Task 3: Function Properties of Carbohydrates- Gelatinisation

In your own words, summarise what you have learnt about the chemical and physical properties of carbohydrates in relation to gelatinisation. As part of your summary comment on something that you did not know or understand before now or something that you still don’t understand and want to know more about.

 You may use the following as discussion points if you are stuck.

•  What is gelatinisation
•  Chemical/physical changes that occur.
•  The experiments and how they helped your understanding.
•  Usefulness of gelatinisation in food processing.

Use diagrams, pictures or videos if these help your understanding.
 However, make sure you explain them!

Yaaaaay for not finding much research on the internet to help me study for gelatinisation! ): 

I'll have to go through my terribly written notes that I wrote in class- and through the experiment information sheet.

Okay our topic for today, Gelatinisation. First thing that comes to mind is risotto-lucky we used that for our experiment example. Now, What is Gelatinisation you say?

Gelanisation is where in the presence of heat, mixtures can thicken with starch by adding absorbing liquid. Gelatinisaton takes place regardless of the type of starch, so whether its rice, quinoa, millet- or any other type of grain or starchy product. The physical qualities of the gel produced however are determined by the ratio of amylopectin and amylose and the method used to prepare the food. -Ash when you read this, I have trouble remembering about those A words, so can you please help me with them (:

I have now expanded my knowledge from the first task, knowing now that starch molecules are made up of two substances: amylose and amylopectin. So the ratio of these two substances will vary, therefore creating different functions and qualities of each different starch molecules. 

What I didn't know was that:  Most starches contain around 25% amylose and 75% amylopectin.

Interesting fact: High amylose cornstarch and rice starch are used to make edible packaging films on lollies!

Now usually when you add the liquid of choice(usually in risotto you would use a stock of some sort) the starch(rice) will absorb and expand in size and shape. Due to experimental failure of time, caused our risotto to be a big clump of uncooked riceyness- that was over flavoured with salt-YUCK. 

 

This is such a yummy risotto; made this last night for dinner! Chicken and Roast pumpkin barley risotto- Low GI, and high in omega 3, this ones a winner. Picture source: http://lowgicooking.com/chicken-pumpkin-barley-risotto/

So lets do a little bit of chemistry talk, 

I talked about starch a little bit in my first task- where I mentioned Carbohydrates.

There's pretty much 3 factors that contribute to the affect of the Gelatinisation of Starch molecules and they are:

1. Temperature
2. Agitation
3. Other ingredients and pH

So what I understand from this, is that the temperature affects the way the gelatinisation works-common sense tells me that a warmer, more moist condition would determine a better result. Which is proven and evident in my notes, telling me that when the temperature reaches a certain temperature (86degrees Celsius- 90degrees Celsius) the starch granule bursts and the two A words from before-amylose and amylopectin are released, capturing the liquid and causing it to thicken and form a glorious gel.

Next up-Agitation, so when I think of agitation, its pretty simple knowledge of stirring a saucepan filled with beautiful bechamel sauce for example-you need to constantly stir the sauce after making the rue when adding the milk otherwise it becomes lumpy and gross. To prevent the lumps from forming, agitation occurs!

And last but not least, gelatinisation can the changed by additives! So when either sugar or acid is added to the mixture, the pH level is altered giving different results. For example, adding sugar raises the temperature of gelatinisation, while acids such as lemon juice or vinegar affect the final thickness of the mixture.

I have mentioned plenty of uses for gelatinisation in food processing through this lovely blog post, but I'll do some more-just because I'm a top student (;
 So plain flour, along with corn flour are the most common used flours in the kitchen to thicken liquids. While in the hospitality industry, potato starch is often used in soups, we learnt about the different gels formed with the different flours today-although we didn't completely finish the experiment!