The effects of maltodextrin/starch in soy protein isolate–wheat gluten on the thermal stability of high-moisture extrudates

Abstract

This study aimed to investigate the interaction between maltodextrin/starch of different molecular weight distributions and soy protein isolate (SPI)–wheat gluten (WG) matrix during high-moisture extrusion. Two maltodextrins (dextrose equivalent (DE): 10 and 20) and wheat starch were extruded with SPI–WG blend in a system of 65, 70, and 75% moisture to investigate their effects on texture and thermal stability. Incorporating 5% maltodextrin (DE10) in the SPI–WG matrix improved the fiber structure and thermal stability. When wheat starch was thoroughly gelatinized during subsequent sterilization, the fiber structure and thermal stability were also improved. It was found that the plasticization caused by small-molecular weight saccharides and enhanced phase separation caused by large-molecular weight saccharides changed the melting temperature of blends and significantly improved the texture and thermal stability of extrudates.

Keywords

• high-moisture extrusion
• protein
• saccharide
• fiber structure
• textural properties
• rheology