Delineating the protein changes in Asian noodles induced by vacuum mixing.

In this study, the effect of vacuum mixing on Asian noodle qualities was investigated based on protein components changes and gluten formation. The results showed that the proportion of salt-soluble proteins decreased in vacuum mixed noodles while alcohol and alkali soluble proteins increased. The free sulfyhydryl content decreased significantly (P<0.05) in low protein (LP) noodles while slight and not significant (P>0.05) decrease was detected in high protein (HP) samples. Remarkable protein aggregates were observed in non-reduced SDS-PAGE patterns for LP noodles. The changes in secondary structure were reflected by the increase in α-helix and β-sheet as well as the decrease in β-turns. Furthermore, vacuum mixing conferred a more continuous and compact microstructure to both HP and LP noodle sheets as well as an increased breaking force and extensibility. In addition, less deterioration in noodle structure and water migration was observed by magnetic resonance imaging (MRI) for vacuum mixed samples during storage.