Abstract:

The adhesiveness of extruded cereals is an important affecting factor of their edible quality, which is greatly affected by processing parameters. The individual and interactive effects of water content, extruding screw rolling speed and three barrel temperature distribution on the adhesiveness of extruded cereals were examined using single factor method and general rotation orthogonal combination design combined with response surface analysis, respectively. Results showed that the optimal parameters were as follows: water content 22.6%, extruding screw rolling speed 32.6 r/min, and three barrel temperature distribution 109.3, 119.3 followed by 129.3 ℃. Under the optimal parameters, the predicted value of adhesiveness of extruded cereals was － 375.278178 g·s, which approximated the experimental value of 378.365 g·s and the value of commercial extruded konjac flour (－346.487 g ·s) and was lower than that of commercial extruded rice (－ 394.678 g·s, a lower value represents better adhesiveness). Organoleptic examination demonstrated that the extruded cereal products obtained approximated commercial extruded rice and was superior to commercial extruded konjac flour in edible quality.

Key words: extruded cereal, adhesiveness, optimization of process parameters