Food colour – it's more important than you think
By Martin Whitworth - 24 April 2017
Colour is one of the most important sensory aspects of food and drink. As well as indicating its likely freshness and flavour, it can also influence consumer choice and enjoyment of a product.
Since the 1980s, there has been a reduction in the use of artificial colours and a move towards clean label ingredients. With an explosion in the number and variety of products on the market and greater consumer demand for clean label ingredients, it has never been more important for formulators to perfect their product’s colour. This is particularly important for products sold in transparent packaging.
As well as appearance, colour can also influence the perception of flavour. In one study, the addition of red colouring to an otherwise clear solution was shown to reduce the detection threshold for bitterness. In another study, members of a consumer test panel incorrectly identified a cherry flavoured beverage as having a lime flavour after it was coloured green.
Sensitivity of colour
While artificial colours generally have a high tolerance to pH, light, temperature and oxidation, clean label colours are generally less stable. The processing of beverages can have a significant effect on their colour, especially for those that are thermally processed. Red or pink drinks in clear packaging can even be prone to browning due to the effect of natural UV light. If you understand the factors that affect natural colours during thermal processing and throughout the product’s shelf life, you will be able to achieve brighter and more stable colours without the need for artificial colours.
Measuring food colour
A consistent and objective approach to colour measurement is needed to determine whether a product’s colour changes after processing or throughout its shelf life. The chosen technique also needs to be suitable for the colour testing required.
Chromameters and spectrophotometers are widely used for food colour measurement in the food industry, with the latter typically used for transparent liquids such as drinks and colouring agents.
Product images are widely used as a visual reference when determining specifications for appearance, but care is required to ensure reliable colour reproduction. At Campden BRI, we use a DigiEye imaging system for this.
Although lab equipment can be used to measure colour, assessment by trained sensory panels under controlled conditions is still a critical step to identify the products that are most appealing.
How can we help?
Colour is a very important consideration for beverage NPD and as an ongoing quality control benchmark. To find out how we can help you develop, test and monitor your food and beverage colours, please get in touch.
Martin Whitworth is a Principal Scientist in Campden BRI's Primary Production and Processing Department. He has an MA and PhD in physics from Cambridge University, is a member of the Institute of Physics and a Chartered Physicist. Read more...