The impact of extrusion parameters on the glutenin macropolymer content of flour-water dough

Abstract

Wheat quality, dough properties and the extent of dough formation can be predicted by the glutenin macropolymer (GMP) content. To provide the selection and control of GMP content in the flour-water dough by using extrusion technology, the relationship between the GMP content and the extrusion parameters was investigated. Different dough moistures (25%–45%), barrel temperatures (30 °C–50 °C), screw speeds (100–200 rpm), pressures (with die or without die), and extrusion rounds (1–3 rounds) were investigated during the flour-water dough extrusion processing trials, and the GMP content was detected. The results demonstrated that the sodium dodecyl sulfate (SDS)-soluble protein content increased from 83.0 mg/g to 100.7 mg/g and the GMP content decreased from 30.8 mg/g to 18.3 mg/g when the specific mechanical energy (SME) increased from 30.09 kJ/kg to 178.14 kJ/kg, which indicated the GMP was converted to SDS soluble proteins. Dough moisture and extrusion round significantly facilitate the reduction of GMP content. Temperature has a relatively insignificant effect on GMP content. The GMP content suggests the negative relationship (r = −0.77) with SME. This study highlighted the complex interplay of extrusion processing variables that affect the interaction of protein components, with consequent effects on protein solubility.