Simple and rapid determination of free fatty acids in brown rice by FTIR spectroscopy in conjunction with a second-derivative treatment

Takuma Genkawa; Tofael Ahamed; Ryozo Noguchi; Tomohiro Takigawa; Yukihiro Ozaki

doi:10.1016/j.foodchem.2015.02.014

Simple and rapid determination of free fatty acids in brown rice by FTIR spectroscopy in conjunction with a second-derivative treatment

Food Chem. 2016 Jan 15:191:7-11. doi: 10.1016/j.foodchem.2015.02.014. Epub 2015 Feb 10.

Authors

Takuma Genkawa¹, Tofael Ahamed², Ryozo Noguchi², Tomohiro Takigawa², Yukihiro Ozaki³

Affiliations

¹ Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, Japan. Electronic address: genkawa.takuma.fm@u.tsukuba.ac.jp.
² Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, Japan.
³ School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337, Japan.

PMID: 26258695
DOI: 10.1016/j.foodchem.2015.02.014

Abstract

A simple and rapid method for the determination of free fatty acid (FFA) content in brown rice using Fourier transform infrared spectroscopy (FTIR) in conjunction with second-derivative treatment was proposed. Ground brown rice (10g) was soaked in toluene (20mL) for 30min, and the filtrate of the extract was placed in a 1mm CaF2 liquid cell. The transmittance spectrum of the filtrate was recorded using toluene for the background spectrum. The absorption band due to the CO stretching mode of FFAs was detected at 1710cm(-1), and the Savitzky-Golay second-derivative treatment was performed for band separation. A single linear regression model for FFA was developed using the 1710cm(-1) band in the second-derivative spectra of oleic acid in toluene (0.25-2.50gL(-1)), and the model displayed high prediction accuracy with a determination coefficient of 0.998 and a root mean square error of 0.03gL(-1).

Keywords: Brown rice; FTIR spectroscopy; Fat acidity; Free fatty acid; Second-derivative treatment.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Fatty Acids, Nonesterified / analysis*
Oryza / chemistry*
Spectroscopy, Fourier Transform Infrared / methods*

Substances

Fatty Acids, Nonesterified