Brought to my attention by a former student – many thanks P.
A special item from New Scientist all about imag[in]ing fluid dynamics. The images come from physicists at the American Physical Society’s [link] Division of Fluid Dynamics meeting in Minneapolis, Minnesota. New Scientist though that these were their best experimental images in their “gallery of fluid motion“. You can see more here [red dye splash in milk] and here.
What’s “foody” about this?
Well it’s all the chemistry of surfaces and polymers in solution etc that guide the behaviors of foods when they are deformed by a force or forces during mixing, or emulsification/homogenization, or carbonation, or foaming, or chewing, or during fermentation in breadmaking etc.
In the New Scientist gallery these images were most “food chemistry” for me.
Image 2 – the “anti-bubbles” – these must be present in liquid food systems with mixtures of entrained air and surfactants under vigorous mixing.
Image 3 – injecting ketchup into gelatin. Not sure why you would do this to food, except as a physics experiment, but the choice of a polymeric gel and an odd material [ketchup] that has a high concentration of particulates and exhibits a yield stress is interesting. It makes me wonder what the shape might have been had they injected, say a 2% w/v xanthan solution using a high molecular weight xanthan? Maybe this is a way of creating new and intriguing compoite textures.
Image 4 – Weird behavior at immiscible interfaces. maybe this is what the micro-structure of an un-emulsified vinaigrette looks like before it’s shaken up and just after we hit it with the laser stun gun.
Image 5 – splashing behavior of viscous fluids – is their a new idea in creating new shapes/textures/products by “splashing” at low atmospheric pressures where the fluid just spreads – maybe a neat way of creating smooth amorphous glassy solids* from polymer solutions or melts by quenching on a cold surfaces at low pressure.
* as opposed to structured crystalline solids
Image 7 – This is just cool, maybe what a drop of really thick gelatine solution looks like dropping into hot water where it is soluble.
Image 9 – bubble behavior – just very interesting and salient to all the bubbles we create in all sorts of foods and beverages.
And if you think bubbles in food are just trivial then you might need to defend that concept against the editors, authors, and presenters and the 2 Bubbles in Food Conferences and the 2 books of proceedings that came from them.
Bubbles in food –
Beer, champagne, bread, cakes, biscuits/cookies, bubbled chocolates, the crema on an espresso, the foaminess of lattes or meringues, expanded extruded snack foods, the giant bubble that is pita bread baked well.
We clearly love bubbles – one of the seemingly most trivial and often most ephemeral structures in foods.