For this round of TGRWT I decided to use the recipe (Chocolate Carbonara with Parmigiano Reggiano Cream and a Chocolate-Dipped Grissini Wrapped in Prosciutto di Parma) by Masaharu Morimoto which I’ve blogged about previously. I was quite intrigued by that recipe and wanted to try it! So here it is, converted to metric units with some small adjustments. The original recipe called for 4 eggs, but this rendered the pasta dough to hard. I added two of the whites which were left over from the sauce. BTW this is why one of should better weigh out eggs instead of count them (too bad I didn’t think about his from the beginning so I could have weighed the eggs I used). The original recipe called for bread sticks with chocolate and prosciutto di Parma which I skipped (but which nonetheless sounds like a good accompaniment – as you’re probably aware of meat and chocolate also go very well together!).

Chocolate tagliatelle
450 g plain flour
4 eggs + 2 whites (adjust according to size of eggs)
55 g cocoa powder
1 T olive oil (leave out? – see comment in text)

Knead. Let rest for 30 minutes or more. Use pasta machine to work through dough until smooth. Roll out to desired thickness and cut into tagliatelle or spaghetti.

To start with the dough was not very elastic, so I immediately regretted that I had added the olive oil (which I optimistically added to the dough, hoping that it would perhaps help bind the crumbles together – only to discover that more eggs were needed anyway). The reason for this is that the olive oil interferes with the formation of gluten because it covers the proteins glutenin and gliadin and prevents them from reacting with each other to form gluten. So next time I would try without the olive oil (or at least wait until after the dough had rested before adding the oil to allow time for the flour to be completely hydrated).

I used a manual pasta machine to knead through the dough and make tagliatelle strips of the dough.

The color is wonderful and handling sheets like this certainly sparks new ideas. How about a chocolate lasagna with a custard cream?

When partly dry, the surface easily cracks.

Parmesan cream
5 dL cream (38% fat)
4 egg yolks
100 g sugar
50 g grated parmesan

Bring cream to boil. Remove from heat. Add sugar and parmesan while stirring. Add egg yolks. Whisk and heat to 80-85 °C. Serve with chocolate tagliatelle.

Verdict: Very nice! Because of the rich cream, it’s a good idea not to serve a large plate of it though. As was the case last time I tried the cocoa/parmesan combo, it was as if something was missing. Probably something acidic like lemon or lime. The cream is quite sweet, so the dish would probably work best for a dessert (but a guest I served it too said he wasn’t quite sure whether it was a starter or a dessert). I think a lemon or lime sorbet/sherbet would be nice with it! Or why not try Morimoto’s breadstick with prosciutto?

Tasting the parmesan cream by it self was quite surprising, because – believe or not – it reminded me of vanilla! In fact I’m quite sure that many would be convinced that it was vanilla cream (with a special little twist added). Certainly the color and the texture look a lot like vanilla, but the flavour also reminded me of vanilla. This was perhaps the most fascinating discovery and I’ll certainly have to explore this further. The weird thing of course is that once I start googling for parmesan and vanilla I find both recipes and menu examples (Sour dough loaf with parmesan, vanilla & truffle butter, Fava Bean Custard with Parmesan/Vanilla Foam & Grilled Belgium Endive). There is nothing new under the sun

Having initiated the TGRWT event I figured I should try to see if there was any OAV data available for coffee, chocolate and garlic. I was lucky to find OAVs for coffee (both arabica and robusta beans) and cocoa. To compare coffee and cocoa I sorted the flavour compounds in a descending order based on the OAV, keeping only the 20 first compounds. I turned out that 7 out of 20 key odorants in coffee and cocoa are shared, corresponding to 28/25% and 39% respectively of the total “odor activity” (= sum of OAV of top 20 odorants). Here’s the whole list:

(I hope the authors stuck to the IUPAC naming conventions as I did not take the time to check if synonyms were present in the compounds lists)

To compare this with a random pairing I search for more OAVs and found data for parmigiano reggiano and mango, so I repeated the excercise. Among the 20 odorants with the highest OAVs respectively for coffee and mango there was no overlap. A neglibile overlap was found between cocoa and mango: one odorant (linalool) was present in both with OAVs corresponding to 0.03% and 0.05% of the “odor activity” respectively. The fact that there is no overlap between coffee or cocoa and mango does not imply that they don’t go well together, only that their key odorants don’t match. Parmigiano reggiano and cocoa however had a lot in common, as seen from the table below. In fact 6 out of 20 key odorants, representing 36% and 89% of the “odor activity” for parmigiano reggiano and cocoa respectively.

The degree of overlap between parmesan and cocoa is in fact better than for coffee and chocolate when judging by the percentages (albeit with one less odorant), so this pairing will certainly be included in a future TGRWT event! A quick google search revealed that chef Masaharu Morimoto has come up with a recipe combining cocoa and parmesan:

Chocolate Carbonara with Parmigiano Reggiano Cream

Chocolate Pasta:
1 pound all-purpose flour
4 eggs
½ cup cocoa powder
1 Tablespoon olive oil

Pasta Sauce:
2 cups cream
4 egg yolks
½ cup sugar
½ cup Parmigiano Reggiano

For the Chocolate Pasta:
Sift flour and cocoa powder together and knead in the eggs and olive oil for 15 minutes. Rest for another fifteen minutes then roll and cut in a pasta machine. Heat up a pot of lightly salted water and boil pasta until al dente.

For the Pasta Sauce:
In a medium sauce pot scald the cream. In a separate bowl, whisk together egg yolks, Parmigiano Reggiano, and sugar. Temper this mixture into the hot cream and bring to a light simmer, whisking constantly to prevent curdling.

Unfortunately I couldn’t find any OAVs for garlic, so I haven’t been able to verify the triple pairing forming the basis for TGRWT #1. The claim was that coffee has dimethyl sulfide in common with garlic, and methyl pyrazine in common with chocolate. The table above confirms that coffee and chocolate have several methyl pyrazines in common, but dimethylsulfide is not among the 20 key odorants in coffee. This puzzles me, but there could of course be other volatile compounds that garlic shares with coffee. There should also be quite a difference between raw garlic (not to mention between whole, crushed and possibly even minced) and roasted garlic. If I overlooked something (or perhaps a paper with OAVs for garlic), please drop me an email about this. The OAVs of garlic could easily be calculated if data on volatile compounds in garlic and threshold concentrations are available.

I did a search on coffee, cocoa and garlic on The Good Scents Company website as described previously and found the following compounds either naturally occuring or used for recreating the aroma of coffee, cocoa and garlic:

So there are obviously similarities similarities between coffee, chocolate and garlic, but the question is whether these compounds are key odorants or not.

It’s only fair enough to add that the concept of odor activity values has it’s limitations. Some are related to matrix effects, because thresholds are not necessarily recorded in a matrix mimicking the food product. Possible synergies between flavour compounds are disregarded (examples are known where sub-threshold concentrations are detected in the presence of other volatile compounds). Also, the underlying assumption that the odor intensity increases linearily is not quite correct. The typical intensity vs. concentration curve is more ‘S’ shaped with an expansive, linear and compressive region as shown below. At low concentrations (expansive region) synergism (also known as hyperadditivity or mutual enhancement) is observed. At high concentrations (compressive region) antagonism (or subadditivity or mutual suppresion) is observed. This means that a high OAV overestimates and a low OAV underestimates the impact of the individual compounds. This also means that the odor activity percentages calculated for the pairings above should be take with a pinch of salt. In between these extremes normal additivities are observed.

Even though OAVs are not phsychophysical measures of the perceived odor intensity, they compare quite well with models that take different aspects of sensing into accout. The validity of the found OAV can also be tested by a recombination of the flavour compounds to see how good it imitates the original product studied. I can recommend the freely downloadable article “Evaluation of the Key Odorants of Foods by Dilution Experiments, Aroma Models and Omission” (DOI: 10.1093/chemse/26.5.533) for those interested in reading more about the science.

Despite the drawbacks and limitations I think OAVs can and will be helpful when studying the flavour pairing hypothesis.

Tips: You can read more about OAVs in books which are (partly) available through Google books.