Posts Tagged ‘impact odorants’

Flavor pairing revisited

Tuesday, March 8th, 2011


Foamy strawberries with coriander (cilantro) from TGRWT #3 turned out to be a delicious combination. Could it possibly be a category 2d predicted aroma similarity?

As mentioned in my previous post about the flavor pairing presentation given by Wender Bredie as part of the Copenhagen seminar on molecular gastronomy I’m really happy that the topic has been brought into the scientific community. At the same time is has also become very clear to me that the term flavor pairing needs some clarification. First of all I have come to realize that the the term flavor pairing is slightly misleadning, and I wonder if aroma similarity perhaps is a more precise term. As I see it, today the term flavor pairing is used in a range of different ways: (more…)

TGRWT #18: Plum and blue cheese

Sunday, August 2nd, 2009

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Finally it’s time for a new round of TGRWT. It’s the 18th round and the host this time is Aidan Brooks, a trainee chef who works in Spain. In his blog he’s touched upon flavor pairing several times and also wrote a blog post on the same topic for “Word of mouth”, the food blog of The Guardian. The foods to pair this time are plum and blue cheese, and as usual you can read more about how to participate in the announcement post. The deadline for submissions is September 1st.

TGRWT is not a competition, but Aidan wanted to add a little competitive element to round of the meal. (more…)

French book on flavor pairing of food and wine

Wednesday, July 22nd, 2009

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The Canadian sommerlier François Chartier (he has an extensive website featuring several blogs, including a section named Sommellerie moléculaire) is out with a new book on food and wine pairing. It’s not just another (superfluous) book on the subject. As the title Papilles et molécules (= Tastebuds and Molecules, unfortunately not available in English) suggests there is some science involved. It turns out in fact that he has applied the principles of flavor pairing to food and wine. With help from Richard Béliveau from Agriculture and Agri-Food Canada and Martin Loignon from PerkinElmer he has analyzed wines and food and comes up with the following suggestions for lamb, as described in the article “Chemistry-set wine pairing”:
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The Flemish Primitives: A travel report (part 1)

Friday, January 9th, 2009

I had a wonderful trip to Brugge/Bruges to attend the foodpairing seminar The Flemish Primitives. I got to meet many interesting people including Heston Blumenthal, Peter Barham, Andrew Dornenburg, Karen Page, Ben Roche and Tony Conigliaro to mention a few. I also finally had the opportunity to talk to my fellow Swedish food bloggers Lisa Förare Winbladh (Matälskaren, Swedish only but Google can translate) and Malin Sandström (Matmolekyler, Swedish only but Google can translate) who’ve recently been awarded money to write a Swedish book about molecular gastronomy for home cooks. I even talked to several people who read Khymos! It’s always nice when I can attach some faces to the crowd out there in the big, unpersonal blogosphere.

As you see from this long post the day was packed and believe it or not – there will be a couple more posts in the next few days. One on the surprise “chocolate box” (for me this was the highlight), a summary of the interview with Heston Blumenthal and some info on the chemistry behind the glowing lollipops! I’ll also try do dig up the recipe for the chocolate dip that came with our lunch fries.
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TGRWT #12: Chanterelle and apricot

Tuesday, November 4th, 2008

Tri-2-cook has announced the foods to pair in the twelfth round of “They go really well together” (or TGRWT for short): apricot and chanterelle. More information on how to participate can be found in the announcement post. If the ingredients are out of season where you live, remember that you can use ingredients that are dried, canned or preserved. The heating and/or air exposure can of course alter the flavor composition, but it’s still worth giving it a try.

Regarding the chemistry behind this flavor pairing I’ve found the following. Based on quantitative measurements Greger and Schieberle identified 18 compounds with odor activity values (OAVs) greater than 1 in apricot (Prunus armeniaca). I have not been able to locate any studies of chanterelle (Cantharellus cibarius) with OAV values, but there are a couple of articles which list volatile compounds. Comparing these lists with the OAV data for apricots there is not much overlap. The only compounds which had an OAV > 1 in apricots and were also found in chanterelle are 1-octen-3-one (OAV in apricot = 55) and hexanal (OAV in apricot = 15) shown in the figure below.

It’s interesting to note that OAV studies often come with certain surprises regarding flavor compounds. As Greger and Schieberle point out in their abstract:

certain lactones, often associated with an apricot aroma note, such as gamma-undecalactone, gamma-nonalactone, and delta-decalactone, showed very low OAVs (<5) (...) Omission experiments indicated that previously unknown constituents of apricots, such as (E,Z)-2,6-nonadienal or (Z)-1,5-octadien-3-one, are key contributors to the apricot aroma.

Some compounds that are present at higher concentrations are less important because they have a high odor threshold, whereas other compounds which are present in minute quantities play important roles because we can detect them at very low concentrations. Once again this shows how important it is to use OAV values when looking for flavor pairings!

TGRWT #9: Parmesan and cocoa

Saturday, February 9th, 2008

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It’s time for a new round of food pairing! Robert of lamiacucina is hosting TGRWT #9 and the foods to pair this time are parmesan and cocoa. I’ve previously blogged about this combination and odor activity values (OAV) are available for both parmesan and cocoa. These are the molecules that significantly impact the odor of both parmesan and cocoa:

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Don’t forget to check out Chad’s roundup of TGRWT #8 where several professional chefs participated!

Ten tips for practical molecular gastronomy, part 8

Sunday, February 3rd, 2008

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Read about the physics behind the balancing fork trick.

8. Experiment!

Dare to experiment and try new ingredients and procedures. Do control experiments so you can compare results. When evaluating the outcome, be aware that your own opinions will be biased. Have a friend help you perform a blind comparison, or even better a triangle test to evaluate the outcome of your experiments.

In a scientific context, an experiment is a set of actions and observations performed in the context of solving a particular problem, in order to support or falsify a research hypothesis. In a kitchen context, the problem to solve would typically be related to taste, aroma, texture or color. And the required actions and observations would be cooking and eating.

An essential part of the scientific method is that new knowledge is gained when, based previous knowledge, an assumption is made and tested. In the kitchen, this is exactly what you do when you taste your concoctions repeatedly as you cook. And it is also what makes you an experienced cook, because you remember and learn from your previous successes and mistakes. It might sound very complicated, but here’s how it goes:

1) Observation: soup lacks flavor
2) Hypothesis: adding something with flavor might help
3) Experiment: add more spices
4) New observation: soup tastes more (or less)
5) Hypothesis is either supported (or rejected)

Of these steps, I think observation is the easiest. Coming up with a hypothesis however can sometimes be difficult. If you have lumps in your custard or a sauce that’s separating, it isn’t always easy to think of what to do. This is where books on popular food science and molecular gastronomy might help you.

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Think outside the cook book! I mentioned in previous post that you should always question authorities and cook books. And even when you have a recipe that works, remember that it’s nothing more than a suggestion. For instance, it can be useful to know when to be sloppy and when to be accurate with measurements. The smaller amount you measure, the greater the precision should be. Let’s consider a hypothetical recipe that calls for 1000 g flour and 1 g of saffron. Whether you use 999 or 1001 g of flour makes no difference, but using 1 or 2 g of saffron will be quite noticable. A good rule of thumb is that you should measure to within +/- 10% of the given amount. But again, don’t follow this blindly. Experience will show when you can be even more sloppy.

Thinking of good experiments to do requires both creativity and experience, and there are many sources of inspiration. The molecular gastronomy movement has come up with a number of books and blogs which point towards new ingredients and procedures. There are several approaches to flavor pairing (i.e. a general one based on experience and a chemical one based on impact odorants). Further more there’s a lot of inspiration to get from regional cooking – also for molecular gastronomists! Lastly, I think considering not only the food but the whole atmosphere and the setting of the meal is important, because our senses are connected!

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The best way to judge the outcome of a new procedure or ingredient is to compare it with the original. I’ve previously termed this “parallel cooking”. In scientific contexts it’s very common to do control experiments and I can’t see why this shouldn’t be done in the kitchen routinely. Im convinced that this could have saved us from many kitchen myths!

Once you’ve done your parallel cooking, you have to taste it. If you did the cooking, you’ll probably have an opnion or expectation that the new dish is better or worse than the original. The big problem here is that due to confirmation bias, if you know what you are eating, this will influence your perception of it. Therefore it’s crucial to do a blind tasting (or a double-blind tasting). Have friend help you label each dish with random three digit numbers (to avoid thinking about ranking) and give them to you. If the dishes can easily be recognized due to color, it’s important that the lights are turned down or that you are blindfolded. State which dish you prefer and have your friend reveal the identity of the dishes tasted.

A slightly more sophisticated test is the triangle test which is commonly used in the food industry. The tester is presented with three samples of which two are identical and the task is to pick the odd one out. Using statistics, it’s possible to evaluate the outcome of repeated tests. The number of correct assignments in a number of triangle tests required for you to be 95% sure there is a difference are given in the table below. Read more about simple difference tests here.

Number of tests performed Number of correct assignments required
3 3
4 4
5 4
6 5
7 5
8 6
9 6
10 7

Bionomial distribution for a triangle test (p=1/3) at 0.05 probability level. A more extensive table can be found here.

It seems that this would be the ultimate way to determine whether or not there is a difference between pepsi and coke. It’s more than 50 years since the first experiments were conducted. The theory is simple, but in the real world things aren’t always that simple. Read the entertaining story about Fizzy logic.

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There are several examples of experimental cooking out on the net, and I thought I’d share some of them with you as this might illustrate my ideas on the subject.

Many cooks have strong opinions about how garlic should be treated. Should it be minced, crushed or microplaned? And does this really influence the taste and aroma? Or does it only affect the degree of extraction and hence the intensity of the flavor? Dominic of Skillet Doux had a excellent post on this subject in 2006, Deconstructing garlic. The task was formulated as follows:

The subject of this experiment is the effect that various methods of breaking down garlic have on its flavor when used to prepare a dish. The hypothesis is that not only does mincing garlic create a different flavor than crushing it, but also that mincing is the preferred method for pasta sauces. Furthermore, the experiment is intended to determine if microplaning garlic achieves a character different from mincing or crushing.

In his conclusion, Dominic writes ” I was surprised to discover that the difference between the minced and crushed garlic sauces was even more significant than I had previously thought”. Check out his post to find out which kind of garlic treatment he prefers for his pasta sauces. As a side comment it can be mentioned that a group of researchers in 2007 studied the effect of cooking on garlics ability to inhibit aggregation of blood platelets. They found that crushing could reduce the loss of activity upon heating. But unfortunately they didn’t report anything about the flavor.

Other food bloggers have also adopted experimental cooking with emphasis on systematic and thorough testing. Examples include Chad’s experiments with gellan, konjac and iota/kappa carrageenans, Michael Chu’s parallell cooking of bacon and his eggplant test and Papin’s comparison of orange juices – to mention but a few! And I shouldn’t forget Dylan Stiles either whom I mentioned in part 5 of this series:

A challenge with aroma molecules is that they should remain intact during storage and not be released until cooking (or even better, until consumption). A example would be to install a Liebieg condenser over your pot. Dylan Stiles has explored this in his column Bench Monkey by placing a bag of ice on top of the lid. He claims that his roommates preferred the curry which has been cooked under “reflux conditions”. The study was performed in a double blind manner (which I will come back to in part 8 of this series).

An extreme example of the application of the scientific method to cooking appeared in the news last spring when the recipe for the ultimate bacon buttie was revealed by scientists from Leeds University. Commissioned by Danish Bacon, the study evaluated more than 700 variations of a bacon buttie. They even came up with a “formula” for the perfect bacon buttie and quantified the required crispiness and crunchiness. The news story was picked up by many news agencies, so although it wasn’t necessarily ground breaking science, at least it was clever marketing.

*

Check out my previous blogpost for an overview of the 10 tips for practical molecular gastronomy series. The collection of books (favorite, molecular gastronomy, aroma/taste, reference/technique, food chemistry, presentation/photography) and links (webresources, people/chefs/blogs, institutions, articles, audio/video) at khymos.org might also be of interest.

TGRWT #8: White chocolate soufflé with caviar

Wednesday, January 30th, 2008

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As a late (but just in time for the deadline) response to TGRWT #8 which was announced by Chadzilla in December last year – here is finally my write up on a recipe and a little on the background of this flavor combination which has become a classic in molecular gastronomy.

Heston Blumenthal introduced it around 2002 at The Fat Duck. It’s well worth reading what Heston wrote about this combination back then. He describes how salt can help bring out the flavor of many desserts. At one point he tried caviar and white chocolate – the effect was stunning. He then wanted to find out why this combination was so successful:

I gave some caviar and chocolate to François Benzi, who works for Firmenich, the flavourings and perfumes company based in Geneva. He was so surprised at the way that the caviar and chocolate melded together that he excused himself for half an hour while he tried to discover the reason behind the success of this union.

When he returned, the response was that both the chocolate and caviar contain high levels of amines. These are a group of proteins that have broken down from their amino acid state but not so far as to become ammonia. Amines contribute to the desirable flavours that we find in cooked meats and cheeses, among other things.

Some might object to using caviar but remember that there is no need to turn to sturgeon caviar as this species is endangered. I used caviar from Capelin which costs less than $4/€3 for a box of 50 g. As I have never tasted the “real” stuff I’m not the right person to judge about similarity or difference in aroma. And in case you also wondered about the terminology – roe is the fully ripe egg masses of fish whereas caviar refers to processed, salted roe. I decided to make a soufflé and based the recipe loosely on one of the soufflé recipes in my Larousse Gastronomique.

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White chocolate soufflé with caviar
40 g white chocolate
30 g flour
1 dL milk
35 g caviar
3 eggs, separated
nutmeg

Melt chocolate on very low heat. Add 1/3 of the flour and stir, heating gently. Add a 1/3 of the milk and mix thoroughly. Add another 1/3 of the flour, then more milk and so on. Add finely ground nutmeg. Add 3 egg yolks and heat until right before the mixture sets (yeah – I admit – this is not very precise…). Then add the caviar. Beat egg whites stiff and fold them in. Pour into greased soufflé dish and bake at 220 °C for about 15 min.

Verdict: Aromas blend well together, but when eaten alone it’s perhaps a little bland. But I’m quite sure that it could be succesfully incorporated into a menu together with something acidic. The texture was nice, but the soufflé quickly falls together once it’s removed from the oven (I’ll have to post more on the chemistry of soufflés some other time – Hervé This has written a lot about this).

If you try to make this – note that white chocolate doesn’t behave excately like butter when you add the flour. It all got very thick, very fast – that’s why I started adding milk early. I also guess you have to be really careful when heating the whtie chocolate, but I didn’t do any stress tests here.

white-chocolate-caviar-1.jpg
This is what the mix looks like before I folded in the egg whites.

For my first attempt at this recipe I used 20 g flour and 15 g caviar. The result was that the caviar sedimented before the soufflé had set, besides the fact that one could hardly taste the caviar at all. On my second attempt however, there was enough flour to keep the caviar suspended until the soufflé set. And one could actually also taste the caviar.

white-chocolate-caviar-4.jpg

And now on to the chemistry behind:
I promised that I would come back with more information about the chemistry behind this pairing, but there isn’t very much information out there. There is one paper on aroma development in block-milk which used in the production of white chocolate. This paper lists a couple of volatiles, but only with their relative peak areas. Turning to caviar (or roe), there is a recent paper on flavor characterization of ripened cod roe, and this paper includes qualitative information about odor intensity.

Comparing the list of volatiles, the following volatiles which contribute substantially to the odor of ripened cod roe are also found in block milk (followed by odor thresholds in water, given in ppb, taken from this page):

2-butanone (50000 ppb)
2-methylbutanal (1 ppb)
3-methylbutanal (0.2-2 ppb)
pentanal (na)

Of these, the first has a high odor threshold, so it’s not likely to be an impact odorant in block-milk (and white chocolate). The methylbutanals however probably contribute to the overlapping aroma of roe and white chocolate. I didn’t find any threshold value for pentanal.

One group of compounds which was not mentioned in the paper on cod roe odor from 2004, but which was mentioned in a Russian paper from 1967 are amines (Golovnya: “Gas-chromatographic analysis of amines in volatile substances of salmon caviar”). Considering the fact that trimethylamine has a threshold in the range of 0.37-1.06 ppb, and that trimethylamine is found in block-milk suggests that it might contribute significantly to the odor of both white chocolate and roe. I guess the reason trimethylamine (and the whole range of other, closely related amines) is not found in the odor analysis in the 2004 paper has to do with the analytical method used.

The fact that amines are crucial is further supported by the Guardian article I quoted from in the beginning where Heston Blumenthal describes how he turned to François Benzi, a flavor chemist at Firmenich, to find out why white chocolate and caviar is such a good match. Benzi concludes that it is due to the presence of similar amines in white chocolate and caviar.

Foodpairing website launched

Thursday, November 22nd, 2007

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The long awaited website on foodpairings has now been launched, and they’ve also registred the corresponding blogspot name (which isn’t online yet as of today). The beautiful photos, great design and easy maneuvering makes it an excellent place to start if you are looking for some new and perhaps surprising combinations of foods. The foods are grouped into categories such as cocoa (?), dairy, fruits, meat, sea food and vegetables. One of the vegetables listed is cauliflower, and clicking it reveals that the topic of TGRWT #7 (caramelized cauliflower and cocoa) is one of several possible combinations. This is how it is displayed (an important detail is that the shorter the distance between the names, the more flavours they have in common):

foodpairing-cauliflower.jpg
(click to open the full picture from the foodpairing.be site)

As an added bonus interchangeable herbs and spices are also listed. This is how it works:

A food product has a specific flavour because of a combination of different flavours. Like basil taste like basil because of the combination of linalool, estragol, …. So if I want to reconstruct the basil flavour without using any basil, you have to search for a combination of other food products where one contains linalool (like coriander), one contains estragol (like tarragon),… So I can reconstruct basil by combining coriander, tarragon, cloves, laurel. The way to use it is to take from each branch of the plot one product and make a combination of those food products.

It should be noted that the proximity of the foods in the diagrams is based on the number of volatile compounds they have in common, not the actual key odorants. As I have elaborated on previously, pairings like these should preferably be based on odor activity values (OAV). Or to put it differently, if the volatiles shared by two foods are not the ones that actually contribute to the overall flavor, there is no reason to expect that they go well together from a chemical perspective (which is not to say that they won’t match, only that if they do, it is for some other reason). This is a limitation both of the foodpairing site, but of course also of the food blogging event They Go Really Well Together (or TGRWT) which I have initiated. Having said this, I still believe that the foodpairing site is an excellent place to start, especially if you like to improvise in the kitchen. I sincerely believe that the site will spark the creativity both of professional and amateur cooks (just like TGRWT already has)! I should add that the website is set up by the people behind Food for Design, so no wonder it looks so good!

TGRWT #5: Chocolate and meat

Sunday, August 5th, 2007

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Amrita of Le Petite Boulanger has announced the foods to pair for the fifth round: chocolate and meat! And in case you didn’t notice, Dennis has written an excellent summary of the mustard-mint recipes of round four.

I was not able to figure out which odorants actually formed the basis for the mustard-mint pairing (and perhaps there is none… as I’ve touched upon before, some of the data is hard to come at so it’s difficult to check all the entries of my compiled list). At M’s blog however you can find more info on the cold receptors which are triggered by both mint and mustard.

Fortunately data for chocolate and meat is available: odor activity values for cocoa and flavour dilution values for boiled beef and roasted beef. All flavour compounds were ranked and compounds given the same color coding as before. As you can see, there is considerable overlap between chocolate and meat.

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(click to enlarge)

And here’s what the molecules that are found both in cocoa and beef look like. Notice that this pairing is dominated by furanones and pyrazines. The molecules are ranked according the the odor activity values in cocoa.

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