Optical and Structural Properties of Zein‐Xanthan Gum Biofilms

Abstract

Structural and optical characteristics of zein‐based films produced with different xanthan gum concentrations have been studied in this work. Scanning electronic microscopy (SEM) and optical microscopy (OM) were performed to identify if the incorporation of the material into the matrix film, formed a homogeneous structure, as well as to characterize its constituents as the colour and shape. SEM showed a homogeneous matrix for the control (0% xanthan) with good lipid distribution. However, when the samples were investigated by OM, lipids globules in the control biofilm appeared larger and more dispersed in the matrix than the others samples. Transparency/opacity test measurements by UV‐VIS analysis indicated that the addition of xanthan to the film matrix lowered significantly its transparency properties Overall, the addition of xanthan gum favoured lipid dispersion in the matrix, making biomaterials more homogeneous, although with less transparency.

Effect of zein coating enriched by addition of functional constituents on the lipid oxidation of roasted hazelnuts

“…The method of de Almeida and Filho () was used with some modifications. Zein was dissolved in aqueous ethanol (75%) to a concentration of 16% (w/v) by mixing slowly with a magnetic stirrer.…”

Microbial polysaccharide‐based membranes: Current and future applications

“…Microbial polysaccharides, such as gellan, pullulan, xanthan, bacterial cellulose, curdlan, and GalactoPol have been applied in the development of stand‐alone films. In addition, some of those polysaccharides, mostly gellan, pullulan, and xanthan, have been also applied in edible coatings, which consist on a relatively thin layer of material with a specific composition applied and formed directly on food product's surface, which may be eaten along with the product…”

“…Xanthan gum is mainly used as thickening agent in the food industry. When applied in the development of biodegradable films, it has been used mostly in polymer blends, namely with starch and zein protein . Studies regarding the improvement of the mechanical and oxygen barrier properties of single pullulan films, by blending it with other polymers, namely chitosan and gelatin, were reported.…”

Efecto de la temperatura y composición de solvente en la estructura secundaria de las α-zeínas

“…Ambas aplicaciones fueron consideradas dada la alta anfifílicidad de la proteína (superior a cualquier otras zeínas), característica que le permite atrapar solutos hidrofóbicos cuando precipitan en la misma solución, la nula toxicidad por consumo dado su grado alimenticio (GRAS) y capacidad de generar estructuras laminares debido a cambios en las condiciones del solvente, las cuales pueden agruparse para formar películas o bien nuclearse en nano o micro esferas, dependiendo de las condiciones de auto ensamble utilizadas 51 . En ambos casos se han obtenido resultados satisfactorios, lográndose formular biopelículas antimicrobianas de α-zeínas con quitosano y/o goma xanthana adherida [52][53][54][55] , o bien formadas por la precipitación de micro esferas de la prolamina con antibióticos encapsulados. Por otro lado diversos trabajos han logrado obtener suspensiones coloidales estables de micro y nano esferas de α-zeínas encapsulando solutos como aceites esenciales 49,50,56,57 , potenciales fármacos anti cancerígenos como el resveratrol 58,59 , ácidos grasos esenciales 60, 61, agentes antioxidantes [62][63][64][65] , entre otros.…”