Bringing food chemistry to life






         A blog about food and its components – feel free to comment

May 18, 2010

A winter of food chemistry instruction

Can’t show the students for administrative reasons, but we had a good and educational time once again.

Bringing you highlights from the second iteration of  ”BRINGING FOOD CHEMISTRY TO LIFE”.

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DISPERSED SYSTEMS:

Mayonnaise and egg white foams, and ways of messing them up that were instructive for the chemistry lesson.

POLYMERS 101:

Using the Brookfield viscometer to show how viscosity changes with molecular weight @ equivalent w/w concentration, and how it changes with w/w concentration @ equivalent molecular weight. The Brookfield with the helipath stand was also good for demonstrating how the viscosity of the mayonnaise decreased with increasing shear rate [shear thinning]. The helipath stand makes sure the sensor is going through an as yet unsheared region, taking time-dependent thixotropic behaviors largely out of play.

Fun with spherification whilst experiencing the gel forming capabilities of biopolymers with different gelling mechanisms [alginates, glucomannans, methylcellulose].

COFFEE WEEK: browning reactions, & foam and emulsion production and stability in espresso as related to roast degree [and therefore  the interplay between arabinogalactan peptide, and maybe galactomannan, extractability [during hot water extraction] and thermal degradation [during roasting] in determining the stability of the espresso crema]

Prepared for a cupping [monsooned, versus washed arabicas, versus robusta]

Color versus roast degree via tri-stimulus color meter.

How fun to have an espresso machine as part of the lab equipment! And coffee roasters too.

The instructor/barista hard at “work”

STARCH WEEK: not just formal viscometric studies, but also hands on experience of the different gelatinization temperatures and pasting behaviors of a variety of starches [e.g. potato versus wheat].

The instructor/starchista hard at work.

Using freshly made noodles as a way of bringing to life the profound  functional influence of differences in starch amylose content on food texture.

MEAT WEEK: As a plant scientist I find this work really hard to clean up because of all the fats!

Water holding capacity, gelation with salt and heat, transglutaminase, effect of pH and nitrites on color

Transglutaminase



3 Comments »

  1.   Martin — May 21, 2010 @ 2:26 pm    

    Wow – that look so fun :) I wish I could’ve taken part in all those experiments!

  2.   Michael — May 22, 2010 @ 9:52 pm    

    Awesome experiments with the students. I would love to do something similar with my class. Keep up the good work!

  3.   Erik fooducation — June 28, 2010 @ 12:24 am    

    A bit late, but anyway: great work, looks like the students are very fortunate. Keep up the work :)

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