Exploiting Jello’s elastic properties – Liz Hickok

Via “Chowhound‘s” Food Media

Liz Hickok makes sculptures of San Francisco in jello. This is Telegraph Hill shaking and wobbling.

You can see the whole “San Francisco in Jell-O” series on Youtube at her channel http://www.youtube.com/user/ehickok or with much more on her own website http://www.lizhickok.com/

Of course if you were at MIT you could simulate Jello for a class project but it seems much easier to just make the jello !

Christine Joly-Duhamel and colleagues in 2002 * suggest that the basis of jello (an all gelatin gel) elasticity is the extent and size of the triple helix regions – and therefore I infer, not the entropic contribution of the highly flexible coils separating them. An entropic contribution would come from the coiled regions being straightened out on deformation. Straightening the coils would make them more ordered, thus decreasing entropy, and so there would be a restorative force “seeking” to return to the higher entropy (more disordered) state. Although never purely entropic, polypeptide gels have been considered more entropic than enthalpic (Rheology of fluid and semisolid foods – M. A. Rao page 326), but Joly-Duhamel’s model suggests a more enthalpic type gel for gelatin than was thought previously. Enthalpic restorative forces in gel elasticity come from the energetics of bending and otherwise straining bonds in relatively stiff chains – a model considered valid for many polysaccharide gels.

*All Gelatin Networks: 2. The Master Curve for Elasticity. Christine Joly-Duhamel, Dominique Hellio, Armand Ajdari, and Madeleine Djabourov. Langmuir, 2002, 18 (19), 7158-7166• DOI: 10.1021/la020190m • Publication Date (Web): 27 July 2002

Pacific Northwest wheat farmer highlighted in the NY Times

This article: on traceability “Forging a Hot Link to the Farmer Who Grows the Food”  was sent to me by my friends at the San Francisco Baking Institute . The article mentions the Shepherd’s Grain folk from the Pacific Northwest.

I have used Shepherd’s Grain flour and was happy with the results:  I am trying more of it periodically, now that I have honed the skills I learned at SFBI and got my bakery conditions under control.


I hope the topping is good…

Dateline March 27 2009 – Rome – Peter Popham of The Independent (London UK) reports on a new vending machine that ” makes and delivers pizza in three minutes” and which “will make its appearance in offices and factories around Italy from next week“.

Others have reported on the machine, but mostly rehashes of the press release. You can [kinda]  see it in action here…

I like the idea of the dough mixer for fast testing of dough properties, a perpetual goal in wheat variety development  (my day job) and wheat trading, but I guess the University of Bologna and Unilever and Claudio Torghele have the technology all tied up. None the less, the dough can have little flavor (NO fermentation time) hence my hope that the topping is good. According to Serious Eats – Slice the picture on Flickr makes it look like a frozen pizza, echoing the Italian pizza-maker Paolo Pagnani on the video who reckon’s that a jukebox has more charm.  There are pretenders to the the fastest-pizza “throne” – “Wonderpizza Italy” here in the USA has a similar looking machine that holds about 100 premade pizzas on sealed trays that are then baked in the machine.

All a far cry from Mark Bittman’s fear of pizza dough, and the care and attention to both the dough and the toppings, and the beautiful looking end result in his recent post on the NY Times Bitten blog.

If you have the dough ready, it’s not that hard to make a wonderful, customized pizza at home – as the pizza primer at TheFreshLoaf says “If teenagers working at Dominos for 6 bucks an hour can make a decent pizza, you shouldn’t have any problem doing it yourself at home!

Still, according to Daniel Flynn (Reuters Life!) the machine has Italian chefs in a spin. But even the developer Claudio Torghele admits that if he wants great pizza he’d go to a pizzeria.

‘Nuff said.

Interesting post from Khymos – and some other things


Martin Lersch has a post (Dangerous names)  inspired by an article entitled  “If It’s Difficult to Pronounce, It Must Be Risky” by Hyunjin Song and Norbert Schwarz of the University of Michigan and published in Psychological Science


So… you think there’s nothin’ obviously dangerous sounding in the ciabatta pictured below ? – think again –

It has 80 baker’s % DHMO

and it has a fair splash of durum flour, which is enriched in 1,3,3-trimethyl-2-[(1E,3E,5E,7E,9E,11E, 13E,15E,17E)-3,7,12,16-tetramethyl-18-(2, 6,6-trimethyl-1-cyclohexenyl)-octadeca-1,3,5,7,9,11,13,15,17-nonaenyl]cyclohexene

This chemical gives the bread a nice yellow color and seems to carry more flavor as do some other non-polar triacylglycerol-soluble molecules.


(recipe adapted from “Bread Baking: An Artisan’s Perspective” by Daniel T. DiMuzio)

BUT – if you like your chemicals silly and have a open-minded sense of humor then this is the site for you: authored by Paul May of the Bristol University School of Chemistry


Molecular mixology

From Kelsey Munro in tomorrow’s Sydney Morning Herald (well it is already March 17th there)

“It’s gin and tonic but not as we know it. A cube of G&T jelly sits on a thin slice of lime that’s been fired to a caramelised crisp by a blowtorch. White powder on top fizzes on the tongue like sherbet. The bite-sized gulp is served on a spoon. It’s delicious: an unexpectedly elegant fusion of flavour, texture and alcohol… … “.

The full story van be found here. http://www.smh.com.au/articles/2009/03/16/1237054730948.html

Also more information here

An Introduction to Molecular Mixology

and at


A list of wordpress blogs with “molecular mixology”


Buzz Andersen

Hopefully some food chemistry came to life…

There are many elements needed to create a good and compelling class – good material, a willing instructor, but the essential element is enthusiastic and dedicated students.  It is a circular argument: enthusiastic students generate enthusiasm in the instructor, which generates enthusiasm in the students, and around we go again.

I was privileged to have an almost uniquely good natured, good humored, and hard-working group who were willing to participate in this experiment in teaching food chemistry. Of course not everything that was tried worked flawlessly – but no good thing was ever perfect the first time around. And we were not having enough fun…

The key structural element of the class that I believe led to our moderate success was the use of case studies to highlight many of the basic elements of food chemistry. The two more successful ones were bread making and espresso.

Breadmaking was viewed as a system both in narrow and broad senses. In the narrow sense: a matrix of interacting components in the dough and in the finished product. In the broader sense; as the progress of a variable agricultural raw material through its intermediate processing steps (e.g. milling) through to final processing, storage, and consumption.

In the narrow sense we were able to incorporate elements of…

Polymer Science (entanglements, glassy and rubbery states and their responses to changing temperature and plasticization [water])

Rheology (viscoelasticity)

Starch behavior (gelatinization, susceptibility to attack by amylases, & retrogradation [junction zone nucleation and growth] and staling)

Maillard reactions (the effects of water activity, temperature, pH [mostly with the pretzel lab], and the contribution of fermentable reducing sugars from damaged starch)

Foams and foam stability (dough gas cells as a solid/liquid foam stabilized by proteins and lipid-based surface active components, the foam to sponge transition from dough to bread)

Enzymatic activity and thermostability (mostly amylases:  the increasing susceptibility to hydrolysis of undamaged and damaged starch granules and finally gelatinized starch; the different windows of opportunity for extensive hydrolysis of gelatinized starch during baking by fungal, cereal, and bacterial amylases )

In the broad sense we were able to observe elements of…

Genetics (the interaction with genetically determined kernel hardness and subsequent starch damage during milling, fermentable sugar production by amylases, and Maillard development of crust color; the genetics of gluten protein variability and its effects on gluten and dough viscoelasticity),

Rheology/Polymer science (fracture mechanics of kernels, polymer entaglements – stress build up and subsequent relaxations as vital steps in the transformation of flour, water, salt, and leavening [yeast or sourdough] to bread)

Espresso was also viewed in these two ways.


In the narrow sense we were able to incorporate elements of…

Rheology – the contribution of particulates to viscosity, the contribution of polymer size to viscosity and to the persistence of espresso crema as expressed by changes in foam drainage related to viscosity

Maillard (of course) – during roasting, the delay while the beans dry out, the increasing darkness, the formation of aromatic volatiles, the production of carbon dioxide, and the role of carbon dioxide in the formation of the cream foam.

Microstructures and inhomogeneity – the idea of espresso as a polyphasic colloidal system (e.g. Piazza, L; Gigli, J; Bulbarello, A (2008). Interfacial rheology study of espresso coffee foam structure and properties. Journal of Food Engineering 84 (3) 420-429. )

In the broad sense we were able to incorporate elements of…

The idea of coffee as an agricultural product; variability in composition related to species, region of growth, the fact that it needs intermediate processing before it can be roasted (allowing an opportunity to explore cell wall polysaccharides in detail  – particularly the pectin in the cherry mucilage).
Of course there was much more – but this is just a summary.

And of course student engagement is vital. The following pictures tell the story, and I need to express tremendous thanks the class for their collective contribution to a successful term !!!

Starch lab

Pretzel lab

Coffee day

Starch again

Meat lab

Baking lab

Beer wins – beats wine !!!

Dateline 24th October 2008: Researchers Armindo Melo, Olga Viegas, Catarina Petisca, Olivia Pinho, and Isabel  Ferreira from Portugal show that beer marinade is more effective at reducing heterocyclic aromatic amines (HAs) in pan-fried beef. HAs, according to Armindo Melo and colleagues, have been identified by the International Agency for Research on Cancer (IARC) as potential carcinogens and IARC has recommended reducing human exposure.

According to the researchers “Marinating with beer or with red wine resulted in decreased levels of HAs” and based on a multivariate statistical analysis of the results beer was more effective at reducing specific HAs. But the kicker was that beer won on sensory side. Unmarinated and marinated beef samples were tested and the beer marinade was better at retaining the expected quality of the pan-fried steaks.

Effect of Beer/Red Wine Marinades on the Formation of Heterocyclic Aromatic Amines in Pan-Fried Beef
Armindo Melo, Olga Viegas, Catarina Petisca, Olivia Pinho, and Isabel M. P. L. V. O. Ferreira
J. Agric. Food Chem., 2008, 56 (22), 10625-10632• DOI: 10.1021/jf801837s • Publication Date (Web): 24 October 2008.
Link to the abstract here

“Reprinted with permission from “Effect of Beer/Red Wine Marinades on the Formation of Heterocyclic Aromatic Amines in Pan-Fried Beef .” Melo et al  J. Agric. Food Chem., 2008, 56 (22), 10625-10632. Copyright 2008 American Chemical Society.”

Another shameless plug… Oregon State U. Food and Fermentation Science Programs

Brewer and scientist Jeff Clawson in our pilot plant…

He will be talking in town (Corvallis) on Monday at the Science Pub Corvallis in the Old World Deli on 2nd. Details can be found at the link to Life@OSU.

According to Life@OSU, “this effort is a new collaboration between Oregon State University, the Oregon Museum of Science and Industry and the Downtown Corvallis Association that aims to present fascinating findings from leading researchers in an unexpected place: the local pub.
“Science Pub Corvallis” premieres on Monday, March 9, with, appropriately enough, “Beer: A Tasty Blend of Art, History and Science,” featuring Jeff.

Hopefully this link will stay active for a while — video of Jeff with some of our committed and enthusiastic fledgling fermentation scientists courtesy of KMTR 16 Eugene OR