Optimization of the roasting temperature and time for preparation of coffee-like maize beverage using the response surface methodology

Abstract

The response surface methodology (RSM) was used to determine the optimal roasting temperature and time for preparing a coffee-like beverage from maize kernels. Maize kernels were roasted at different temperatures (160–240 °C) for different lengths of time (10–50 min) and subsequently extracted with hot water. Yield, levels of free sugar and phenolic compounds, antioxidant activity, and sensory scores for overall preference of the maize beverage were significantly affected by the roasting conditions. Roasting temperature was the most important factor affecting the quality indicators of the maize beverage. Surface and contour plots indicated that the optimal roasting temperature and time were 207 °C and 24 min, respectively.