Related Experiment Video
Updated: May 21, 2026
Enhanced Photoluminescence of Curcuma longa Extracts via Chitosan-Mediated Energy Transfer for Textile Authentication Applications
Published on: December 22, 2023
[Rapid determination of Sudan dyes adulterated in natural paprika red by FTIR]
Wei-wei Zhang1, Ling-ling Liu, Yan-wen Wu
1Department of Food Science and Engineering, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China.
Abstract:
How to rapidly determine synthesized pigments or dyes adulterated in natural pigments is a difficult problem for food analysts. Natural paprika red is widely used in foods because of its coloration and pharmaceutical effect, but it is sometimes adulterated with Sudan dyes for its poor stability under light or heat treatment. In the present paper, the macro-fingerprint characteristic of infrared spectroscopy was utilized to identify Sudan dyes adulterated in paprika red. The strong peaks at 1 621, 1 500 and 751 cm(-1) in FTIR spectra and at the fingerprint region of 753, 684 and 496 cm(-1) in the secondary deriative FTIR spectra were remarkable characteristics for Sudan dyes adulterated in paprika red, of which the limit of determination was about 1%.
