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

Abstract

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. Practical applications The present work optimized of red popcorn grain drying and provides scientific support for obtaining a dry product with excellent popping properties and high nutritional value.

Impact of processing parameters on physicochemical properties and biological activities of Qingke (highland hull‐less barley) treated by steam explosion

“…According to Pratico (2013) and Pohndorf et al. (2019), popcorn popping relies on the grain pericarp, which acts as a pressure vessel and moisture barrier. Heating changes the water in the endosperm into steam and causes the translucent endosperm to crystallize and melt.…”

“…The UKR also varied from 0.193 to 0.317, and runs 5, 9, and 17 had the lowest UKR (Table 1). High P, high T, and low W caused a more pronounced reduction in UKR and improved the Qingke utilization rate, because higher temperature and longer time made it easier to produce high pressure inside the grains while excessive water content can cause advanced starch gelatinization (Pohndorf et al., 2019).…”

“…Considered one of the most important attributes by consumers, the volume of popcorn particles is mainly measured by ER and UKR (Shimoni, Dirks, & Labuza, 2002). According to Pratico (2013) and Pohndorf et al (2019), popcorn popping relies on the grain pericarp, which acts as a pressure vessel and moisture barrier. Heating changes the water in the endosperm into steam and causes the translucent endosperm to crystallize and melt.…”

Infrared radiation drying of parboiled rice: Influence of temperature and grain bed depth in quality aspects

“…Then, the complementary drying was carried out through a hot air dryer at 30°C and an airspeed set at 0.5 m.s −1 . In all drying, the rice grain surface temperature was registered and grain moisture was controlled by weight difference according to Equation 1, where m f is the weight of the final sample (g), m i weight of the initial sample (g), U i initial moisture (g g −1 ), and U f is the final moisture (g g −1 ) (Pohndorf et al, ). …”

Effects of drying methods and temperatures on protein, pasting, and thermal properties of white floury corn

“…The fixed‐bed drying was carried out in the same dryer used for tempering‐drying. The grains (5 kg) were dried at 70 °C and 90 °C, an airspeed of 0.5 m/s (Pohndorf et al., 2019), and a grain bed depth of 200 mm (Figure 1b). The grain’s temperature was also measured with a digital thermometer (Infrared Thermometer, model Jumper JPD‐FR100).…”