The effect of the amylose content and milling fractions on the physico-chemical features of co-extruded snacks from corn

The suitability of corn fractions (break meal: 250-500 mu m; flour: < 150 mu m) from hybrids with different amylose contents (conventional: 18%; high-amylose: 42%; waxy: 2%) and their blends, to produce co-extruded snacks was assessed. Corn flour exhibited a higher content in total soluble phenolic acids (+34%) than break meal. The high-amylose hybrid maintained a higher antioxidant capacity and phenolic acid content (+52% for soluble and + 54% for cell-wall bound phenolic acids), even after extrusion, than the conventional one. Because of its gelatinization properties (high pasting and peak temperatures; low maximum viscosity), the high-amylose hybrid produced co-extruded snacks characterized by low section areas and large inner areas. The blends led to snacks whose features (sections and inner areas, porosity and hardness) did not follow a linear trend with the amylose content, suggesting the need for further studies to better understand the starch interactions that take place among the various hybrids.

Automated summary

The study found that high-amylose corn hybrids had better antioxidant capacity and phenolic acid content when used to produce co-extruded snacks, but the characteristics of the blends did not follow a linear trend with amylose content. Further research is needed to better understand the starch interactions among the various hybrids.