Food additives are added to foods to increase shelf-life of products and can also serve as cheaper fillers or ingredients. Case in point, high fructose corn syrup is cheaper than traditional can sugar, hence the reason it is now in so many products. The bottom line is that additives increase companies profits. These increases revenue has made additives very popular, though they don't always benefit consumers that are prone to allergies or asthma.
So without further adieu, here are some interesting "How you make them" food additive facts.
Caramel coloring is a food dye that is used in lots of soft drinks. Some forms of caramel coloring are manufactured by reacting sugars with ammonia and sulfites under high pressure and temperature.
High fructose corn syrup
Typically when you break corn down, you get glucose. But glucose doesn't taste nearly as sweet as fructose, so chemists developed a method of rearranging the atoms in glucose so that it becomes fructose. Thus with this process corn could be broken down and altered to make fructose. This modified formula is then combined with regular corn syrup so that it becomes a 45% glucose 55% fructose solution. This sweeter solution is cheaper than regular sugar, hence the reason it's in so many products now.
Gelatin, which is used to thicken foods (just think of jello) is made from boiling skin, muscle and hooves. This process releases collagen, which is an elastic connective tissue and results in a thickening, stabilizing ingredient.
Carmine is a red food dye that is made from boiling crushed cochineal insects' exoskeletons in water, then treating the resulting solution with the chemical compound alum.
Sulphur dioxide is a preservative that also keeps dried fruits, like apricots and golden raisins, from darkening. It is made by burning of common sulfur-rich materials including wool, hair, rubber, and foam rubber.
Xanthum gum, which is a sticky goo that thickens and stabilizes food like ice cream, is made by fermenting corn sugar with bacteria. It is popular among people that can't digest gluten since it is a gluten free product.
If you are concerned about processed food in your kiddos diets', the Center for Science in the Public Interest has a great list of which additives are safe, questionable of best avoided. As a rule of thumb, the less ingredients a product has, the less additives it will contain and it's also more likely to be less allergenic.
Related reading: Soda and cancer risk
High fructose corn syrup and why you should avoid it
Why is my cheese yellow?