25 Dec 2010

New chocolate & dispersion article out in Norwegian school science periodical

A popsci article on chocolate truffles/ganache and dispersions recently published in the Norwegian school science periodical (print and web).

As a starting point for the text, I use a recipe for chocolate ganache from the Oslo chocolatier Deux chocolatiers. From there, I describe chocolate and ganache as dispersions and how we can understand the structure/texture of chocolate, why chocolate seizes and where chocolate ganache/truffles come into the picture. The article can be found at www.naturfag.no/mat:
Also, recommendable is Anu's blog molekyyligastronomia with two entries recently on chocolate ganache (look forward to the day comes that google translate deals efficiently with Finnish grammar, though).

To round off the season, Muppet Show's own gastronomical column headed by the Swedish chef making chocolate Moose must be one of the ultimate Christmas treats treat wrap up the fooducation blog before Christmas holidays :)




Some more posts on chocolate

7 Dec 2010

Why are some considered food lovers whereas others are considered food geeks?

Often, when I talk about food I'm met with an attitude that I'm talking chemistry and for that reason whatever I say is incomprehensible. The blinds go down and I see the eyes of the person I talk with go all shifty. Probably, he or she considers me being a food geek...

Whereas "food lover" has mostly positive connotations, "food geek" has this mixed flavour to it. Could it be that the "food geek" (whoever that might be) holds some concepts which he applies in considering the food and which sets him apart from the food lover?

One reason that food geeks are considered as, simply geeks, might perhaps find it's reason in what has by pedagogics researchers Meyers & Land (2003, 2005) been coined "threshold concepts". Take any stereotypical notion of a geek, and you'll probably find that one important reason that you consider him a geek is because he holds some knowledge or a world view that lies beyond your grasp (for simplicity I'll use "he" for the geek, but it could of course be a "she" as well. Likewise, I'll use "you" for the non-geek). This could e.g. be a view coloured by mathematical insight (maths/physics geek) or chemical insight (chemistry geek). Often he sees things using his mathematical or chemical spectacles that you normally would consider everyday matters. Accordingly, for many "food geeks" food is not only food but an assembly of plant/animal cells, molecules or even "chemicals" that can be manipulated. The result is a gap between his way of seeing things and your way of seeing things, in this case food and cooking; he becomes the geek.

15 Nov 2010

Dancing the structure of a molecule + scent vs music revisited

Some time ago I caught a glimpse of a headline about some researchers "dancing their natural science projects", more specifically a biochemist dancing the structure of certain biochemical compounds. I thought the idea was rather far-fetched and didn't give it further thought. After seeing it just recently I find myself being so very wrong... Second part of the post contains a few recent thoughts about a project on scent vs. music.

Have a look at the video below. In the start of the video I didn't see the point, but after a while things started to dawn on me.


After watching the video I realised that this did indeed illustrate behaviour of the molecules in question in a very vivid way. I'm of the opinion that one should look for as many possible ways of describing and explaining a phenomenon as possible. If a student tells you they don't understand what you're saying there is seldom any help in repeating the same words one more time. You need to find new words, some other metaphor, another mental representation.

10 Nov 2010

How small are actually the things food is made of?

How small are single plant cells, proteins, sugar molecules? What about those things that spoil our food: bacteria, enzymes? All of them are really small, but when things get this small it is often difficult to grasp that there are huge differences in smallness as well. Below is a tip on how you might get to grips with this.

When dealing with food we talk or read about proteins, carbohydrates, plant cells, enzymes, bacteria and lots of different "really small things". Enzymes react, making fruit brown, proteins and sugars react to give what we perceive as brown coloured and pleasant smelling bread crust. Plant cells absorb or lose water through osmosis to become hydrated or dried, resulting in crunchy or dry/flabby vegetables or fruit. Bacteria and fungi either help us making leavened bread or yogurt, or they spoil our food rendering it unappetizing or even unhealthy.

Usually we talk of these things as macroscopic entities: proteins = eggs, fungi = visible mould on old bread, carbohydrates = sugar in the sugar cup. However, some times these are referred to in terms of their microscopic properties, and this is among the challenges when teaching about food (many of these things are actually submicroscopic, but in educational context we commonly refer to this as the "micro level").

The concept of "smallness"
During my time of teaching, I've realised that many people in general have not reflected on several aspects of this feature:
  1. there is indeed a microscopic world behind the macroscopic sensible/tangible world, and the latter is often a reflection of the former (after all, eggs are cooked because protein molecules react in certain ways)
  2. there are huge differences in actual size between these things which we commonly just think of as "really small"

7 Aug 2010

Miraculin!

For some time now, there has been somewhat of a hype about the miraculous berry that makes everything sour taste sweet. Some time ago, I ordered a packet of dried and powdered miracle fruit tablets and gave it a try. The following post gives some background and the results of a truly fascinating experience.

The miracle fruit is a a berry containing the glycoprotein miraculin with the unlikely effect that when your taste buds meet this substance, you taste sour foods as they were sweet. That is, your perception of sourness is altered. In certain parts of the world, the substance has been used for quite long, whereas in USA and Europe it has not yet been cleared for use as additive. The berry in itself is allowed, but unfortunately they don't keep for long and are apparently not suited for shipping fresh. However, a freeze dried version made into tablets does exist and this is the version I tried.


There is quite some amount of research on the effect and mechanism of miraculin on our tongue as a google scholar search for "miraculin" reveals. The first scientific report was in Nature as early as in 1968. There is also research indicating that other plants exhibit similar effects, such as curculin from the Curculigo latifolia plant. The miraculin protein structure shown here is taken from the Swiss protein structure homology-modeling service.*

An ordinary google search gives various producers and web shops for buying the stuff. Adding to the fun are the conspiration theory-like suggestions (two refs.) of the sugar industry's ways of stopping miraculin approval in the USA since the product might reduce the population's consumption of sugar (which of course is beneficial for everyone except the sugar industry). There are also efforts being made on producing the miraculin glycoprotein using genetic engineering methods, and I guess the hope is that one might efficiently produce miraculin or a relative using common plants or organisms such as lettuce or E-coli bacteria (same as is done with production of other proteins/enzymes such as medicinal insulin or rennet for cheesemaking).

29 Jul 2010

"Anyone for aN 'espresso?" - Machine made coffee seen through transparent glass

A short summer reflection: I've never thought about looking through a cup of espresso, or lungo, or americano, until this holiday. To my surprise the lungo is not always homogeneous (it shouldn't have been, however).

At the house we are exchanging for this summer, in the middle of Paris :), there is a Nespresso machine. At home, we have an rather ordinary/mainstream espresso machine, whereas Nespresso claims to give you a good cup of espresso or lungo without all the hassle: insert one of the many varieties of ready made coffe capsules, press the button, and you get a good(?) cup of espresso without the need for grinding, cleaning etc.


28 Jun 2010

Molecular gastronomy through the eyes of cultural studies

It is fascinating when someone else analyses the things you're interested or involved in from a different perspective. Recently, a paper emerged in European Journal of Cultural Studies called "Liquid nitrogen pistachios: Molecular gastronomy, elBulli and foodies".

The paper gives a short historical description of molecular gastronomy and goes on to describe MG as a phenomenon from three different perspectives.



23 Jun 2010

"Culinary precisions" and/or "Kitchen stories" at science education conference


Last week, I attended the IOSTE XIV symposium. The topic of my presentation was a follow-up of three previous blogposts on culinary precisions: a framework on teaching "nature of science" (argumentation and inquiry) using culinary precisions.


The biannual conference was hosted by IOSTE, the International Organization for Science and Technology Education. It involved more than 200 participants from 47(?) countries from all continents, located in the beautiful Slovene town of Bled. A true pearl.


BACKGROUND
A year ago I wrote three posts on these matters, and these are the background for an exciting new collaboration with researchers from Finland (links below). The posts were:


6 Jun 2010

Foolproof chocolate Chantilly, part 3:3. Dark chocolate mousse w/orange


This is the third post on chocolate mousse; pure and clean
containing only chocolate and flavourings. The process is very straightforward, although this dark variety might be the most tricky one among the three published. However, 'tricky' is not really that tricky...

This post is the last on chocolate mousses for now: white-, milk- and dark chocolate. Previous posts are
Refer the two previous ones for discussions on the how's and why's on this way of making chocolate mousse. This time, I'll get to the point right away.

9 May 2010

Foolproof chocolate Chantilly, part 2:3. Earl Grey milk chocolate mousse with coffee/cocoa nibs

Numerous blogs, web sites and newspaper articles have picked up variations of the "molecular gastronomic recipe" for making chocolate mousse with only chocolate and water first presented by Hervé This. However, most these recipes tell you to try-and fail. I have for some time felt that there is a need for making this recipe foolproof. And on top of it all, it's quite straightforward to make as long as you're precise with the measurements.

This post is the second out of three on chocolate mousses: white-, milk- and dark chocolate. Part 1 was white chocolate mousse w/ginger. I've chosen to give recipes for mousses with added flavours rather than the pure ones. Hence, the recipe might not work out properly if other ingredients, or pure water, is used as liquid.

The main reason for doing these experiments is that most of the recipes on the "molecular gastronomic mousses" tell you to try and fail until you're satisfied. That's ok if you are to serve the mousse right away. However, the mousse will firm up upon storage, starting after 1-2 hours I want a recipe I can trust even when the mousse is kept in the fridge, not having to make it or, even worse, repair it while the guests are waiting.

Video shows texture of mousse after one night in the fridge made according
to recipe below. Also some microscope pictures of the same mousse

EARL GREY MILK CHOCOLATE MOUSSE/CHANTILLY
4 portions

12 Apr 2010

"The fun-flavoured way to learn science"

Paulina Mata and her colleagues in Portugal have produced a very interesting booklet on "Experiments for the family to do together" (...in the kitchen).

In a previous post on inquiry-based teaching methods and promoting students' argumentation skills I referred to a European Commission report. In this report, it is referred to two best practice examples, one of them being the project Pollen (EU Sixth Framework Programme 2002-2006). Slightly embarrassed, I must admit not knowing that a part of this was a resource for families to learn experimenting with and through food.


The Portuguese Pollen team together with Paulina Mata have developed the booklet "The fun-flavoured way to learn science - Experiments for the family to do together" in Portuguese and English.

The booklet is written in a very simple language and seems to be aimed at a general public, both children and adults, in order to stimulate adults to experiment more at home together with their children (or vice versa). It starts out with some general comments and recommendations on experimenting at home, and goes on with a number of very simple and straightforward experiments. One might say that many of the experiments are overly simple ("Why does an ice cube float?", "Do vegetables contain water?" etc.). However, I think that such a "low-level" approach might be a very good idea of several reasons:

25 Mar 2010

Foolproof chocolate Chantilly, part 1:3. White chocolate mousse with ginger

Numerous blogs, web sites and newspaper articles have picked up variations of the "molecular gastronomic recipe" for making chocolate mousse with only chocolate and water first presented by Hervé This. However, most these recipes tell you to try-and fail. I have for some time felt that there is a need for making this recipe foolproof.


This post is the first out of three on chocolate mousses: white-, milk- and dark chocolate. I've chosen to give recipes for mousses with added flavours rather than the pure ones. Hence, the recipe might not work out properly if other ingredients, or pure water, is used as liquid.

The main reason for doing these experiments is that most of the recipes on the "molecular gastronomic mousses" tell you to try and fail until you're satisfied. That's ok if you are to serve the mousse right away. However, the mousse will firm up upon storage, starting after 1-2 hours. I want a recipe I can trust even when the mousse is kept in the fridge, not having to make it or repair it while the guests are waiting.


Video shows texture of mousse after one night in the fridge made according to
recipe below. Also some microscope pictures of the same mousse





2 Mar 2010

One major and one minor literature reference on Molecular gastronomy

At last(!) there is a comprehensive and broad focussed review on molecular gastronomy (MG) in the scientific literature. Also, I stumbled over another scientific paper on the same topic from 2007 which has missed my attention until now.

An important (and seminal?) contribution
Martin at khymos has written a short post on the most recent and comprehensive addition to the scientific publications on MG: "Molecular Gastronomy: A New Emerging Scientific Discipline" written by eight(!) researchers in the field, and is open access. What a gift!

Since it was mentioned already in a paper from 2008 (van der Linden, McClements & Ubbink, ref. here), I've been waiting for this paper for at least a year. It is incredibly welcome that others than Hervé This writes about MG in scientific papers, and now we have several contributions with slightly different viewpoints on the same phenomenon.