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

Wholegrain sorghum (Sorghum bicolor) is nutritious and gluten-free. Despite its health benefits, the potential for wholegrain sorghum to be incorporated into a large range of food products in Western countries is yet to be realised. In this study, we developed oven-baked sorghum-based tortilla chips to create a healthy sugar-free product 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 well as a corn-wheat control (85:15% w/w). Three parameters for the baking process were varied: dough sheet thickness (0.95 and 1.45 mm), baking temperature (160 and 180 degrees C) and baking time (2 and 4 min). Physicochemical properties 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 decreased moisture content, water activity and degree of puffiness, but increased hardness, fracturability and brownness index. Among those tested, the best conditions for preparing sorghum tortilla chips were dough sheet thickness of 0.95 mm, baking temperature of 160 degrees C and baking time of 4 min. The properties of the white sorghum tortilla chips were closer than the red sorghum tortilla chips to those of the corn-wheat control. The sorghum tortilla chips developed are a healthy gluten-free snack with favourable physiochemical properties. The effects of using dough based on wholegrain flour from red sorghum, white sorghum and corn (control) and varying baking conditions on the physical properties of tortilla chips were investigated. Both the white sorghum chips and red sorghum chips have the potential for a healthy, gluten-free product for the snack market.image