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

Abstract

The main objective of this study was to optimize the infrared radiation (IR) drying of parboiled rice on the temperatures of 70, 100, and 130°C and grain bed depth of 5, 10, and 15 mm. The effects of the temperature and grain bed depth on drying kinetics, head rice yield (HRY), milling and color parameters, and cooking properties were evaluated using response surface methodology. The drying temperature and bed depth presented a significant effect on HRY, whiteness, transparency, milling degree, L*, C*, relative crystallinity, cooking time, leached amylose, solubilized protein, and hardness. The longer exposure times to IR resulted in grains with an increase in the intensity of endosperm fissures and lower HRY. There is a tendency that the best condition to dry parboiled rice with IR is at higher temperatures and lower grain bed depth. Practical applications The present study optimized infrared radiation drying of parboiled rice as a function of the drying temperature and grain bed depth. The results provide scientific support on making decision during industrial rice processes. Severe infrared radiation drying conditions can reduce the HRY, increase cooking time, and intensify undesired sensory attributes.

Drying modeling, cooking characteristics, pasting properties, and crystallinity of fortified rice kernels

“…The suitability of the Page model was also reported by Lang et al. (2018) for black rice and Timm, Lang, Ferreira, et al (2020) for parboiled rice. Almeida et al.…”

“…The cooking analysis revealed that the FRK dried at 40°C did not disintegrate and retain the shape during cooking, while FRK dried at 50–70°C could not retain the integrity and disintegrated. The reason was fissures formation inside the FRK due to stresses (compressive and tensile) developed during drying at higher temperature (Behera & Sutar, 2020; Timm, Lang, Ferreira, et al, 2020). Cnossen et al.…”

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

“…The infrared radiation drying was carried out in a grain bed depth of 10 mm, with an infrared radiation (IR) emitter (Moisture Balance, Gibertini, model Crystaltherm, Italy) with a power of 300 W (equivalent to 38.19 kW/m 2 IR intensity), located 150 mm above and perpendicular to the grain bed (Timm, Lang, Ferreira, Pohndorf, & Oliveira, 2020) (Figure 1c). In this method, the temperature of the grains was the same drying temperature during the whole process (70 °C and 90 °C).…”

A moisture content prediction model for deep bed peanut drying using support vector regression

“…The drying models reported in the literature were Page model (Diamante & Munro, 1993; Timm, Lang, Ferreira, Pohndorf, & Oliveira, 2020), modified Page model (Overhults, White, Hamilton, & Ross, 1973), two‐term exponential (Kardile, Nema, Kaur, & Thakre, 2019), Henderson and Pabis model (Thalerngnawachart & Duangmal, 2016), Newton model (Lewis, 1921; Sokhansanj, 1987), the diffusion approach model (Yaldýz & Ertekýn, 2001). Goneli et al (2017) studied these mathematical models with peanut kernels drying in thin layer.…”