Baked sorghum tortilla chips: effects of baking conditions on physicochemical properties

Abstract

Wholegrain sorghum (Sorghum bicolor) is nutritious and gluten-free. Despite its health benefits, the potentialfor wholegrain sorghum to be incorporated into a large range of food products in Western countries is yet tobe realised. In this study, we developed oven-baked sorghum-based tortilla chips to create a healthy sugar-freeproduct for the snack market. Tortilla chips were made separately with flour from white sorghum (cv. Liberty)and a red sorghum (cv. Taurus), each mixed with corn flour (85:15% w/w) to give a gluten-free product, as wellas a corn-wheat control (85:15% w/w). Three parameters for the baking process were varied: dough sheetthickness (0.95 and 1.45 mm), baking temperature (160 and 180 °C) and baking time (2 and 4 min). Physicochemicalproperties of the tortilla chips were then determined: moisture content, water activity, degree of puffiness,colour and texture parameters. Dough sheet thickness had significant effects on tortilla chip quality,although baking time and temperature had the greatest effects. Increasing temperature and time decreasedmoisture content, water activity and degree of puffiness, but increased hardness, fracturability and brownnessindex. Among those tested, the best conditions for preparing sorghum tortilla chips were dough sheet thicknessof 0.95 mm, baking temperature of 160 °C and baking time of 4 min. The properties of the white sorghum tortillachips were closer than the red sorghum tortilla chips to those of the corn-wheat control. The sorghum tortillachips developed are a healthy gluten-free snack with favourable physiochemical properties.