Saturday, October 18, 2008

Extracting the Facts About Green Tea Extracts

So most of your experience with extracts is in baking …then you notice green tea extract as a liquid and wonder what it actually is, how it is made and how it compares to brewing a tea using a bag and hot water.
Green tea extract as a liquid is often produced as a result of an extraction process where by the fresh or dried tea leaves are immersed in an extraction fluid or what is technically called a menstruum and agitated daily for a 2 to 4 week period. The menstruum is a fluid that is designed to pull or draw out from the green tea leaves the active constituents leaving behind the cellulose and the fiber. A menstruum will more than likely have a solvent such as alcohol as part of the solution.
Solvents are selected for their ability to soften and break down the plant to facilitate optimal extraction of the active and beneficial constituents. Digestible solvents include water, alcohol, glycerine and vinegar. Non-digestible solvents can be very efficient but are hard to remove after extraction without damaging important and beneficial plant constituents. Still, traces of these non-digestive solvents are left behind regardless of efforts undertaken to remove them. Therefore, many consider them to be a poor choice for an herbal extraction.
The most popular and effective solvent is organically grown, distilled corn grain alcohol. A very popular menstruum is made by mixing this corn grain alcohol with filtered spring water. The raw herb material is often prepared in some way for immersion in the menstruum. The formal term for this preparation is the comminution of the herb material.
Comminution usually involves grinding the fresh undried tea leaves into a wet mush or the dried herb into a grind of course powder. Once the herb material is saturated in the menstruum it undergoes a process of maceration.
Maceration is from a Latin word which means to soften. This maceration process involves allowing the mixture of herb and menstruum to be agitated daily as mentioned before for a period of about 2 to 4 weeks. The final step is a process of separating the liquid from the spent herb material and an additional step of filtering out any small plant particles from the liquid extract.
This herb to menstruum ratio of 1:1 would result in a 1:1 herbal extract. Thus an extraction resulting from a process utilizing an herb to menstruum ratio determined the classification of the resulting herb extraction. For example: 1:1 means that there is equal part herb and equal part menstruum mixed together that makes up the resulting extraction.

Before the advent of new technological advances in extraction processes, it used to be that the herb to menstruum ratio is expressed as two numbers with a semicolon in the middle.
However, as mentioned there have been technological advances in the processes used to produce herbal extractions. At this point different makers of herb extractions may add additional processes in their production that remove alcohol or water with low heat or hydraulic machinery which can further concentrate the resulting liquid extraction. How the resulting herbal extraction is then classified can depend on the original herb to menstruum ratio or how concentrated it has become as a result of post extraction processes.
Herbal Solutions for Healthy Living offers the following guide for classifying the resulting liquid extraction according to the Herb Strength Ratio. The example that is offered is as follows: An herb strength ratio of 1:1 would mean that 1000 grams of raw herb produced 1 liter of liquid herb extraction. An herb strength ratio of 1:5 would mean that 1000 grams of raw herbal material produced 5 liters of a liquid extraction.
This reference then offers the following as a guide for classifying the liquid herbal extractions according to their degree of concentration or herb to strength ratios.
A tincture is classified as having an herb strength ratio of 1:5, a saturated tincture has a ratio of (1:3), fluid extract (1:1), and a solid extract (2:1) or greater. Some say a solid extract should have an herb strength ratio of 4:1 or greater.
The process of removing the alcohol and water or the components of the menstruum to concentrate the resulting liquid extraction is also used to make the alcohol free extracts.
Some makers claim they can remove virtually all the alcohol (which for many herbs acts as a superior solvent or extractor) and replace it with vegetable glycerine which can then serve to stabilize and preserve the resulting liquid extraction.
So alcohol is initially used in the menstruum to facilitate the extraction and then is removed, according to some manufacturers, and is replaced with slightly sweet tasting glycerine which then serves as a preservative to stabilize the liquid extraction. This is a common way alcohol-free herbal extractions are produced, especially ones marketed as suitable for children.
Let's walk through the extraction process with a specific brand of green tea extract to understand in more detail what one is getting when purchasing a liquid extraction product. According to a company spokesperson, Green Tea Extract from Gaia Herbs is made using 8 pounds of dried herb and one gallon of menstruum, which also happens to weigh 8 pounds.
As a result the herb to menstruum ratio is 1:1. The product comes in a 1 fluid ounce bottle. There are 900 drops in each bottle. The percentage of alcohol in the menstruum is 35 to 45 percent. Thus, in a 30 drop serving 3 to 4 are alcohol. Because 8 pounds of dried herb were used at an herb to menstruum ratio of 1:1 to make the extract, there is about 1000 mg per serving.
of the ground green tea leaves. A serving of 30 drops is pretty close to a single brewed cup (about 8 oz.) made from a tea bag containing about a 1000 mg. Almost all of those polyphenols (80%) are the Epigallocatechin gallates or OGCg's which researchers are focusing on as being responsible for much of the benefits green tea consumption can offer.

of polyphenols in each 30 drop serving. There is 70 mg. of caffeine in each serving. Also, there is 20 to 25 mg.
In order for the liquid extraction of green tea to be placed in a capsule, an effort must be undertaken to remove the alcohol. This process usually results in a higher concentrated form enclosed in each capsule as the weight to volume or herb strength ratio will be 1:1 or even higher, perhaps 2:1 or more. The amount of extraction liquid in a single gel cap serving will be closer to 15 drops or about a ½ a milliliter given that it has undergone a process to remove the alcohol.
Once again because of the higher concentration of the green tea liquid, there will be about 150 mg of polyphenols in a 15 drop gel cap. There will be a slight bit more than 20-25 mg. of caffeine because the liquid in the gel capsule has a higher concentration.
Nothing in this article should be misconstrued as medical advice. Should you have questions, we urge you to contact the manufacturer of the herbal product and/or a qualified medical professional to discuss your own unique circumstances. It has been our experience that most reputable companies are very willing to answer questions about how their herbal products have been made and details of their contents.

The processes and constituent values will vary from product to product. Of course these are approximate values, to be used as a general rule of thumb for comparing different products.
And now a final word about possible pesticides, fluoride and metals in herbal products. The manufacturers that we have contacted for this article have concerns about unwanted elements such as these in herbal products. Often, herbal manufacturers will establish a relationship with an organic grower and after initial testing, conclude that the grower can be relied upon as a quality organic source of raw herb product and may or may not conduct additional testing going forward. Others may screen for some but not all of the three, pesticides, metals and fluoride.
Other herbal product makers will screen the raw herbs used to make their products and also claim in their advertising that certain processes are then undertaken to remove these three unwanted elements and others. Certain herbal product makers will even claim on their product labels and product literature that they are pesticide, metal and/or fluoride free.
Again, if you are concerned and or unsure about the contents of the herbal products that you are or are considering taking, we urge you to contact the manufacturer. Most have toll free numbers to call or provide a way to contact them through their website.
Also, we urge that you to talk to your physician or other medical practitioner regarding the health risks of pesticides, metals, fluorides, and other unwanted elements versus the benefit(s) of taking an herb product.
Finally, some medical practitioners say the minute amounts of these unwanted elements.
J. Kratz is a contributing editor to
He has interests in nutrition and the use of plant based medicines in supporting the body's natural healing abilities. He has come to recognize the connection between emotional or spiritual well-being and good health. He has studied and written about various medical philosophies and systems including osteopathy, ayurveda, naturopathy, and traditional Chinese medicine. He also served as an associate producer for call in radio talk shows "Doctortalk" and "Second Opinion, Please" featuring alternative practitioner Howard Hagglund M.D. which aired in Oklahoma and Texas.


Blogger template 'Kiwi' by 2008