RESUMO
This study describes the synthesis of a new bioadsorbent with zwitterionic characteristics and its successful application for removal of a cationic dye (crystal violet, CV) and an anionic dye (orange II, OII) from single component aqueous systems. The new bi-functionalized cellulose derivative (MC3) was produced by chemical modification of cellulose with succinic anhydride and choline chloride to introduce carboxylic and quaternary ammonium functional groups on the cellulose surface. MC3 was characterized by several wet chemical and spectroscopic methods. The effects of solution pH, contact time, and initial solute concentration on removal of CV and OII by MC3 were investigated. Studies of the desorption and re-adsorption of the dyes were also carried out. The isotherms for adsorption of CV and OII on MC3 were satisfactorily fitted using the Konda and Langmuir models. MC3 showed experimental maximum adsorption capacities of 2403 mg g-1 for CV and 201 mg g-1 for OII. The desorption and re-adsorption results showed that MC3 could be reused in successive adsorption cycles, which is essential for minimizing process costs and waste generation. The findings showed that MC3 is a versatile biosorbent capable of efficiently removing both cationic and anionic dyes.
Assuntos
Violeta Genciana , Poluentes Químicos da Água , Adsorção , Compostos Azo , Benzenossulfonatos , Celulose , Corantes , Concentração de Íons de Hidrogênio , CinéticaRESUMO
RESUMEN Los recubrimientos se definen como productos comestibles que forman una fina capa sobre el alimento y se caracterizan por que constituyen una barrera semipermeable a los gases y al vapor de agua que retrasa el deterioro del alimento, mejoran las propiedades mecánicas, ayudan a mantener la integridad estructural del producto que envuelven, ayudan a retener compuestos volátiles y pueden actuar como vehículo de aditivos alimentarios. Se evaluó el desempeño de los biorecubrimientos sobre el aguacate mediante la determinación de propiedades sensoriales y fisicoquímicas. Los resultados muestran que todas las variables están significativamente influenciadas por la biomolécula empleada "almidón modificado de ñame variedad espino", observando un desempeño favorable en los biorecubrimientos comestibles, por lo cual se confirma la efectividad de utilizar biorecubrimiento comestible a base de almidón modificado de ñame con anhídrido n-octenil succínico (n-OSA) como una alternativa para la conservación del aguacate mínimamente procesado debido a que presentó menor variación de las propiedades fisicoquímicas.
ABSTRACT Coatings are defined as edible products which form a thin layer on food, and are characterized by a semipermeable barrier for gases and water vapor which slow food spoilage, improve mechanical properties, help maintain the structural integrity of product wrapping, retain volatile compounds and can act as a vehicle for food additives. We evaluated the performance of biofilms on avocado through the determination of physico-chemical and sensory properties. The results show that all the variables were significantly influenced by the biomolecule employed "modified yam variety espino starch", noting a favorable performance in edible biofilms, confirming the effectiveness of using edible biorecubation based on modified yam starch with n-octenyl succinic anhydhyded (n-OSA) as an alternative for the preservation of minimally processed avocado because it had less variation in physicochemical properties.
RESUMO
Coatings are defined as edible products which form a thin layer on the food, and are characterized by it constitute a semipermeable barrier to gases and water vapor retarding food spoilage, improve the mechanical properties, help maintain the structural integrity of the product wrapping, to retain volatile compounds and can act as a vehicle for food additives. We evaluated the performance of the biofilms on melon through the determination of physico-chemical and sensory properties. The results show that all the variables are significantly influenced by the biomolecule employed "modified starch", noting a favorable performance in the edible biofilms.
Los recubrimientos se definen como productos comestibles que forman una fina capa sobre el alimento y se caracterizan por que constituyen una barrera semipermeable a los gases y al vapor de agua que retrasa el deterioro del alimento, mejoran las propiedades mecánicas, ayudan a mantener la integridad estructural del producto que envuelven, ayudan a retener compuestos volátiles y pueden actuar como vehículo de aditivos alimentarios. Se evaluó el desempeño de los biorecubrimientos sobre el melón mediante la determinación de propiedades sensoriales y fisicoquímicas. Los resultados muestran que todas las variables están significativamente influenciadas por la biomolécula empleada "almidón modificado", observando un desempeño favorable en los biorecubrimientos comestibles.