A method to determine ingredient functionality in baked tortilla chips

Abstract

An air impingement oven was used to evaluate the structures developed by different ingredients in baked corn chips and baked tortilla chips. Dry masa flour (DMF) was hydrated into masa, sheeted and cut. Masa triangles were baked in an air impingement oven to produce baked corn chips. Masa pieces were baked in a three-tier oven and then in an air impingement oven to produce baked tortilla chips. All chips were additionally dried in a forced air oven to reach the desired moisture content. Normal and waxy rice flours, sorghum flour, waxy sorghum flour, and waxy corn starch were evaluated. The starch and flours were gelatinized and tested. Chip texture was measured with a texture analyzer rupture test and a breakage susceptibility test. Selected baked corn chips were viewed through an environmental scanning electron microscope. A sensory panel for baked corn chips was conducted. Chips prepared with different ingredients through the two baking processes developed substantially different textures and structures. Gelatinization promoted puffing during baking through the development of a tight gel matrix that hindered the escape of steam by covering surface pores. Waxy ingredients helped develop a porous structure with numerous small air cells, probably due to their higher swelling capacity and to the slow reassociation of amylopectin chains. The extent of gelatinization prior to baking and the amylose/amylopectin ratio in each formulation significantly contributed to the structure and texture developed during and after baking. The air impingement baking procedure proved to be useful to evaluate the functionality of various additives that produced baked chips with significantly different structures and textures. This process is probably not directly scaleable for large production but it is a promising technique that points out what changes might be expected when different ingredients are added to masa in an effort to improve baked chip texture.