Quantifying food drying rates from NMR/MRI experiments: Development of an online calibration system

Abstract

In this work, an online calibration system with an electric balance is integrated to a novel NMR/MRI system which has continuous and controlled air supply. The water status and distribution of the internal moisture content and total moisture content are measured simultaneously, respectively, by the NMR/MRI and the balance. Fresh and pretreated broccoli stalks and potatoes were employed as the food materials. Data obtained from the integrated balance were compared with the data obtained from NMR and MRI. The results show that the signal intensity is linear against the moisture content (R²>0.90). However, the linearity of the NMR data is much better than that of the MRI data, which is due to the device characteristics. The detection limits of the moisture content were about 11% and 20% for NMR and MRI, respectively. The study demonstrates that LF-NMR/MRI can be used as an online analytical method to quantify the moisture content and drying rates during drying of vegetables.

Keywords:

• Hot air drying
• moisture transport
• NMR/MRI
• data calibration

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

We thank the financial support from National Key R&D Program of China (2017YFD0400905) and Natural Science Foundation of Jiangsu Province (No. BK20150318), and Xiao Dong Chen acknowledges the present startup grant from Soochow University and the grant for Soochow Green Chemical Engineering Laboratory from Suzhou City.