Detection of Synthetic Colours in Selected Foods&Beverages Available in Colombo District, Sri Lanka

Colour is used in foods and beverages to make them more attractive to increase consumer's acceptability. Synthetic food colours are often preferred over natural colours today because they are less expensive, more stable, blend more easily, add no flavor and can be used in tiny amounts because they are more intense. Various food products available in the market may contain harmful non-permitted colors. The consumption of eatables mixed with non-permitted colors, may lead to potential health hazards, such as increased mortality, retardation of growth, , decreased food intake and fertility rate. It also causes damage to organs like kidney, liver, heart, lungs, eyes etc. All these colors also have mutagenic properties and most of them have identified as potential carcinogens. Even, permitted food colors can prove to be toxic if used or consumed indiscriminately. In this study, different types of food stuffs available at Colombo district were analyzed for the detection of the added synthetic colours. A total of 120 samples of different food stuffs including Boondi, Bubble gum, Seeni murukku, Coconut toffee, Burfi, Muscut, Ice packet, Sherbet drink, Jelly, Bottled fruit drinks (each n=12) were collected from small and medium scale vendors and supermarkets in Colombo district from August to September in 2016. The samples were tested using Thin Layer Chromatography (TLC) method and UV-Spectrophotometric method by using synthetic colour standards which are permitted according to the food act regulations of Sri Lanka. The results of this study revealed the frequency of occurrence of permitted colours as well as indiscriminate use of non-permitted colours in some foods and beverages available in Colombo district. A majority of samples (85%) contained only permitted colours. Tartrazine (55.83%) was the frequently used synthetic colour in analyzed food stuffs. Subsequently, 30.83%, 25%, 20.83%, 14.17%, 3.33%, and 3.33% of total samples contained Carmosine, Sunset yellow, Brilliant blue FCF, Ponceau 4R, Erythrosine and Allura red respectively. Indigo carmine and Fast green FCF did not contained any tested samples. Only 9.2% of samples did not contain any synthetic colour. But 5.8% of samples contained a non-permitted colour namely Alizarin. Thus, frequency of occurrences of synthetic food colours is still high and incidence of the use of non-permitted colour in foods and beverages is at unsatisfactory level in Colombo district.