RT info:eu-repo/semantics/bachelorThesis
T1 Estudio del proceso de extracción de compuestos fenólicos a partir residuos de mazorca maíz
A1 Pacio Teso, David
A2 Universidad de Burgos. Departamento de Biotecnología y Ciencia de los Alimentos
K1 Phenolic compounds
K1 Extraction
K1 Byproduct valorisation
K1 Antioxidant capacity
K1 Solid by product valorisation
K1 Corncob
K1 Biorefinery
K1 Compuestos fenólicos
K1 Extracción
K1 Valorización de subproductos
K1 Mazorca de maíz
K1 Biorrefinería
K1 Ingeniería química
K1 Chemical Engineering
K1 Alimentos
K1 Food
AB Corn is currently one of the most cultivated cereals in the world, obtaining many agriculturalsolid residues. Corncob residue can be considered as a subproduct due to the presence of aphenolic fraction rich in flavonoids, which could be used as a substitute of synthetic antioxidantadditives for different food and pharmaceutical applications. This work was focused onstudying different extraction processes and operating conditions aimed at the recovery of thephenolic fraction from corncob, as well as an identification study in order valorise the finalextracts. Experiments were performed by using bath extraction with rotary agitation,ultrasound-assisted extraction, and microwave-assisted extraction. The effects of contact time,temperature (40 and 70ºC) and solvent (ethanol, water, and different ethanol-water mixtures)were also examined.Throughout the work it was possible to verify that with the use of the temperature of 70 ºCbetter results of extraction of polyphenolic compounds and flavonoids were achieved; Like theethanol:water mixtures, they are more effective than the use of pure solvents, the 70% mixturebeing the most effective. Thanks to the extractions in which mixtures are used as solvents,better results were achieved for the percentage of total polyphenolic compounds with respectto the total dry solids. It was verified that by means of the 70% ethanol-water mixture, thereducing capacity of the extract was correlated with the flavonoid fraction, in extraction withethanol with the polyphenols and if water was used, a very poor correlation was obtained.Regarding the identified compounds, both in the ethanol:water mixtures and in the ethanol thesame compounds were identified, although all of them in greater quantity in the mixtures, beingthe 70% where the most was obtained. In the extraction with water it was also possible toidentify gallic acid, p-hydroxybenzoic acid and vanillinic acid. The compound that was identifiedin the greatest amount was ethyl ferulate, followed by p-coumaric acid, syringic acid andkaempherol. Regarding the extraction techniques, the ultrasound-assisted one turned out tobe the most effective, since compared to the agitated bath, it was possible to extract morepolyphenolic compounds and flavonoids in less time. With the use of microwaves, extractionresults were obtained that were very similar to those obtained by means of a bath, but usingonly a few minutes of extraction compared to hours in the bath, thus resulting in being moreefficient.
LK http://hdl.handle.net/10259/7111
UL http://hdl.handle.net/10259/7111
LA spa
DS Repositorio Institucional de la Universidad de Burgos
RD 08-may-2024