Abstract

IDENTIFICATION AND ESTIMATION OF NON-PERMITTED FOOD COLOURS (METANIL YELLOW AND ANILINE DYES) IN TURMERIC POWDER BY RAPID COLOR TEST AND THIN LAYER CHROMATOGRAPHY

Shruti Singh, Himani Shah, Krishna Shah and *Ritika Shah

ABSTRACT

A study was carried out determine the presence of metanil yellow and aniline dyes, both qualitatively, in nine turmeric samples collected from the western region of Mumbai. For the purpose of this study, both branded as well as non-branded turmeric samples were chosen at random to test for adulteration. The standard (metanil yellow) and turmeric samples were prepared of desired concentrations using isopropyl alcohol as a diluent for thin layer chromatography. Out of the nine turmeric samples, all samples (100%) showed positive results for metanil yellow and for aniline dyes and 89% tested positive by TLC. The present study indicates the presence of metanil yellow and aniline dyes in spices. According to various governmental regulations, the use of metanil yellow and aniline dyes in spices in strictly prohibited because metanil yellow is known for affecting the brain adversely while aniline dyes have been known to cause hyperkinesis in children. In this study, we have presented a simple, convenient, and expeditious method that includes rapid color test and thin layer chromatography to prove the presence of metanil yellow and aniline dyes in spices. The results thus obtained were compared to multiple external standard methods. The aim of this study is to bring about awareness among the people on the subject of food adulteration and the various simple methods to detect the same.

Keywords: Non-permitted food colors, metanil yellow, turmeric powder, color test, thin layer chromatography.