https://hdl.handle.net/10259/3592 2026-04-17T17:33:44Z https://hdl.handle.net/10259/9192 Hydrolysis of Lactose: Conventional Techniques and Enzyme Immobilization Strategies on Polymeric Supports Vallejo García, Jorge Lucas; Cutillo Foraster, Alessandra; Arnáiz Alonso, Ana; Vallejos Calzada, Saúl; García Pérez, José Miguel; Muñoz Santamaría, María Asunción; Trigo López, Miriam This chapter explores lactose hydrolysis, emphasizing conventional techniques and the noteworthy immobilization of β-galactosidase on polymeric matrices to enhance the process. Lactose, present in milk and dairy, poses challenges for lactoseintolerant individuals, requiring enzymatic hydrolysis for lactose-free product development. The presence of other milk components, such as proteins and minerals, can indirectly influence the efficiency of lactose hydrolysis by potentially interacting with β-galactosidase enzyme or affecting its stability and activity, making it necessary to control factors such as enzyme concentration, temperature, pH, and reaction time to improve lactose hydrolysis rates. The chapter delves into established methodologies, covering enzymatic kinetics, reaction conditions, and substrate concentrations. It also describes the innovative approach of immobilizing β-galactosidase on polymeric supports to enhance enzyme stability, reusability, and overall efficiency in lactose hydrolysis. Discussions include the design of suitable polymeric matrices, providing insights into mechanisms governing catalytic performance. This comprehensive exploration contributes to understanding lactose hydrolysis, offering valuable insights for developing efficient and sustainable enzymatic processes applicable to the food and pharmaceutical industries. 2024-05-22T00:00:00Z https://hdl.handle.net/10259/9085 Using excitation-emission matrix fluorescence to evaluate the performance of water treatment plants for dissolved organic matter removal Rodríguez Vidal, Francisco Javier; García Valverde, María; Ortega Azabache, Beatriz; González Martínez, Ángela; Bellido Fernández, Ana This study is aimed at assessing the performance of water treatment plants (both wastewater and drinking water treatment plants) for dissolved organic matter (DOM) removal using excitation-emission matrix fluorescence (EEMF) as the monitoring technique. The influent from the wastewater treatment plant (WWTP) of Burgos (Spain) is characterized from the presence of protein-like peaks (T1 and T2) and humic-like peaks (A and C), T2 and A showing the highest fluorescence intensity. The percentages of total removal in the effluent were in the following order: peak T1 (65%) > peak A (45%) > peak C (34%) > peak T2 (26%). The humic-like peaks were the most removed at the primary sedimentation stage, whereas peak T1 was by far the most removed in the biological reactor. Protein-like peaks T1 and T2 experienced a slight increase in the final effluent in comparison to their fluorescence at the previous stage (the exit of the biological reactor), an increase that can be explained by the release of SMP (soluble microbial products) from the biomass in the secondary clarifier. A poor correlation was obtained between peak T2 fluorescence and COD, BOD (r2 = 0.34–0.38). The natural water from the Úzquiza reservoir in Burgos (Spain) is characterized by the only presence of humic substances: a majority peak A (fulvic-like) and a weak peak C (humic-like). The whole fluorescent DOM was removed by coagulation-flocculation but a low fluorescence peak T2 appeared at the final stage, coming from protein-like SMPs released by the biomass attached to the filters. 2021-03-01T00:00:00Z https://hdl.handle.net/10259/9084 Characterization of urban and industrial wastewaters using excitation-emission matrix (EEM) fluorescence: Searching for specific fingerprints Rodríguez Vidal, Francisco Javier; García Valverde, María; Ortega Azabache, Beatriz; González Martínez, Ángela; Bellido Fernández, Ana Excitation-emission matrix (EEM) fluorescence spectroscopy has been applied to characterize several urban and industrial wastewaters (effluents from different types of industries: brewery, winery, dairy, biscuit, tinned fish industry, slaughterhouse, pulp mill, textile dyeing and landfill leachates), searching for specific fluorescence fingerprints. Tryptophan protein-like peaks (T1 and T2) are the predominant fluorescence in urban and food industry wastewaters (brewery, winery, dairy/milk, biscuit and fish farm industries) but no special fingerprint has been found to discriminate among them. Protein-like fluorescence also dominates the spectra of meat/fish industries (effluents from a tinned fish industry and a slaughterhouse), but in this case tyrosine protein-like peaks (B1 and B2) also appear in the spectra in addition to tryptophan-like peaks. This fact might constitute a specific feature to differentiate these wastewaters from others, since the appearance of peaks B is quite uncommon in wastewaters. The textile dyeing effluent shows a characteristic triple humic-like fluorescence (peaks A, C1 and C2) that may represent a specific fingerprint for this kind of effluent. Leachates from medium-aged and old landfills might also show a specific fingerprint in their EEM spectra: the sole presence of the humic-like peak C with very high fluorescence intensity. This feature also allows differentiating them from young landfill leachates, which show predominance of protein-like peaks. The fluorescence index (FI) does not seem to be very appropriate to characterize wastewaters and its usefulness might be limited to the study of humic substances in natural waters, although further studies are needed on this topic. However, the humification index (HIX) and the biological index (BIX) do seem to be useful for studying wastewaters, since they have provided consistent results in the present work. This study shows the potential of EEM fluorescence to identify the origin of some industrial effluents, although more research is needed to check these preliminary results. 2020-06-01T00:00:00Z https://hdl.handle.net/10259/8613 Keto-Enol Tautomerism in Passerini and Ugi Adducts Pertejo Fernández, Pablo; Sancho Medina, Andrea; Hermosilla, Tomás; González Saiz, Beatriz; Gómez Ayuso, Javier; Quesada Pato, Roberto; Moreno Mediavilla, Daniel; Carreira Barral, Israel; García Valverde, María The use of arylglyoxal as starting material in Passerini and Ugi reactions affords βketoamides. This has allowed to study keto-enol tautomerism in these systems and assess the way in which the presence of acyloxy or aminoacyl groups bound to the C2 position affects such tautomerism, and to investigate the reactivity of both the enol and carbonyl forms. In this work we also prove the versatility of the Passerini reaction, since depending on the conditions to which the corresponding adducts are subjected different products of synthetic interest can be obtained. 2021-02-01T00:00:00Z