Monthly Archives: October 2010

The bitter truth – now in genotype form!


Isn’t this a fantastic scenario: you’re sitting at your desk and a mysterious white powder floats through the air and lands on your face. Some of it lands on your lips and, being the risk-taking individual that you are who is apparently not averse to putting unidentified powders in your mouth, you taste it and immediately complain to your colleagues about how disgustingly bitter it is. The powder has landed on their faces too and they taste it too and… no, it doesn’t taste of anything, actually. It’s not bitter in the least, they say to you with suspicious eyes and 50% of their eyebrows raised. Well then, aren’t you quite the weirdo? Please take your imaginary bitter taste and go sit in the corner.

This is how they discovered that people can experience tastes quite differently from each other. It was only 1930 when A.L. Fox accidentally released some phenylthiocarbamide into the air in his lab while trying to create an artificial sweetener and it landed on the faces of his colleagues (good work!), and while some of them complained of its bitterness (you’d think that would be the least of their problems if they’re working in a lab where chemicals routinely drift onto their faces and into their lungs), Fox himself couldn’t taste the bitterness. It turned out that about 30% of people find phenylthiocarbamide tasteless, whereas the rest find it moderately to intensely bitter.

It’s not exactly uncommon knowledge now that the ability to taste bitterness varies from person to person and that this is down to genetics. A whole heap of studies over the years have looked at how genetic variants within the TAS2R family of genes mean that some people taste bitterness of particular substances more easily than others. For TAS2R38, the gene that codes for the protein that allows phenylthiocarbamide to be tasted, you can have one of three possible combinations of variants, allowing you to be either a non-taster, a medium taster, or… a supertaster, in which case you can taste that phenylthiocarbamide better than about 75% of the population! Well done, you.

So, like I was saying, we know bitterness perception varies from person to person due to genetics, but it’s kind of boring if you just look at that within the scope of “Oh, Person X can taste this very specific chemical really easily whereas Person Y can’t taste it at all”. Pretty limited relevance. The interesting part is how it affects behaviour — how well you can taste bitterness can affect how much you like particular foods, and that can have a reasonably big impact on eating behaviours.

Studies have been a bit inconclusive when it comes to bitterness gene variants and liking for somewhat bitter vegetables (such as broccoli, spinach, Brussels sprouts, kale and cucumber), with high-tasters of bitterness sometimes liking these vegetables more than low-tasters, and sometimes less. However, sensitivity to bitterness changes with age, so maybe you need to look at these things in particular age groups to get a clearer picture. Certainly, some studies have found that in children, non-tasters who aren’t so sensitive to bitterness find these vegetables more pleasant to eat than the tasters who are sensitive to bitterness, and non-tasters generally eat more vegetables than tasters. Some studies have found the same in adults.

Consumption of bitter fruits can also be affected by genes, with female adult supertasters finding a drink containing naringin (a compound from grapefruit peel) less pleasant, and the same went for just plain grapefruit juice. It looks like the intensity of the bitterness matters too, since taster children were no different from non-taster children when drinking a mixture of 25% grapefruit juice and 75% orange juice, but then the tasters disliked a more bitter mixture of 50% grapefruit juice and 50% orange juice compared to non-tasters.

So it all sort of makes sense — people who are more sensitive to bitterness kind of dislike things that are a bit bitter. However, the intrigue continues with research that has found that genetic variants for bitterness are also associated with different perception of sweetness and saltiness and sourness, the detection of the pungency or flavour of food, and also the ability to discriminate fat content in food and drinks.

But I will go into detail for those in future posts, and for now, you can make some Pimm’s Cup cupcakes. Complete with whipped lemonade and simulated cucumber! It’s a bitter orange and cucumber gel, cut into sticks, to which I attached real cucumber skin. Don’t you want to do something so convoluted and arduous too?

Read on for the recipe for Pimm’s Cup cupcakes.

The art and not-really-science of pretty plating


So I finally decided to give making an amuse bouche a go, spurred on mainly by the singularly amazing amuse bouche spoons Jenn posted at My Boyfriend Cooks For Me. “How precious,” I thought. “I must put tiny amounts of tiny things on tiny spoons.” So I did, and the things were: blueberry foam (because I’ve been wanting to try making a foam for ages), baked flour nuggets (because I could kind of imagine what baked flour tasted like but I wanted to try it for real to confirm) and poor man’s sous-vide blueberries (where you use a sandwich bag, your lungs and a bowl of water over a saucepan of boiling water because you don’t have the $3000 of essential professional sous-vide equipment).

Then I arranged it all as prettily as possible on the spoon.

Then science told me I did it wrong.

That arrangement — all wrong. Shameful. Offensive.

Well, I don’t know if I’d say science told me, per se. This type of thing is a bit on the way to earning the inverted commas of “science”, but at the moment it’s more like you call it science but you narrow your eyes when you say it and look sideways in a shifty manner. Like, yeah… sciencesure

This study looked at the effect of balance and complexity of food arrangement on a plate upon the perceived attractiveness of that food, the willingness of people to try the food, and the ultimate liking of the food. Balance was investigated by making the food arrangement either (durr) balanced or unbalanced, whereas complexity was investigated by using either a monochromatic or coloured palette for the bits of food.

Now I have to say upfront that I have a number of issues with this study. The food presentation would baffle most people except perhaps the hardiest degustation-menu-ordering molecular-gastronomy-lovers. Seriously, it’s slices of water chestnut along with smears of tahini, and the tahini is either normal coloured or artificially coloured to be red and green. How something so stylised and so blatantly unappetising can be used to generalise results to, say, how to plate a confit salmon fillet and wilted greens or how to arrange berries as suitably as possible on a tart… I don’t know. But I’ll work with what I’ve got. I’ll try.

From the ratings given by the 68 undergraduate New Jersey university students, we find that balance and colour do affect the attractiveness of the food (at least to undergraduate New Jersey university students). And because the photos in the paper are copyrighted by the publisher, you have the honour of seeing my beautiful diagrammatic illustrations instead. Keep in mind: the little circles are water chestnut slices, the dot and the stripes are smears of tahini.

So, using colour in a balanced food arrangement…

… vastly improves attractiveness ratings compared to monochromatic balanced food arrangements…

Strangely enough, however, incorporating colour into an unbalanced food arrangement…

… makes it less attractive than a monochromatic unbalanced food arrangement…

Now the authors say that the explanation for these findings is that colour adds complexity in the balanced arrangement and is therefore visually pleasing, but the colour carries with it weight (it is perceived as being visually “heavier” than a lack of colour). So adding colour to the unbalanced arrangement causes the addition of weight towards the right-hand side of the plate, therefore causing even less balance, and the plating is perceived as less attractive. That’s certainly an interesting interpretation… given that there was actually no significant difference reported between the attractiveness ratings colour-unbalanced and monochromatic-unbalanced arrangements. Colour significantly increased the attractiveness of the balanced arrangement (from 16.8 on a rating scale of -100 to 100 for the monochromatic-balanced to 48.7 for the colour-balanced), but the colour-unbalanced and monochromatic-unbalanced just weren’t that different (12.4 and 19.4 respectively).

But we have to keep in mind that this is just ratings of attractiveness, as if the food was simply an artwork to be evaluated. What would be more interesting is the effect of balance and colour on the willingness of people to try the food. And it turns out… monochromatic is better. People were significantly more willing to try the monochromatically presented food:

 

Delicious!

But then I don’t buy that either. Sure, monochrome colours might make people feel like they’re taking less of a risk than bright colours (the authors explain that the plain brownish colours of the monochromatic arrangement might be more normal and familiar to people). However… maybe if you want to know if people are willing to try something colourful or not, you shouldn’t manipulate colour by adding it to something that’s not usually that colour. It has the texture of tahini, it has the smell of tahini… but it’s bright red. What the hell is it? Whereas if it was a bright red tomato purée… not so weird, huh?

In the end, we find out that the final outcome being assessed, liking for the food, is not affected by balance or colour — hurrah! So the effects of balance and colour on liking were non-significant, although I do wonder if increasing the number of participants would detect a difference, because there seems to be a trend there: monochromatic arrangements were enjoyed more than coloured arrangements, e.g. a rating of -1.7 for colour-balanced versus 13.3 for mono-balanced, and 2.2 for colour-unbalanced versus 13.6 for mono-unbalanced. (Granted, the standard deviations for the ratings are massive, i.e. the ratings were all over the place, so it’s difficult to know if it is an actual trend or not without the original data plus more data.)

So there you go. Maybe opt for a balanced food presentation, and maybe make it coloured. Or don’t. Or recreate a Piet Mondrian artwork with your food and see how that goes with your dinner guests. Who knows? Science doesn’t. Yet.

ETA: Check out the compositions from the Ikea cookbook — adhering to the science or defying it??

(Now I feel dirty for having written about such an underwhelming and inconsequential bit of research. It’s a little bit nifty, but… I promise arrestingly interesting genetics in relation to food in the next post. How do your genes influence your response to food? Ah, you wish you knew! But I’d need a shower first.)

Read on for the recipe for deconstructed blueberry pie.

Conference consommé

Banana consommé. Pure, clear, unadulterated, liquid essence of banana. (Actually, it’s technically a consommé of roasted, caramelised bananas.) This precious liquid was obtained using a gelatin filtration method, which allows the liquid containing the soluble flavour compounds to be removed while the flesh of the banana remains trapped behind due to the network that the gelatin forms in the mixture.

I bet you never knew how much you needed banana consommé in your life until now! It must have a million purposes! Mix it with… other liquids! Make it into… ice cubes? I don’t know…

But there’s a beautiful story behind this banana consommé’s existence.

When some other lab members and I went to a conference on the frontal lobes of the brain in Toronto in March this year, we were all horrifically jet-lagged. I spent the week experiencing almost constant nausea. We were falling asleep during so many of the talks. Our resident psychiatrist was have lucid dreams in which he saw the current speaker giving harsh scores to children for their figure-skating routines. However, in our semi-conscious state, there was one thing that several of us took away from the conference: banana juice, and the importance thereof. Turns out that macaques (the primates often used in neuroscience experiments) absolutely love banana juice. One of the speakers was saying that macaques love banana juice above all else: apple juice, sultanas, grape juice, whatever, don’t bother, it’s all about the banana juice.

If you want to train a macaque to do a task, use banana juice as a reward. If you want to study the reward circuitry of the brain in macaques, use banana juice (or cocaine… or juice and cocaine, as this study did). If you want to see macaque neurons fire in response to a cue on a computer screen, make sure that cue is usually followed by a drink of banana juice, and then you’ll see particular neurons fire in anticipation of the banana juice.

But what is banana juice? Is it just puréed banana? Because that, my friend, would be banana purée. How does one juice a banana?

These were incredibly important questions in our jet-lagged brains.

Ultimately, it resulted in my decision to make banana consommé, to bring into existence an unadulterated banana essence. This, I decided, was closest one could possibly get to the definition of banana juice. And it was beautiful to behold.

I imagine macaques would gnaw through a brick wall to get to this stuff.

Later on, I decided to follow up my consommé-ing success with another tribute to our Toronto trip: clamato consommé, since clamato juice was served on the plane between Vancouver and Toronto. Clamato juice is clam juice and tomato juice, for the lucky souls who have been fortunate enough to avoid knowing about its existence. None of us had heard of it or tried it before and we all desperately wish we could repress our memories of it now, because our simple minds were not prepared for it.

I couldn’t get any clams for my recipe, so I used mussels. I blended them with tomatoes (almost breaking my 600W stick-blender in the process because of the horrible sinewy tissue of the mussels), did a gelatin filtration, and produced clamato (well, musselato) consommé.

Then I took it to work and made our resident psychiatrist drink it. I think he had tears in his eyes.

I then put the clamato juice in the fridge at work, with a smiley-face on it and I don’t know what happened to it but it did eventually disappear.

Read on for the recipe for banana consommé using gelatin filtration. And feel free to suggest interesting potential uses for banana consommé, because I only really made this as a proof of concept and didn’t think much beyond that…

Darkplace soup

May I tempt you with this alluring and sophisticated dish?

It’s a poached egg in soup.

Used since ancient Greek times to woo one’s objet d’amour, poached egg in soup remains one of the most alluring, enchanting and salacious gastronomical expressions of undying passion. The egg, representing fertility and perched perkily upon the thick molten soup, is like an unblinking bulbous eye within which you glimpse an unmistakeable come-hither look.

Or so I imagine. All I can say is that this is my loving, labour-intense, bizarre, gastronomical tribute to Garth Marenghi’s Darkplace, one of the greatest television shows ever. In the mighty concluding episode of the series, Dr Lucien Sanchez, hotshot surgeon, woos Linda, the woman who is slowly turning into broccoli, using an egg poached in soup. Such a poignant and beautiful gesture… that looks like this:

My variation has nothing on the original, of course, but I have exerted myself and my creativity to produce this dessert version of the egg poached in soup: a strawberry mousse tinged with Grand Marnier and dark chocolate (and a bucket of food colouring — damn, that mousse was a delicate pale pink), a circle of vanilla milk gel, and a yolk made out of a sphere of saffron-flavoured apricot nectar.

And so with this I salute you, Garth Marenghi: author, dream-weaver, visionary, plus actor. You taught me to love, and to convey that love through an egg poached in soup (mayhap with a pork pie or sausage roll). If only there was more of such epic beauty in the world.


(Darkplace Episode 1 Part 1 here.)

As for the neuroscience for this post, just a quick mention of something very interesting I came across when reading up on lexical-gustatory synaesthesia, when people experience particular tastes in response to hearing, reading or thinking particular words (see my previous post if you haven’t already).

We’re all familiar with that indecently enraging thing known as the tip-of-the-tongue phenomenon. You’re trying to think of a word and YOU. JUST. CAN’T. BUT. YOU. HAVE. ALMOST. GOT. IT. IT’S ON THE TIP OF MY TONGUE. OH. GOD. I’M SO ANGRY. This is a pretty difficult thing to research — everyone will have different words that cause this phenomenon for them (compromise and renege do this to me endlessly for some reason, and yes, they did it while I was writing this, gaaarrghhh), and once you’ve reminded someone of the word then there’s no point in testing them with that word again any time soon.

Apparently researchers have worked out some words that are pretty good at generating the phenomenon. For example, “What’s the name of the navigation instrument you use to measure the angle between two objects?” — the answer is a sextant, which is apparently a difficult word to recall (I had no problem recalling when my psychology lecturer asked that in one of my undergraduate courses, and it’s not like I’ve ever so much as held one, although at least half of the class did have trouble recalling the name). Another one that often generates tip-of-the-tongue is platypus, apparently. That’s really not going to work for anyone who grew up in Australia, that’s for sure — I think most 5-year-olds here could name a platypus without hesitation.

Anyway, the tip-of-the-tongue phenomenon occurs when you can access the word’s meaning from your memory, but you can’t quite remember its actual sound.

The particularly interesting part is when you try to generate a tip-of-the-tongue state in a lexical-gustatory synaesthete. Why?

Because they experience the taste before they can recall the word.

So for instance, one participant, MK, was shown a picture of castanets and was asked to say what they were. She couldn’t quite remember the name, but she did experience the taste of tuna while trying to figure out the name of what she was looking at. Then, later on, when she was asked what taste is usually associated with castanets, she confirmed it was tuna. And just to be extra thorough and make sure she wasn’t just saying that castanets was associated with the taste of tuna because that’s what the researchers would like to hear, a year later, the participants in this study were given a surprise re-test and asked which tastes were associated with which words. And yep, MK again said that castanets was associated with tuna.

This tells us something pretty interesting about lexical-gustatory synaesthesia, then: it’s not the actual phonological sound of the word that triggers the associated taste, but its meaning, since the tip-of-the-tongue phenomenon occurs when you can dredge up the word’s meaning from your memory but can’t quite get the word itself.

Which makes it all the more odd that these synaesthetes experience tastes in association with made-up, non-existent words, like keach or spluk (like I mentioned in this post). Maybe there are different levels of processing going on in lexical-gustatory synaesthesia? One involving the meaning of words and one involving their orthographic and phonological aspects, and these levels of processing can sometimes work independently of each other? Maybe the initial association between the word and a taste is based on orthographic or phonological aspects of the word, but then the association becomes so strong and automatic that the taste is conferred to the word’s meaning instead? I don’t know, but there is the potential for some very interesting and elegant studies to be formulated to answer those questions!

And now, what you really wanted: the recipe for fake egg poached in soup, brought to via a brief detour through the outer regions of molecular gastronomy land.

Read on for the recipe for fake egg poached in soup — strawberry mousse, vanilla milk gel and saffron apricot nectar sphere.

Hot ice-cream success! (And synaesthesia.)


You might remember my previous attempt at making hot ice-cream — the ice cream that you poach in hot water and then it melts as it cools to room temperature. It worked, technically, but I wasn’t happy with the flavour since it just tasted like cream cheese, which, you know, doesn’t taste like ice-cream (unless you have cream cheese ice-cream, I guess, but who has that? That’s right, no one. Well, some people, but they’re not the sort of people I want anything to do with).

So I went on the quest to develop a hot ice-cream recipe that tastes like normal vanilla icecream. And after some experimentation and various mishaps, ye gods, I think I’ve actually done it.

Jack at Homologous Legs happened to tweet about the old recipe at one stage, saying that he’d be all for it if the hot ice-cream was in iced chocolate, as opposed to the iced coffee I’d put it in to make the reverse affogato. And I thought yes, that’s a good point. So in this iteration of the recipe, I changed the lovely bath in which the hot ice-cream resides from iced coffee to a cinnamon chocolate frappé. Just because I can. (But methylcellulose also thickens at low temperatures as well as 50°C+ temperatures, so the frappé is going to cause the ice-cream to melt and then solidify again, which I pretend is all part of the thrilling and dynamic dining experience.)

So there you go. Hot ice-cream that melts as it cools. It’s kind of amazing and it defies the senses.

You know else is kind of amazing and defies the senses? (Behold the world’s most stunning segue.)

Synaesthesia.

For those of you who have the unfortunate circumstances of not knowing about the mind-melting amazingness of synaesthesia, it is a condition in which perception of a stimulus in one modality is experienced in an additional modality. What does that mean?

Well, imagine that every time you heard a dog bark, your visual perception was spontaneously and involuntarily tinged with purple.

Or imagine that as you read this blog, you’re visually experiencing a relentless cavalcade of colours with each different letter you look at.

That happens to synaesthetes — they experience a vivid and completely involuntary cross-over between senses (and possibly cognitive systems). And there are different kinds of synaesthesia involving cross-over between different senses and cognitive processes such as language processing. Grapheme-colour synaesthesia is the one where people experience a colour in association with different letters or numbers (e.g. the letter A conjures up the perception of red or is perceived as being inherently red). Sound-colour synaesthesia is the one where hearing a particular noise or even a particular note on a musical instrument causes the synaesthete to experience a particular colour. And studies have shown that these particular associations (such as A = red or dog barking = purple) generally remain steady over the synaesthete’s lifetime. So play a B-flat on a cello for a synaesthete and perhaps they see orange, then come back 25 years later and play that B-flat on a cello again and ask them what colour they experience — it’ll be orange.

But within the scope of the neuroscience of taste perception, one type of synaesthesia is just lobe-explodingly interesting: lexical-gustatory synaesthesia. When people with this synaesthesia hear or read or even think a particular word, they consequently experience a particular taste. Not just that, but words conjure up the sensation of taste and temperature and texture in the mouth (perhaps not surprising to those of you who remember when I discussed the primary taste cortex in this post and mentioned that some neurons in the primary taste cortex fire preferentially to particular food temperatures and textures as well as tastes).

It’s estimated that less than 0.2% of the population experiences this lexical-gustatory synaesthesia, so it’s pretty uncommon and it’s difficult to research when there are so few potential research participants (damn it, I find it hard to get research participants and all I need are right-handed males aged 18-40). But here are some of the word-taste associations that lexical-gustatory synaesthetes experience, according to the literature…

  • “for synaesthete JIW, the word jail floods the mouth with the taste of bacon”
  • “for SKM, the word dean evokes the precise and consistent notion of minced beef in gravy”
  • “for synaesthete JG for example, the name Adrian tastes of lettuce coated with Caesar salad dressing, and for CS, part tastes of chicken noodle soup”
  • “for JIW, the words message, college and edge all taste of pork-pie/sausage meat”
  • tambourine is very crumbly biscuit”
  • “for synaesthete JIW, words containing /k/ tend to taste of egg/yolk, e.g. accept, York, chuck, fax
  • “for example, Alessandro tasted of ‘fried potatoes’ and gave the smell of ‘burnt wood’”.
  • “for example, for JIW, the non-word spluk tastes of yoghurt, and so does its near-neighbour luck
  • “for LAS, for example, beef tastes of ‘horrible overcooked, dried-out beef’”
  • “for JIW, the word this tastes of bread soaked in tomato soup, while the name Philip tastes of unripe oranges”
  • “for participant GS, the word clue tastes of ‘cold, leftover potato scraps with congealing pot-roast gravy’”

 
Pretty specific, huh? And kind of, well, unpleasant in some cases. I’m in no hurry to taste congealing pot-roast gravy, never mind have it forced upon me by my brain every time I read Nancy Drew (I’ve never read Nancy Drew, but what if I wanted to? What if I wanted to?!).

You might have guessed from those little excerpts the direction in which lexical-gustatory synaesthesia research has headed — what are the specifics of a word that mean it’s associated with a taste? Are there generalisable trends within each synaesthete, e.g. do words that sound the same generate similar tastes? And what about made-up words — do they generate a taste? And if they do, why? More, tell me more!

Well, to start with, one thing is pretty straight forward — if something has a taste, the word for that something will generally taste like that something. So the word asparagus conjures up the taste of asparagus. It might be the taste of over-cooked asparagus for one synaesthete and raw asparagus with freshly ground pepper for another, but generally there is a pretty blatant link between food words and their respective food tastes.

Another of the most clear-cut findings is that sometimes there are obvious associations between parts of words and the name of what they taste like. For example, “cinema tastes of ‘cinnamon rolls’ (JG), Jackson tastes of ‘Cracker Jacks’ (both MZ and CS), village tastes of ‘vanilla slice’ (SKM), and dogma tastes of ‘hotdogs’ (DMS).” So there’s some sort of word-association going on here based on key sounds and letter groups within a word.

It also seems like particular sounds within words might be the point that the taste association clings to. That’s why message, college and edge taste of sausage meat (the /dzj/ sound in all of them and in sausage) and things with a /k/ sound taste of egg yolk to JIW.

This all kind of makes sense, but what would you predict would happen with made-up words, non-words? These do generate tastes in the synaesthete, even if the synaesthete has never encountered them before. It looks like non-words associate with a taste based on how similar they are to real words. For example, if presented with the non-word keach, a lexical-gustatory synaesthete might experience the taste that’s usually associated with beach or teach. Even non-synaesthetes can see the similarity between those words, but synaesthetes might have a broadened sense of word similarity, in that a word like spluk results in the taste that’s usually associated with luck, even though spluk and luck are technically very different words.

Despite there being very few individuals with lexical-gustatory synaesthesia to study, there are a few papers out there on the topic that suggest some very interesting theoretical underpinnings for this type of synaesthesia, and some incredibly nifty experiments have gone down. I will, however, go into that another time (well, in my next post).

In the mean time, just reflect on the fact that you are not currently tasting lumpy gravy or cold potato skins or oily salad dressing while reading this. If you were anything like the synaesthete JIW, you would be experiencing tastes in response to 56% of words from your own speech, the speech of others, inner speech and reading. An almost constant parade of tastes…

Personally, my strategy would be that I’d memorise a list of all the words that don’t generate a taste, then try to speak and think exclusively in those words, just for a little respite. Think of it as being like that guy who wrote a story that didn’t contain the letter E. So… difficult… I think… hi… how do you do today… do you… want to… stuff into your mouth… hot rich dairy product? Look down for… instructions…

Read on for the recipe for hot vanilla ice-cream in cinnamon chocolate frappé.