Author: Peter Török

Mushroom risotto two ways with Tom Aikens

Our entire risotto project with Lara was inspired by J. Kenji López-Alt’s blog on pressure cooker made risotto. The actual project idea came from Dr Matthew Foreman who sent me a copy of a paper on the gelatinisation of starch in rice. We decided to investigate the effect of toasting rice, cooking temperature, and time on the consistency of risotto. Lara has already reported on some aspects of the work in earlier posts and we are currently writing up the results for a scientific paper. So that we can celebrate a successful project we decided to cook a mushroom risotto also testing the conclusions of Lara’s work in practice. 

The Effect of Sodium Bicarbonate on the Water-holding of Pork Loin

Xiao-Liu Chu, Peter Török, Carl Paterson and Tom Aikens

Imperial College London


We investigated the effect of a 3% concentration solution of sodium bicarbonate (treatment A) and pure sodium bicarbonate (treatment B) on pork loin samples. These were compared to a 5% salt brine (treatment C), controls consisting of tap water (treatment D) and untreated samples (treatment E).

Pork loin samples under treatment A experienced a (50 ± 14)% higher increase in weight after 390 minutes of marinating as compared to treatment D. This suggests an increase in water holding capacity. The result of heating pork samples subjected to treatments A and B lost, in comparison to control, (39 ± 7)% and (33 ± 10)% less in weight respectively.

Exploring the polymorphic structures in Milk Chocolate, Dark Chocolate and Cocoa Butter

Michelle Tan || 7th October 2014

Abstract The analysis was carried out using X-Ray diffraction1–3 (XPertPro Panalytical) of polymorphic forms of Milk chocolate, Dark Chocolate and pure Cocoa Butter samples. Sugar was removed from the samples as sucrose signals interfere with those of cocoa butter. The XRD patterns obtained for the Milk Chocolate and Dark chocolate were compared to that of the pure cocoa butter. Strong peaks were observed at 4.16Å (Form I), 4.24Å (Form II), 4.24Å (Form III), 4.38Å (Form IV) and 4.56Å (Form V), which can be used to infer the various crystal structures of the polymorphs of cocoa butter.

Research Blog: Predictive Microbiology (Vedish Bhatoolaul)

Thoughts and Analysis

This blog post is intended to be more of a collection of my personal thoughts, opinions and questions on the research area I am currently working on rather than a microbiologically correct treatise on the subject.

As a theoretical physicist, my microbiological insight will be rather limited and sparing at best; hence the conjectural and interrogative tone of this account.

Please note that this account is chronological and is being continuously updated. (Posts at the end of the account will be most up-to-date with findings compared to earlier ones.)

As you will eventually gather by reading my posts, I am working on building an Individual-based Model to try and predict bacterial growth and inactivation.

Potato density changes with age – by Karim Bahsoon

Potato density vs Age (expiration date of potatoes 1st March 2011)

As discussed we have been measuring the density change of the potato over a number of days. The potato was left out at room temperature and the density measurements were carried out using the same method as before (filling measuring jug with water to assess volume/mass change).

DATE MASS (g) VOLUME DISPLACED (ml) DAYS AFTER EXPIRY DENSITY (g/ml) 24/02/11 142 130 -5 1.092307692 25/02/11 142 130 -4 1.092307692 28/02/11 140 129 -1 1.085271318 01/03/11 140 129 0 1.085271318 03/03/11 139 129 2 1.07751938 07/03/11 138 128 6 1.078125

The density change has been fairly minimal, and the precision of the scale (accurate to 1 gram) has perhaps hindered the experiment somewhat.

Starch concentration measurement in potatoes – by Jason Chang

New density measurements and Calibration

As advised from the last meeting we placed the measuring jug on an electronic scale, reset the scale to zero and filled it with 400g worth of water. We found that there was a small error in the jug which produced the systematic errors in our previous measurements. We marked the real 400ml mark with a pen and took new volume and weight measurements. I also skinned two of the potatoes to check the removal of skin didn’t significantly change the density (The rows highlighted in the same colour correspond to the same potato). Below is a table of results of potatoes with the skin on:

Measuring the density of french fries

As part of his MSci project Karim Bahsoon has been investigating the effects of varying blanching time on the properties of french fries. Jason Chang, who works with Karim, is involved in measuring surface starch content and crunchiness of the ready chips.

Potatoes were cut into fries and placed in boiling water for times varying from 0-12 minutes. These were then submerged in vegetable oil at 170C for 4 minutes and then fried again at a higher temperature of 190C for a further 2 minutes. The second fry is thought to help with crust formation and adds to the crunchiness of the fries.

FoodCycle charity event with Tom Aikens

Imperial College FoodCycle is organising a charity dinner cooked by Tom Aikens. It will be held on the 21 March 2011 at Whole Foods Market, High Street Kensington. FoodCycle is an organisation that uses raw food ingredients donated by various supermarkets and other suppliers, that would otherwise be wasted, to cook meals for people who cannot afford a hot meal. An excellent example to follow!

Chocolate mousse with Tom Aikens

As a part of the MSci project on Cooking a Steak, we would like to communicate the physics and those physical processes that take place during cooking to the general public. Karim Bahsoon and Jason Chang are the two fourth year undergraduate students working on this project.

The dessert course of the menu will be a chocolate mousse by Tom Aikens. Tom is a Visiting Researcher at the Physics Department and he has been advising us on the menu. In addition to his help Tom actually cooked all the courses for us so that we know how the original versions taste.