Estudo de feijões transgênicos e convencionais através da RMN HR-MAS
Data
2011-04-15
Autores
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Federal de Goiás
Resumo
In this work, a new methodology which allows differentiating conventional
and transgenic common beans, grown in greenhouse or under field
conditions, based on modifications in chemical composition using 1H HRMAS
NMR and infrared is proposed. Through NMR it was possible to identify
differences in chemical composition between the beans, according to
transgenic or conventional source, especially in aromatic hydrogen region.
The 1H, gHSQC and gHMBC experiments conducted to the flavonoids
quercetin and myricetin structures, present in higher contents in genetically
modified cultivars. Moreover, through 1H HR-MAS NMR was also possible to
identify, in mixture, the aminoacids threonine, valine, isoleucine, and lysine,
and the oligosaccharides stachyose, raffinose, and verbascose. The NMR
spectra of Pérola 5.1 and BRS Pontal 5.1, to which the transgene was
received from Olathe 5.1, using crosses and backcrosses, showed the same
signal pattern observed in Olathe 5.1 bean. This study also demonstrated
that the influence of typical variables from field planting conditions had no
significant influence on the ability of separation between cultivars transgenic
and conventional. This methodology was corroborated by multivariate data
analysis of the 1H NMR spectra. On the other hand, the infrared studies
showed less conclusive results. The study of the influence of exposure to air
indicated a decrease in the flavonoid myricetin content. For quercetin no
change was observed. This study also points out the simplicity of using the
HR-MAS NMR technique for food analyses. The measurement is highly
simplified because it does not require any pretreatment of the sample apart
from the addition of a small amount of D2O necessary to produce
homogeneous dough and a field frequency lock. Moreover, due to the high
concentration of the sample, measurement time in HR-MAS NMR is very
short.
Descrição
Palavras-chave
Citação
CHOZE, Rafael. Estudo de feijões transgênicos e convencionais através da RMN HR-MAS. 2011. 122 f. Tese (Doutorado em Química) - Universidade Federal de Goiás, Goiânia, 2011.