Best Way to Cook Vegetables

Best Way to Cook Vegetables

August 17, 2019 100 By William Morgan


“Best Way to Cook Vegetables” I’ve made videos on how
not to die from heart disease, how not to die from cancer, how not to die from other
deadly diseases like diabetes, but some of the most popular
videos on the site are like “the best way to cook
sweet potatoes.” All right, then, what’s the best
way to cook bell peppers? Here’s the antioxidant power of raw
green peppers and red peppers, and microwaving or stir-frying
doesn’t seem to do much, though with boiling
there’s a drop. But then if you measure the antioxidant
activity of the leftover boiling water, the antioxidants weren’t destroyed but
just leached out into the cooking water. So the researcher’s conclusion is
that it’s vital to consume the water used for boiling—
in addition to the peppers— as bioactive compounds
will be left over in the water. But that’s not the take-away
I get from this study. Drink the water or not, red
peppers have nearly twice the antioxidant power of green,
no matter what you do. So while both peppers are, by
definition, green-light foods, the red peppers, ironically,
are even greener. What about mushrooms? Probably best not to eat them raw,
but what’s the best way to cook them? Since cooking techniques clearly influence the nutritional
attributes of mushrooms, the proper selection of cooking
method may be a key factor to prevent or reduce
nutritional losses, and microwaving and grilling
were established as the best processes to maintain the
nutritional profile of mushrooms. For example, a significant decrease
was detected in the antioxidant activity of mushrooms especially
after boiling and frying, while grilled and microwaved
mushrooms reached, in some cases, higher antioxidant activity. Boiling had a similar negative impact
on the antioxidant power of cauliflower, which serves as just kind of a rough
proxy for how many phytonutrients of potential benefit we might be losing. Blanching was better, where the cauliflower here
was dunked into boiling water for three minutes and then run under
cold water to stop it from cooking. I’d never heard of steam
blanching, but same idea. Steam for three minutes,
then cool off, which appears to be better since
you’re not immersing it in water. Though note: there’s not much difference
between steaming for six minutes and steaming for three, and
then running under cold water. Too bad they didn’t
look at roasting; that’s how you make
cauliflower taste good. In fact, I’ve got two recipes
on roasted cauliflower in my How Not to Die Cookbook, for which all my proceeds
go to charity, of course. There are certain antioxidants we’re
especially interested in, though, like the eyesight and brain-protecting
green vegetable compound lutein. Here’s the back of the eyeball. What lutein does is protect those
sensitive light sensing nerves by blocking the high
energy blue light rays, which helps us see better, and
may help us think better too. So researchers looked at the effects
of four different cooking methods on lutein concentrations.
The first thing you’ll notice is that broccoli has like 50
times more than cauliflower. Not a surprise since lutein is a plant
pigment and cauliflower is too white. Here is it graphically so you
can appreciate the difference. Then they compared it boiling, steaming,
microwaving, and sous vide cooking, which is like a fancy name
for boiling in a plastic bag. And boiling actually
made lutein levels go up! How is that possible?
Heat can actually disrupt the cell walls and all the
little subcellular compartments that can enhance the release
of antioxidant compounds. Sous vide was similar, microwaving
detrimental at least for the broccoli, and steaming the superstar,
nearly doubling lutein levels. Heat isn’t the only way to liberate
lutein from greens though. If you finely chop spinach, you can
double the amount of lutein released during digestion in this
experimental model. And make a green smoothie or pesto
or some kind of pureed spinach dish and you may triple the bioavailability.
But you have to watch the heat. Steaming or boiling is one thing, but super high heat,
like stir-frying, can reduce lutein levels
to nearly nothing. Frying is also bad for the purple
pigments in blue potatoes; even air-frying, they just seem
sensitive to extremely high heat. These special antioxidant plant
pigments appear to be sensitive to really high temperatures, so we should try to avoid frying,
especially deep frying. That was one of the conclusions of
an expert panel on cooking methods: avoid deep frying foods. Not only the nutrient losses,
but all the added oil, not to mention the production of some
toxic compounds at those temperatures. So that continues to be
a challenge to the food industry. What’s their solution?
Forget deep fat frying. Let’s try frying in pure molten sugar. It’s like the SnackWell cookie phenomenon
taken to its logical conclusion. Oh, you want low fat?
We’ll fry in sugar.