Aloe vera (Aloe barbadensis) is a succulent that evolved in warm, dry climates in Africa, Asia and Southern Europe. It is cultivated widely both outdoors and indoors for the thick gel in the interior of its thick, fleshy leaves that is used to treat burns and as an ingredient in skin balms, ointments and lotions. Extracting the gel from the leaves is not difficult, but lay persons should not ingest it for laxatives or other medicinal purposes.
A thin layer that adheres to the underside of the thick green aloe vera rind contains tubes that contain aloin, a yellow latex or sap that is high in anthraquinones, a substance that absorbs ultraviolet rays; this prevents water in the interior of the leaf from getting too hot. Aloin is a harsh laxative that should not be consumed.
A thick, slimy layer of mucilage containing xylem and phloem lies beneath the aloin. Xylem are vessels that store and transport minerals and waters from the roots to the leaves; phloem is tissue that transports starches to the roots.
The interior and major portion of the leaf contains a gel or gel fillet that stores carbohydrates needed by the plant.
The rind is only good for compost. The mucilage and gel fillet are removed for medicinal uses.
The best leaves are older mature leaves that are close to the ground; these are cut as low to the ground as possible. They are soaked to loosen the dirt, then washed and rinsed. They are then placed upright in a container for 10 minutes to allow as much aloin as possible to drain out. Gloves are worn during this process.
Removing the Gel
The leaves are placed flat on a cutting board; a knife is used to remove their tips and serrated edges. The leaves are then sliced lengthwise, separating the front and back of the leaves. A spoon or butter knife is used to scoop out the slimy mucilage and the clear, solid gel fillet. This is done firmly, but using too much force can scrape out the aloin.
Bending the gel creates a "juice" that is useful for burns and skin conditions. This will have an unpleasant odor that is not present in aloe processed commercially.
It is not recommended to process aloe vera leaves at home for internal use. If aloe leaves are processed at home, care should be taken to use only the clear gel fillet; this reduces the possibility of contamination by aloin. The gel fillet should be rinsed in vinegar to remove aloin.
Aloin acts as a laxative by irritating the large intestine. The anthraquinones in the aloin can turn urine red; a large dose can inflame the kidney