Fast, easy, cheap, robust and safe method of analysis of Sudan dyes in chilli pepper powder

Abstract

Illicit use of Sudan dyes, a group of harmful and carcinogenic azo dyes, in the food industry has taken a surge in various parts of the world, especially in Africa. Their use in food as additives pose a dire health risk to consumers and have been banned by various food regulatory bodies worldwide. To help increase surveillance, various methods have been proposed for their analysis in literature. This study also sought to experiment and propose an alternative method for quick, easy, cheap, robust and ecologically safe analysis of Sudan dyes in chilli pepper powder and similar matrices. The optimized method used a 6.0 mL mixture of acetone:acetonitrile (1:5 v/v) solvent in a modified QuEChERs method for extraction of Sudan dyes I-IV. The simultaneous analysis of the dyes were achieved on Shimadzu prominence UFLC 20AD coupled with SPD 20AX UV detector operated at dual wavelength of 500 and 480 nm. A total of twenty four (24) chilli pepper powder samples from eight different vendors on the Ghana market were analysed using the optimized method. Quantitation of analytes were done using the external standard calibration method with determination coefficient, R 2 > 0.9999. The limit of detection (LOD) and limit of quantitation (LOQ) of the method were 0.02–0.04 mg/kg and 0.05–0.13 mg/kg respectively. A good recovery range between 85.3 – 121.2% were obtained for a spike level of 1.0 mg/kg in real samples. ANOVA analysis at 95% CL showed statistically no significant difference (p > 0.05) in the recoveries between samples and also between the individual compounds. The method experimented and proposed in this study is fast, easy, cheap, robust and ecologically safe, presenting an alternative method for routine analysis for increased rate of surveillance against the illicit use of Sudan dyes as food additives.

Feasibility of a chromameter and chemometric techniques to discriminate pure and mixed organic and conventional red pepper powders: A pilot study

“…The majority of the food fraud research have dealt with the addition of a cheaper natural or synthetic ingredient or colorant into food products. Spices are one of the food categories susceptible to fraud mainly with synthetic organic dyes such as Sudan dyes (azo dyes) which are classified as carcinogens (Adjei et al., 2020; Hong et al., 2017). Red pepper, black pepper, saffron, turmeric, and onion powder are among the mostly adulterated spices (Khan et al., 2019).…”

“…Ultrafast LC coupled with ultra‐violet detector (UFLC‐UV) was used by Adjei et al. (2020) to detect Sudan dyes in red chilli pepper powders. In addition, Sannino and Savini (2021) used ultra‐high‐performance LC (UHPLC) to determine synthetic dyes in chilli pepper.…”