The Effect of Combination of Sorbitol and Polyethylene Glycol on Physicochemical Properties of Gelatin Films Made From (Parastromateus Niger)

• Main Authors: Hoda Fahim, Ali Motamedzadegan, Shabnam Hamzeh
• Format: Article
• Language: fas
• Published: Research Institute of Food Science and Technology 2017-09-01
• Series: Pizhūhish va Nuāvarī dar ̒Ulūm va Sanāyi̒-i Ghaz̠āyī
• Subjects: fish gelatin film; plasticizer; polyethylene glycol; sorbitol
• Online Access: http://journals.rifst.ac.ir/article_68276_57acec4d9f04e8981e94225136fa8d6d.pdf

In current  study, the effect of two plasticizers, sorbitol and poly ethylene glycol 400 (PEG 400), at different ratios (5:5, 5:10, 5:15, 10:5, 10:10, 10:15, 15:5, 15:10 and 15:15) of on physicochemical properties of gelatin films from black pomfret (<em>Parastromateus niger</em>) were investigated. Plasticizers are low-molecular-weight Compounds which compounded into polymer molecules to improve its flexibility. With increasing amount of plasticizers, tensile strength and elastic modulus of gelatin films decreased whereas elongation at break (EAB) increased. That effect was the result of plasticizer molecules diffusion into polymer and weaken the polymer-polymer interactions which significantly led to increasing film elongation. High degree of opacity of the films was observed in the high plasticized films and the opacity of PEG plasticized films at 15% concentration was higher than the sorbitol ones at the same concentration (<em>P</em><0.05). Water vapor permeability (WVP) of the films was mainly dependent on the amount of plasticizer, regardless of the plasticizer type, WVPs increased from 1.001 to 1.901 mm.gr/pa.h.m2 for the films, those contained lowest and highest plasticizers, respectively. There was a significant difference in the solubility of films depending upon plasticizer concentration, the highest and lowest water solubility belonged to  the sample containing 15% and 5% sorbitol or PEG around 70% and 15.5% respectively (<em>P</em><0.05). The solubility of the films mostly depending upon plasticizers concentration than plasticizers type and increased with increasing in plasticizer content. Totally, the  increase in film solubility and WVP was the result of plasticizer molecules penetration between polymers and subsequent increase in free volumes.