Physical Properties of Gelatin Films Plasticized by Blends of Glycerol and Sorbitol

Abstract

: The addition of plasticizers increases the flexibility and workability of films based on biopolymers. However, the use of some plasticizers cause undesirable results, such as the migration of these additives out the film or crystallization during shelf life. Thus, the aim of this study was to evaluate the effect of blends with different ratios of sorbitol and glycerol, at 2 plasticizer concentrations, on mechanical, viscoelastic, and water vapor barrier properties of films based on gelatin. The films were prepared with 2 g gelatin/100 mL of water and with 25 or 55 g plasticizer/100 g gelatin. The ratio, glycerol to sorbitol, was studied as 0:100, 20:80, 40:60, 60:40, 80:20, and 100:0. The increase of plasticizer concentration from 25 to 55 g plasticizer/100 g gelatin caused an increase of flexibility and reduction of resistance and water vapor barrier as expected. In relation to the effect of the mixture, the increase in the proportion of glycerol caused a reduction of the puncture force, tensile strength, modulus of elasticity, and an increase of the puncture deformation, elongation at break, and water vapor permeability due to the higher plasticizing effect of glycerol. This behavior was explained in terms of molecular weight of the plasticizers, which demonstrated that the studied properties could be considered as functions of the number of molecules of plasticizers in the films.

The Properties of Edible Film Derived From Bovine Split Hide Gelatin With Isolated Soy Protein Using Various Levels of Glycerol in the Presence of Transglutaminase

“…The effect of the TGase treatment on the film properties had been investigated in several proteins such as soy flour (Mariniello et al, 2003), gelatin (Thomazine et al, 2005) and combine bovine gel with exogenous protein using Tgase (Erwanto et al, 2005). Cross-reactions can also be applied to the glutamine and lysine of two different types of proteins, resulting in the formation heteropolymers (De Jong and Koppelman, 2002).…”

Influence of bloom number and plastifiers on gelatin matrices produced for enzyme immobilization

“…Structural changes occur in the gel network through the action of the plastifiers, which can retard or facilitate the transport of water according to their concentration (Piermaria et al, 2011). An increase in the plastifier concentration leads to an increase in the interaction with the water due to the reorganization of the protein network and consequent increase in the free volume (Thomazine et al, 2005).…”

“…Concentrations of gelatin were chosen to evaluate a broad range, because there are gaps in the literature for the effects of gelatin at various concentrations, both on the gel and on the immobilization of enzymes. The definition of the concentrations of plasticizers were based on studies by Vanin et al, (2005), Thomazine et al, (2005), Bergo and Sobral (2007) and Rivero et al (2010).…”

Development and characterization of orally-disintegrating films for propolis delivery

“…The mechanical properties of the films were evaluated by the tensile test using a texturometer TA.XT (Stable Micro Systems, TA.XT.plus, Godalming, England) (THOMAZINE; CARVALHO; SOBRAL, 2005). The samples were cut into strips (15 × 100 mm), the grid separation was maintained at 80 mm, and the speed of testing was fixed at 0.9 mm.s -1 .…”