Optimization of roasting conditions of microwave roasted Pistacia terebinthus beans

Abstract

The possibility of using microwave energy as a quick and practical method for roasting of P. terebinthus beans was investigated. P. terebinthus beans were roasted at 360 W, 540 W and 720 W for 5, 11 and 17 min. A three-level two factor (3(2)) full factorial design was used to determine the effect of microwave roasting power and roasting time on physicochemical properties such as color, moisture content, density and breaking force, and sensory attributes of the P. terebinthus beans. L* value, moisture content, density and breaking force of microwave roasted P. terebinthus beans decreased with increasing the roasting power and roasting time. Dark roasted P. terebinthus beans took the highest acceptability scores in acceptability tests by the assessors. The changes in physicochemical properties and sensory attributes during microwave roasting were successfully described by the quadratic models developed and using response surface methodology (RSM). Optimum region of roasting conditions was determined by RSM in which superimposed contour plots yielded the optimal microwave roasting powers and roasting times corresponding to the dark roast. (C) 2017 Elsevier Ltd. All rights reserved.