Myrosinase is an enzyme found in certain plants, especially in seeds like mustard and broccoli. It helps break down specific chemicals called glucosinolates into active compounds, which give these plants their characteristic taste and smell.
Full definition
The seeds also contain
myrosinase enzymes that can break apart the glucosinolates into other phytonutrients called isothiocyanates.
Between 1 - 10 minutes, loss
of myrosinase activity will become greater and greater with each additional minute of heating and with each increase in cooking temperature.
When cruciferous vegetables are consumed in cooked form, and especially if they have not been allowed to sit chopped for several minutes prior to cooking, there is unlikely to be much enzyme activity (including
myrosinase activity), and the digestive products of the cruciferous vegetables are more likely to pass through the upper digestive tract unabsorbed and continue down into the lower digestive tract (colon).
All plants in the cruciferous vegetable family that contain glucosinolates also
contain myrosinase enzymes.
When raw cruciferous vegetables are chopped or chewed, an enzyme
called myrosinase comes into contact with glucoraphanin and produces sulforaphane.
Furthermore, the same goes when consuming them freshly after cutting and chopping, and not allowing adequate time
for myrosinase to jump into action.
In broccoli sprouts, its precursor, glucoraphanin, exists and is converted into sulforaphane
by myrosinase contained in broccoli itself and produced by microbes in the gut.
This makes sense when we understand the complex interaction needed
between myrosinase and glucoraphanin that creates sulforaphane.
The team reported that stir - frying
inactivated myrosinase (a substance that breaks down glucosinolates) thereby helping to prevent their release and loss.
This is because the glucosinolate - ITC conversion process requires the presence of the enzyme
myrosinase which is destroyed during cooking.
When myrosinase enzymes convert glucosinolates found in cruciferous vegetables into thiocyanates (including isothiocyanates), some of the thiocyanates formed have the ability to bind together with free iodine found in the body.
Freshly harvested cruciferous vegetables eaten in raw form will typically have a significant percentage of their glucosinolates converted into isothiocyanates by still
active myrosinase enzymes and these isothiocyanates will become available in the upper digestive tract (small intestine) for absorption into the bloodstream.
Sulforaphane is formed when fresh broccoli is chopped or chewed, bringing its precursor glucoraphanin and the enzyme
myrosinase into contact with each other.
(4, 5]-RRB- When kale is damaged via chopping or chewing, the enzyme
myrosinase helps release isothiocyanates by interacting with glucosinolates.
So the researchers decided to expose frozen broccoli to
myrosinase from a related cruciferous vegetable.
Sulforaphane is created when the enzyme
myrosinase transforms the glucosinolate glucoraphanin into sulforaphane.
Since myrosinase and glucoraphanin are found in different parts of the plant, this change happens when the plant is damaged (by chewing, blending, chopping, etc.) allowing the two compounds to mix and react.
Sulforaphane was found to be 7 times greater in fresh broccoli sprouts vs supplements with
inactive myrosinase (R).
This process will
allow myrosinase enzymes to go to work prior to their deactivation by cooking heats.
For instance, studies reveal that isothiocyanate metabolites can be detected in the blood and urine after cooked glucosinolate - containing foods are eaten, although to a lesser extent than their raw glucosinolate - containing counterparts.69 In far messier studies, scientists have taken cooked watercress and simply mixed it with human feces, which converted the glucosinolates to isothiocyanates through their
intrinsic myrosinase activity.
When you cook cabbage, you kill the
special myrosinase enzyme that makes the cabbage so healing, thus making cabbage less effective as anti cancer food.
Cruciferous vegetables contain isothiocyanates, and so because of this, she typically eats them with mustard powder sprinkled on top to increase the amount of
myrosinase available.
When cruciferous vegetables are cooked,
plant myrosinase is inactivated thus the hydrolysis of glucosinolates is prevented.
Naturally occurring sulforaphane in cruciferous vegetables is formed from glucosinolates, which are produced with the help of an enzyme
called myrosinase.
The chart below shows five very well - studied glucosinolates, the best cruciferous vegetables for obtaining them, and some key isothiocyanates that form after the glucosinolates have been acted upon
by myrosinase enzymes:
Adding myrosinase enzymes in the form of even a pinch of mustard powder to cooked cruciferous (cabbage - family) vegetables like kale, collards or Brussels sprouts can offer anti-cancer sulforaphane levels comparable to raw, removing the necessity to pre-chop for maximum health benefits.
By the time they reach our bowels, the critters that live there take over
for myrosinase to produce sulforaphane from the more heat - stable glucosinolates.
But they had previously had success using other food sources
of myrosinase to boost broccoli's health benefits.
Freshly harvested cruciferous vegetables not consumed in raw form, but chopped and allowed to sit for several minutes prior to cooking will typically have some of their glucosinolates converted into isothiocyanates by still
active myrosinase enzymes, and these isothiocyanates will also be available for absorption in the upper digestive tract.
More accurately, Brassica vegetables
contain myrosinase, which helps break down glucosinolates like glucoraphanin into usable forms of isothiocyanates including sulforaphane.
In freshly harvested plants,
myrosinase enzymes continue to function, but this function decreases over time.
For more information on broccoli and
myrosinase, check out this article.
Myrosinase is also anti-inflammatory, so it will help keep your body healthy in many ways!
Of course, glucoraphanin requires the enzyme
myrosinase for conversion, but broccoli sprouts are particularly high in myrosinase, so you're ending up with plenty of sulforaphane either way.
In a study that compared steaming versus microwaving of raw cabbage, researchers found that it took 7 minutes of steaming to result in the same about of enzyme (
myrosinase) destruction that occurred with only 2 minutes of microwaving.
In other words, short steaming was much better than microwaving for preserving
some myrosinase activity in the cabbage.
When they used a temperature of 76ºC, 82 percent of the enzyme
myrosinase was preserved without compromising food safety and quality.
The extreme heat destroys the enzyme
myrosinase, which is necessary to form sulforaphane, the powerful cancer - preventive compound in broccoli, she said.
Phrases with «myrosinase»