Optimisation of stimuli-responsive films based on dynamic alpha, beta-unsaturated imines from chitosan and trans-2-hexenal to enhance the antimicrobial acid-response

[EN] Trans-2-hexenal (HX) is a potent antimicrobial which can be reversibly stabilised in chitosan (CS) films forming alpha, beta-unsaturated imines. The hydrolysis of the imines promoted by acid environments triggers the release of HX to the media exerting its antimicrobial activity. It is known th...

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Detalles Bibliográficos
Autores: Esteve-Redondo, Patricia, Heras-Mozos, Raquel, Hernández, Rebeca, Hernández-Muñoz, Pilar, GAVARA CLEMENTE, RAFAEL|||0000-0001-6376-8939
Tipo de recurso: artículo
Fecha de publicación:2025
País:España
Institución:Universitat Politècnica de València (UPV)
Repositorio:RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
Idioma:inglés
OAI Identifier:oai:dnet:riunet______::1da163f45b09384010003e561fa197ad
Acceso en línea:https://riunet.upv.es/handle/10251/233949
Access Level:acceso abierto
Palabra clave:Chitosan
Trans-2-hexenal
Alpha, beta-unsaturated imines
PH-responsive
Antimicrobial films
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Descripción
Sumario:[EN] Trans-2-hexenal (HX) is a potent antimicrobial which can be reversibly stabilised in chitosan (CS) films forming alpha, beta-unsaturated imines. The hydrolysis of the imines promoted by acid environments triggers the release of HX to the media exerting its antimicrobial activity. It is known that besides imines, the electrophilic ß-alkene carbon of HX can form Michael adducts with primary amino groups of chitosan. However, the formation of nucleophile-C bonds is undesired since these bonds are barely hydrolysed and limit the release of HX and by hence, the effectivity of the film. Thus, the aim of this work has been to optimise the formation of trans-2-hexenal-imine-chitosan films employing response surface methodology in order to favour the formation of conjugated imines avoiding Michael adducts. The optimisation of the reaction parameters indicated that synthesis temperature of 10 °C and without the use of an acid catalyst favours the formation of conjugated imines. Spectroscopic techniques, elemental analysis and swelling behaviour in various media were used to characterise the optimised films. The release kinetics of HX and the antimicrobial activity of the films were also studied. The present work provided relevant information to increase the antimicrobial efficacy of trans-2-hexenal-imine-chitosan films for the development of active food packaging.