Hyeon Woo Park

Effect of drying and grinding characteristics of colored potato (Solanum tuberosum L.) on tribology of mashed colored potato paste

ABSTRACT The mouthfeel of mashed potato prepared with steamed purple flesh potato (SPFP) was investigated by measuring tribological and rheological characteristics. Mathematical models describing pre-processes such as drying and grinding associated with physical properties of mashed potato were also explored. The effect of drying temperature (60, 70, 80, and 90°C) on quality changes (moisture and anthocyanin content) of SPFP was successfully described (R2 > 0.9583). The sigmoid model was suitably applied to estimate particle sizes of dried SPFP during grinding (R2 > 0.9864). As the particle size of mashed SPFP increased, friction coefficient increased, and storage and loss modulus decreased. Taste, smoothness, and after-feel sensation were increased as particle sizes decreased, while appearance and odor showed no significant differences. To predict the sensory property using tribology and rheology, the specific conditions were successfully determined (R2 > 0.9926).

Effect of Grain Size and Drying Temperature on Drying Characteristics of Soybean (Glycine max) Using Hot Air Drying

ABSTRACT The effects of drying temperature on drying characteristics of soybeans with different grain sizes [6.0 (S), 7.5 (M), and 9.0 mm (L) (±0.2)] with 25.0% (±0.8) initial moisture content were studied. Drying temperatures varied at 25, 35, and 45°C, with a constant air velocity (13.2 m/s). Thin-layer drying models were applied to describe the drying process of soybeans. The Midilli-Kucuk model showed the best fit (R 2 >0.99). Based on the model parameters, drying time to achieve the target moisture content (10%) was successfully estimated. Drying time was strongly dependent on the size of soybeans and the drying temperature. The effective moisture diffusivity (D eff ) was estimated by the diffusion model based on Ficks second law. D eff values increased as grain size and drying temperature increased due to the combined effect of high temperatures and high drying rates, which promote compact tissue. D eff values of S, M, and L estimated were in the range of 0.83×10 -10 to 1.51×10

Drying Characteristics of Soybean (Glycine Max) Using Continuous Drying and Intermittent Drying

Abstract The effects of drying temperature by continuous and intermittent drying on the drying characteristics of soybean were determined in this study. Among the thin-layer drying models, the Midilli–Kucuk model showed the best fit (R2 > 0.99) to describe the drying of soybean. At 300 min of the effective drying time, the moisture content of continuous drying at 35, 40, and 45 ºC were 9.38 (±0.00), 8.69 (±0.17), and 7.70 % (±0.48), respectively; while the moisture content of intermittent drying at 35, 40, and 45 ºC were 8.28 (±0.21), 7.31 (±0.41), and 6.97 % (±0.07), respectively. The image analysis method for detection of the crack in soybean demonstrated that at the target moisture content (7.7 %), cracked grain ratios with intermittent drying at 35, 40, and 45 ºC were reduced by 52.08, 27.59, and 18.24 %, respectively. With the effective drying time, the activation energy for intermittent drying (9.33 kJ/mol) was significantly lower than that value for continuous drying (21.23 kJ/mol).

Prediction of the intermittent drying behavior of soybeans [Glycine max (L.)] using novel multilayered mass transfer simulation with an image analysis

Abstract This study developed a multilayered moisture conservation model (MCM) to reflect the structural differences of soybean. The blue-channel image derived from image analysis revealed two different structure regimes in the soybeans. Computational fluid dynamics simulations were used to simulate the flow fields of the convective dryer and estimate the mass transfer coefficient from the local air velocity (2.04 m/s). The MCM accurately predicted the moisture changes of soybean during continuous and intermittent drying (RMSE <0.214). During an effective drying time of 600 min, increasing the intermittency from 0 to 0.5 decreased the moisture content from 8.04 to 6.57%.