Investigation of moisture distribution and drying kinetic in noncentrifugal cane sugar during hot‐air drying using LF‐NMR

Abstract

Drying is an important part of noncentrifugal cane sugar (NCS) processing. The moisture population and migration are key factors that affect the drying rate. This study investigates the drying kinetics and changes in moisture in NCS during hot‐air drying. NCS kinetics were analyzed, and effective diffusivity was calculated. The effective diffusivity increased from 1.65 to 4.51 × 10−10 m2 s−1 along with an increasing temperature. An Arrhenius relation with an activation energy value of 30.15 kJ/mol expressed the effect of temperature on diffusivity. The experimental data were fitted to three empirical kinetic models, with the Page model showing the best simulation. Low‐field nuclear magnetic resonance technology was used to evaluate moisture status and distribution. Two moisture statuses were detected, namely, bound water and semi‐bound water, and the relationship between moisture status and structural properties was used to construct a moisture distribution model during drying. Novelty impact statement This study intends to contribute in modeling of drying kinetic and understanding the behavior of drying rate degradation. The effect of moisture migration on the structural properties of noncentrifugal cane sugar was investigated by low‐field nuclear magnetic resonance technology, which could provide valuable information to improve their drawbacks and recommend it for sugar industry.

Effects of different drying methods on quality and water distribution of Lycium barbarum

“…The transverse relaxation time ( T 2 ) determined by NMR analyzer is widely used to evaluate the mobility of moisture in foods (Wen et al, 2022). Therefore, the content and mobility of moisture in the samples before and after different drying methods can be analyzed with results presented in Figure 2.…”