pilot case 3 – Computational protocol for simulating the colour optical properties of natural dyes for food industry

(Key Person: S. Baroni, SISSA, in collaboration with a major multinational food company)

The increasing public sensitivity to the healthiness of the food we consume and the current uncertainty of the legislative framework regulating the food use of artificial colours requires companies (confectionery/food) to develop materials and technological solutions to allow a global change from artificial to non-artificial colours. The figure below shows the global market size for natural dyes together with its trends.

The unfortunate reality of using naturally sourced colourants in food processing is that there are typically severe trade-offs relative to the well-established artificial colourants, including lack of stability, higher cost, presence of odours and flavours and critical limitations in the range of possible colours –in particular the blue colour.

In 2007 a research funded by the UK FSA suggested that a mix of certain artificial food colours and preservative sodium benzoate could be linked to attention deficit and increased hyperactivity in children. Since 2010 EU warns that any food and drink containing any of the six additives reported in the box on the left may have adverse effect on children’s activity and attention.

Therefore, research into the fundamental chemistry of selected natural colourants will bring knowledge to increase stability and hence control colour expression. SISSA and MaX are collaborating with a major multinational food company to identify suitable natural replacements for the artificial colourants that are presently in use in the confectionery that they produce, with particular focus on a specific class of molecules: anthocyanins. The complexity of intra- and inter-molecular interactions, which ultimately defines the molecular shape and electronic state – and thus colour – of an anthocyanin chromophore is poorly understood and not necessarily intuitive, thus requiring advanced research to determine suitable solutions.

As a product of this collaboration, SISSA and MaX are engineering and making publicly available a multi-scale protocol to simulate the colour optical properties of complex anthocyanins in solution. The implementation of this protocol is based on GROMACS and Quantum ESPRESSO for classical and quantum-mechanical simulations, respectively, and on a set of user interfaces designed on purpose.

The current version of the protocol includes: