Gelatin is a staple ingredient used in the making of capsules and jelly, giving these items the ability to have a strong wobble and a strange transparent look to them. But what exactly makes it wobble like that? Well, research shows it is made of collagen, a fibrous protein that makes up almost one-third of the human body's proteins. It strengthens the body's connective tissues, allowing them to be elastic and stretch without breaking easily. (Goodsell, 2011)
However, gelatin is unable to be dissolved by water in its natural state. Because of this, it must be first dissolved by a strong acid or base, followed by boiling, washing and filtering. During these processes, it is slowly broken up into pieces until it ends up as a gelatin solution. The solution is chilled into a jelly-like material, cut, then dried under special conditions. The product is ground once it is ready.
At room temperature, the gelatin protein purchased is in the form of a triple helix. This is a fairly ordered structure in contrast with DNA. In DNA, two chains of nucleotides are twisted together in a spiral pattern resembling a ladder, in a design known as a double helix. In the gelatin protein, three separate chains of amino acids (called polypeptide chains) have lined up and twisted around each other. Those amino acids are mostly glycine, proline and hydroxyproline. Weak bonds hold the helix together.
In order to make the usual gelatin, hot water is added to the powder and stirred.The energy of the heated water breaks the weak bonds that hold the gelatin strands together. The helical structure unwinds, and you're left with free-floating protein chains. When you add cold water and refrigerate the gelatin mixture, the chains begin slowly to reform into the tight triple helix structure. As it cools, the mass acts like a sponge, soaking up the water you added. But in some places, there are gaps in the helix, and in others, there is a tangled web of polypeptide chains. The chains form a sort of net, and the net traps water inside pockets between the chains.(GEA, 2011)
Problem with Gelatin Capsules
There are two kinds of capsules: hard ones and soft ones. The kind of capsule used is dependent on the kind of drug being administered. Powdered medicine is put in hard capsules, which is made only when the medicine will dissolve easily in the stomach. Medicine like oils is put in soft capsules, which is made so that the capsule shell will melt within minutes in the stomach.(n.d, 2015)
The problem is the capsules must be made under very different conditions, as the hard capsules must be made with hard gelatin and the soft capsules must be made with soft gelatin. These conditions must be met in order to create the right kind of gelatin for the different types of capsules.
A student wanted to find out what conditions are the best for making the strongest gelatin.
In order to answer their question, we needed to find out how different factors affect the strength of gelatin that is usually used in medical capsules.
The independent variables are:
- The amount of stirring of the mixture
- The powder-water ratio
The dependent variable is:
The crushing weight of the gelatin produced, which will be tested by placing weights on top of the gelatin until it breaks.
The constants are:
- The volume of the mixture in each container
- The type and brand of gelatin used
- The material of the containers used
- The number of containers of gelatin being tested at a time
- The shape of the containers used
The hypotheses are:
- As the number of times the mixture is stirred increases, the weaker the gelatin produced is.
- The more powder used in the mixture, the weaker the gelatin produced is.