Painting the picture of food colouring agents: near-ubiquitous molecules of everyday life – a review

Background: Colour is a key component to increase product value and consumer acceptance. The substances used to impart colour, the colouring agents, are near-ubiquitous in broad areas of human activity, including the food industry. Scope and approach: In recent years, colouring agents from chemical synthesis have been heavily scrutinized, due to their impacts on human health, the environment and sustainability models. Molecules from natural sources are once again preferred, and with innovation and development in the fields of green chemistry, synthetic biology or metabolic engineering can be enhanced as part of a wider circular bioeconomy. Key findings and conclusions: We summarized the most common synthetic and natural colourants already on the marketplace, and their advantages and/or disadvantages (applications, risks or benefits, status of approval, or production methods) along with novel, innovative substances under development as a roadmap for the future.