RT info:eu-repo/semantics/bachelorThesis
T1 Extracción con agua subcrítica y ultrafiltración para la obtención de pecto-oligosacáridos a partir de residuos de piel cebolla
A1 Hernández Manchado, Javier
A2 Universidad de Burgos. Departamento de Química
K1 Subcritical water
K1 Oligosaccharide fractionation
K1 Ultrafiltration
K1 Diafiltration
K1 Onion skin waste
K1 Biorefinery
K1 Ingeniería química
K1 Chemical engineering
K1 Alimentos
K1 Food
AB In this work the purification by ultrafiltration using tubular ceramic membranes of pecticoligosaccharides (POS) extracted from onion skin wastes (OSW) was studied.In the first stage of the work, subcritical water was used to promote the hydrolysis of OSW andobtain a liquid hydrolysate rich in POS. For this purpose, three different combinations oftemperature and extraction time (115 ºC – 180 min; 125 ºC – 150 min and 135 ºC – 90 min)were used in a batch extractor at 25 bar. In order to consider the combined effect of thetemperature and the extraction time, the severity factor (log Ro) was calculated, resulting to bein the range 2.88 to 3.29. The best results in terms of POS concentration (5643 ± 84 mg/L) inthe hydrolysate was obtained in the experiment carried out at 125 ºC (log Ro = 3.16). It wasalso possible to demonstrate that the composition of the liquid hydrolysate was stronglyinfluenced by the extraction conditions: the higher the severity factor the higher theconcentration of impurities (organic acids, HMF and furfural) and higher the POS hydrolysisrate. This was demonstrated by the increased concentration of free monosaccharides(glucose, xylose, galactose and arabinose) and the decrease in the POS molecular weight.In the second stage of the work, the aim was to study the separation of POS from the impuritiesformed during the subcritical water hydrolysis stage, using an ultrafiltration process indiafiltration mode. For this purpose, a 50 kDa tubular membrane was firstly used (TamiIndustries, active layer of TiO2 and 132 cm2 of effective area). The fouling mechanism,hydraulic resistance and the purification extent were studied. Important differences in thepermeate flux (J) were observed as a function of the subcritical water hydrolysate composition.The permeate flux obtained when filtering the 115 ºC hydrolysate decreased dramatically atthe beginning of the experiment to achieve a constant value, whereas the hydrolysatesobtained at 125 and 135 ºC exhibited a different behaviour: an initial fast decline of thepermeate flux followed by a slower continuous decrease. This result for 125 and 135 ºChydrolysates can be justified due to the effects of the membrane fouling (fouling mechanismwas cake layer formation, according to Hermia’s model). Using this 50 kDa membrane, thePOS recovery was 76 % (115 ºC hydrolysate), 58 % for the 125 ºC hydrolysate and 56% forthe 135 ºC hydrolysate. In all the cases, a complete removal of the impurities was achievedafter the dilution factor of 3.5.To complete the purification experiments, the effect of the removal of the colloidal matter (bycentrifugation) present in the 125 ºC hydrolysate was studied using two different membranes(50 and 5 kDa). In the hydrolysate, it was observed the formation of a black precipitate thatwas responsible for the membrane fouling, hindering the filtration process. The removal of thiscolloidal matter, which did not affect the POS fraction, was responsible for the reduction of thecolour of the hydrolysate by 60 % and the promotion of the filtration process (a faster removalof the impurities was achieved) without loss of the POS fraction. Finally, when a 5 kDamembrane was used, the retention of the POS fraction was higher than 80 % in comparisonto the 60 % obtained for the 50 kDa membrane.
LK http://hdl.handle.net/10259/9132
UL http://hdl.handle.net/10259/9132
LA spa
NO El trabajo presentado ha sido desarrollado en el seno del Grupo de Investigación Biotecnología Industrial y Medioambiental, reconocido por la UBU (GIR-UBU BIOIND) y por la Junta de Castilla y León como Unidad de Investigación Consolidada UIC-128, en el marco de los siguientes proyectos de investigación:PID2020-116716RJ-I00 - Tecnologías de fluidos presurizados para la valorización de subproductos de la industria agroalimentaria: recuperación de pectina y otros compuestos bioactivos de alto valor, financiado por la Agencia Estatal de Investigación.PDC2022-133443-I00 – Diseño de un prototipo para la extracción de bioproductos con agua subcrítica, financiado por el Ministerio de Ciencia e Innovación.TED2021-129311B-I00 - Tecnologías verdes basadas en el empleo de fluidos presurizados para valorizar biomasa lignocelulósica mediante la producción de furfural, financiado por el Ministerio de Ciencia e Innovación.BU050P20 - Valorización de la fracción proteica de subproductos de la industria agroalimentaria de Castilla y León mediante tecnologías de fluidos presurizados, financiado por la Junta de Castilla y León y el Fondo Europeo de Desarrollo Regional (FEDER).
DS Repositorio Institucional de la Universidad de Burgos
RD 02-jun-2024