Films and edible coatings containing antioxidants - a review

Abstract

SummaryThe incorporation of natural antioxidants into fi lms and edible coatings can modify their structure, improving their functionality and applicability in foods, such as in fresh-cut fruits. This paper reviews the more recent literature on the incorporation of antioxidants from several sources into fi lms and edible coatings, for application in fruits and vegetables. The use of synthetic antioxidants in foods has been avoided due to their possible toxic effects. Instead, a wide range of natural antioxidants (such as essential oils and plant extracts, as well as pure compounds, like ascorbic acid and α-tocopherol) have been incorporated into edible fi lms and coatings to improve their bioactive properties. Films and coatings containing added antioxidants help to preserve or enhance the sensory properties of foods and add value to the food products by increasing their shelf life.Key words: Bioactive compounds; Natural additives; Functionality; Essential oil; Extracts. ResumoA incorporação de antioxidantes naturais em fi lmes e coberturas comestíveis pode modifi car sua estrutura, melhorando sua funcionalidade e aplicação em alimentos, tais como as frutas. Este artigo apresenta uma revisão da literatura mais recente sobre a incorporação de antioxidantes, de diversas fontes, em fi lmes e coberturas comestíveis aplicados em frutas e vegetais. A utilização de antioxidantes sintéticos em alimentos tem sido evitada em razão do seu possível efeito tóxico. Assim, inúmeras categorias de antioxidantes naturais -tais como óleos essenciais, extratos de plantas e compostos puros, como ácido ascórbico e α-tocoferol -têm sido adicionadas a fi lmes e coberturas comestíveis, para melhorar suas propriedades bioativas. As embalagens aditivadas com antioxidantes podem preservar ou melhorar as qualidades sensoriais dos alimentos sobre os quais são aplicadas e agregar valor a produtos alimentares pelo aumento de sua vida de prateleira.

Chemical and Sensory Quality Preservation in Coated Almonds with the Addition of Antioxidants

“…Previous studies on edible films enriched with antioxidant compounds reported protective effects on the food product studied (Eça and others ; Riveros and others ). Ponce and others studied different edible films (chitosan, CMC, among others) enriched with oleoresins.…”

Enhancing mechanical properties of chitosan films via modification with vanillin

“…Therefore the application of such composite films prepared from hydrophilic cross-linking agents for food preservation was limited [41,42]. These results indicated that adding cross-linking agent of vanillin, especially the addition amount of 5%, the structure of chitosan film was enhanced by forming a relatively dense network and the capacity of the structural elements were decreased that did not lead to the structural relative movement during the tensile test.…”

Green Development of Biodegradable Films Based on Native Yam (Dioscoreaceae) Starch Mixtures

“…Starch is the most applied material to develop biodegradable packings due to the advantages described above. Nevertheless, it presents technological challenges due to its hydrophilic character resulting in reduced mechanical (little flexibility and brittleness) and permeability properties (high water vapor and oxygen permeability) . Therefore native starch is blended with other polymers, different plasticizers or native starches from different botanical origins to enhance the mechanical and barrier properties mantaining the biodegradability …”