Effects of corn dough fermentation on the physicochemical, starch microstructural, and rheological properties of <i>Ga kenkey</i> , a fermented corn dumpling

Abstract

Ga kenkey production is time-consuming, and uncontrolled processing factors influence its quality characteristics. This work studied the effects of corn dough fermentation on the physicochemical, starch microstructure, and rheological properties of Ga kenkey to provide more insight into the structural changes while maintaining quality. Corn was steeped for 24 h, milled, and used to make a stiff dough, fermented spontaneously at 28 °C for 24, 48, and 72 h. The fermented dough samples were dried to facilitate transportation for further experimentation. The dried dough was rehydrated to the appropriate moisture content, then used to prepare Ga kenkey. Parameters determined included pH, water activity, falling number, moisture content, pasting properties, texture profile, and microstructure. The pH of the control dough decreased significantly from 6.12 ± 0.01 to 4.32 ± 0.01 after 72 h fermentation. The water activity for all the Ga kenkey samples was above 0.98, with falling numbers greater than 300 s. While stickiness significantly increased with longer fermentation times, no significant change in cohesiveness of Ga kenkey dough. Peak, setback and final viscosities significantly changed with fermentation, but not the pasting temperature (91.10–93.90 °C). Based on the observed textural and pasting characteristics, a fermentation period of 48 h is sufficient to produce acceptable Ga kenkey with high stickiness. The study presents possibility of reducing the fermentation time from 72 h to 48 h, while maintaining product quality. The findings of this study could provide the basis for improving application of fermentation time for commercial-scale Ga kenkey production systems.