Person: García Martín, Alberto
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First Name
Alberto
Last Name
García Martín
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Químicas
Department
Ingeniería Química y de Materiales
Area
Identifiers
3 results
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Item Extraction of Antioxidants from Grape and Apple Pomace: Solvent Selection and Process Kinetics(Applied Sciences, 2022) Garcia Montalvo, Jorge; García Martín, Alberto; Ibañez Bujan, Jon; Santos Mazorra, Victoria Eugenia; Yustos Cuesta, Pedro; Bolívar Bolívar, Juan Manuel; Ladero Galán, MiguelPolyphenols have become a research target due to their antioxidant, anti-inflammatory and antimicrobial activity. Obtention via extraction from natural sources includes the revalorization of food wastes such as grape pomace (GP) or apple pomace (AP). In this work, GP and AP were submitted to a liquid–solid extraction using different solvents of industrial interest. Process kinetics were studied measuring the total phenolic content (TPC) and antioxidant capacity (AC), while the extraction liquor composition was analyzed employing chromatographic methods. Extraction processes using water-solvent mixtures stood out as the better options, with a particular preference for water 30%–ethanol 70% (v/v) at 90 °C, a mixture that quickly extracts up to 68.46 mg GAE/gds (Gallic Acid Equivalent per gram dry solid) and 122.67 TEAC/gds (TROLOX equivalent antioxidant capacity per gram dry solid) in case of GP, while ethylene water 10%–ethylene glycol 90% (v/v) at 70 °C allows to reach 27.19 mg GAE/gds and 27.45 TEAC/gds, in the case of AP. These extraction processes can be well-described by a second-order kinetic model that includes a solubility-related parameter for the first and fast-washing and two parameters for the slow mass transfer controlled second extraction phase. AP liquors were found to be rich in quercetin with different sugar moieties and GP extracts highlighted flavonols, cinnamic acids, and anthocyanins. Therefore, using identical extraction conditions for AP and GP and a comparative kinetic analysis of TPC and AC results for the first time, we concluded that ethanol/water mixtures are adequate solvents for polyphenols extraction due to their high efficiency and environmentally benign nature.Item Pectooligosaccharides rich in galacturonic acid produced from Orange Processing Waste by autohydrolysis: Process optimization and kinetic analysis(Bioresource Technology Reports, 2023) Pablo Comendador Morales; García Martín, Alberto; Ladero Galán, MiguelPectooligosaccharides (POS) are notorious for their prebiotics and elicitor activities. In this work, we have optimized the autohydrolysis of Orange Processing Waste (OPW) to obtain POS fractions via a Taguchi approach, maximizing homogalacturonan oligosaccharides yield by considering several process variables: particle diameter, stirring speed, liquid-solid ratio and time, determining that only time had a significant effect in the studied range. 19.38 % w/w POS yield from OPW was obtained in optima conditions. After ensuring no limitation due to mass transfer, the kinetic analysis assumed that homogalacturonan was converted into high, medium and low molecular weight oligosaccharides, and galacturonic acid. Moreover, we considered that there is one pseudohomogeneous reaction type combined with three irreversible, elemental, of pseudo first global order (first order with respect to the reagent which is hydrolysed) reactions in series. The model successfully reproduced experimental data at constant temperature (150 ◦C–180 ◦C) and pH (3.73).Item Fumaric Acid Production by R. arrhizus NRRL 1526 Using Apple Pomace Enzymatic Hydrolysates: Kinetic Modelling(Processes, 2022) Martín Domínguez, Víctor; García Montalvo, Jorge; García Martín, Alberto; Ladero Galán, Miguel; Santos Mazorra, Victoria EugeniaFumaric acid is one of the most promising biorefinery platform chemicals, fruit residues being a very suitable raw material for its production in second generation biorefineries. In particular, apple pomace is a plentiful residue from the apple juice industry, with apple being the second largest fruit crop in the world, with a production that increased from 46 to 86 Mtons in the 1994–2021 period. With a global apple juice production of more than 4.5 Mtons, a similar amount of apple pomace is produced yearly. In this work, apple pomace hydrolysate has been obtained by enzymatic hydrolysis and further characterized for its content in sugars, phenolics and nitrogen using different analytic methods, based on HPLC and colorimetric techniques. Previous to the use of this hydrolysate (APH), we studied if the addition of fructose to the usual glucose-rich broth could lead to high fumaric acid yields, titers and productivities. Afterwards, APH fermentation was performed and improved using different nitrogen initial amounts, obtaining production yields (0.32 gFumaric acid/gconsumed sugar) similar to those obtained with synthetic media (0.38 gFumaric acid/gconsumed sugar). Kinetic modelling was employed to evaluate, explain, and understand the experimental values and trends of relevant components in the fermentation broth as functions of the bioprocess time, proposing a suitable reaction scheme and a non-structured, non-segregated kinetic model based on it.