Task 5: Function Properties of Protein- Denaturation and Enzyme Activity

In your own words, summarise what you have learnt about the chemical and physical properties of proteins in relation to denaturation and enzyme activity. 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 denaturation 
•   Chemical/physical changes that occur.
•  The experiments and how they helped your understanding.
•  The effect of enzymes on the denaturation process
•  Usefulness of denaturation in food processing.

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



Probably the best experiment we've done so far- Chicken Stir Fry with rice.
It looked pretty much exactly like that, yummmo!

Okay so short and sweet Denaturation can occur through many different things in food processing, the aim of our experiment was to show how denaturation affects the tenderness of chicken in a stir fry. So, to marinade or not to marinade?

Our results proved that marinading chicken before cooking it in the stir fry had better results. The chicken end up moist, tender, juicy and full of flavour, while the un-marinaded chicken was dry and tasteless-in doing it that way the vegetables soaked up all the flavour, making them soggy and leaving the chicken bland.

So what makes denaturation occur? and why were we learning this through making chicken?
Several factors  affect the denaturation process in food. Whether its temperature, acidity and agitation, salt or sugar, theres one factor that sticks out the most for me. The enzymes.

For any of you that don't know, enzymes are responsible for speeding up chemical reactions. They are also known as catalysts. Enzymes break down protein into individual amino acids. So when we were marinading our chicken, because it had pineapple juice in it(which contains the enzyme bromelin-which breaks down the proteins myosin, elastin and collagen) it helps speed up the denaturation process which was evident in our experiment results.

The second experiment helped me understand the importance of different ingredients-and how they can denature protein. When adding heat, the higher the temperature, the more quickly proteins will denature-then coagulate and clot. When the pH of a food is less than 7, proteins will denature. So by adding an acid to a protein, the acid begins attacking and breaking the bonds between amino acid strands.

The mechanical action in food handling causes protein strands to stretch, when too much mixing occurs the protein becomes denatured also. Salt can denature and coagulate protein, for example adding salt to boiled eggs so that if there is a crack in the shall, the salt water helps minimise loss of white. Last but not least, in the presence of sugar, proteins can tolerate higher temperatures by denaturating and coagulating-which was evident when we made Baked Custard Tarts.

Task 4: Function Properties of Protein- Coagulation

In your own words, summarise what you have learnt about the chemical and physical properties of proteins in relation to coagulation. 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 coagulation
•  Chemical/physical changes that occur.
•  The experiments and how they helped your understanding.
•  Usefulness of coagulation in food processing.

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


I'm just going to start out this blogpost with this recipe for baked custard tart with toffeed mango(shown above). Now after we made our custard tarts in class- I was the only person game enough to actually try the ones left over. They tasted like actual bollucks, just like egg, not enough sugar, hey Ash! But I've tried out this recipe with my Nan, and these ones worked a treat(: http://ten.com.au/the-circle-recipes-sweet-things-baked-custard-tart-with-toffeed-mango.htm

Alrighty, so for task 4, I'm supposed to talk about coagulation. Straight up, coagulation means egg to me after this experiment haha. But its the protein in eggs is what makes it coagulate. So coagulation pretty much means curdling, so when liquids solidify or semi solidify and sometimes become lumpy.

It is a bit confusing learning about the two different forms of proteins I often get confused but the little diagram on the class notes help alot!

So theres two forms of proteins as far as I'm concerned: and this is a bit technical in the wording and confusing but I'll write it anyway!

1. Fibrous Proteins= the coiled helix structure is elongated to form a strand(prettymuch saying its formed like a twisty shape like when you twist your hair around-same sort of shape) Fibrous proteins are found in muscle fibres of meat, poultry and fish, and also in flour products that contain gluten.
2. Globular Proteins= protein strands are twisted into a rounded, compact shape(what I get from this diagram is like Mr. Messy-the shape of him). Globular proteins are found in eggs, dairy products and enzymes.

 

See, the mish-mashed lines on Mr Messy looks like the diagram of globular proteins! 

That's just how I remember it anyway..

This experiment of making Baked custard tart help my understanding of coagulation quite alot. Although I already knew that when you bake custard it solidifies after becoming cool, I didn't know the term for it. And I had no idea so many things could make coagulation occur in food processing!

Theres a lot of usefulness in coagulation in relation of food processing, for example if your making a quiche, when you bake it the egg coagulates. Anything with egg in it prettymuch, even when poaching an egg-if you add an acid like vinegar or lemon juice to the water you are helping the coagulation process speed up and your also helping the poor little egg stay together in the boiling water by become a solid.
Eggs Eggs Eggs! 

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!

Task 2: Function Properties of Carbohydrates- Dextrinisation

In your own words, summarise what you have learnt about the chemical and physical properties of carbohydrates in relation to dextrinisation and caramelisation. 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 ONLY as a guide if you are unsure what to comment on.

•  The difference between dextrinisation and caramelisation
•  Chemical/physical changes that occur.
•  The experiments and how they helped your understanding.
•  Usefulness of dextrinisation in food processing.

Just saying, that cooking and applying knowledge of food science through conclusion questions is so much easier then learning through power points and notes from textbooks! We did these experiments focusing on the functional properties of carbohydrates- better worded as we got to make chocolate chip cookies, toffee, and honeycomb! YUM YUM YUM!

 

When we were doing this experiment at school, a lot of people were finding it hard, burning there sugar in the pan turning it black and the smell was disgusting- this was hard to understand for me, because I have been making these, and doing these specific 'experiments' in the kitchen my whole life. When they couldn't understand why when you added the bicarb soda(the acid) to the sugar mixture is aerated and created a gas, but then traps itself inside the mixture forming a fluffy honeycomb mixture- I was so confused. I mean why did I understand this but they didn't? I'm usually the quiet one that doesn't share my opinions about things in class. But I knew that I was one of the most knowledgeable person when it came to the practicals in the kitchen.

 

So when reading through my notes about this experiment, I came to the conclusion that the things we learn in this class helps me so much in my career- not only is learning about all these chemical structures hard, but its also really interesting. My aspiration of becoming a chef, has only increased my interest in learning about food science, and the chemistry of food, and not only can I help my peers almost every time when they need it, I can better my knowledge and understanding of this subject-which is really exciting! 

So lets get down to business with the differences between Dextrinistation and Caramelisation..

Firstly, lets do definitions

Dextrinisation is prettymuch where things that have starch in them become brown through heating. The more complicated definition is the process in which starch breaks down into dextrins. For example, you know when your toast goes brown and burnt if you toast it for too long? Thats because the starch molecules have broken down into dextrins, and because of the amount of exposure to the dry heat in the toaster and the temperature, it burns pretty easily if you don't keep an eye on it!

Where as Caramelisation is where things that have sugar in them go brown when coming in contact with heat. I know your reading this going.. what is this chick on, she just said that? So yes, its pretty much the same method as dextrinisation in the form of heat application to either starch or sugar and making it brown. The difference is the starch or the sugar. The degree of caramelisation that occurs is determined by the length of heating time, the addition of other ingredients(eg, fat, bicarbonate soda), the type and amount of sugar used and the temperature at which the sugar reaches.

So remember if it has starch- its dextrinisation
and if it has sugar in it- its caramelisation or even crystallisation!

The usefulness of dextrinisation in food processing is pretty simple to explain, as dextrinisation is responsible for bread turning brown during toasting(as mentioned before), the formation of the brown crust you see on baked bread, pastries and baked starchy vegetables such as potatoes, sweet potatoes etc, baked breakfast cereals and the delicious brown gravies for your beautiful baked dinner. Did you know that dextrins are also used as a colouring agent, and also a sweetening agent?

As for Carmelisation, its used for the maiking of all your yummy cakes, baked products, ice-cream, honeycomb, creme caramel(one of my absolute favourites!) and pretty much all confectionery products.

Just because I mentioned creme caramel, I'll leave you with this pretty one, with whipped cream on the top, surrounded by a sugar cage(made of toffee-get it, cause we we're talking about making toffee) I think I might make one of these for dessert tonight! 

Task 1: Essential Nutrients

So I've Finally put all of my notes together and instead of using crappy CLC I've decided to make a blog instead! First up, Nutrients..

In your own words, outline what you have learnt about macro and micro nutrients. You might like to note 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 like use the following as a guide if you are unsure what to comment on.

•      Essential nutrients and why are they needed for a healthy diet.
•    Differences between micro/macro nutrients.
•     Food sources of nutrients.
•    Chemical structure of various macro nutrients

So what is a nutrient you ask?
Nutrients are chemical compounds that are needed for growth , energy and health.

What are the Essential Nutrients to sustain life?
The essential nutrients to sustain and healthy life consist of: Fats, Water, Minerals, Carbohydrates, Vitamins- A,B(fat soluble) C, D, E, K(water soluble). The essential nutrients are broken down into two categories- Macro and Micro nutrients.

Macro nutrients(BIG)
"A nutrient required in large amounts for the normal growth and development of an organism"


Macro nutrients are: Fat, CHO(Carbohydrate), Protein, H2O(Water), Fibre

So a little bit about one of the macro nutrients..

Personally, I think the biggest macro nutrients that we need in our bodies are Carbohydrates. 45-65% of the total daily intake should be Carbohydrates- that is a MASSIVE 225-325g per day! A carbohydrate is a nutrient made up of carbon, hydrogen and oxygen. Carbohydrates are essential because they provide energy(from the sugar and the starches),  and did you know that cellulose is also used to stimulate the digestive tract?

Yum Pasta! Spaghetti with a Napolitana sauce, with fresh basil and grated parmesan cheese on top! Picture Source: mammas-italian-recipes.com


So there are 3 types of carbs:

1. Monosaccharides(simplest form)
   - Glucose(found in fruit, vegetables, honey)
   - Fructose(found in fruit and honey)
   - Galactose(found in milk, sugar)
2. Disaccharides(which have 2 monosaccharides in each)
   - Sucrose(glucose+ fructose)- found in cane sugar, fruits, vegetables
   - Lactose(glucose +galactose)- pretty obvious that this is found in milk!
   - Maltose(two molecules of glucose)- found in malt sugar
3. Polysaccharides(many molecules of monosaccharides)
   -Starch- found in cereals, pasta, bread and starchy vegeables such as potatoes!
   -Cellulose(Fibre)- found in the structure of plants

picture source: chemistry2.csudh.edu


Now for micro nutrients, the small buggers!

Micro nutrients(SMALL)
"Essential dietary elements that are needed only in small quantities, micro nutrients are also known as trace elements"


Micro nutrients are: Vitamins( A, B group, C, D, E, K) and Minerals( Calcium, Iron, Magnesium, Phosphorus, Potassium, Zinc, etc)


Just quickly I'll go over abit about Calcium (Ca)- One of the many micro nutrients that we need to help our body function properly. Calcuim is essential for many functions in the body: bones, blood clotting, development of teeth and gums etc..
Calcium is found in many food sources such as: almonds, brazil nuts, broccoli, kale, dairy foods, soy beans/soy products and green leafy vegetables. For someone that doesn't consume much dairy products like me, I take a calcium supplement daily(Caltrate)-so I don't become calcium deficient. I also need plenty of calcium to help with my teeth-as I had an accident when I was younger, braking my 2 front teeth.
 
Picture Source: nutritionistics.wordpress.com


So, In this lesson I learnt a lot about the essential nutrients and why they are needed, I learnt this difference between macro and micro nutrients. Learning all the different chemical structures was really tricky though! I had a lot of trouble processing them, I understood it, but it was a bit hard remembering them- I've made it a challenge to read over my notes and some of the chemical structures every night before I go to bed so hopefully it will sink in eventually!