Kinetic evaluation and optimization of red popcorn grain drying: Influence of the temperature and air velocity on the expansion properties and beta-carotene content

In order to obtain popcorn grains with excellent popping properties and a high β‐carotene content, the drying kinetics were investigated, and response surface methodology was used to optimize the drying process of red popcorn at temperatures of 40, 70, and 100°C and air velocities of 0.5, 1.5, and 2.5 m/s. The Page equation satisfactorily described the drying kinetics of red popcorn. Both variables (temperature and air velocity) had a significant effect on the popping yield, expansion time, and β‐carotene content. For the expansion time, only the air velocity had a significant effect. Based on an established quality standard, the temperature range of 40 and 50°C and air velocity from 0.5 to 1.2 m/s provided popcorn grains with a popping yield, expansion capacity, and β‐carotene content above 7%, 9 mL/mL, and 7.4 mg/100 g, respectively, and an expansion time below 130 s.