Physical and mechanical properties of a new edible film made of pea starch and guar gum as affected by glycols, sugars and polyols

Abstract

The influence of different plasticizers (glycols, sugars and polyols) on the moisture sorption, mechanical, physical, optical, and microstructure characteristics of pea starch-guar gum (PSGG) film was studied. All plasticizers formed homogeneous, transparent, and smooth films, while PEG-400 did not produce film with suitable characteristics. Fourier transform infrared (FTIR) spectroscopy results indicated some interaction between plasticizers and the polymers. Scanning electron microscopy (SEM) observations of the films presented surfaces without cracks, breaks, or openings which were indicator of the miscibility and compatibility of employed plasticizers with PSGG films. The results showed that the films containing plasticizers with higher functional groups had lower equilibrium moisture content at aw <0.4. In general, a reduction in tensile strength and Young's modulus and an increase in elongation at break were detected when molecular weight of plasticizers and relative humidity increased in all film formulations. Films plasticized with monosaccharide showed similar mechanical properties to those with sorbitol, but lower solubility and water vapour permeability (WVP), higher transparency and moisture content than the sorbitol-plasticized films. The most noticeable plasticization effect was exerted by following order: glycerol > EG > PG > xylitol > fructose > sorbitol > mannitol > galactose > glucose > sucrose > maltitol.

Synthesis and characterization of eco-friendly bioplastic from low-cost plant resources

“…Water solubility of the film samples was determined according to method determined by Saberi et al [17]. All the bioplastic film samples were cut into 2 cm × 2 cm pieces, dried at 60 °C for 2 h and weighed.…”

“…The crystalline nature of starch is destroyed in the presence of heat and excess water during melting process that makes the amylose and the branched chains of amylopectin to break and form hydrogen bonding. Additionally, there may be some exposed hydroxyl groups of amylose and amylopectin not involved in cross-linking with plasticizers, which react with water when exposed leading to swelling of the film [17]. Polylactic acid-based starch film (PV) may have less cross-linking with starch; PLA easily takes up moisture content; hence, a higher swelling is observed.…”

Low Transition Temperature Mixtures (LTTM) Containing Sugars as Potato Starch Plasticizers

“…Similar results were obtained in work of ref. presenting pea TPS‐guar gum films modified with different sugar plasticizers where TS and YM increased in order Suc > Gluc > Fruc (RH 43.2%), but EB decreased in the same sequence. However, the literature data should not be directly compared with our results, as most of available studies related to films obtained via casting method or mixed with presence of other polymers.…”

Preparation and Properties of Solution Cast Films From Pennycress Protein Isolate

“…The impact of atmospheric moisture on the properties of bio‐based polymers has been documented. The properties of carbohydrate (Saberi, Chockchaisawasdee, Golding, Scarlett, & Stathopoulos, ) and protein (Fernández‐Espada, Bengoechea, Cordobés, & Guerrero, ; Gennadios, Brandenburg, Park, Weller, & Testin, ; Lawton, ) films change after storage at various RH. At elevated RH, more water is absorbed by the polymer, and with water acting as a plasticizer, properties will change.…”