Aloe and its Quality Control - Checking upon the Genuineness of Products

Aloe is an extraordinarily beneficial plant remedy, but it has unfortunately been subject to misleading statements on product labels and in promotional literature. Dilution with water and adulteration with cheap additives have been common. This newsletter examines this extremely important aspect of Aloe.

Introduction

It is the straightforward requirement of the consumer to be supplied with Aloe Extract which is genuinely from the Aloe plant and which has not been contaminated with anything else. The consumer can come to realise that some preservatives are needed, otherwise the Aloe vera Extract cannot possibly be stabilized for distribution and marketing. So far as that is concerned, he or she will always want to see the amount of preservatives kept down to the minimum needed and will also want to be sure that only the most benign preservative compounds are employed. So far as any other additives are concerned, the consumer would usually rather be without them, but, where they are used, the most important thing is that full information should be given so that it becomes clear to the consumer that certain named brands of Aloe are either diluted with water or adulterated with cheap non-Aloe solids, enabling rational purchase decisions to be made. The tendency, which has long been rather rife in this Industry, to sell very diluted products, or to sell products adulterated with cheap non-Aloe additives, without any clear label declaration, is to be deplored.

This Newsletter should be read in conjunction with Newsletter No 8 on "The Crucial Importance of Correct Processing". One needs to bear in mind that an Aloe vera which has not been diluted or adulterated, may nonetheless be degraded in its biological activities. Because of that, any product tests that do not measure biological activity have distinct limitations from the standpoint of the consumer.

The Problem of Dilution

The oldest trick in the trade in selling any valuable product in solution is to dilute it with more water. That can sometimes be true of Scotch Whisky, though there is a limit to which the dilution can be taken before the consumer begins to notice that something is missing. In the case of Aloe vera, it seems that the consumer is very insensitive to noticing the effects of dilution. Lee Ritter, in his book "Aloe Vera - A Mission Discovered" quotes one Dr. R McDaniel as having tested over 200 Aloe vera beverages in the mid 1980's (presumably in the United States) and having found that of these only three "contained sufficient Aloe to be of any medical value to the consumer". He goes on to say that at the time of writing (1993) according to his own tests "less than one percent of readily available brands contain acceptable levels of Aloe vera".

It has also become known that one well-known U.S. brand of Aloe vera effectively contains no Aloe at all. It has been claimed to be a distillate of Aloe - a claim which seems to signify that water is turned into steam in the presence of some Aloe leaves. The steam which comes off is purported to carry with it volatile constituents of Aloe. The trouble with that is that the product apparently contains not enough of these to be readily detectable. The question arises as to how much Aloe is actually used in this boiling off operation - can it be possible that the same Aloe leaves are used over and over again? The question is academic anyway, because all research on Aloe shows that its active constituents are components of the solid fraction of the plant and would not distil over. The product which gets sold from this operation is the condensate of the steam, and it has been described as nearly pure water.

The Detection of Dilution

If the supplier is quite simply adding a major amount of water to an Aloe vera product, this will become obvious as soon as one measures the "total solids" of the product. An Aloe vera Gel product typically contains about 0.46 to 0.6% solids. The reader may be surprised that the concentration is so low. However, one should remember that Aloe vera gel is the water-storage organ of the plant. Hence the above figures are normal values - i.e. they are what one expects Aloe Gel to contain. If a party were to dilute the Gel ten-fold, this would become 0.05% to 0.06%. The picture is likely to be complicated by the addition of preservatives. What would happen in this case is that the preservatives content would tend to dominate the Aloe content because the latter had fallen to such low levels. Ultimately one may need to elucidate the preservative content separately. However, the fact remains that if the solids of the whole product is extremely low, much less than the normal content of solids in Aloe vera Gel, then dilution has certainly occurred. The usual method of measuring the total solids level is to evaporate a known volume of the solution to dryness in a vacuum oven and carefully weigh the residue.

Adulteration with Cheap Non-Aloe Solids

Clearly, the people who sell almost pure water and pass it off as Aloe are easy to detect and, equally obviously, they are not afraid of being detected. The circumstances just have not been created yet to make life sufficiently uncomfortable for them, even though the Trades Descriptions Act gives the theoretical ability to take action. Other suppliers who dilute Aloe try to make out that they are not diluting it, by adding back some solids of a different kind, i.e. non-Aloe solids.

When this is done, simple measurement of the total solids in the product is no longer capable of exposing the dilution of the Aloe. Total solids can be made to look normal, but the point is that the solids are of the wrong kind and will not possess the biomedical properties of Aloe. This calls for a slightly more sophisticated form of chemical analysis which is capable of distinguishing between Aloe solids and non-Aloe solids.

Chemical Analysis to Detect Adulteration

To attempt to distinguish between one plant extract and another by chemical analysis is not easy without resorting to degrees of sophistication which make the whole process too expensive for routine use. This arises from the fact that all plant extracts from different species have numerous components in common. However, Aloe can be distinguished from other species to a certain degree by its special polysaccharide (carbohydrate) component, called "glucomannan". Tests to distinguish the glucomannan clearly from polysaccharides of other plant species would have to be sophisticated. However, testing for the presence of polysaccharide per se is not. It is done by means of a test called the "alcohol precipitable hexose" test. The plant extract is first mixed in fixed ratio with alcohol (often methanol is used) and this produces a precipitate (i.e. a coming out of solution) of a material which contains the Aloe carbohydrate. This precipitate can be separated out and weighed to give a measure of the amount of "methanol precipitable solids" (MPS) present in the sample. Because these "methanol precipitable solids" contain the actual polysaccharide component of Aloe, values of MPS are often quoted by suppliers to give a crude measure of the biological activity of their product. This "MPS" value is certainly better than nothing. For example, we can be sure that if a product gave an "MPS" value of zero, then the product would contain none of the type of biological activity which is associated with the polysaccharide fraction.

The commonest substance used for the adulteration of Aloe is maltodextrin - a cheap carbohydrate material obtained from corn starch. In the chemical analysis maltodextrin records largely as "alcohol precipitable hexose", and is potentially very misleading because it could make it look as if the Aloe sample was supremely good in respect of its "alcohol precipitable hexose" content even though, of course, it has absolutely no biomedical activity. Fortunately, though, the maltodextrin can be detected as an adulterant because it always raises the result of the "alcohol precipitable hexose" test to quite abnormally high levels which would never be attained with real Aloe. Hence the artificiality of the position becomes exposed.

The International Aloe Science Council's Certification Programme

This programme has already been referred to in NewsLetter No 8. It is very much the practical side of the Industry seeking to get its own house in order. The work of the International Aloe Science Council based in Dallas, Texas, is laudable. They will provide Certification of products as being genuine Aloe. Of course, this is wholly good, and it is accompanied by a programme of plant and process inspections intended to make sure that the certified product cannot be diluted or adulterated. By definition, these steps cannot have any effect upon parties who do not choose to apply for certification.

Nonetheless it is this author's opinion that the Council needs to give urgent consideration to moving to a system of analysis and certification based upon measuring the biomedical actions of the Aloe or the biochemical substances that are directly responsible for mediating these biomedical actions. So long as biomedically inactive marker substances, such as calcium or malic acid are used, they are capable of being met by artificial additions to Aloe products which would do nothing to ensure the levels of biomedical activity wanted by consumers.

The "X" System

We have now to focus upon the designation of Aloe products according to a system of "X" numbers which have long been used in the industry. The "X" is supposed to mean the number of times or "fold" which an Aloe product has been concentrated over and above natural strength. Inherently, there is no good reason why such a system could not have worked in a useful way. However, given the nature of this Industry, which has spawned many misleading statements about Aloe, it was probably always doomed to fail as a reliable index of the strength of Aloe extracts.

Given that Aloe vera Gel at natural strength is typically 0.46 to 0.6% solids, it follows that if you concentrate it by evaporation of water so as to double its strength, one should reach a strength of 1.0 or 1.2% solids. This would be referred to as a "2X" concentrate. Similarly, if enough water is removed by evaporation to increase the strength tenfold, the concentration of solids must rise to 5 to 6% and such a product would be known as "10X". Intermediate values would obviously be possible, such as a "4X".

This highlights the first vital weakness of the "X" system. If a product is a "2X", i.e. a two-fold concentrate, then what is it? Two times what? The lack of such a definition undermines the system. In other words, it fails the consumer by failing to define just what it is that the consumer is getting.

A most unfortunate practice which has emerged is the tendency to call a "2X" Whole Leaf Extract by the designation "5X", simply because it has five times the solids content of a Gel. That is one reason why the "X" system should be abandoned. This system gets abused worst when like is not compared to like. A Whole Leaf Concentrate should never be expressed on the scale of values which properly applies only to Gel products unless the basis of comparison is stated clearly.

Scrapping and Replacing the "X" system

In reviewing this matter carefully, this author has come to the conclusion that it would be in the best interests of the Aloe Industry to scrap the "X" system, since it has inherent flaws and has been brought into disrepute by being deliberately stretched to yield various tendentious and wrong meanings.

Hence, reporting upon "Aloe solids" is honest when done according to correct arithmetic. It guarantees the consumer the first thing he or she needs to know - to what extent the product comes from Aloe. The information about biological activity usually cannot be presented. So marketing companies do best to avoid pretending about that and to avoid vague terms such as "strength" or "power" unless they really do have supporting data. Solids may be accompanied by proportionate levels of strength or power, but on the other hand they may not.

Ultimately, of course, the consumer's interest has to be not so much in solids as in biological activity. Solids are just that - solids. Who wants inactive Aloe solids? Who is remotely interested in having more solids if it means having just the same amount of biological activity - there is no advantage. That is why the Industry needs to move forward towards defining Aloe product according to biological activity and nothing else, according to recognised testing procedures. We are simply not there yet. Hence a clear statement of Aloe solids and to what extent they are derived from Whole Leaf or Gel would leave the consumer much better placed than at present.