Influence of coating-blanching in starch solutions, on the drying kinetics, transport properties, quality parameters, and microstructure of celery root chips

Abstract

The possibility of using different types of starches as the drying aid materials before hot air drying (HAD) (110 degrees C, 1.5 m/s) of celery root chips to improve drying kinetics and the quality of products were investigated. The influence of coating-blanching pre-treatment of the samples in the native and modified corn, tapioca, and wheat starch solutions (0.1%, 0.3%, 0.5% (w/w)) on the drying kinetics, transport properties, microstructure, color, and texture of the samples was studied. The effective diffusion coefficients varied from 0.735 x 10(-9) m(2)/s to 2.396 x 10(-9) m(2)/s. The drag force, heat, and mass transfer coefficients were determined as 8.327 x 10-6 N, 41.21 W/m(2)K, and 0.0341 m/s, respectively. In terms of mathematical modeling, the Midilli & Kucuk model was the best for describing the drying behavior of the samples. The fracturability of all samples increased after coating-blanching and the highest L* value and the maximum compact microstructure were observed in the native and modified corn starch samples. Coating-blanching in the native and modified corn starch solutions was a promising alternative technique to reduce drying time and improve drying kinetics, texture, and color of celery root chips.