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ROHA Guest Post – Types and Applications of Synthetic Food Colours

The colour of the food we are eating has a direct impact on our appetite and influences how good we perceive the food to taste and smell. When we see a dish that is red in colour, our brain automatically registers it as spicy while a bright yellow juice would be immediately thought of as fresh and cooling. Even within red, different shades may mean different things to our brain. For example, Erythrosine colour or watermelon red is used liberally in jams, frostings and icings while Annatto colour is an orange-red colour that is used in butter, cheese, margarines and fruit fillings for a more yellowish colour.  This is why advertisements showing food products seem so appealing and make us salivate even when we are not physically near it and our other senses are not affected by the food. If you have noticed, advertisements always show food to be bright and colourful. They do this with the help of natural or synthetic food colours.


There are a variety of dyes and pigments that are used as food colourants. Food colourants are primarily divided into two – natural food colours and synthetic food colours.

Natural food colours – The colours that are procured from nature through extraction from organic vegetables or flower pigments are known as natural food colours. Natural food colours are more expensive than synthetic colourants.

Synthetic food colours – Colours that are produced inorganically in a laboratory are known as synthetic food colours. These colours can be further classified as Azo dyes like tartrazine, amaranth, allura red AC, triarylmethane dyes like patent blue, brilliant blue and green S and chemically related colours  like quinoline yellow, erythrosine, etc. Synthetic colours are relatively much cheaper to manufacture and are therefore more popular in food units that use large quantities of food colours.


Every country has its own set of regulations about which food colours are allowed to be used in edible substances. However, a universally accepted standard notation is the International Numbering System (INS) for food additives which authorizes food dyes as food additives and names it with a letter prefix – usually ‘E’. The guidelines on safety of these food additives is globally administered by the JECFA, a joint FAO/WHO expert committee. All food colour manufacturers are expected to adhere to the established guidelines during production.


Based on how water soluble they are, synthetic food colours are commonly divided into three types – primary food colours, blended food colours and lake colours.

Primary Colours – Synthetic colours that dissolve easily in water and exhibit their colouring power are known as primary colours. They are used in a wide number of products including soft drinks, jams and jellies, toothpastes, animal feeds, shampoos, washing detergents, and writing inks.

Blended Colours – When two or more colouring agents are blended together to create unique colours or even different shades of a single colour, they are known as blended food colours. Blended food colours are very popular in the dairy and processed food industries.

Lake Colours – Lake pigments are insoluble in water because they contain an oil coating and are created by precipitating soluble dyes with metallic salt. This enables them to be mixed well with oils, sugars and fats and are popular in the animal food industry.