and high power for 1 H decoupling (DEC), known as CPMAS, have the potential to increase sample temperature, which may disrupt the solid–liquid content, crystallization dynamics, and polymorphism of the fat samples. While the heating effects observed in CPMAS experiments have been well documented, they have not yet been studied in fat samples. Accordingly, the present study examines the influence of sample spinning frequencies (SF) and radio frequency irradiation (RFI) due to DEC, on sample heating using cocoa butter (CB), chocolate, and animal fats. The results of the variation in the 1 H chemical shift of the water peak in the butter sample indicate that the use of routine CPMAS parameter results in an increase in sample temperature of up to 15 ◦C. This temperature is sufficient to affect various physicochemical properties of fats, including partial or total melting when the experiments are performed with an air stream at ambient temperature. The results demonstrate that a SF of approximately 3 kHz and a recycle delay exceeding 10 s for a decoupler power of 70 W for 50 ms result in an increase of less than 1 ◦C in sample temperature in 13C CPMAS experiments. These experimental conditions were successfully employed to study the CB crystallization process, which exhibited the presence of the α form at the beginning of the process and the β form at its conclusion. MenosThe physical and chemical properties of solid triacylglycerols (fats) have been investigated through the use of 13C solid-state nuclear magnetic resonance (SS-NMR). However, the 13C SS-NMR experiments performed with crosspolarization (CP), magic angle sample spinning (MAS) and high power for 1 H decoupling (DEC), known as CPMAS, have the potential to increase sample temperature, which may disrupt the solid–liquid content, crystallization dynamics, and polymorphism of the fat samples. While the heating effects observed in CPMAS experiments have been well documented, they have not yet been studied in fat samples. Accordingly, the present study examines the influence of sample spinning frequencies (SF) and radio frequency irradiation (RFI) due to DEC, on sample heating using cocoa butter (CB), chocolate, and animal fats. The results of the variation in the 1 H chemical shift of the water peak in the butter sample indicate that the use of routine CPMAS parameter results in an increase in sample temperature of up to 15 ◦C. This temperature is sufficient to affect various physicochemical properties of fats, including partial or total melting when the experiments are performed with an air stream at ambient temperature. The results demonstrate that a SF of approximately 3 kHz and a recycle delay exceeding 10 s for a decoupler power of 70 W for 50 ms result in an increase of less than 1 ◦C in sample temperature in 13C CPMAS experiments. These experimental conditions were successfully... Mostrar Tudo |
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Palavras-Chave: |
CPMAS; Sample heating; Solid state NMR. |
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Categoria do assunto: |
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Marc: |
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Registro original: |
Embrapa Instrumentação (CNPDIA) |
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| 1. |  | BIEGELMEYER, R.; ANDRADE, J. M. M.; ABOY, A. L.; APEL, M. A.; DRESCH, R. R.; MARIN, R.; RASEIRA, M. do C. B.; HENRIQUES, A. T. Comparative Analysis of the Chemical Composition and Antioxidant Activity of Red (Psidium cattleianum) and Yellow (Psidium cattleianum var. lucidum) Strawberry Guava Fruit. Journal of Food Science, v. 76, n. 7, p. 991-996, 2011.| Tipo: Artigo em Periódico Indexado | Circulação/Nível: A - 2 |
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| 2. | | ANDRADE, J. M. M.; ABOY, A. L.; APEL, M. A.; RASEIRA, M. do C. B.; PEREIRA, J. F. M.; HENRIQUES, A. T. Phenolic Composition in Different Genotypes of Guabiju Fruits (Myrcianthes pungens) and Their Potential as Antioxidant and Antichemotactic Agents. Journal of Food Science, v. 76, n. 8, p. 1181-1187, 2011.| Tipo: Artigo em Periódico Indexado | Circulação/Nível: A - 2 |
| Biblioteca(s): Embrapa Clima Temperado. |
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