Aloe Vera, The Whole Leaf Advantage
Excerpts By Ivan E. Danhof, M.D., Ph.D.
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centuries, have been replaced by laxative agents possessing fewer undesirable side-effects.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 and Aloe Leaf Processing |
|
Process
Fraction
|
Hand Filleting
(%)
|
Whole Leaf
(%)
|
Total Solids
(without preservatives
or additives) |
0.45 - 0.65
|
1.30 - 3.50
|
Polysaccharides |
0.12
|
0.16
|
|
In Table I, the data reveals that the quantity of desirable polysaccharides is 2 1/2 to 3
times the yield using the hand filleting methods.
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 and Constituents |
|
Method Of
Preparation
|
pH
|
Aloin
(ppm)
|
(%)
H 20
|
(%) Total
Solids
|
Hand-filleting |
4.27
|
6
|
99.25
|
0.48
|
Roller |
4.30
|
32
|
99.61
|
0.39
|
Leaf Splitter |
4.24
|
18
|
99.61
|
0.42
|
Whole Leaf |
4.09
|
1
|
98.62
|
1.38
|
|
Table II data compares various processing methods and the effect on yield (total solids),
aloin concentration, and the distribution of sizes of constituents. The whole leaf method can produce an Aloe
juice which is high in total solids, high in retained high dalton (molecular weight) polysaccharides with their
scientifically demonstrated benefits, while the aloin concentration is at a very acceptable low level.
Cold Versus Heat Processing Methods
Data suggest that the time interval between leaf harvesting and processing (sun exposure)
should be minimized (less than 24 hrs); heat exposure during processing should be minimized, especially if high
temperatures are maintained for an hour or more.
How To Release The Gel From An Aloe Vera Plant - Video
Advantages Of The Whole Leaf Cold Processing MethodsAdvantages of the whole leaf,
cold-processed, approaches include the following:
- Maximizes the yield of desirable constituents.
- Increases cost effectiveness of processing.
- Increased total solids concentration.
- Increased polysaccharide concentrations.
- Virtual absence of undesirable anthraquinones.
- Improved desirable characteristics for cosmetic usage.
- Increased concentration in permeability factors increasing transdermal penetration.
- Improved taste palatability.
- Increased concentration of growth factors responsible for accelerating of healing.
- Increased concentration of factors responsible for the stimulation of the immune system.
Aloe Vera, The Whole Leaf Advantage
|