318 Effect of different ingredients on extrusion behavior of corn grit.

P. K. Bath and N. SINGH. Department of Food Science and Technology, Guru Nanak Dev University, Amritsar-143005, India.

Regression to fit a response surface analysis was used to study the effect of honey, sodium bicarbonate, monoglycerides, rice grit and extrusion temperature on extrusion behavior of corn grit using Brabender single screw extruder. A central composite design was used to determine the effects of independent variables on extruder parameters such as die pressure, specific energy consumption and extrudate properties such as expansion, water absorption and solubility indices. Hydroxymethyl furfural (HMF) content of extrudates was also determined. The extrudates were cooked in milk and evaluated for sensory attributes such as appearance, taste, consistency, flavour and overall acceptability. Viscosity of the same was measured by Brookfield viscometer. Specific energy consumption and die pressure of extruder as well as expansion and water solubility of extrudates decreased with the increase in extrusion temperature. However, a reverse effect of extrusion temperature was observed on water absorption. HMF formation increased with the increase in extrusion temperature and sodium bicarbonate levels. Viscosity of extrudates decreased with the increase in levels of honey and monoglycerides and increased with the increase in extrusion temperature. Sensory evaluation of extrudates, extruded at 175C with 15 percent honey, cooked in milk showed highest overall acceptability scores. All the computed quadratic models were significant at <0.013 and had R(^2) value in the range of 90.8–96.6 percent. The models computed can be used as tool to predict the effect of different ingredients on extrusion behaviour and product characteristics of corn grit.