Modelling the Effects of Processing Factors on the Changes in Colour Parameters of Cooked Meatballs Using Response Surface Methodology

A three-factor Box-Behnken design was adopted for studying the simultaneous effects of processing variables such as fat (10-30%), wheat bran (5-15%) and NaCl (0-2%) on the colour changes (L*, a*, b*, whiteness index, saturation index, hue-angle, total colour difference and browning index) of cooked beef meatballs. In addition, the ridge analysis was conducted to find the values of processing variables that maximize and minimize the colour parameters. Experimental design allowed for evaluation of potential interactive and quadratic effects between these variables. The results showed that the processing variables had a significant effect on the colour parameters. L* and whiteness index values of meatballs were decreased by the wheat bran addition. b* and saturation indexvalues were increased by fat addition. ∆E value was decreased by the wheat bran addition. Increase in the fat content increased the browning index values; however, salt addition showed an inverse effect.