Another form of alcohol is glycerin (C3H8O3). It is of special interest to the food chemist because it enters into the formation of all fats.
d ALDEHYDES AND ETHERS
How formed
These are compounds containing carbon, hydrogen, and oxygen, and are closely related to alcohols. In fact they are formed from alcohols by a process of oxidation, hence contain a little larger proportion of oxygen than the related alcohol.
Uses of formaldehyde
An example of aldehyde with which many are familiar is formaldehyde, which is used in laboratories for the preservation of animal-tissues for dissection. This formaldehyde is a very strong germicide; that is, it is poisonous to bacteria or germs. For this reason it is used as a preservative of milk, a use which is forbidden by the "Food and Drugs Act," because formaldehyde is also poisonous to the human system.
Uses of ether
Ethyl ether, which is used as an anesthetic or to produce insensibility to pain, will serve as an illustration of this group of compounds. When analyzing foods in chemical laboratories, ether is commonly used for dissolving fats.
e ORGANIC ACIDS