Abstract

LOPEZ, LB et al. Quantification of egg in dried noodles by electrophoretic methods (SDS PAGE). Diaeta [online]. 2011, vol.29, n.135, pp.35-39. ISSN 1852-7337.

The objective of this work was to use the SDS-PAGE method for the quantification of egg in dry noodles made with flour and added egg. 6 model systems (MS) of noodles containing 0.0, 1.0, 2.5, 4.0, 6.0 and 8.0% of egg powder were analyzed. Total proteins with a buffer containing sodium dodecyl sulfate (SDS) and 2-mercaptoethanol were extracted and electrophoresis with SDS polyacrylamide gel was carried out. The relationships of the peak areas of the densitograms (egg and wheat) that allow a proper quantification of the percentage of egg added were established. 11 commercial samples in which quantification of egg was carried out were analyzed, with values ranging between <1.0% and 8.8% of egg powder. In the analyzed MS and in the commercial samples the cholesterol content (enzymatic method) was also determined and the egg content was determined by the method ELISA. Cholesterol values in the MS increased with the increase of the added egg powder, while in the samples, low levels of cholesterol were found for the lowest egg levels and high values for the highest egg levels. With the ELISA method a correct quantification of egg up to 4.0% was achieved, but low results were obtained in the higher systems (6.0 and 8.0%). This could be due to the significant dilution that must be made from the extracts of the samples to determine their content. With respect to the commercial samples, in 8 similar values to those of electrophoresis were obtained, while in other 3, the values were different. The electrophoretic method is a useful tool for the detection and quantification of egg in these samples when you have MS with known powdered egg concentration.

Keywords : Noodles; Egg; SDS-PAGE; ELISA; Cholesterol.

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