Mechanical and Microstructural Properties of “Wet” Alginate and Composite Films Containing Various Carbohydrates

Abstract

Composite "wet" alginate films were manufactured from alginate-carbohydrate solutions containing 5% alginate and 0.25% pectin, carrageenan (kappa or iota), potato starch (modified or unmodified), gellan gum, or cellulose (extracted or commercial). The "wet" alginate films were used as a model to understand co-extruded alginate sausage casings that are currently being used by several sausage manufacturers. The mechanical, optical, and microstructural properties of the calcium cross-linked composite films were explored. In addition, the water holding capacity and textural profile analysis properties of the alginate-carbohydrate gels were studied. The results indicate that the mechanical properties of "wet" alginate films/casings can be modified by adding various carbohydrates to them. Alginate films with pectin, carrageenan, and modified potato starch had significantly (P < 0.05) greater elongation values than pure alginate films. The alginate-pectin films also had greater (P < 0.05) tensile strengths than the pure alginate films. Alginate films with extracted cellulose, commercial cellulose, and modified potato starch had lower (P < 0.05) puncture force, distance, and work values than the alginate control films. Transmission electron microscopy images showed a very uniform alginate network in the control films. Several large cellulose fibers were visible in the films with extracted cellulose, while the cellulose fibers in the films with commercial cellulose were difficult to distinguish. Despite these apparent differences in cellulose fiber length, the 2 cellulose films had similar puncture and tensile properties.

Effect of Incorporation Nanocrystalline Corn Straw Cellulose and Polyethylene Glycol on Properties of Biodegradable Films

“…The appearances of upper and lower surfaces of the films were different. The films attached to the side of plexiglass films applicator was shiny, while the other side was dark(Galus and others ; Harper and others ). The interior of the films presented a uniform network structure through the incorporation of CSC and NCSC.…”

Approaches in Animal Proteins and Natural Polysaccharides Application for Food Packaging: Edible Film Production and Quality Estimation

“…Co-extrusion is the process of simultaneous extrusion of two or more materials to form a multilayer film or coating [ 220 ]. This method is also used for applying an edible film/coating to food products, for example, a film of calcium alginate formed on the surface of minced meat when they simultaneously pass through a co-extrusion die [ 221 ]; alginate films with various polysaccharides (carrageenan, pectin, starches, cellulose, and gums) applied for sausage products packaging [ 222 ]; sodium alginate films with additives used for packaging sausages made by dry fermentation [ 223 ]; collagen films [ 224 ].…”

Active edible films: Current state and future trends

“…Crystalline cellulose nanofibrils isolated from cotton linter by acid hydrolysis were used to prepare composite films with clear enhancements in the optical and mechanical properties, water vapor barrier properties, and thermal stability . Composite alginate films were manufactured from alginate–carbohydrate solutions containing 5 wt % alginate and 0.25 wt % pectin, carrageenan (κ or ι), potato starch (modified or unmodified), gellan gum, or cellulose (cellulose extracted from soybean chaff or commercial cellulose) . All of those carbohydrates were able to form composite films with the alginate matrix.…”