For over a decade consumers have become finely attuned to E-numbers, flavourings, colourings and additives in our food. Food manufacturers have changed the way they do things in pursuit of 'clean label' - a more natural sounding ingredients list. But do we fully understand the new processes involved, the terms used and how safe they really are?

Sheila Dillon talks to Joanna Blythman, in her first broadcast interview about her new book 'Swallow This' in which she investigates some of the processes involved in making products taste and look good and last longer and her concerns about the ingredients and the secrecy that often surrounds them. We hear reports from food development teams about how they find new ways to produce food and ask the regulators if we can be sure they're safe.

Photo by Alan Peebles.