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

Wheat and barley – HEALTHGRAIN Conference

From Eurekalert

Health benefits of wheat can be improved by plant breeding

Wheat products, and in particular, wholegrain products, are important sources of dietary fibre, vitamins, minerals and other components which are beneficial for human health. Analysis of a diverse range of wheat varieties within the HEALTHGRAIN project of the European Union has shown substantial variation (up to four-fold) in the content and composition of these components.  Peter R Shewry  http://www.eurekalert.org/pub_releases/2010-05/vtrc-hbo050410.php

Rye and barley products facilitate blood glucose and appetite regulation

Evidence from observational studies indicates that diets rich in whole grain reduce risk of obesity and other diseases related to the metabolic syndrome, e.g. type 2 diabetes and cardiovascular disease. The mechanisms involved are only partially elucidated. Work within HEALTHGRAIN has revealed novel insights regarding some potential mechanisms.  Inger Bjorck  http://www.eurekalert.org/pub_releases/2010-05/vtrc-rab050410.php

GO WHOLE GRAINS!