hosted by
publicationslist.org
    
Monica Gonzalez

mgonzal@icia.es

Journal articles

2004
 
DOI   
PMID 
Jesús Méndez, Mónica González, M Gloria Lobo, Aurelio Carnero (2004)  Color quality of pigments in cochineals (Dactylopius coccus Costa). Geographical origin characterization using multivariate statistical analysis.   J Agric Food Chem 52: 5. 1331-1337 Mar  
Abstract: The commercial value of a cochineal (Dactylopius coccus Costa) sample is associated with its color quality. Because the cochineal is a legal food colorant, its color quality is generally understood as its pigment content. Simply put, the higher this content, the more valuable the sample is to the market. In an effort to devise a way to measure the color quality of a cochineal, the present study evaluates different parameters of color measurement such as chromatic attributes (L*, and a*), percentage of carminic acid, tint determination, and chromatographic profile of pigments. Tint determination did not achieve this objective because this parameter does not correlate with carminic acid content. On the other hand, carminic acid showed a highly significant correlation (r = - 0.922, p = 0.000) with L* values determined from powdered cochineal samples. The combination of the information from the spectrophotometric determination of carminic acid with that of the pigment profile acquired by liquid chromatography (LC) and the composition of the red and yellow pigment groups, also acquired by LC, enables greater accuracy in judging the quality of the final sample. As a result of this study, it was possible to achieve the separation of cochineal samples according to geographical origin using two statistical techniques: cluster analysis and principal component analysis.
Notes:
2002
 
PMID 
Mónica González, Jesús Méndez, Aurelio Carnero, M Gloria Lobo, Ana Afonso (2002)  Optimizing conditions for the extraction of pigments in cochineals (Dactylopius coccus Costa) using response surface methodology.   J Agric Food Chem 50: 24. 6968-6974 Nov  
Abstract: A simple method was developed for the extraction and determination of color pigments in cochineals (Dactylopius coccus Costa). The procedure was based on the solvent extraction of pigments in insect samples using methanol:water (65:35, v:v) as extractant. Two-level factorial design was used in order to optimize the solvent extraction parameters: temperature, time, methanol concentration in the extractant mixture, and the number of extractions. The results suggest that the number of extractions is statistically the most significant factor. The separation and determination of the pigments was carried out by high-performance liquid chromatography with UV-visible detection. Because the absorption spectra of different pigments are different in the visible region, it is convenient to use a diode array detector to obtain chromatographic profiles that allow for the characterization of the extracted pigments.
Notes:
Powered by publicationslist.org.