Kinetics of color development of peanuts during dry roasting using a batch roaster

Abstract

AbstractThe kinetics of color development during peanut roasting were investigated at roasting temperatures from 149 to 204°C which produced Hunter L color values of 25–65. Preliminary and equivalent roasting trials were conducted using a batch roaster simulating the parameters of an industrial continuous belt roaster. Hunter L and b values of the roasted peanuts were fitted well to first‐order models (mean R2 > 0.93). The activation energy calculated from the first‐order model of the L and b values ranged from 1.0 to 1.1 × 108 J/kg mol. High‐temperature roasting decreased the uniformity of color development from seed to seed and throughout of the kernel. A zc value of 37.6°C was calculated using the first‐order model of the L values. The cook values were 11.5–23.6, 24.5–31.6, and 41.5–57.5 min for light, medium, and dark roasting, respectively.