Copenhagen MG seminar: Flavor pairing (part 2)

Wender Bredie presented results from experiments designed to test the flavor pairing hypothesis

A topic that I was particularily excited to hear about at the molecular gastronomy seminar in Copenhagen was flavor pairing. Since Heston Blumenthal presented his white chocolate and caviar combination based on amines in 2002 and Francois Benzi of Firmenich the pork liver-jasmine combination based on indole the idea has been further elaborated by Bernard Lahousse and Lieven De Couvreur who launched the foodpairing website and by me in the TGRWT food blogging event. Despite the interest and fascination it is fair to say the flavor pairing is still controversial – see for instance the discussion with in particular Jorge Ruiz. What is clearly lacking in the field is a more stringent scientific approach (as well as someone with time, interest, a sensory panel and the money to finance the activities…). It was therefore great to hear that sensory science professor Wender Bredie together with PhD student Ditte Hartvig actually set out to test the flavor pairing hypothesis formulated as: if major volatiles are shared between two foods it may very well be that they go well together. To achieve this they used a sensory panel to assess the odor of food pairs mixed and unmixed. Bredie proposed that a hyper addition of odor intensities would perhaps be the holy grail of flavor pairing – that is if the intensity of the mixed odors would be more than the sum of the unmixed intensities. Or even better: if there would be a hyper additive effect on pleasantness. 

A finding in their initial study with 8 pure volatiles smelled alone and in pairs was that the total odor intensity only increased when combining up to 2-3 components. This is in accordance with Fechner’s law which states that it takes a larger difference in physical stimuli to give the same rise difference in perceived intensity. The pleasentness of the individual components decreased when mixed. In a further study they prepared 53 binary mixtures from 19 food odors. The recorded responses were: intensity, pleasantness, complexity, “harmonic” and novelty. They found no real hyper additive effects for intensity – in 91% of the cases the mixture was perceived to be more intense than one compound perceived alone, but less intense than the other (= compromise region of hypo-addition). But turning to pleasantness there were a couple of interesting findings which were presented as the good, the bad and the ugly combinations, based on the pleasantness score from the sensory panel:

The good
lemon peel + butter
cinnamon + apple
ginger + apple
cinnamon + peanut butter
malt + peanut butter
cacao + malt
lemon peel + strawberry

The bad
ginger + blue cheese
caviar + apple
basil + caviar
vanilla + blue cheese
anis seed + basil
basil + green tea
anis seed + caviar

The ugly
cinnamon + blue cheese
anis seed + garlic
cacao + garlic
cinnamon + garlic
malt + blue cheese
caviar + blue cheese
malt + caviar

To test the flavor pairing hypothesis they then took the pairings and analyzed the overlap of volatiles using data from the VCF database. They found absolutely no correlation between the hedonic score of the food pairings and the overlap of volatile flavors! But knowing that many (if not most) of the volatiles compounds found in foods do not contribute to the aroma this is not very surprising. A further interesting test was to evaluate pleasantness as a function of complexity, but the conclusion in short was that one cannot use complexity to predict hedonic response.

Wender concluded that flavor pairing should be the subject of further and more elaborate studies, for instance at lower concentrations (in the so-called hyper additive region where the intensity increases exponentially with increasing concentration). Another approach could be to study sensory (dis)similarity rather than chemical similarity. One could also explore the arousal potential in pairs of dissimilar but liked flavours. He also suggested that one should keep on searching for additive hedonic responses. And he finished his presentation with the following quote:

“Flavour pairing is like painting in the dark… you do not really know what you are creating, but at daylight you may discover that you have moved art beyond imagination”.

I’m really happy that the topic has been brought into the scientific community – and I’m very much looking forward to see the results published. At the same time is has also become very clear to me that the term flavor pairing needs some clarification. I’ll discuss that in a separate post.