Efecto del pH sobre el perfil de péptidos potencialmente bioactivos producidos por Lactococcus lactis subsp. cremoris NCFB 712
Milk protein derived peptides could exert physiology functions in human body, mainly antihypertensive activity by the inhibition of the Angiotensin Converting Enzyme (ACE). These peptides can be liberated by proteolytic microorganism during fermentation. In this work the effect of pH on the producti...
| Autor: | |
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| Tipo de recurso: | tesis doctoral |
| Estado: | Versión publicada |
| Fecha de publicación: | 2012 |
| País: | México |
| Institución: | Universidad Autónoma Metropolitana |
| Repositorio: | Repositorio Institucional de la UAM Iztapalapa |
| Idioma: | español |
| OAI Identifier: | oai:bindani.izt.uam.mx:4m90dv72s |
| Acceso en línea: | https://doi.org/10.24275/uami.4m90dv72s |
| Access Level: | acceso abierto |
| Palabra clave: | info:eu-repo/classification/LEM/Fermentation info:eu-repo/classification/LEM/Productos lácteos -- Microbiología info:eu-repo/classification/LEM/Lactococcus lactis subsp info:eu-repo/classification/LEM/Dairy products -- Microbiology info:eu-repo/classification/LEM/Fermentación info:eu-repo/classification/LEM/Péptidos info:eu-repo/classification/LEM/Peptides info:eu-repo/classification/cti/6 |
| Sumario: | Milk protein derived peptides could exert physiology functions in human body, mainly antihypertensive activity by the inhibition of the Angiotensin Converting Enzyme (ACE). These peptides can be liberated by proteolytic microorganism during fermentation. In this work the effect of pH on the production of bioactive peptides during milk fermentation by Lactococcus lactis subsp. cremoris NCFB 712 was studied. The proteolytic activity (measured by TNBS) was higher in the fermentations with pH control (pH 6.2) than in the fermentations without control even it was not observed higher concentrations of peptides of less than 10 k Da compared to the fermentation without pH control. The peptide profiles in both fermentations showed differences since the eighth hour of fermentation, when the pH value of the fermentations began to show statistical significance. It is thought that these differences in peptide profiles are mainly due to effect of pH on both proteolytic activity and specificity of cell wall proteinase type 1 (CEP-I), that is the type of enzyme that has the microorganism used for supported their growth in milk. The fermentation without pH control has a higher percent of ACE-inhibitory activity and a lower IC50 value, therefore has higher ACE- inhibitory potency. However when carry out the simulation of gastrointestinal digestion (with pepsin and trypsin) the ACE-inhibitory activity of this hydrolysates decreased in 14%, while the fermentations with pH control keep their ACEinhibitory activity after an enzymatic digestion. The peptide fraction with higher ACE-inhibitory activity has a having a molecular weight determinate by exclusion HPLC close to 0.58 kDa which is very important because the majority of the peptides with ACE-inhibitory activity have molecular weights less than 1 kDa. This fraction was re-fractionated by RP- HPLC finding 4 sub-fractions; three of them showed high ACE- inhibitory activity and one a higher concentration than the others. With respect to the binding of minerals was observed that the pH-controlled fermentation has the ability to bind iron and calcium while the samples from the fermentation without pH control only have the ability to bind calcium in a lower concentration than in fermentations with pH control. |
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