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Rodriguez-Fernandez M.,CSIC - Institute of Marine Research | Cardelle-Cobas A.,Catholic University of Portugal | Villamiel M.,Institute Investigacion En Ciencias Of La Alimentacion | Banga J.R.,CSIC - Institute of Marine Research
Journal of Biotechnology | Year: 2011

The production of prebiotic galactooligosaccharides (GOS) from lactose has been widely studied whereas the synthesis of new prebiotic oligosaccharides with improved properties as those derived from lactulose is receiving an increasing interest. Understanding the mechanism of enzymatic oligosaccharides synthesis from lactulose would help to improve the quality of the products in a rational way as well as to increase the production efficiency by optimally selecting the operating conditions. A detailed kinetic model describing the enzymatic transgalactosylation reaction during lactulose hydrolysis is presented here for the first time. The model was calibrated with the experimental data obtained in batch assays with two different β-galactosidases at various temperatures and concentrations of substrate. A complete system identification loop, including model selection, robust estimation of the parameters by means of a global optimization method and computation of confidence intervals was performed. The kinetic model showed a good agreement between experimental data and predictions for lactulose conversion and provided important insights into the mechanism of formation of new oligosaccharides with potential prebiotic properties. © 2011 Elsevier B.V. Source

Gamboa-Santos J.,Institute Investigacion En Ciencias Of La Alimentacion | Soria A.C.,Institute Quimica Organica General CSIC | Villamiel M.,Institute Investigacion En Ciencias Of La Alimentacion | Montilla A.,Institute Investigacion En Ciencias Of La Alimentacion
Food Chemistry | Year: 2013

The effect of previous ultrasound and conventional blanching treatments on drying and quality parameters (2-furoylmethyl-amino acids -as indicators of lysine and arginine participation in the Maillard reaction-, carbohydrates, total polyphenols, protein profile, rehydration ratio, microstructure changes) of convective dehydrated carrots has been assessed. The most striking feature was the influence of blanching on the subsequent 2-furoylmethyl-amino acid formation during drying, probably due to changes in the protein structure. The highest values of 2-furoylmethyl-amino acids were found in carrots conventionally blanched with water at 95 °C for 5 min. However, samples previously treated by ultrasound presented intermediate values of 2-furoylmethyl-amino acids and carbohydrates as compared to the conventionally blanched samples. Dried carrots previously subjected to ultrasound blanching preserved their total polyphenol content and showed rehydration properties, which were even better than those of the freeze-dried control sample. The results obtained here underline the usefulness of 2-furoylmethylamino acids as indicators of the damage suffered by carrots during their blanching and subsequent drying. © 2013 Elsevier Ltd. All rights reserved. Source

Perez-Vega J.A.,National Polytechnic Institute of Mexico | Olivera-Castillo L.,National Polytechnic Institute of Mexico | Gomez-Ruiz J.T.,Institute Investigacion En Ciencias Of La Alimentacion | Hernandez-Ledesma B.,Institute Investigacion En Ciencias Of La Alimentacion
Journal of Functional Foods | Year: 2013

Sea cucumber is a benthic marine organism distributed worldwide and used as food in several Asian countries. The species Isostichopus badionotus is captured intensively off the Yucatan Peninsula, Mexico. Boiled I. badionotus was subjected to in vitro simulated gastrointestinal digestion using pepsin and a pepsin-Corolase PP® mixture. ACE-inhibitory and radical scavenging activities, iron reducing capacity and cytotoxic effects against colorectal cancer cells were evaluated in the hydrolysates and their ultrafiltered fractions. ACE-inhibitory activity was potent in fractions containing peptides <3000Da, an effect augmented with combined action of gastric (pepsin) and intestinal (Corolase PP®) enzymes (IC50=0.038±0.004mg/mL). Antioxidant activity was exerted by peptides with low and high molecular weights, depending on hydrolysis method. This is the first report of cytotoxic capacity against colorectal HT-29 cells in peptides from sea cucumber. Sea cucumber hydrolysates and ultrafiltered fractions are potential ingredients for development of functional foods. © 2013 Elsevier Ltd. Source

Diez-Municio M.,Institute Investigacion En Ciencias Of La Alimentacion | Herrero M.,Institute Investigacion En Ciencias Of La Alimentacion | Jimeno M.L.,Centro Quimica Organica Lora Tamayo CSIC | Olano A.,Institute Investigacion En Ciencias Of La Alimentacion | Moreno F.J.,Institute Investigacion En Ciencias Of La Alimentacion
Journal of Agricultural and Food Chemistry | Year: 2012

This work describes an efficient enzymatic synthesis and NMR structural characterization of the trisaccharide β-d-galactopyranosyl-(1→4)- β-d-fructofuranosyl-(2→1)-α-d-glucopyranoside, also termed as lactulosucrose. This oligosaccharide was formed by the Leuconostoc mesenteroides B-512F dextransucrase-catalyzed transfer of the glucosyl residue from sucrose to the 2-hydroxyl group of the reducing unit of lactulose. The enzymatic reaction was carried out under optimal conditions, i.e., at 30 °C in 20 mM sodium acetate buffer with 0.34 mM CaCl2 at pH 5.2, and the effect of factors such as reaction time (0-48 h), enzyme charge (0.8, 1.6, and 2.4 U mL-1), and sucrose:lactulose concentration ratios (20:40, 30:30, and 40:20, expressed in g/100 mL) on the formation of transfer products were studied. The highest formation in lactulosucrose was attained at 8 and 24-32 h by using 20%:40% and 30%:30% sucrose:lactulose mixtures, respectively, with 1.6 or 2.4 U mL-1 dextransucrase, leading to lactulosucrose yields of 27-35% in weight respect to the initial amount of lactulose. Furthermore, minor tetra- and pentasaccharide, both probably derived from lactulose, were also detected and quantified. Likewise, the capacity of lactulosucrose to act as d-glucosyl donor once the sucrose was consumed, could explain its decrease from 16 to 24 h when the highest charge of dextransucrase was used. Considering the chemical structure of the synthesized oligosaccharides, lactulosucrose and its derivatives could potentially be excellent candidates for an emerging prebiotic ingredient. © 2012 American Chemical Society. Source

Martos G.,Institute Investigacion En Ciencias Of La Alimentacion | Lopez-Fandino R.,Institute Investigacion En Ciencias Of La Alimentacion | Molina E.,Institute Investigacion En Ciencias Of La Alimentacion
Food Chemistry | Year: 2013

Hen egg white comprises of a complex mixture of proteins, which greatly differ in their physicochemical characteristics and relative abundance. We aimed to identify potential undiscovered egg allergens within the egg white proteome and investigated the existence of matrix effects on the proteolytic stability and resultant IgE-binding of the allergenic proteins. In addition to the main egg allergens: ovalbumin (OVA), ovomucoid (OM) and lysozyme (LYS), two minor egg white proteins, tentatively identified as ovoinhibitor and clusterin, were found to react with serum IgE from egg-allergic patients. Egg white exhibited residual immunoreactivity after gastrointestinal digestion due to the presence of intact OVA and LYS, as well as of several IgE-binding peptides derived from OVA. The presence of egg yolk slightly increased the susceptibility to hydrolysis of egg white proteins and abrogated bile salt-induced precipitation of LYS in the duodenal medium. However, the resultant immunoreactivity against IgE of egg white proteins after in vitro digestion was not significantly modified by the presence of yolk components. © 2012 Elsevier Ltd. All rights reserved. Source

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