Properties of Extruded Vital Wheat Gluten Sheets with Sodium Hydroxide and Salicylic Acid
Henrik Ullsten, Sung‐Woo Cho, Gwen Spencer, Mikael Gällstedt, Eva Johansson, Mikael S. Hedenqvist
Biomacromolecules
Abstract
This paper presents a novel approach to improve the barrier and mechanical properties of extruded glycerol-plasticized vital wheat gluten sheets. The sheets were extruded with a single screw extruder at alkaline conditions using 3-5 wt % NaOH. Salicylic acid (SA), known to improve the extrudability of wheat gluten, was also added alone or in combination with NaOH. Oxygen transmission rate and volatile mass measurements, tensile tests, protein solubility, glycerol migration, infrared spectroscopy, and electrophoresis were used to assess the properties of the extrudate. Electrophoresis showed that the gluten/glycerol sheet and the sheet with 3 wt % NaOH and 1 wt % SA contained the same building blocks in terms of proteins and protein subunits, although the protein solubility in these samples was different. The oxygen barrier, at dry conditions, was improved significantly with the addition of NaOH. On the other hand, the addition of salicylic acid yielded poorer barrier properties. The extrudate was placed on a blotting paper and its aging properties were investigated during the first 120 days. It was observed that the extrudate with 3 wt % NaOH had the most suitable combination of properties (low oxygen permeability, large strain at break, and relatively small aging-induced changes in mechanical properties); the reason is probably due to low plasticizer migration and an optimal protein aggregation/polymerization.
Extracted Claims
4 claims extracted from this paper into the knowledge graph
vital wheat gluten sheets had poorer barrier properties with the addition of salicylic acid
“On the other hand, the addition of salicylic acid yielded poorer barrier properties.”
vital wheat gluten sheets improved by extrusion with NaOH and salicylic acid
“This paper presents a novel approach to improve the barrier and mechanical properties of extruded glycerol-plasticized vital wheat gluten sheets.”
vital wheat gluten sheets had the most suitable combination of properties with 3 wt % NaOH
“It was observed that the extrudate with 3 wt % NaOH had the most suitable combination of properties (low oxygen permeability, large strain at break, and relatively small aging-induced changes in mecha...”