Zein−Iodine Complex Studied by FTIR Spectroscopy and Dielectric and Dynamic Rheometry in Films and Precipitates

Abstract

In the present study the effect of iodine on properties of zein films and zein precipitates obtained after hydrophobic aggregation was evaluated. Zein films were cast with and without glycerol (as plasticizer) after incorporation of iodine at different levels (2-8%, zein wt basis). Zein films were characterized by secondary structure (determined by infrared spectroscopy) and dielectric and mechanical properties. The rheological properties of zein precipitates as a function of frequency and temperature were evaluated using a dynamic rheometer. Inclusion of iodine changed the secondary structure of zein films and decreased their tensile strength as well as strain at failure. In aggregates, changes in G' (elastic modulus) and G'' (viscous modulus) during heating were affected by the presence of iodine due to the inhibition of aggregation. The water-holding capacity of precipitates precipitated in the presence of iodine was higher than that of those without iodine.

Influence of palm oil and glycerol on properties of fish skin gelatin-based films

“…This could increase the elasticity and flexibility of films as evidenced by the higher EAB along with lower TS. Furthermore, the addition of iodine at higher concentrations (2-8 %) was found to decrease TS of zein film to a higher extent (Singh et al 2009). Therefore, the mechanical properties of resulting films were influenced by both palm oil and glycerol.…”

“…Amide-I and Amide-II bands of zein film were found at the wavenumbers of 1650 and 1545 cm -1 , respectively. The amplitude of amide-II band of zein film plasticized with 30 % glycerol increased as the concentration of iodine added increased from 2 to 8 % (Singh et al 2009). Amide-A peak of control film found at wavenumber of 3290 cm -1 , which was lower than that of emulsified film (3309 cm -1 ).…”

Zein-based films and their usage for controlled delivery: Origin, classes and current landscape

“…Recently, the potential of zein as an active ingredient for direct compressed tablets and film-based delivery carriers has been investigated in detail [76][77][78][79][80][81][82][83][84][85][86][87][88][89][90][91]. Moreover, zein was considered a promising film coating material for novel biomedical applications such as medical devices [92][93][94], nanoparticles [95], quantum dot and nanofiber [96,97].…”

“…Numerous studies have revealed that zein film itself could function as a controlled release matrix for the delivery of active components, such as salicylic acid [80], acetyl salicylic acid [80], iodine [81], nisin [83,84], lysozyme [82,[84][85][86][87], EDTA [82,84], thymol [90,91], catechin [85,87,89], gallate ester [88] and gallic acid [89]. Although these zein films may have different usages, the controlled release profiles of active components are the focus of attention.…”

Effect of acid and base treatments on structural, rheological, and antioxidant properties of α-zein

“…With the second derivative and FSD, it has been identified that the signal of a-helix in zein appeared around the wavenumber of 1648-1659 cm À1 ; b-sheet was at 1627-1629, 1681-1682, and 1694-1697 cm À1 ; while random coil and b-turn structures were respectively detectable at 1638-1640 and 1681-1682 cm À1 (Forato, Bicudo, & Colnago, 2003;Singh, Georget, Belton, & Barker, 2009;Yong et al, 2004).…”