D2O assisted FTIR spectroscopic analysis of moisture in edible oil

Qin Ye; Xianghe Meng; Linjiang Pang

doi:10.1016/j.fochx.2023.100679

D₂O assisted FTIR spectroscopic analysis of moisture in edible oil

Food Chem X. 2023 Apr 13:18:100679. doi: 10.1016/j.fochx.2023.100679. eCollection 2023 Jun 30.

Authors

Qin Ye¹, Xianghe Meng², Linjiang Pang³

Affiliations

¹ College of Biology and Environmental Engineering, Zhejiang Shuren University, Hangzhou 310015, China.
² College of Food Science and Technology, Zhejiang University of Technology, Deqing 313200, China.
³ College of Food and Health, Zhejiang A&F University, Hangzhou 311300, China.

Abstract

D₂O-assisted moisture analysis of edible oils was investigated. The acetonitrile extract of the oil samples was split into two parts. The spectrum of one part was taken as is, another was recorded after addition of excess D₂O. Changes in spectral absorption of the H-O-H bending band (1600-1660 cm^-1) was used to calculate moisture in oil samples. To effectively depleting absorption of water in the acetonitrile extract, a 30-fold excess of D₂O is required. The typical OH-containing constituents in oil did not show significant interference on the H/D exchange. Validation experiments by using five oils with five levels of moisture spiked (50-1000 μg/g) suggested that the prediction tracked the spiked amounts well. The results of variance analysis indicate that there is no difference in terms of analytical methods and oil types used (p < 0.001). The D₂O method developed is generally applicable to the accurate analysis of moisture at trace levels (<100 μg/g) in edible oils.

Keywords: Acetonitrile extraction; Deuterium oxide; Edible oil; Fourier transform infrared spectroscopy; Water content.