Rapid screening for anthocyanins in cane sugars using ESR spectroscopy

Kheamrutai Thamaphat; Bernard A Goodman; Pichet Limsuwan; Siwaporn Meejoo Smith

doi:10.1016/j.foodchem.2014.08.126

Rapid screening for anthocyanins in cane sugars using ESR spectroscopy

Food Chem. 2015 Mar 15:171:123-7. doi: 10.1016/j.foodchem.2014.08.126. Epub 2014 Sep 10.

Authors

Kheamrutai Thamaphat¹, Bernard A Goodman², Pichet Limsuwan³, Siwaporn Meejoo Smith⁴

Affiliations

¹ Green Synthesis and Application Laboratory, Department of Physics, Faculty of Science, King Mongkut's University of Technology Thonburi, Bangkok 10140, Thailand. Electronic address: s903607@yahoo.com.
² Health and Environment Department, Unit of Environmental Resources & Technologies, Austrian Institute of Technology, A-2444 Seibersdorf, Austria.
³ Green Synthesis and Application Laboratory, Department of Physics, Faculty of Science, King Mongkut's University of Technology Thonburi, Bangkok 10140, Thailand.
⁴ Center of Excellence for Innovation in Chemistry and Department of Chemistry, Faculty of Science, Mahidol University, Rajathevi, Bangkok 10400, Thailand.

PMID: 25308651
DOI: 10.1016/j.foodchem.2014.08.126

Abstract

Anthocyanin, which is soluble in water and released into sugar steam during extraction, was investigated in this study. The anthocyanin content in refined sugar, plantation white sugar, soft brown sugar and raw sugar was determined using electron spin resonance (ESR) spectroscopy, which was operated at room temperature, and compared with spectra from standard anthocyanin. The ESR spectra of red and violet anthocyanins was predominantly g ≈ 2.0055, which corresponded to an unpaired electron located in the pyrylium ring. Signals for Fe(III) and Mn(II), which naturally occur in plants, were found in raw sugar, soft brown sugar and standard anthocyanin but were absent from refined sugar and plantation white sugar due to the refining process. In addition, the ESR results were correlated with the apparent colour of the sugar, which was determined using the method of the International Commission for Uniform Methods of Sugar Analysis and inductively coupled plasma optical emission spectroscopy.

Keywords: Anthocyanins; Cane sugar; Electron spin resonance; Sugar colour.

Publication types

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

MeSH terms

Anthocyanins / chemistry*
Carbohydrates / chemistry*
Color
Electron Spin Resonance Spectroscopy*
Ferric Compounds / chemistry
Food Analysis / methods*
Iron / chemistry
Manganese / chemistry
Saccharum / chemistry
Water

Substances

Anthocyanins
Carbohydrates
Ferric Compounds
Water
Manganese
Iron