ANALYSIS OF VARIANCE AND EXPERIMENTAL DESIGN IN THE OPTIMIZATION OF EXTRACTION OF CARMINIC ACID FROM COCHINEAL

As a result of the collaboration with Teno Osorio, from I.E.S. Teguise (Lanzarote), David Soto Saiz has presented his Bachelor thesis “Analysis of variance and experimental design in the optimization of extraction of carminic acid from cochineal” on 15th September 2020. Remote education applies for all students at the University of Burgos due to coronavirus pandemic, so a virtual thesis defence was held.

Carminic acid, or E-120, is a natural dye that is found in the insect (Dactylopius coccus), which lives on cactus plants in the Canary Islands and South American countries. Commercial products are obtained from different extracts from dried cochineal. Water, ethanol or mixtures of both of them, and several salts may be used to improve the extraction. Analysis of variance and experimental design are used to optimize the extraction procedure; spectrophotometric determination of carminic acid is performed to carry out the study.

Fisrtly, the dependence with regard to pH of the spectra of extracts of cochineal from Lanzarote is explored. However, due to the alert state of Covid-19 pandemic, experiments could not be continued, so data collected from bibliography were used. Carminic acid percentages obtained from 75 cochineal samples when extraction is performed at different temperatures with different amounts of sodium carbonate in the medium were found. Two and multi-factor analysis of variance (ANOVA), factorial and response surface designs are employed to study and optimize the extraction conditions. Experimental design methodology makes found the highest carminic acid extraction possible with a minimum experimental effort.