Análise do teor e da qualidade dos lipídeos presentes em sementes de oleaginosas por rmn de baixo campo

Constantino, André F.; Lacerda, Valdemar; Santos, Reginaldo Bezerra dos; Greco, Sandro J.; Silva, Renzo C.; Neto, Álvaro Cunha; Barbosa, Lúcio L.; Castro, Eustáquio Vinícius Ribeiro de; Freitas, Jair C. C.

doi:10.1590/s0100-40422014000100003

Cited by 9 publications

(7 citation statements)

References 23 publications

(50 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Este teor é muito superior a espécies oleaginosas usadas na fabricação de óleos comerciais, tais como: soja (18-20%), algodão (21%), canola (24-27%), amendoim (41,3%) (Constantino et al, 2014;Silva et al, 2015), porém inferior a amendoim (44,57%), avelã (63,18%), baru (41,04%), castanhade-caju (42,06%), castanha-do-Brasil (64,94%), macadâmia (66,16%), noz (65,07%), pecã (62,14%) e pistache (45,83%) (FREITAS & VELOSO, 2010).…”

Section: Resultsunclassified

Perfil De Ácidos Graxos De Folhas E Amêndoas Orgânicas De Guariroba

Julio¹,

Keglevich²,

Venturoli³

et al. 2016

Encicl. Biosf.

View full text Add to dashboard Cite

RESUMOSyagrus oleracea Becc., espécie nativa do Cerrado, pode contribuir com a segurança alimentar, geração de renda para agricultores e para a preservação da espécie, devido aos múltiplos produtos produzidos pela planta. Devido à falta de estudos sobre as propriedades e o aproveitamento de óleos essenciais produzidos por S. oleracea, objetivou-se caracterizar o perfil de ácidos graxos de folhas e amêndoas de guariroba presentes em sistema orgânico. As folhas e os frutos maduros, presentes no chão, de guariroba foram coletados de plantas presentes em Jandaia -Goiás sob sistema orgânico. Determinou-se os seguintes atributos: Umidade e Material Volátil, Acidez (% ácido oléico), Índice de saponificação, Teor de Lipídios e composição/teores de ácidos graxos. Foram encontrados 12 ácidos graxos nas amêndoas e 10 nas folhas. As amêndoas possuem mais ácidos graxos saturados (87,51%), enquanto nas folhas há uma tendência de equilíbrio entre saturados (57,39%) e insaturados (42,61%). O índice de acidez dos óleos (%ácido oléico) obtidos das amêndoas e folhas foram de 20,94% e 2,13%, respectivamente. Os óleos de guariroba oriundos de folhas e amêndoas apresentam composição distinta de ácidos graxos. O óleo das folhas é composto majoritariamente por ácido oléico. Já o óleo das amêndoas é formado principalmente por ácidos graxos saturados, como o ácido láurico. Esta diferença de composição influencia no potencial de uso e possíveis aproveitamentos, e conseqüentemente representa mais alternativas de renda para os agricultores. Palavras-chave: Indústria, Óleos Essenciais, Sub-produto.

show abstract

Section: Resultsunclassified

Perfil De Ácidos Graxos De Folhas E Amêndoas Orgânicas De Guariroba

Julio¹,

Keglevich²,

Venturoli³

et al. 2016

Encicl. Biosf.

View full text Add to dashboard Cite

show abstract

“…The Blight and Dyer 31 method is a fast and efficient method and a great reference for the extraction and purification of total lipids from biological samples. 33,[49][50][51] A mixture of chloroform, methanol, and water must be able to extract neutral and polar lipids. This mixture is sufficiently nonpolar to break the associations with the cell membrane and/or lipoproteins.…”

Section: Lipid Extractionmentioning

confidence: 99%

“…Furthermore, the mixture also must be sufficiently polar to release electrostatic forces and hydrogen interactions. 31,33,50,51 Fish lipids are strongly related to the availability of food and energy storage. In a period in which there is a high availability of food, fish tend to store more lipids than in decreased food availability where the fish energy storage decreases because of lipid use for the maintenance of vital functions.…”

Section: Lipid Extractionmentioning

confidence: 99%

A Protocol for Fish Lipid Analysis Using Nuclear Magnetic Resonance Spectroscopy

Mor

Correia

Val

et al. 2020

J. Braz. Chem. Soc.

View full text Add to dashboard Cite

This article reports on an easy-to-follow methodology for fish lipids analysis, including the biological sample collection, lipid extraction, sample preparation, nuclear magnetic resonance (NMR) spectroscopy analysis and statistical data analysis, with details on parameters used for the NMR analysis and the care needed in each step execution. As an example of the biological matrix of lipids, for the entire procedure, we have used two Amazonian fish samples. Phenotype factor was taken into account when lipid contents of the Amazonian fish samples were evaluated, such as fish-eating habits in distinct Amazon seasonal periods, the flood and the drought. Results demonstrated the applicability of NMR as a powerful and useful tool for fish oil analysis. The omnivorous (T. elongatus) and the piscivorous (C. monoculus) Amazonian fish differ in composition and distribution of lipids, which show differences not only because of the different eating habits between the two species, but also by the availability and quantity of food along the year, i.e., during the flood and drought Amazon periods.

show abstract

“…Rodrigues et The CWFP signals have been used to study the oilseed quality in static and flowing modes. CWFP and CP-CWFP signals have been used to measure oil viscosity and fatty acid composition using multivariate statistics [42,43].…”

Section: Polymersmentioning

confidence: 99%

Applications of Continuous Wave Free Precession Sequences in Low-Field, Time-Domain NMR

2019

View full text Add to dashboard Cite

This review discusses the theory and applications of the Continuous Wave Free Precession (CWFP) sequence in low-field, time-domain nuclear magnetic resonance (TD-NMR). CWFP is a special case of the Steady State Free Precession (SSFP) regime that is obtained when a train of radiofrequency pulses, separated by a time interval T p shorter than the effective transverse relaxation time (T 2 *), is applied to a sample. Unlike regular pulsed experiments, in the CWFP regime, the amplitude is not dependent on T 1 . Therefore, T p should be as short as possible (limited by hardware). For T p < 0.5 ms, thousands of scans can be performed per second, and the signal to noise ratio can be enhanced by more than one order of magnitude. The amplitude of the CWFP signal is dependent on T 1 /T 2 ; therefore, it can be used in quantitative analyses for samples with a similar relaxation ratio. The time constant to reach the CWFP regime (T*) is also dependent on relaxation times and flip angle (θ). Therefore, T* has been used as a single shot experiment to measure T 1 using a low flip angle (5 • ) or T 2 , using θ = 180 • . For measuring T 1 and T 2 simultaneously in a single experiment, it is necessary to use θ = 90 • , the values of T* and M 0 , and the magnitude of CWFP signal |M ss |. Therefore, CWFP is an important sequence for TD-NMR, being an alternative to the Carr-Purcell-Meiboom-Gill sequence, which depends only on T 2 . The use of CWFP for the improvement of the signal to noise ratio in quantitative and qualitative analyses and in relaxation measurements are presented and discussed.to suppress these anomalies using a small variation of T p that cancels the echo component. In the same year, Schwenk [4] proposed the Quadriga Fourier Transform (QFT) to suppress these anomalies. The QFT method was based on a small variation in frequency offset. Although these procedures minimize these anomalies, SSFP sequences were not routinely used in high resolution NMR.We revised these methods and suggested some modifications to increase the applications of SSFP in high-resolution NMR using the Traff apodization function [5] to minimize the truncation problem, or processing the SSFP time domain signal with a parametric method based on Krylov Basis Diagonalization Method (KBDM) [6]. KBDM solves the truncation and phase anomalies but not the amplitude problem. Therefore, SSFP sequences cannot be used to efficiently enhance signal to noise ratio (SNR) in high-resolution NMR. SSFP sequences have been successfully used in magnetic resonance imaging [7,8] and in low-field, time-domain NMR [9][10][11]. The use of a SSFP sequence in low field time domain (TD-NMR) started in year 2000 [12,13]. The applications of SSFP sequences in TD-NMR can be performed under the drastic condition where T p < 1 ms. Under this condition, a truly continuous wave free precession (CWFP) regime is obtained [13]. Normally, CWFP sequences use T p < 0.5 ms, as T p has to be shorter than T 2 *, which is in the order of 1 ms in most TD-NMR spectrometers.In the CWFP regime, F...

show abstract

Análise do teor e da qualidade dos lipídeos presentes em sementes de oleaginosas por rmn de baixo campo

Cited by 9 publications

References 23 publications

Perfil De Ácidos Graxos De Folhas E Amêndoas Orgânicas De Guariroba

Perfil De Ácidos Graxos De Folhas E Amêndoas Orgânicas De Guariroba

A Protocol for Fish Lipid Analysis Using Nuclear Magnetic Resonance Spectroscopy

Applications of Continuous Wave Free Precession Sequences in Low-Field, Time-Domain NMR

Contact Info

Product

Resources

About