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 trees 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.
Expeller Pressed And Cold Pressed
Expeller pressing refers to the process of slowly breaking down almonds under mechanical pressure, such as two rotating metal plates, to release the fats from the almond. Cold pressed means that the oil was expeller pressed at a low temperature. The low temperature prevents the oil from spoiling. Almond oil produced by a cold press process is darker in color than a refined process, but is believed to be higher in the properties that make the original plant valuable, including its monounsaturated fats and antimicrobial activity.
Distillation extraction for the essential oils of sweet almonds is not usually necessary because the oils are so abundant in the seeds. Even a home process is enough to release the oil.
Distillation extraction means exposing a plant to water or steam to break down the plant material and release the essential oil. The oils are cooled and condensed for collection.
Distillation extraction is used to extract amygdalin from bitter almonds. Amygdalin is not present in the raw oil, so expeller extraction would not work. The amygdalin is made by the action of emulsin, a component of the bitter almond that is activated when water is present. If the temperature is too high when this reaction happens, the emulsin breaks down and the amygdalin cant be released.
When amygdalin is produced, the bitter almond also releases the essential oil benzaldehyde and a small amount of hydrocyanic acid, also called prussic acid. This prussic acid, or cyanide, is extremely toxic but can be removed with an additional distillation, leaving oil of bitter almond free from prussic acid, also referred to as oil of bitter almond, FFPA. This is the flavoring popular in cooking. Even without the cyanide present, the benzaldehyde and amygdalin are also toxic so the bitter oil is used in drop doses.
Bitter almond oil extract has a strong almond flavor and is used in cooking. Raw bitter almonds are not sold in the U.S. Commercial sources of almond extract may be made from amygdalin-producing fruit from the same family as the almond, including peaches or apricots. These fruits produce less amygdalin, however, so the flavor is less strong than when the amygdalin is taken from bitter almonds.amazon.com.