Almond Oil – The almond is not technically a nut or fruit! It is a drupe, which refers to its multiple layers. The outer hull of an almond tree’s fruit is a thick, green coating. Inside the hull is the endocarp, which is hard and woody, similar to the outside of the pit found in its cousin, the peach. Inside the endocarp lies the seed, or almond. Almond oil is extracted from this ripe seed.
Avocado Oil – Avocado oil is made from the fruit of the ripe avocado. More oil is extracted from fruit that is past the peak of the ripeness, but if it is rotten when processed, the collected oil has a foul smell. The skin and the seed are removed before processing. There are many suggestions for how to make avocado oil at home, but they often use coconut cream as part of the process. While it is removed via straining at the end, it is not pure avocado oil.
Lemon Oil – The essential oils of the lemon are taken from the bright yellow peel. This outer peel is called the “flavedo”, and it is covered with tiny glands. Each gland contains one drop of essential oil. To extract the organic oil, the glands of the peel must be physically broken open. The main volatile oils in lemon peels are limonene, alpha-terpinene, alpha-pinene, and the main polyphenols in lemon peels are eriocitrin, hesperidin, narirutin, and diosmin.
Orange Oil – The essential oils of the orange are taken from the bright orange peel. This outer peel of citrus fruits is called the “flavedo,” and it is covered with tiny glands. Each gland contains one drop of essential oil. To extract the organic oil, the peel must be physically broken open. The main components of orange oil are somewhat different between a sweet orange and a bitter orange oil.
Apricot Oil – The apricot is a drupe, like fellow members of the prunus genus such as the peach, plum and the almond. The downy outer layer is called the exocarp, and the fleshy fruit is the mesocarp. These layers surround a hard and woody endocarp. Inside the endocarp lies the seed, or apricot kernel. Apricot kernel oil is extracted from this ripe seed.
Evening Primrose Oil – Expeller pressing refers to the process of slowly breaking down evening primrose seeds under mechanical pressure, such as two rotating metal plates, to release the fats. Cold pressed means that the oil was expeller pressed at a low temperature. The low temperature prevents the oil from spoiling and helps it retain the beneficial properties of the plant, including plant sterols. The volatility of the valuable compounds being extracted make it a very delicate process that must be carried out in a narrow temperature range.
Olive Fruit Oil – Olives have traditionally been collected by hand, which is the surest way to protect both the olive and the tree itself. Modern techniques that use sticks or machines to shake olives loose from the trees may be faster and more profitable, but they often bruise the fruit, compromising the flavor.