Effect of Flaxseed Oil Inclusion and Extrusion Cooking Parameters on Extruded Snack-food Physical and Functional Properties

Aims: Attempts were made to study flaxseed oil incorporated extruded snack by adopting response surface methodology (RSM) approach.

Study Design: Central Composite Rotatable Design (CCRD).

Place and Duration of Study: Department of Food Processing Technology, A.D. Patel Institute of Technology, Po Box 52, New Vallabh Vidya Nagar, Anand.

Methodology: Feed moisture (12 -16%, wb), flaxseed oil (3-7%), extruder barrel temperature (115-145⁰C and screw speed (345 – 375 rpm) were selected as independent variable at three levels. The Central Composite Rotatable Design (CCRD) was employed to study linear, interactive and quadratic effect of selected independent variables on measured responses (expansion ratio ER, breaking strength BS, overall acceptability score OAA, starch-lipid complexing index CI).

Results: The physical properties of extrudate (ER at 0.05 and BS at 0.10 level) and functional properties (OAA at 0.05 and CI at 0.01 level) were significantly influenced by flaxseed oil inclusion level. The quadratic effect of feed moisture and barrel temperature were found to be significant on each response (p<0.01). After numerical optimization, flaxseed oil of 6%, feed moisture content of 14.5% (wb), barrel temperature of 1300C and screw speed of 355 rpm were optimized.