The tasters' stunned faces made me chuckle, but the experiment highlighted the importance of colour to the organoleptic assessment of food and drink. The colour red immediately forced the brain into a subroutine of describing red wine characteristics, like blackcurrant and strawberry, even though the wine was a Pinot Gris white wine from Alsace.
I enjoyed the rest of the programme because, for a change, it showcased positive applications of food additives rather than scaremongering. Other examples included the extraction of cochineal (E120) from insects (very natural) and the use of green dye to colour canned peas, which look almost grey without a dash of E-number.
In my public analyst days, I gave food science talks at primary schools. My favourite was on E-numbers. Most kids thought E stood for evil, so I would flash up E175 and ask "Cheap or expensive?" Most chose cheap, so were amazed to find that E175 was pure gold and used as a cake decoration.
My next question was "E300 unhealthy or healthy?" I'd reveal "Vitamin C" to gasps of wonder, then review the pros and cons of E-numbers, and hoped that I had added something to the curriculum.
Leatherhead's recent report Global market for food colours shows the trend for 'natural' colours continues. But maybe E-numbers aren't so bad they are thoroughly safety-tested. 'Natural' isn't always good (eg salmonella).
The programme I enjoyed was called E numbers an edible adventure, with Stefan Gates. The trilogy also included well-balanced programmes on preservatives and sweeteners. Well done BBC2!
Paul Berryman is chief executive of Leatherhead Food Research.