Physico-Chemical Properties of Extruded Copolymer Film

Abstract

The aim of this study was to investigate the properties of copolymer films made from cassava starch and jellyfish gelatine with glycerol or sorbitol as a plasticizer. The concentrations of gelatine used were 1 and 3% (wt/vol). The prepared copolymer of cassava starch solution (5%) and gelatine solution (1:1 (vol/vol)) was mixed with glycerol or sorbitol (30%) prior to extrusion. The feeding rate of solution was 1 kg/h and the extruder screw speed was 30 rpm. The films were dried by an infared dryer. All extruded films had the thickness of 0.10–0.30 mm. At 1% jellyfish gelatine, the glycerol plasticized copolymer film yielded higher tensile strength, water vapor transmission rate, oxygen transmission rate and %solubility than the sorbitol plasticized film. As the concentration of jellyfish gelatine increased to 3%, the elongation of glycerol plasticized film increased approximately five times compared to two times for sorbitol plasticized films. Practical Applications Gelatine, a denatured form of collagen protein, can be derived from pig, beef or fisheries products such as fish, squid and jellyfish. The application of gelatine is widely used for food and biomedical aspect. The film copolymer of cassava starch and gelatine can be formed by a single screw extruder with glycerol or sorbitol as a plasticizer. The copolymer film with glycerol showed noticeable elongation property, which could be benefit for the development of edible film.

Influence of collagen and some proteins on gel properties of jellyfish gelatin

“…In this study, no bleaching step was applied during extraction. The color was similar to the sample of type A jellyfish gelatin that appeared in yellow shades that were reported earlier [ 21 ].…”

“…Apart from application in food products, jellyfish gelatin is applied in film formation. Extruded copolymer film composed of 3% jellyfish gelatin and 5% cassava starch solution showed that elongation of glycerol plasticized film increased greater than that of sorbitol plasticized film [ 21 ].…”

“…Fish gelatin has also been potentially certified in accordance with kosher and halal regulations [ 6 , 7 ]. In addition to fish gelatin from commercially available tilapia, marine species such as Hoki ( Macruronus novaezelandiae ) [ 6 ], clown featherback [ 7 ], unicorn leatherjacket [ 8 , 9 ], Atlantic salmon [ 10 ], bigeye snapper [ 11 – 13 ], brown stripe red snapper [ 13 ], seabass [ 14 ], catfish [ 15 ], tuna [ 5 , 16 ], brown-banded bamboo shark [ 17 ], and blacktip shark [ 17 ], and jellyfish [ 18 – 21 ] have been researched as other sources of commercial gelatin production. However, such marine gelatins have shown inferior gel strength and thermal stability (gelling and melting temperatures) compared to bovine and porcine gelatins.…”

“…With the benefit of minimal fat content, the preparation step for jellyfish gelatin production does not require excessive chemical treatment [ 18 – 20 ]. However, jellyfish gelatin’s gel strength is from 47–118 g [ 18 – 21 ], while most fish gelatin samples were reported as having gel strength higher than 200 g, including gelatins from brown stripe red snapper, catfish, brown-banded bamboo shark, and blacktip shark [ 13 , 15 , 17 ]. To date, the predictability of weak gel behavior of jellyfish gelatin, based on the identification of proteins by the mass spectrometric method, is possible but not well reported.…”

Effect of glycerol and sorbitol on the mechanical and barrier properties of films based on pea protein isolate produced by high‐moisture extrusion processing

“…The higher OTR values of films containing 40%–50% sorbitol compared to films containing 40%–50% glycerol may reflect the presence of randomly placed micro‐cracks, which would increase the permeability to oxygen as well as water vapor. Thumthanaruk et al [ 32 ] showed that the glycerol and sorbitol content of all copolymer films had no significant effect ( p ≥ 0.05) on OTR values, but concluded that bubbles and bumps may influence the oxygen permeability. McHugh and Krochta [ 33 ] concluded that the oxygen permeability of sorbitol films was lower than that of glycerol films, despite the higher sorbitol concentration.…”