97 documents found, page 1 of 10
Polyamide microparticles with immobilized enological pectinase as efficient bio...
Oliveira, Sandra Cristina Gomes; Araújo, Samuel M.; Dencheva, Nadya Vasileva; Denchev, Z.Free pectinase is commonly employed as a biocatalyst in wine clarification; however, its removal, recovery, and reuse are not feasible. To address these limitations, this study focuses on the immobilization of a commercial pectinolytic preparation (Pec) onto highly porous polymer microparticles (MPs). Seven microparticulate polyamide (PA) supports, namely PA4, PA6, PA12 (with and without magnetic properties), a...
Enological pectinase immobilized on polymer microparticles as efficient biocata...
Denchev, Z.; Oliveira, Sandra Cristina Gomes; Araújo, Samuel; Dencheva, Nadya VasilevaOne of the key areas of polymer biotechnology is the use of high molecular weight compounds as supports for enzymes, enhancing their utility in industrial applications. Free pectinase is commonly employed as a biocatalyst in wine clarification; however, its removal, recovery, and reuse are not feasible. To address these limitations, this study focuses on the immobilization of a commercial pectinolytic preparati...
Immobilized enzyme cascade for the synthesis of polyaniline
Dencheva, Nadya Vasileva; Guimarães, Sofia Alexandrina da Silva; Braz, Joana Filipa Barros; Denchev, Z.Polyaniline (PANI) is an intrinsically conductive polymer with significant applications, such as in drug delivery, microelectronics, photovoltaic cells, plastic batteries, display devices, and chemical electrodes. PANI is typically synthesized through chemical or electrochemical oxidation polymerization of the ANI monomer. However, these methods have notable drawbacks, including harsh synthesis conditions such ...
Development of a foam-filled steel web sandwich panel for the rehabilitation of...
Gontijo, Guilherme Lopes; Filho, Marco Antonio Santiago Abreu; Benzo, Pier Giovanni; Pereira, João Miguel; Machado, José; Denchev, Z.; Sena-Cruz, JoséLightweight sandwich panels offer a prominent solution for the rehabilitation of timber floors. This paper addresses the development of a solution capable of continuous production for a foam-filled steel web sandwich panel for floor rehabilitation. The newly designed flooring solution is tested in full-scale quasi-static flexural campaigns. The tests validate the analytical design’s compliance with Ultimate lim...
Polyamide-based supports for multi-enzyme bio-catalysis
Braz, Joana Filipa Barros; Dencheva, Nadya Vasileva; Denchev, Z.Polyamide-Based Supports for Multi-Enzyme Biocatalysis Joana Barros Braz*1, Nadya Vasileva Dencheva1 and Zlatan Zlatev Denchev1 1: IPC – Institute for Polymers and Composites, University of Minho, Guimarães, Portugal *Presenting author: joanabraz@dep.uminho.pt Abstract text: 250 words max. Enzymatic catalytic processes are known to be much more effective and environmentally friendly as compared to most conventi...
Porous Polyamide microparticles as effective carriers for cascade bio-catalysis
Braz, Joana Filipa Barros; Dencheva, Nadya Vasileva; Denchev, Z.In the last decades, cascade biocatalysis has attracted significant interest from both academia and industry as a promising technology for green and sustainable chemical production. Unlike the stepby-step synthesis, cascade biocatalysts accomplish two or more consecutive reactions in one-pot, thus avoiding isolation and purification of intermediates. Nowadays, numerous drugs and fine chemicals, as well as some ...
Polyamide microparticles as promising enzyme carriers and their application in ...
Braz, Joana Filipa Barros; Dencheva, Nadya Vasileva; Oliveira, Sandra Cristina Gomes; Araújo, Samuel; Denchev, Z.The widespread use of industrial-scale processes employing enzymatic catalysts is still hindered by the inactivation of free enzymes due to various denaturant agents and the difficulty, or even impossibility, of their recovery from the reaction medium after use. To address these limitations, a new strategy has been proposed, centered on polymer-assisted biocatalysts created through the non-covalent immobilizati...
Immobilization of enological pectinase by absorption on polyamide 6 micropartic...
Oliveira, Sandra Cristina Gomes; Dencheva, Nadya Vasileva; Denchev, Z.Introduction: Enzymes are widely used as efficient biocatalysts in the food industry for various purposes. In winemaking, a specialized sector where enzymes play a crucial role, pectinases occupy a central position. These enzymes significantly influence the sensory properties of wines by catalyzing the hydrolysis of pectin, responsible for wine cloudiness. This contributes to enhancing clarification and filtrat...
Immobilization of enological pectinase on magnetic sensitive polyamide micropar...
Oliveira, Sandra Cristina Gomes; Dencheva, Nadya Vasileva; Denchev, Z.The use of free pectinases as clarification biocatalysts constitutes a well-established practice in the large-scale production of various types of wines. However, when in the form of free enzymes, the recovery and reusability of pectinases is difficult if not impossible. To address these limitations, the present study focuses on the noncovalent adsorption immobilization of a commercial pectinolytic preparation ...
Fast, multiple-use optical biosensor for point-of-care glucose detection with m...
Braz, Joana Filipa Barros; Dencheva, Nadya Vasileva; Tohidi, Shafagh Dinparast; Denchev, Z.Non-invasive glucose determination provides major advantages in health monitoring and protection. It enables widespread point-of-care testing, which is affordable, sensitive, specific, rapid and equipment-free. This work reports on the development and analytical performance of a colorimetric biosensor in detecting glucose in human urine. Highly porous polyamide microparticles were synthesized as the support for...