Colligative property of ice cream HELP

In summary, the colligative property of ice cream is that the freezing of a liquid is affected by the presence of dissolved molecules (mainly milk proteins and sugars). This depresses the freezing point and is known as a colligative effect. The presence of the solute broadens the range of temperature that freezing will occur as well as when freezing begins. The number of solute molecules determines these effects. Consequently the amount of ice at a given temperature is sensitive to the change in solute concentration.
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Colligative property of ice cream HELP!

How is the colligative property in effect during the manufacture of ice cream, and in the ice cream??
 
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The reason is that the freezing of a liquid is affected by the presence of dissolved molecules (mainly milk proteins and sugars). This depresses the freezing point and is known as a colligative effect. The presence of the solute broadens the range of temperature that freezing will occur as well as when freezing begins. The number of solute molecules determines these effects. Consequently the amount of ice at a given temperature is sensitive to the change in solute concentration. As proteins are fairly large their colligative effect is small in comparison to that of the number of moles of sugar. Therefore, the amount of ice in an ice cream at a given temperature can be estimated by the sugar concentration.
http://www.chm.bris.ac.uk/webprojects2003/brown/thepropertiesoficecream.html

During the manufacture of ice cream one uses chilled brine (water with dissolved salt that lowers the freezing point) to get the temperature of ice cream down below the freezing point of water. Also, the freezing point of ice cream is reduced as mentioned in the quote and reference.

Colligative Property of Water Containing Rock Salt - http://www.waycross.edu/faculty/bmajdi/coligative%20properties%20of%20ice%20creaqm.htm [Broken]

See also - http://pubs.acs.org/cen/whatstuff/stuff/8245icecream.html

Colligative Properties:Properties which depend on the number of molecules in solution, a function of concentration and molecular weight, rather than just on the total percent concentration. Such properties include boiling point elevation, freezing point depression, and osmotic concentration.
- http://www.foodsci.uoguelph.ca/dairyedu/glossary.html

http://hyperphysics.phy-astr.gsu.edu/hbase/chemical/meltpt.html
http://hyperphysics.phy-astr.gsu.edu/hbase/chemical/collig.html#c1

:biggrin:
 
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WOW Jeez man, I can see why you added the grinning smilie at the end. . Thank you. :biggrin:
 
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I can vouch for the colligative properties of the brine solution with ice cream. I've been using a White Mountain hand crank freezer for over 20 yrs and I've noticed (qualitatively) the higher the proportion of rock salt to crushed ice layered between the can and the wooden bucket, the smoother the texture of the ice cream.:tongue2: Presumeably, the cream is freezing faster and therefore yields smaller ice crystals.

Now if you really want to accelerate the freezing process, you might want to try what two http://www.iastate.edu/IaStater/2001/may/icecream.html [Broken] did out in Iowa. The use liquid nitrogen in their recipe and claim it freezes almost instantaneously, giving a uniquely smoother ice cream. They are or in the process of patenting their process.
 
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I've wanted to make liquid nitrogen ice cream for two or three years. If you got one of those ice cream makers, and poured in liquid nitrogen where the ice+salt would be, would it work??
 
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Actually of the methods I've heard about, they pour the liquid nitrogen (-200 deg C) directly into the mixture that becomes ice cream. http://www.polsci.wvu.edu/Henry/Icecream/Icecream.html

I've never tried pouring liquid nitogen in replacement of the ice/salt mixture (-17 deg C). I am guessing that the wooden tub would freeze and could shatter. If the turning mechanism still functions, then you probably could freeze the ice cream that way. Let me know if you try this experiment. :smile:

Another chilling agent that is sometimes used to replace the ice/salt mixture, is dry ice (liquid [itex]CO_2[/itex], -78.5 deg C).
 
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Ooops I knew that. :redface: It was in popular science before too.
 
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Ouabache said:
Actually of the methods I've heard about, they pour the liquid nitrogen (-200 deg C) directly into the mixture that becomes ice cream. http://www.polsci.wvu.edu/Henry/Icecream/Icecream.html

I've never tried pouring liquid nitogen in replacement of the ice/salt mixture (-17 deg C). I am guessing that the wooden tub would freeze and could shatter. If the turning mechanism still functions, then you probably could freeze the ice cream that way. Let me know if you try this experiment. :smile:

Another chilling agent that is sometimes used to replace the ice/salt mixture, is dry ice (liquid [itex]CO_2[/itex], -78.5 deg C).
So the liquid nitrogen should just evaporate off the ice cream as you mix it? I need to try this out.
 
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TheStatutoryApe said:
So the liquid nitrogen should just evaporate off the ice cream as you mix it?
That's true.
(always take the necessary precaution's when working with liquid nitrogen and dry ice. You can get some serious frostbite ).
 
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1. What is the colligative property of ice cream?

The colligative property of ice cream refers to the physical changes that occur in the ice cream when solutes, such as sugar or salt, are added to the mixture. These changes include a decrease in freezing point, an increase in boiling point, and a decrease in vapor pressure.

2. How does the colligative property affect the texture of ice cream?

The colligative property of ice cream is what allows it to have a smooth and creamy texture. When solutes are added, they lower the freezing point of the mixture, preventing large ice crystals from forming. This results in a smoother and softer texture.

3. Why is it important to understand colligative properties in ice cream making?

Understanding the colligative properties of ice cream is important for achieving the desired texture and consistency of the final product. By controlling the amount of solutes added, the freezing point can be adjusted to create a smoother and more creamy ice cream.

4. How do different solutes affect the colligative property of ice cream?

Different solutes have different effects on the colligative property of ice cream. For example, adding more sugar will result in a lower freezing point and a softer texture, while adding more salt will result in a lower freezing point and a harder texture.

5. Can the colligative property of ice cream be manipulated for specific purposes?

Yes, the colligative property of ice cream can be manipulated for specific purposes. For example, adding more solutes can result in a longer melting time, making it ideal for outdoor events on hot days. Similarly, adjusting the freezing point can create a softer or harder texture, depending on personal preferences.

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