Moisture profiles in cheese drying determined by TD-NMR: Mathematical modeling of mass transfer

• Published in: Journal of food engineering Vol. 104; no. 4; pp. 525 - 531
• Main Authors: Castell-Palou, A., Rosselló, C., Femenia, A., Bon, J., Simal, S.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-06-2011; [New York, NY]: Elsevier Science Pub. Co; Elsevier
• Subjects: Biological and medical sciences; Cheese; Cheese drying; Diffusion model; Diffusivity; Drying; External resistance; Food engineering; Food industries; Fundamental and applied biological sciences. Psychology; General aspects; Magnetization; Mass transfer; Mathematical models; Milk and cheese industries. Ice creams; Moisture; Moisture profiles; Nuclear magnetic resonance; TD-NMR; VAR; Cheese drying; Moisture profiles; External resistance; TD-NMR; Diffusion model; Dairy product; Cheese; NMR spectrometry; Modeling; Profile; Mass transfer; Resistance; Humidity; Models; Diffusion; Drying
• ISSN: 0260-8774; 1873-5770
• DOI: 10.1016/j.jfoodeng.2011.01.010

A time-domain nuclear magnetic resonance (TD-NMR) method is proposed to quick and easily determine moisture profiles during cheese drying. The method consists of a combined relaxation analysis, where the magnetization at a certain time is determined by both the longitudinal and the transverse NMR relaxation processes. The drying experiments were carried out at 16
°C and 0.2–0.5
m/s for 32
days, and allowing only one-direction mass transfer. A diffusion model was formulated taking into account the external resistance to mass transfer. Both effective moisture diffusivity and external mass transfer coefficient were simultaneously identified (3.71
×
10
−11
m
2/s and 2.95
×
10
−8
m/s, respectively). The proposed model allowed a satisfactory simulation of both the drying curve (mean relative error (MRE)
=
0.4% and percentage of explained variance (%var)
=
99.7%) and the moisture profiles (average MRE
=
4.4% and %var
=
94.5%).