Functional Properties of Bioplastics Made from Wheat Gliadins Modified with Cinnamaldehyde

Abstract

Cinnamaldehyde is a naturally occurring α,β-unsaturated aldehyde. Its potential as a natural cross-linker to improve the physical performance of cast wheat gliadin films was evaluated. The cross-linking reaction was found to be dependent on the pH of the reaction medium, with pH 2 as the optimum. The water resistance (weight loss after immersion), mechanical properties (Young's modulus, tensile strength and elongation at break), thermal properties (T(g) and decomposition behavior), optical properties and morphology of films were evaluated. Cross-linked films showed high transparency, maintained their integrity after immersion, and displayed significant improvements in tensile strength and Young's modulus without impairment of their elongation properties. These effects, which were proportional to the amount of cinnamaldehyde added, highlight the possible formation of intermolecular covalent bonds between "monomeric" gliadins, leading to a polymerized network. Thus, this treatment could provide a new alternative to the toxic cross-linkers commonly employed and so extend the use of gliadin films.

Antifungal properties of gliadin films incorporating cinnamaldehyde and application in active food packaging of bread and cheese spread foodstuffs

“…Glycerol was added as plasticizer to the film-forming solutions at 25% (g glycerol/100 g protein). The pH of the mixture containing protein, glycerol, and cinnamaldehyde was adjusted to 2.0 with HCl, the most suitable for producing the cross-linking reaction of gliadins by means of cinnamaldehyde (Balaguer et al, 2013(Balaguer et al, , 2011a(Balaguer et al, , 2011b, and the mixture was stirred for 30 min to produce a complete homogenization.…”

“…As film G5C_pH2 showed the best antifungal capacity as well as the best functional properties (Balaguer et al, 2011a), it was selected for further assays performed in a food model. Fungal growth development on the bread slices packaged with or without the antimicrobial films is shown in Table 2.…”

Biocomposite edible coatings based on cross linked‐sesame protein and mango puree for the shelf life stability of fresh‐cut mango fruit

“…Contrarily, biopolymer coatings have usually poor barrier and mechanical performance, limiting their practical applicability. Mobility of the polymer structure is reduced by crosslinking and usually improves its mechanical and barrier properties and its water resistance (Balaguer et al, ), reduces its swelling capacity and water solubility (Azeredo & Waldron, ). Crosslinking reactions may also decrease the biodegradability of protein as reported for gelatin (Martucci & Rusekaite, ).…”

Development of crosslinked sesame protein and pineapple extract‐based bilayer coatings for shelf‐life extension of fresh‐cut pineapple

“…Crosslinking is described as the process of linking polymers chains by covalent and noncovalent bonds (Balaguer, Gomez‐Estaca, Gavara, & Hernandez‐Munoz, ). Films from proteins and polysaccharides have been applied to food surfaces to reduce water permeability and gas exchange.…”