Inedible Azo Dyes and Their Analytical Methods in Foodstuffs and Beverages

Abstract

Edible colorants, as an important part of food additives, can not only enhance the sensorial attributes of foodstuffs, but can also increase one's appetite. They hold a very important position in food processing. In the past decades, the illegal addition of the inedible colorants has become one of the major issues of food safety. Industrial dyes, especially some azo dyes, are illegal additives frequently found in foodstuffs. They cannot provide any nutrients for the human body and even have toxicity, carcinogenic, or mutagenic effects, which may cause serious damage to consumers' health. There is an increasing demand to detect the inedible azo dyes in foodstuffs for health and safety reasons. In this review, the types and the physicochemical properties of the inedible azo dyes adulterated in foodstuffs and beverages are summarized, and the emphases are focused on the sample pretreatment methods and analytical techniques for monitoring of these dyes in foodstuffs and beverages.

A Fast and Simple Method for the Determination of 12 Synthetic Dyes in Spicy Foods by UHPLC-HRMS

“…34 Butter yellow was added illegally at the level of 0.65−174 mg/kg to spices such as curry powder, chili powder, barbeque kebab powder, and a spice mixture imported from India, Ghana, and China. 35 Para red was found at concentrations of 97 μg/kg to 416 mg/kg in herbs and spices imported from the Russian Federation. 36 The present analytical method also could be useful for determining the small amounts of illegal dyes (parts per billion) found, for example, in eggs.…”

“…For Sudan IV, levels of 230 mg/kg in chili powder and 380 mg/kg in paprika spice were found. , Rhodamine B was found at a concentration of 7 mg/kg in herbs and spices and 17 μg/kg in sauces and condiments . Butter yellow was added illegally at the level of 0.65–174 mg/kg to spices such as curry powder, chili powder, barbeque kebab powder, and a spice mixture imported from India, Ghana, and China . Para red was found at concentrations of 97 μg/kg to 416 mg/kg in herbs and spices imported from the Russian Federation .…”

The Use of Chemical Bleaching and Thin-layer Chromatographic Methods for the Detection and Identification of Sudan-III Dye in Adulterated Palm Oil

“…Azo dyes are industrial colourants which comprises; lipophilic, acidic and basic azo dyes [12]. The above-mentioned azo dyes are commonly used as colourants in the chemical industries including oils, waxes, petrol, textile, leather, printing floor polishing, spirit varnishing, etc.…”

“…The lipophilic azo dyes include mainly the following; Sudan 1 -IV, Sudan red B, Sudan red 7B, Sudan red G, Sudan orange G, methyl yellow, and para red. Sudan dyes have intense red-orange coluor, wide availability, low cost, and chemical stability [12,13,15]. Their use in foodstuffs and beverages, at any level, is forbidden by the European Community and many other countries and organizations [16].…”

UV Spectrophotometric Quantification of Sudan-IV Dye in Palm Oil from Major Markets of Benin Metropolis

“…Sudan-III and Sudan-IV dyes are lipophilic azo dyes that have been found to have carcinogenic and genotoxic effects and as such are not permitted to be used in food [7,11]. These dyes pose serious health risks and diseases including cancer, kidney and liver problems [7,11] as they are likely metabolised in the human body through certain biochemical mechanisms [11].…”