Influence of sorbitol on mechanical and physico-chemical properties of soy protein-based bioplastics processed by injection molding

Abstract

SbstractSoy Protein Isolate (SPI) has been evaluated as useful candidate for the development of protein-based bioplastic materials processed by injection molding. The influence of sorbitol (SB) as plasticizer in mechanical properties and water uptake capacity was evaluated in SPI-based bioplastics. A mixing rheometer that allows monitoring torque and temperature during mixing and a small-scale-plunger-type injection molding machine were used to obtain SPI/Plasticizer blends and SPI-based bioplastics, respectively. Dynamic measurements were carried out to obtain mechanical spectra of different bioplastics. Moreover, the mechanical characterization was supplemented with uniaxial tensile tests. Additionally, the influence of SB in water uptake capacity was also evaluated. The introduction of SB leads to increase the rigidity of bioplastics as well as the water uptake capacity after 24h, however it involves a decrease in strain at break. Final bioplastics are plastic materials with both adequate properties for the substitution of conventional petroleum plastics and high biodegradability.

Functional biodegradable protein‐based matrices as a potential candidate for micronutrients and water supply

“…This procedure has been also applied in previous studies with SPI and Gly where the mixing conditions were optimized. [24,25] In this step, both torque variation (M) and temperature evolution (100Á[T − T 0 ]/T 0 ) were measured in order to make sure that the incorporation of the different salts does not significantly affect homogeneous mixing of the blends. If temperature or torque rises for a long time, the protein can become denatured and would then become unsuitable for this study.…”

Effect of Sorbitol Plasticizer on the Structure and Properties of Melt Processed Polyvinyl Alcohol Films

“…Sorbitol is one kind of polyol. The active hydroxyl groups of sorbitol make it an effective plasticizer for some ‐OH or ‐NH rich polymers (Mohsin and others ), such as plant protein (Felix and others ), chitosan (Chen and Zhao ), starch (Dufresne and Castano ; Rompothi and others ), and so on. Also sorbitol is nontoxic and could be used in some food contacting materials and therefore, is a good choice to make food packaging materials.…”

Processing of biodegradable and multifunctional protein‐based polymer materials for the potential controlled release of zinc and water in horticulture

“…In this procedure, according to Jiménez-Rosado et al, [33] SPI and Gly (1:1 ratio) were processed with 10 wt% ZnSO 4 •H 2 O, which is the maximum injectable percentage of ZnSO 4 •H 2 O. The selected parameters for the mixing were those that optimized Felix et al [34] and Fernández-Espada et al [35] in their works with SPI and Gly bioplastics. Thus, the RM were homogenized for 10 min at 50 rpm in a rotating mixer Polylab QC (ThermoHaake, Germany), under adiabatic conditions at room temperature (26.0 ± 1.0 C).…”