Para citar este trabalho use um dos padrões abaixo:
1H NMR AS A SIMPLE METHODOLOGY FOR BARN VS. FREE-RANGE CHICKEN EGGS DIFFERENTIATION
GERLON DE ALMEIDA RIBEIRO OLIVEIRA
Universidade de Brasília
Agora você poderia compartilhar comigo suas dúvidas, observações e parabenizações
Crie um tópicoChicken eggs are one of the main foods in the world, and the laying chickens are mostly raised in the intensive production system due to the rapid return on investment. This system provides cheap and safe eggs. On the other hand, it exposes animals to stress due to overcrowding on farms [1]. The growing concern with animal welfare has increased the demand for products from the extensive system. Eggs from different rearing systems anecdotally have morphological and sensory differences, such as yolk color and flavor. Some studies have already found differences between eggs from conventional and alternative rearing systems. However, they use time-consuming and environmentally unfriendly methodologies that are difficult to implement in routine quality control [2, 3]. This work compared the lipid composition of chicken egg yolks produced in the conventional system (from 16 farms/brands) with that of eggs produced by free-range chickens (from 6 rural properties), using 1H NMR and chemometrics. Sample preparation consisted of a single-step extraction with a CDCl3:D2O mixture, followed by centrifugation. This method was efficient in the discrimination (Fig. 1) since the eggs from free-range chickens showed more intense signals at 5.50 and especially at 2.85, which indicates higher contents of some polyunsaturated fatty acid (PUFA).
Lorena Mara Alexandre e Silva
Hello Pedro,
nice job you did. Do you think the PUFA difference might be correlated with the sensory difference observed by the consumers?
Lorena Mara Alexandre e Silva
Gerlon, I also would like to know about the axis of the Figure 2. Is a graph of loadings or scores?
GERLON DE ALMEIDA RIBEIRO OLIVEIRA
Hi Lorena, thanks for your interest. Actually, the axis are just the areas of the two discriminant signals, after a normalization pretreatment. The previous chemometric tests revealed that these two signals were the most important in the discrimination, thus we plotted them alone and it was possible to discriminate the samples without a chemometric model.
Lorena Mara Alexandre e Silva
Ah yes. I understand now. Thanks for the answere.
Elenilson de Godoy Alves Filho
Dear Gerlon, congratulations on the great study. I have some questions:
- Around 5 min, are these plots the scores (left) and loadings from PCA, or a correlation between the chemical shifts 5.50 and 2.85 ppm?
- In this evaluation, did you use the area only of these signals describe in the plot or the whole spectrum?
- Instead of placing the chemical shifts on the score axes, wouldn't it be better to put the accumulated variance on each axis?
Thank's for your time.
GERLON DE ALMEIDA RIBEIRO OLIVEIRA
Dear Elenilson, we are pleased to see your interest on our work, thanks very much!
About the questions: the graph is the dispersion of the values of the two variables (spectral area at 5.5 and 2.85 ppm) in the samples. Since these variables were found to have a great influence in the discrimination of the samples in the PLS-DA model, we tried to plot only them and see the dispersion. The area of the other signals were only used in the normalization of the data (unit vector normalization). Thus, although we performed chemometric analyses in order to find the best discriminat variables, we do not report these results here, since two variables were enough to the discrimination purpose. Thanks again.
Com ~200 mil publicações revisadas por pesquisadores do mundo todo, o Galoá impulsiona cientistas na descoberta de pesquisas de ponta por meio de nossa plataforma indexada.
Confira nossos produtos e como podemos ajudá-lo a dar mais alcance para sua pesquisa:
Esse proceedings é identificado por um DOI , para usar em citações ou referências bibliográficas. Atenção: este não é um DOI para o jornal e, como tal, não pode ser usado em Lattes para identificar um trabalho específico.
Verifique o link "Como citar" na página do trabalho, para ver como citar corretamente o artigo
Pedro Henrique Soares Cardoso
Hello, Lorena. Thanks for the question. We can't relate these composition differences to the consumers' claimed sensory differences such as a thicker yolk and a stronger color and flavor for free-range eggs. The higher amount of PUFA probably wouldn't change the color, but some natural pigment due to the food of the hens. Also, we expect a higher amount of PUFA would decrease, and not increase the viscosity of the yolk.
Lorena Mara Alexandre e Silva
Nice. Thanks for your answere