Carrier oils, also known as ‘fatty oils’, are esters of glycerol combined with three fatty acids (triglycerides). The chain length of these fatty acids including their bond status, whereby saturated or unsaturated, can affect the melting profile, crystallization characteristics and the functionality of the carrier oils. Methods of withdrawing the oils from their sources include cold pressed, expeller expressed, solvent extraction and CO2 extraction – a solo process can be used or a combination of methods to ensure high yields. During the manufacturing process, oxidation of triglycerides can occur leading to rancidity with the characteristic malodour. Some oils are therefore subjected to a refining process to remove such undesirable elements thereby adding stability and subsequently extending the shelf life of the oils. In cold conditions, oils containing higher molecular weight triglycerides precipitate giving a cloudy appearance. Refining in combination with a process called ‘winterizing’ filters the sold oil crystals leading to clearer, lighter oils.
