The effect of various hydrocolloids on some physical properties of extruded corn grits

Fourteen hydrocolloids including Methocels (A4M, E4M, F4M and K4M), locust bean, guar, agar, arabic, alginate, tragacanth, carrageenan, xanthan, pectin, and gelatin gums were extruded at levels of 0, 0.1, 0.5 and 1.0% with corn grits in a Brabender Model PL-V500 extruder at barrel temperatures of 50, 75, 100, 125 and 150°C with a 1:1 screw operating at 100 rpm. Resulting products were evaluated for density, breaking strength and water absorption. Significant differences were found as influenced by hydrocolloid type/amount and extrusion temperature. In general, hydrocolloid additions significantly increased product density and either increased or decreased breaking strength and water absorption.