Caracterización, funcionalidad tecnológica y bioactividad de proteínas lácteas glicosiladas vía reacción de Maillard

Tesis doctoral inédita. Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Química-Física Aplicada. Fecha de lectura: 21/1/201

Characterization and improvement of rheological properties of sodium caseinate glycated with galactose, lactose and dextran

10 páginas, 7 figuras, 2 tablas.-- El pdf del artículo es la versión de autor.The aim of this work was to investigate the effect of non-enzymatic glycosylation with galactose, lactose, and 10 kDa dextran on the rheological properties of sodium caseinate. To promote the formation of covalent complexes, the reaction was done in solid state (aw = 0.67), pH 7.0 (0.1 M sodium phosphate buffer), and temperature set at 50 and 60 °C. The progress of Maillard reaction was indirectly traced by measuring the formation of the Amadori compound, through furosine (2-furoylmethyl-lysine) analysis, and brown polymers, and the resulting glycoconjugates were characterized by LC/ESI-MS and SEC. Results showed a higher reactivity of galactose than lactose and dextran to form the glycoconjugates, due to its smaller molecular weight. Glycation with galactose and lactose increased the viscosity of caseinate and also altered its flow characteristics from Newtonian to shear-thinning. Oscillatory testing showed a higher elastic modulus (G′) in glycoconjugates when compared to non-glycated caseinate, especially with galactose, where a gel-like behaviour was observed after long incubation times. Glycation with dextran did not produce substantial improvements in the rheological properties of caseinate, probably due to the limited extent of the reaction. Our results show that by controlling the rate and extent of the Maillard reaction is a technologically feasible operation to improve the viscosity and gelling properties of sodium caseinate-based ingredients.This work was supported by projects Consolider Ingenio 2010 FUN-C-FOOD CSD2007-00063 (Ministerio de Educación y Ciencia), ALIBIRD S-0505/AGR/000153 (Comunidad de Madrid) and Hatch project TEN00332 (University of Tennessee Institute of Agriculture). M. Corzo-Martínez thanks the CSIC for an I3P PhD-grant.Peer reviewe

Childhood B-Cell Preleukemia Mouse Modeling

Leukemia is the most usual childhood cancer, and B-cell acute lymphoblastic leukemia (B-ALL) is its most common presentation. It has been proposed that pediatric leukemogenesis occurs through a “multi-step” or “multi-hit” mechanism that includes both in utero and postnatal steps. Many childhood leukemia-initiating events, such as chromosomal translocations, originate in utero, and studies so far suggest that these “first-hits” occur at a far higher frequency than the incidence of childhood leukemia itself. The reason why only a small percentage of the children born with such preleukemic “hits” will develop full-blown leukemia is still a mystery. In order to better understand childhood leukemia, mouse modeling is essential, but only if the multistage process of leukemia can be recapitulated in the model. Therefore, mouse models naturally reproducing the “multi-step” process of childhood B-ALL will be essential to identify environmental or other factors that are directly linked to increased risk of disease.Research in CV-D group has been funded by Instituto de Salud Carlos III (ISCIII), through a “Miguel Servet Grant” (CPII19/00024-AES 2017–2020); co-funded by the European Union. Research in IS-G group is partially supported by FEDER and by SAF2015-64420-R MINECO/FEDER, UE, RTI2018-093314-B-I00 MCIU/AEI/FEDER, UE, by PID2021-122185OB-I00 MCIU/AEI/FEDER, UE, and by Junta de Castilla y León (UIC-017, CSI001U16, CSI234P18, and CSI144P20). IS-G have been supported by the Fundacion Unoentrecienmil (CUNINA project). CC and IS-G have been supported by the Fundación Científica de la Asociación Española contra el Cáncer (PRYCO211305SANC). Research at CC’s laboratory was partially supported by Ministerio de Ciencia e Innovación/AEI/FEDER (PID2021-122787OB-I00), FEDER MINECO (SAF2017-83061-R), the “Fundación Ramón Areces” and a Research Contract with the “Fundación Síndrome de Wolf-Hirschhorn o 4p-”. Institutional grants from the “Fundación Ramón Areces” and “Banco de Santander” to the CBMSO are also acknowledged. J.M.-C. is the recipient of a UAM FPU fellowship. AC-G (CSI067-18) and MI-H (CSI021-19) are supported by FSE-Conserjería de Educación de la Junta de Castilla y León 2019 and 2020 (ESF—European Social Fund) fellowship, respectively. SA-A is supported by an Ayuda para Contratos predoctorales para la formación de doctores (PRE2019-088887). L.S. is supported by a scholarship from University of Salamanca co-financed by Banco Santander and ESF

Risk Factors and Predictive Score for Bacteremic Biliary Tract Infections Due to Enterococcus faecalis and Enterococcus faecium: a Multicenter Cohort Study from the PROBAC Project

Biliary-tract bloodstream infections (BT-BSI) caused by Enterococcus faecalis and E. faecium are associated with inappropriate empirical treatment and worse outcomes compared to other etiologies. The objective of this study was to investigate the risk factors for enterococcal BT-BSI. Patients with BT-BSI from the PROBAC cohort, including consecutive patients with BSI in 26 Spanish hospitals between October 2016 and March 2017, were selected; episodes caused by E. faecalis or E. faecium and other causes were compared. Independent predictors for enterococci were identified by logistic regression, and a predictive score was developed. Eight hundred fifty episodes of BT-BSI were included; 73 (8.5%) were due to target Enterococcus spp. (48 [66%] were E. faecium and 25 [34%] E. faecalis). By multivariate analysis, the variables independently associated with Enterococcus spp. were (OR; 95% confidence interval): cholangiocarcinoma (4.48;1.32 to 15.25), hospital acquisition (3.58;2.11 to 6.07), use of carbapenems in the previous month (3.35;1.45 to 7.78), biliary prosthesis (2.19;1.24 to 3.90), and moderate or severe chronic kidney disease (1.55;1.07 to 2.26). The AUC of the model was 0.74 [95% CI0.67 to 0.80]. A score was developed, with 7, 6, 5, 4, and 2 points for these variables, respectively, with a negative predictive value of 95% for a score # 6. A model, including cholangiocarcinoma, biliary prosthesis, hospital acquisition, previous carbapenems, and chronic kidney disease showed moderate prediction ability for enterococcal BT-BSI. Although the score will need to be validated, this information may be useful for deciding empirical therapy in biliary tract infections when bacteremia is suspected. IMPORTANCE Biliary tract infections are frequent, and a significant cause of morbidity and mortality. Bacteremia is common in these infections, particularly in the elderly and patients with cancer. Inappropriate empirical treatment has been associated with increased risk of mortality in bacteremic cholangitis, and the probability of receiving inactive empirical treatment is higher in episodes caused by enterococci. This is because many of the antimicrobial agents recommended in guidelines for biliary tract infections lack activity against these organisms. To the best of our knowledge, this is the first study analyzing the predictive factors for enterococcal BT-BSI and deriving a predictive score.8 página

Caracterización, funcionalidad tecnológica y bioactividad de proteínas lácteas glicosiladas vía reacción de Maillard

Memoria presentada por Marta Corzo Martínez para optar al grado de Doctor en Ciencia y Tecnología de los Alimentos y que ha sido realizado en el Departamento de Caracterización de Alimentos del Instituto de Fermentaciones Industriales del C.S.I.C.Esta Tesis ha abordado el estudio y caracterización de subproductos de cebolla con el fin de obtener información necesaria en relación con su idoneidad para el potencial desarrollo de un ingrediente alimentario con carácter funcional. Esto representaría un doble beneficio, por un lado, el aprovechamiento de los residuos de cebolla que suponen un problema medioambiental y, por otro, la obtención de un producto con valor añadido. Así, el objetivo de la presente Tesis Doctoral se centró en la caracterización de residuos de cebolla como fuente de compuestos bioactivos y fibra alimentaria, así como la evaluación del efecto que tenían sobre estos compuestos distintos procesados, tras los que se obtienen diferentes subproductos (Bagazo, Pasta y Zumo), que se someten a distintos métodos de estabilización térmica (Pasterización y Esterilización), todo ello con el fin de evaluar su aplicación potencial como base para la obtención de ingredientes alimentarios funcionales, especialmente ricos en fibra alimentaria. Por otro lado, se obtuvieron y evaluaron concentrados de fibra y se evaluó el potencial funcional de los subproductos y concentrados de fibra de cebolla mediante un estudio de las propiedades hipoglucémicas in vitro y un estudio in vivo usando ratas Wistar. Además, se evaluó la utilización de uno de estos subproductos como ingrediente alimentario mediante su adición a una salsa de tomate.Peer reviewe

Effect of ultrasound on glucose-lysine complexes obtained via Maillard reaction

Resumen del trabajo presentado al 2011 Effost Annual Meeting: "Food process-structure-function relationships" celebrado en Berlín (Alemania) del 9 al 11 de noviembre de 2011..It is well-known that Maillard reaction (MR), that occurs between the ξ-amino group of lysine of aminoacids, peptides or proteins with the carbonyl group of reducing carbohydrates, is one of the most important and complex reactions that may spontaneously occurin living organisms or during food processing. In addition, during the last years, there has been an increased interest in deliberately promoted MR under controlled conditions to obtain glycoconjuga tes with improved functionalities in relation to the initial proteins. In this case, the reaction can be carried out in solution or in dry-state, the later being more time consuming than the former. However, in general, it has been stated that when the reaction is done in solution more structural changes can be produced in the initial proteins. Therefore, the application of other procedures that could improve the manufacture of glycated proteins via MR, as well as reducing the reaction time, is of interest. On the other hand, the application of ultrasound (US) technology in various fields including bioprocess, biotechnology and food processing has increased tremendously in recent years and, it is known that this emergent technology can accelerate different chemical reactions. Thus, effects of US on intermediate products of MR, browning intensity, antioxidative activities and chemical structure of bovine serum albumin glycated with glucose has been previously investigated. However, no evidence of the effect of US on the initial steps of MR has been done and in order to improve a number of functional properties of proteins is necessary to keep MR in the initial steps under very well controlled conditions. In this sense, 2-furoyl-methyl-lysine (furosine) is one of the most important indicators of the initial steps of MR. Thus, in this work, we have evaluated the effect of US (with a probe of 13 mm diameter, maximum wave amplitude of 145μm, 20kHz frequency, and 400W full power) on the formation of furosine in a liquid model system of glucose and lysine at pH7 (buffered solution), temperatures lower than 35°C, wave amplitude of 50% and sonication time of 10 min. Similar heat treatments were also carried out in a conventional bath. In the obtained HPLC profiles, two peaks, corresponding to the glycation of the α-and ξ-amino groups of lysine, were observed, the amount of furosine being higher in the case of samples subjected to US treatment. These preliminary results can indicate the usefulness of US as a MR promoting system to obtain glycated proteins with improved functionalities.This work has been funded by projects ALIBIRD S2009/AGR-1469 (CAM), CICYT through Grant AGL2007-60045, and IBEROFUN 110AC0386 (CYTED). M. Corzo-Martínez thanks Danone Institute for a grant.Peer Reviewe

Effect of milk protein glycation and gastrointestinal digestion on the growth of bifidobacteria and lactic acid bacteria

In this paper, β-lactoglobulin (β-Lg) and sodium caseinate (SC) have been glycated via Maillard reaction with galactose and lactose and, subsequently, the effect of glycoconjugates hydrolyzed under simulated gastrointestinaldigestion on the growth of pure culture of Lactobacillus, Streptococcus and Bifidobacterium has been investigated. Glycopeptides were added to the growth media as the sole carbon source. None of the bacterial strains was able to grow in hydrolysates of native and control heated β-Lg and SC. However, glycopeptides were fermented, in different degree, by Lactobacillus and Bifidobacterium and hardly any effect was detected on the growth of Streptococcus. Digested β-Lg glycoconjugates showed a strain-dependent effect whereas growth profiles of bacteria when hydrolysates of SC glycoconjugates were used as substrates were very similar, regardless of the strain. A general preference towards peptides from β-Lg/SC glycated with galactose, particularly at the state of the reaction in which the highest content in the Amadori compound tagatosyl-lysine is present, was observed. SC glycoconjugates were quickly fermented by some strains, promoting their growth in a greater extent than β-Lg complexes or even glucose. Therefore, from the results obtained in this work it can be concluded that conjugation of both milkproteins with galactose and lactose via the Maillard reaction could be an efficient method to obtain novel food ingredients with a potential prebiotic character.This work has been funded by projects Consolider Ingenio 2010 FUN-c-FOOD CSD2007-00063 (MICINN), ALIBIRD S2009/AGR-1469 (CAM), AGL2009-13361-C02-02 (MICINN) and IBEROFUN 110AC0386 (CYTED). M. Corzo-Martínez thanks Danone Institute for a grant.Peer Reviewe

Presence of mono-, di- and galactooligosaccharides in commercial lactose-free UHT dairy products

In this work a study of mono-, di- and galactooligosaccharide (GOS) content as well as the determination of thermal indicators of different commercial lactose-free UHT (LF-UHT) milks and dairy drinks has been carried out. Moreover, GOS formation during hydrolysis of lactose in a commercial UHT milk using Lactozym® pure 6500 was also studied. Presence of GOS was detected in all analyzed samples ranging from 950 to 4350mg/L in LF-UHT milks and from 600 to 2260mg/L in LF-UHT dairy drinks. Their GOS contents correlate roughly with the remaining lactose content of samples. During enzymatic hydrolysis of lactose in commercial UHT milk, the GOS formed reached a maximum about 10,000mg/L when 75-90% of lactose was hydrolyzed and then gradually decreased to values considerably lower than 5000mg/L when over 99% of the lactose was hydrolyzed. Therefore, GOS formation during low lactose milk manufacture might be improved by controlling enzymatic lactose hydrolysis so that it would be possible to elaborate low-lactose milk products able to satisfy the physiological requirements of the majority of intolerant groups and with a GOS content high enough to confer beneficial effect as prebiotic. © 2012 Elsevier Inc.This work has been financed under a R + D program of the Spanish Ministry of Science and Innovation, Consolider Ingenio 2010 (FUN-C-FOOD): CSD 2007-00063; R + D program of the Comunidad de Madrid, project ALIBIRD 2009/AGR-1469; R + D program of the Comunidad de Castilla-La Mancha POII10-0178-4685 and IBEROFUN P109AC0302 (CYTED). A.I. Ruiz-Matute thanks her JAE-Doc contract from CSIC. M. Corzo-Martínez thanks Danone Institute for a grant.Peer Reviewe

Synthesis of prebiotic carbohydrates derived from cheese whey permeate by a combined process of isomerisation and transgalactosylation

[Background]: Lactose from cheese whey permeate (WP) was efficiently isomerised to lactulose using egg shell, a food-grade catalyst, and the subsequent transgalactosylation reaction of this mixture with β-galactosidase from Bacillus circulans gave rise to a wide array of prebiotic carbohydrates derived from lactose and lactulose. [Results]: Lactulose obtained by efficient isomerisation of WP (16.1% by weight with respect to the initial amount of lactose) showed great resistance to the hydrolytic action of β-galactosidase from B. circulans, which preferentially hydrolysed lactose, acting as a galactosyl donor and acceptor. Lactulose had capacity as an acceptor, leading to the formation of lactulose-derived oligosaccharides. The enzymatic synthesis was optimised by studying reaction conditions such as pH, temperature, time, enzyme concentration and carbohydrate concentration. The maximum formation of galactooligosaccharides with degrees of polymerisation from 2 to 4 was achieved after 5 h of reaction at pH 6.5 and 50 °C with 300 g kg-1 carbohydrates and 3 U mL-1 β-galactosidase. [Conclusion]: These findings indicate that the transgalactosylation of isomerised WP with β-galactosidase from B. circulans could be a new and efficient method to obtain a mixture with 50% of potentially prebiotic carbohydrates composed of lactulose, and galactooligosaccharides derived from lactose and lactulose.This work has been financed by projects AGL2011-27884 and Consolider Ingenio 2010 FUN-C-FOOD CSD2007-00063 from Ministerio de Ciencia e Innovación and project POII10-0178-4685 from Junta de Comunidades de Castilla-La Mancha and the European Regional Development Fund (ERDF). M Corzo-Martínez thanks the Danone Institute for a grant. P Copovi thanks CSIC for a JAE-Tec contract.Peer Reviewe

Effect of storage on quality of industrially dehydrated onion, garlic, potato and carrot

A comprehensive study on physical and chemical quality parameters has been carried out on several highly consumed vegetables that were industrially dehydrated (carrot, onion, garlic and potato). The quality parameters determined were: dry matter, water activity, rehydration ratio, protein pattern, total polyphenols, saccharides and 2-furoylmethyl amino acid (2-FM-AA) content. After dehydration process, the main observed chemical change was the formation of 2-FM-AA, indicating the participation of amino acids (mainly lysine) in Maillard reaction evolution. With respect to the effect of 12-month storage under conditions usually used by consumers (in the dark, 19-27 °C, 15-41% relative humidity), with the exception of carrots, no remarkable amounts of 2-FM-AA were generated, in agreement with the slight variation in proteins pattern and saccharide composition. Particularly interesting is the case of onion and garlic, whose content of fructooligosaccharides (recognized prebiotic saccharides) was preserved during storage. Samples were also stable with regard to their polyphenol content and rehydration ability, showing the importance of sample pre-treatment, processing and storage conditions for preservation of bioactivity and overall quality of dehydrated vegetables. These results underline the usefulness of the indicators here determined for quality evaluation and the value of data reported for technologists, nutritionists and consumers. © 2012 VÚP Food Research Institute, Bratislava.This work has been funded by MICINN (project AGL2007-63462 and Fun-c-Food CSD2007-00063 Consolider-INGENIO 2010) and CYTED IBEROFUN (P109AC0302). Juliana Gamboa-Santos and Ana C. Soria also thank Spanish National Research Council for a predoctoral JAE grant and a Ramón y Cajal contract, respectively.Peer Reviewe