Structural and physical modifications of corn biscuits during baking process

Colour, crust browning and specific volume of batter is essential to the manufacture of biscuit of good quality, but these properties are rarely measured directly in fermenting batter due to lack of suitable instrumentation. The aim of this study was to systematically evaluate the changes in quality parameters and physical properties of corn biscuits during baking in real time and different oven temperatures using a computer vision system. Colour, crust browning and specific volume of corn biscuits were determined by an image analysis technique using a computerized vision system. Additional quality parameters evaluated were weight loss and firmness of corn biscuit samples. Baking experiments were performed at 190, 210, 230 and 250 °C under natural convection. Colour results showed that it is possible to distinguish two stages in the variation of lightness during the baking time of corn biscuit samples, independently of oven temperature. As a result of the drying effect, it was observed a weight loss and superficial dry layer formation in corn biscuit. The computer vision system can be useful to measure some quality parameters in food products because, among other advantages, it is easy to use, as well as faster and flexible.