Met de hand aloe bladen verwerken levert een kwalitatief minder eindproduct op
In the evolution of processing methods of Aloe vera leaves, The hand-filleting procedure was developed to avoid contamination of the internal gel fillet with the yellow sap found in the pericyclic cells of the vascular bundles located just beneath the thick green rind of the leaf. The yellow sap has a number of laxative anthraquinones, the major being aloin. As the laxative action of these anthraquinones may be associated with considerable abdominal cramping in humans, these agents, although widely used from the 17th through the 20th centuries, have been replaced by laxative agents possessing fewer undesirable side-effects.
Aloin contains a glucose molecule attached to the parent anthracane ring. If the glucose is cleaved off, the resulting product is Aloe-emodin, which has, depending on its concentration, a red through brown through black coloration, which is in cosmetic products. Thus, the presence of aloin or its derivatives is undesirable both for internal consumption and topical usage.
Only recently have processing methods using the entire whole leaf been
perfected so the undesirable elements can be selectively removed, while
maximizing the desired constituents. Among the desirable constituents are
the polysaccharides (glucomannans), glycoproteins and associated growth
factors.
| Table I
Yields & Aloe Leaf Processing |
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Occasionally an individual sample may contain more than the amounts indicated in the table; this may occur if the leaves are dehydrated. These ranges will encompass 95% of routine samples based on current in-hand data.
The major undesirable constituents, the polyhydroxyanthraquinones, can
be selectively removed through filtration through charcoal and other absorbents
so the remaining level of aloin is 1 ppm or less.
| Table II
Methods Of Leaf Preperation & Constituents |
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Data suggest that the time interval between leaf harvesting and processing
(sun exposure) should be minimized (less than 2-8 hrs); heat exposure during
processing should be minimized, especially if high temperatures are maintained
for an hour or more.
Advantages of aloevera, cold-processed, approaches include the
following: