Glucosinolate levels in Vegetables
Cruciferous vegetables, such as wasabi (Wasabia japonica), broccoli, cabbage, and kale, are rich sources of sulphur-containing compounds called glucosinolates. Isothiocyanates are the biologically active breakdown products of glucosinolates when in the presence of myrosinase and water. Cruciferous vegetables contain a variety of glucosinolates, each of which forms a different isothiocyanate. For example, Wasabi is the only source of 3 unique powerful glucosinolates which breakdown into 3 unique long chain methyl isothiocyanates, broccoli is a good source of glucoraphanin, the glucosinolate precursor of sulforaphane (SFN), and sinigrin, the glucosinolate precursor of allyl isothiocyanate (AITC). Watercress is a rich source of gluconasturtiin, the precursor of phenethyl isothiocyanate (PEITC), while garden cress is rich in glucotropaeolin, the precursor of benzyl isothiocyanate (BITC).
Wasabi contains 3 unique Glucosinolates which produce corresponding unique isothiocyanates. These unique chemicals which are not found in any other vegetable have been found to be very effective at killing various cancer cells without damaging normal cells. With an effectiveness of 40 times more than sulforaphane, these chemicals are the subject of intense research. At present, scientists are interested in the cancer-preventive activities of vegetables that are rich in glucosinolates as well as individual isothiocyanates.
Metabolism and Bioavailability
Myrosinase, is an enzyme that acts as a catalyst in the presence of water for the breakdown of glucosinolates into Isothiocyanates. It is physically separated from glucosinolates in intact plant cells by a separating cell wall. When cruciferous vegetables are chopped or chewed, myrosinase can interact with glucosinolates and release isothiocyanates. Thorough chewing of raw cruciferous vegetables increases glucosinolate contact with plant myrosinase and increases the amount of isothiocyanates absorbed.
When Sawasabi High Strength Glucosinolate wasabi powder is mixed with water the ITC’s are produced within a few minutes and can be consumed immediately. The product is still in its raw state so the absorption is higher than with cooked vegetables.
Even when plant myrosinase is completely inactivated by heat, the myrosinase activity of human intestinal bacteria allows for some formation and absorption of isothiocyanates. However, the absorption and excretion of isothiocyanates is substantially lower from cooked than from raw cruciferous vegetables.
Cruciferous vegetables, such as wasabi, bok choy, broccoli, Brussels sprouts, cabbage, cauliflower, horseradish, kale, kohlrabi, mustard, radish, rutabaga, turnip, and watercress, are rich sources of a number of useful glucosinolates. Unlike some other chemicals that are found in plants, glucosinolates are present in relatively high concentrations in commonly consumedportions of cruciferousvegetables. For example ½ cup of raw broccoli might provide more than 25 mg of total glucosinolates whereas a single serving of Wasabi provides 67 mg. Total glucosinolate contents of selected cruciferous vegetables are presented in the Table below. Amounts of isothiocyanates formed from glucosinolates in foods are variable and depend partly on food processing and preparation. Consumption of five or more weekly servings of cruciferous vegetables has been associated with significant reductions in cancer risk in some studies.
On a weight for weight basis Sawasabi 100% Pure Wasabia japonica powder contains 11 times more Glucosinolates than its nearest competitor (Brussels sprouts).
Table 1. Glucosinolate Content of Selected Cruciferous Vegetable
|Food (raw)||Serving in grams||Total Glucosinolates (mg)||% of Total|
|Sawasabi Wasabia japonica powder||1 teaspoon, single serving (2.5 gms)||67*||2.680|
|Garden cress||1/2 cup (25 gms)||98||0.392|
|Mustard Greens||1/2 cup, chopped (28 gms)||79||0.282|
|Brussels sprouts||1/2 cup (44 gms)||104||0.236|
|Horseradish||1 Tablespoon (15 gms)||24||0.160|
|Kale||1 cup, chopped (67 gms)||67||0.100|
|Watercress||1 cup, chopped (34 gms)||32||0.094|
|Turnip||1/2 cup, cubes (65 gms)||60||0.092|
|Cabbage, savoy||1/2 cup, chopped (45 gms)||35||0.078|
|Cabbage, red||1/2 cup, chopped (45 gms)||29||0.064|
|Broccoli||1/2 cup, chopped (44 gms)||27||0.061|
|Bok Choy (pak choi)||1/2 cup, chopped (35 gms)||19||0.054|
|Kohlrabi||1/2 cup, chopped (67 gms)||31||0.046|
|Cauliflower||1/2 cup, chopped 50 gms)||22||0.044|
* Independent Laboratory Analysis Results (Unpublished)
More information on the Wasabi Growers Club 70+ Training Modules can be found here.
Michel Van Mellaerts (The Wasabi Maestro) is the recognized World authority and expert on the practical Growing, Processing and Marketing of Wasabia japonica. He and his wife have been commercially growing Wasabia japonica longer than anyone else outside Japan.
Trained as an Electrical and Mechanical Engineer he has invented and installed many improved growing systems into their farms. These enable high quality Wasabi to be grown anywhere in the World.
The Wasabi Maestroes have set up commercial Wasabi growing farms from the Arctic Circle to Southern New Zealand, including the Equator. They have worked with individual growers, national governments, and investment groups on four continents.
These growing systems have reduced growing times by nearly 67%, improved yield and quality of the Wasabi rhizome, and increased the levels of active ingredients by nearly 100%. It is these active ingredients that independent scientific studies show kills cancer cells and improves human health.
They pioneered the use of Wasabia japonica in the Nutraceutical and Medical industries. They are at the leading edge of research into the benefits of Wasabi on human and animal health.
The Wasabi Maestroes offer a Training and Consultancy service for potential and actual Wasabi growers who only want to learn from the best. Others spend their time floundering around trying to find out what information is useful and what isn’t.
The Training has been proven and improved over the last 20 years plus of personal commercial Wasabi growing. This has been hands on, getting wet and dirty work – not guesswork from behind a desk.