The Chemistry of Caramel

Introduction

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Caramel is a beige to dark-brown, sweet confection made by heating many different sugars. You can use it to top your ice cream or to fix your sweet tooth. I chose caramel for my project because while it is a common treat, there is still much mystery surrounding the caramelization process. It is fascinating to me how something so common could be such a mystery. The process of making caramel is something near to my heart because around the holidays me and my father make some together!


Composition of ...

  1. Sucrose

    1. C12H22O11

  2. Milk

    1. 87.3% water

    2. 4.9% lactose

    3. 3.3% protein

    4. .7% other minerals

Main Chemicals, Compounds, Components

Sugar is a sweet-tasting, colorless (white) crystalline powder that is most commonly extracted from a sugar cane. The sugar cane must be crushed to extract the juice. This breaks up the hard nodes of the cane and flattens the stem. The juice is then collected, filtered and sometimes filtered to get the extra water out. The liquid that is left over is left to solidify. Sucrose can be melted into caramel in which it forms a noncrystalline structure. It can also break down into water and carbon dioxide to be rapidly metabolized by the body. Sucrose decomposes and melts at 186 degrees celsius. After it cools it becomes caramel. The maillard process further explains the different properties of the melting and caramelization process. Each different kind of sugar has different properties  (taste, color, aroma) when melted.

Milk is a liquid produced from the mammary glands of mammals. Its high in calcium which helps build strong bones. Lactose is a carbohydrate which is a sugar. It can be created from a lab and is obtained from galactose and glucose. It is made drinkable in hundreds of factories that pasteurize milk. Dairy farms often extract the milk from mammals, namely cows, by using a mechanical vacuum milk machines, that stimulates the sucking of their offspring. This artificial milking occurs twice a day in most farms. The large percentage of milk is water, which is a naturally occurring process, as most mammals are mostly composed of water.


Chemistry's Role

Although the process of caramelization is still only vaguely understood by scientists, there is  some basic processes we do know. Chemistry uses the chemical process of caramelization to form the sweet treat we eat. It is one of the most important chemical processes in food, along with the Maillard Reaction and enzymatic reactions. As caramelization does not involve enzymes, it is a non-enzymatic reaction browning reaction.

Caramelization can only occur when sugar is applied to heat. As the heat is applied to the molecule, it makes the atoms move faster. In room temperature, the sucrose is still slightly moving, but still standing in one place. The heat causes  the atoms to be more freely flowing and turn into a liquid. The force of the heat and the moving of the atoms becomes stronger than the force that holds together the atoms. These break apart and come together to form the caramel.

The Maillard reaction is a chemical reaction between amino acids and reducing sugars. It typically happens when head is raised rapidly from 140 to  165 °C. This happens at a lower temperature than caramelization, but it is what gives it its brown color.

Steps of Caramelization:

  1. Decomposition of Sucrose

    1. Sucrose (table sugar/a disaccharide) must break down into fructose and glucose.

    2. This decomposition occurs at 180 degrees C or 356 degrees F.

    3. This is also called sucrose inversion

    4. C12H22O11 (sucrose) + H2O (water) + heat → C6H12O6 (glucose) + C6H12O6 (fructose)

  2. Decomposition of Fructose and Glucose into Aroma Molecules

    1. Crystallized sugar is not volatile (you can’t smell it) but when the sucrose breaks down into fructose and glucose, your brain can detect the new molecules formed.

      1. New molecules: furans (nutty aroma), diacetyl (butter), maltol (toasty), and ethyl acetate (fruity).

  3. Oligomerization of fructose and Glucose

    1. Brown color and portions of texture are developed.

    2. the individual sugars dimerize (glucose and fructose form one molecule)

    3. As one molecules hydroxyl group and hydrogen of the other combine and leave as water, then leaving the molecules combined

      1. This process is also known as dehydration or condensation.

    4. Even if all the steps are followed properly, it does not always mean your end product will be the same, as in differences in taste.

  4. Caramelization Overview

    1. Sucrose has a double ring structure which is further composed of one five-membered ring which is them bonded to a six-membered ring. As heat is applied to the molecule, water is released through dehydration and the two new molecules (glucose and fructose) are produced. As it is continuously heated, they form hundreds of new aromatics that produces many different flavors.

    2. Stages of caramelization are irreversible

    3. Harder caramel is due to less fat (found in milk or butter)

    4. Milk and Butter added causes the sugar molecules to suspend in a jelly matrix which is semisolid.

Background Research

Caramel is a sweet treat used for topping, flavor, and fillings in desserts. It can also be used as a stand alone sweet treat. Caramel is created basically by the heating of sugar. We call this Caramelization.


Milton Hershey Started Lancaster Caramel Company after moving to Pennsylvania after his failed candy company in New York City. His facility was useless for a caramel company because it lacked a boiler. Caramel was not popular until Hershey started adding it to their candies. Although Hershey is credited for making caramel popular, he was not the one who first created it. The exact discovery of caramel is not known, though many believe the arabs were the first to create caramelized sugar in 1000 AD. Their caramel was more like today’s toffee which was hard and crunchy. The soft and chewy caramel is created by adding milk or fat into the sugar, which did not happen until the 1850s.



Resources

https://en.wikipedia.org/wiki/Caramel

  1. Uses

  2. How it’s made

  3. Element components

  4. Caramelization

http://www.hersheyarchives.org/essay/details.aspx?EssayId=43&Rurl=/resources/search-results.aspx?Type=BrowseEssay

  1. History of caramel

http://sciencegeist.net/the-chemistry-of-caramel/

  1. Steps to making caramel

https://bcachemistry.wordpress.com/2014/05/11/the-chemistry-of-caramel/

  1. Steps to caramelization

  2. History of Caramel

http://chemconfections.blogspot.com/2011/01/caramel-delicious-science-experiment.html

  1. Overview of process

  2. 2 different types of caramelization

http://pubs.acs.org/doi/abs/10.1021/jf204807z

  1. What do scientists know?

http://www.calorieking.com/foods/calories-in-candy-caramel-candies_f-ZmlkPTcwMDc0.html

  1. Food label of caramel

  2. How to  burn off the calories

http://www.appropedia.org/Sugar_Production_from_Cane_Sugar_(Practical_Action_Technical_Brief)

  1. How sugar is extracted from sugar cane

About the Author

Piper Stephens is a Junior at Billings Senior High in Billings, Montana. She loves dogs, family, and of course, caramel.


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