جستجوی مقالات مرتبط با کلیدواژه « فیلم خوراکی » در نشریات گروه « مکانیزاسیون کشاورزی »

The effect of enzymatic treatment time of microbial transglutaminase (MTGase) on the characteristics of whey protein isolate (WPI) films was investigated. Results shown that the properties of MTGase-treated films were affected by increasing the enzymatic treatment time. Enzymatic treatment at lower incubation time, i.e. for 1 h, significantly resulted in higher values of tensile strength (TS) and lower values of elongation at break (EB) as compared to control film. In the MTGase-treated films, the TS values decreased gradually and EB values increased progressively with increasing incubation time from 1 to 3 h. Water vapor permeability (WVP)and total soluble matter(TSM) of control film in comparison with MTGase-treated films decreased from3.6 ×10 10 to 2.31 ×10 10 g m-1 s-1 pa-1 and from 37.07 to 19.97 percent, respectively. However, as the time of enzymatic treatment was increased the TSM and WVP were gradually increased.

Throughout the present، Caseinate based edible films containing extracts of pomegranate peel were prepared in 3 levels of ×1، ×1. 5 and ×2 (MIC) and the physicomechanical، thermal، antimicrobial، and barrier properties of the films studied. To assess the microstructure changes resulting from the addition of the antimicrobial extracts، SEM images were prepared from the surface and cross-section of the films. Addition of the extract at concentrations up to ×2 MIC increased the values for thickness and solubility from 0. 054mm and 92. 18% to 0. 061mm and 95. 37% respectively، and caused the films to become opaque. Also، addition of pomegranate peel extract significantly increased the WVP (upto 3. 90×10-9 g/s. m. pa) of the prepared films، but lowered the mechanical properties. To evaluate the antimicrobial property of the prepared films’ disc diffusion method was applied and the diameter of the formed halo measured. Antimicrobial properties of edible films were tested against two strains of Gram-positive and Gram-negative bacteria. Films were more responsive against Gram-positive bacteria than against Gram-negative ones.

In this study the feasibility of using salep as a new film-forming material was studied. The mechanical properties، water vapor permeability and thickness of salep films incorporated with glycerol were determined. Increasing the content of dry material of salep from 1% to 3% (w/v) increased values for tensile strength and elongation at break from 16. 16% and 18. 85 MPa to 70. 15% and 24. 50 MPa respectively. Also values for water vapor permeability، decreased and then increased. Surface and dorsal of Salep edible films studied by Scanning Electron Microscopy to explain structure properties. This study revealed that the salep had a good potential to be used in producing edible films with interesting specifications.

The effect of oleic and stearic acids on the Water Vapor Permeability (WVP) and mechanical properties of Sodium caseinate films was investigated. Emulsifiers (Span 80 and 85) were employed to produce the base mixture of film. Tensile Strength (TS), Elongation (E) and Young's Modulus (YM) were obtained for both standard (without lipids) and hydrophobic films. Results showed that the addition of oleic and stearic acids caused a reduction in tensile strength and Young's modulus, however increased elongation of films. The presence of lipid compounds decreased the water vapour permeability of film (about 50%). Scanning Electron Microscope (SEM) pictures emphasized the presence of stearic acid on the outer and inner side of film which is indicative of the decrease in WVP of the films.