Evaluation of quality characteristics and engineering of infrared-roasted sunflower seeds kernels by RSM

Roasting is an important step in nuts processing and one of the ways to improve the color, flavor and unique aroma and taste, which can, in addition to positive changes, reduce the amount of nutrients in the nuts. So, It is very important to select the appropriate conditions for roasting. In this study, the effect of infrared (IR) power (400-600 W) and roasting time (4-10 min) on energy consumption, color parameters (L*, a*, b* value, ΔE, BI, SI, WI, hº), texture, moisture content and sensory properties of sunflower kernel were investigated. In addition, the regression models for the responses were obtained and the proper roasting conditions were determined using response surface methodology (RSM). Quadratic model was proposed for color change (L*، a* ،ΔE، hº، WI) and linear relation for texture, BI and moisture content and 2FI for energy consumption. Roasting at 492.5 W IR power for 9.1 min were found to be convenient or proper roasting conditions. Also, roasted kernels had acceptable quality in terms of sensory properties compared to the conventional method (hot air).