%0 Journal Article
%T Properties of Edible Films Based on Oxidized Starch and Zein
%A Elizabeth Arg邦ello-Garc赤a
%A Javier Solorza-Feria
%A J. Rodolfo Rend車n-Villalobos
%A Francisco Rodr赤guez-Gonz芍lez
%A Alfredo Jim谷nez-P谷rez
%A Emmanuel Flores-Huicochea
%J International Journal of Polymer Science
%D 2014
%I Hindawi Publishing Corporation
%R 10.1155/2014/292404
%X The objective of this work was to investigate the effect of zein and film formulation on mechanical and structural properties of native (FNS), and oxidized with 2.5% (FOSA) and 3.5% (FOSB) banana starch. The oxidized starch showed differences from native starch due to the oxidation process, showing a decrease in lipids, proteins, and amylose. The increase of the sodium hypochlorite increased the content of carbonyl and carboxyl groups in the ranges 0.015每0.028% and 0.022每0.031%, respectively. The film obtained from FOSB displayed the highest tensile strength (5.05ˋMPa) and satisfactory elongation value (27.1%). The zein addition caused a decrease in these mechanical properties, as well as a significant decrease in water vapour permeability (WVP). However, films from FOSA and FOSB showed higher permeability than that of the native starch. The addition of glycerol and the level of oxidation increased the films moisture. Micrographs showed that, during the oxidation process, impurities were largely eliminated from the starch granule, noting more homogeneous structures both in granules and films. 1. Introduction There is currently a revival of worldwide interest in the use of biopolymers for applications in which synthetic polymers have traditionally been the materials of choice. Materials of interest include different synthetic or biosynthetic polymers [1, 2], as well as plant based polymers such as polysaccharides, starch, and cellulose, which represent the most characteristic family of these natural polymers [3每6]. In the polymer field, interest in starch, a well-known hydrocolloid biopolymer, has been recently renewed due to its abundance, low-cost, biodegradability, and the possibility of processing, using conventional polymer processing equipment [7每9]. Starch is produced from various sources in the form of granules and is mainly isolated from cereal grains such as maize, wheat, rice, and sorghum although tubers such as potato, cassava, sweet potato, and sago are also used, and it can be found in leaves legume seeds and fruits as well. It is composed of amylose, a linear polymer (poly-汐-1,4-D-glucopyranoside), which is distributed mostly in the starch granule amorphous domains (lamella), with small amounts in the semicrystalline granule ring and amylopectin (poly-汐-1,4-D-glucopyranoside and 汐-1,6-D-glucopyranoside), a branched polymer that gives place to the crystalline lamella [10, 11]. The relative amounts and molar masses of amylose and amylopectin vary with the starch source, yielding materials of different mechanical properties and
%U http://www.hindawi.com/journals/ijps/2014/292404/