| Resumo: |
As a result of providing health benefits in direct expansion snack to differentiate from most of commercial product which raw materials based on starch components, purple corn was used as based ingredient to obtain functional snack from extrusion process. A study was conducted to investigate the effect of screw speed (300, 350 and 400 rpm), barrel temperature: H6 (130, 140, and 150 ◦c) and feed moisture (14.5, 16.5 and 18.5%) on the physical and functional properties of extrudates in snack production using response surface methodology(RSM) and box-behnken experimental design. The results had shown high correlations coefficients(R 2) of multiple regression equations about the relationship among product responses and process variables and no significant lack-of-fit indicating best-fit model. The optimum conditions were overloid area of responses which should have good characteristics of expansion, bulk density and hardness including with higher content of anthocyanin, total phenolic compounds antioxidant activity and resistant starch. The observed values with physical properties of extrudates at selected optimum conditions were not different from the predicted values of regression equations at 95% level confidence. The results suggest that purple corn can be extruded into an acceptable functional direct expansion snack by optimization process for serving the demands of increasingly health-conscious consumers.
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