Preserve Broccoli Anti-Cancer Nutrients By Cooking it The Right Way

how to cook broccoli

The main active substance in broccoli is sulforaphane, which protects our brain, eyesight, body against free radicals and leads to the formation of detoxifying enzymes, preventing disease. Here is a preparation strategy through which you can benefit from these beneficial substances from broccoli.

The main active substance in broccoli is sulforaphane, which protects our brain, eyesight, body against free radicals, leads to the formation of detoxifying enzymes and prevents disease and can even be used to treat cancer.

The process of sulforaphane formation is like a chemical reaction that requires the combination of a precursor compound with an enzyme, usually destroyed by the cooking process. 

This may explain why cancer cells are so effectively suppressed while eating raw broccoli, cauliflower and Brussels sprouts, but there is no effect if they are cooked, microwave-cooked or steamed (except for broccoli, which is more retains some of its anticancer properties). But who would want to eat raw Brussels sprouts?

Here is a strategy to benefit from the qualities of these vegetables and in their cooked state. In raw broccoli, the precursor of sulforaphane, called glucoraphanin, combines with an enzyme – myrosinase – when cut or chewed. Soon – when it waits in the upper part of the stomach to be digested – sulforaphane is born. 

The precursor and sulforaphane are resistant to heat and, therefore, to the cooking process, but not to the enzyme, which is destroyed by cooking. In the absence of the enzyme, sulforaphane is not formed.

That’s why the cutting and waiting technique is recommended – that is, cut broccoli, Brussels sprouts, kale, cabbage or cauliflower and leave them for about 40 minutes, after which you cook them normally. In this phase sulforaphane is already created; the enzyme has completed its task, it is no longer needed.

When cooking broccoli soup, for example, many people do it wrong. First I cook broccoli, then I pass it. Now we know we have to do the exact opposite. We pass first, wait, then cook.

What if we use frozen broccoli? The difference in sulforaphane produced in the body after consuming a soup made from fresh broccoli and one made from frozen broccoli is huge. Commercial frozen broccoli does not have the ability to produce sulforaphane because the vegetables are scalded before freezing, precisely to deactivate the enzymes. 

This increases the shelf life of the product, but the smell is dead when you take the vegetables out of the freezer. No matter how much you cut it and wait, no more sulforaphane is produced. That’s why raw kale leaves neutralize cancer cells 10 times more efficiently than frozen ones.

Frozen broccoli, however, retains the precursor – which is resistant to heat – and we can still get sulforaphane from the frozen product if we add an enzyme from the outside. But where do we get the enzyme myrosinase? Scientists can buy it from a chemical company. We can pick it up from the store.

All cruciferous vegetables contain the enzyme myrosinase. The mustard stem, a cruciferous vegetable, grows from mustard seeds and we can buy it ground in the form of mustard powder. If we sprinkled some mustard powder on frozen and scalded broccoli, could it produce sulforaphane? It seems so.


Boiled broccoli cannot form sulforaphane due to enzyme inactivation. Researchers at the University of Reading, however, found that mustard seed powder sprinkled over cooked broccoli contributes to the formation of a significant amount of sulforaphane. One teaspoon or even half a teaspoon of mustard seed powder can produce sulforaphane. 

Thus, although cooking kills myosinase and prevents the formation of sulforaphane, the addition of mustard seed powder over cooked cruciferous vegetables is a natural source of enzyme that gives them the same value as if they were raw.

So, if we forget to cut the green vegetables and leave them long enough to form the enzyme, or buy them frozen, we add a teaspoon of mustard seed powder and we have solved the problem. The same method can be used for white radish, horseradish or wasabi — all cruciferous vegetables with the same enzyme in the composition. 

Or you can mix some raw vegetables with cooked ones, because raw vegetables contain the enzyme myrosinase, which can also work with cooked vegetables.