Fresh!
Frozen!
Canned!
Do you think that all of these green beans
have the same nutritional value?
I want to say that the fresh ones
are gonna have more nutrition.
Good question, what do you think?
Ah, yeah?
Yeah?
Not 100 per cent confident with that.
Do you think that there's any nutritional loss
in these green beans when they go into a can?
I would think so.
Yeah, 100 per cent.
Yes.
- Yes.
- Yes. - Yes.
By how much?
- A lot.
A lot?
I'm here at CSIRO’s Food Innovation Centre,
where I'm going to meet an old friend
who’s going to answer our questions
on the science of canned fruits and vegetables.
Let's go.
So to prevent any food contamination and food safety,
I've got to put on these steel-capped boots and a lab coat.
Hey, Mala, how are you?
Good, thank you. How are you?
Good to see you again.
Now, Mala, I've asked a lot of Aussies about the nutrition in a can,
and a lot of them seem to think that
the nutrition of the vegetable is lost
when it's gone into a can. Is that true?
Carbohydrate, protein, fat and fibre,
they don't get affected or get reduced
by the canning process,
but mainly the vitamins. Vitamin B and C,
are more susceptible to heat-related losses.
But when we compare the canned products with fresh
we had to take into account some fruits and vegetables
need to be cooked before we eat.
So during the normal cooking process,
there can be similar losses.
And so basically the fruits and vegetables inside the can
are put in raw and it’s basically
cooked in this high pressure cooker very quickly.
and it comes out ready to eat.
What about fresh produce?
Now, you guys know that I'm the Fruit Nerd
and I'm the biggest advocate for fresh fruit and veg.
And that's because fresh produce is
always going to give you the best textural experience.
It's going to be crunchy.
It's going to be firm and crisp.
But sometimes texture isn't important
depending on how you're going to eat it or put it in a meal.
Now the modern, fresh produce industry is quite complex.
It's not as simple as picking something off the tree
and getting to your door.
And here's a great example.
We've got some tomatoes here that were picked yesterday
and they're picked at a slightly more green stage.
It's what the industry calls ‘backwards’.
And what it does is it gives us time
to get the fruit here into the markets.
When you buy it, it might be a little bit more coloured
and it might last even a few more days before you cook it.
Now, the whole process from here, here to here,
and then for you to finally eat it might take days
or even weeks.
And so if you eat a tomato at the incorrect stage
when it's maybe a bit too early,
you might not have the best eating experience
compared to tomatoes which have been canned.
They're almost always picked at the most optimal ripe stage,
where it’s really, really sweet.
Now, some fruits and vegetables have a lot of nutrients
packed inside of it, but if you eat them raw,
you're not actually accessing
all the nutrients inside.
With some fruits and vegetables
you actually need to cook it to access all of its nutrients.
Now, you've probably got a freezer at home,
but let me show you my industrial freezer,
which we use here for our frozen fruit and vegetables.
And it stores 20 tonnes of fruits and vegetables
and it's set at negative 20 [degrees Celcius],
where we still our fruits and veg
like this durian, which was frozen in 15 minutes.
Now, that's much faster than a regular freezer.
But even this freezer
isn't as powerful as the freezers used to snap freeze
your fruit and veg at the supermarket.
Now the temperature in here is set and holds
between negative 19 [degrees Celcius]
down to negative about 21 [degrees Celcius].
Now that that's only one degrees,
whilst you're in freezer at home,
it might have a differential between -5 to -15 [degrees Celcius].
And that's a big variance.
And that big variance means that I guess your frozen veg
isn't going to keep as long as a commercial freezer like this.
Now let's get out of here because I'm freezing.
Now, if you remember Han Solo in Empire Strikes Back.
He gets frozen in carbonate really, really fast.
But when he gets defrosted in Return of The Jedi,
he's basically the same person.
And that's the same for frozen fruit and veg.
If it's frozen, really fast, when it's defrosted,
it's in its same or very similar state.
Freezing fruit and veg really fast
means that the ice crystals are really, really small.
When it's really small,
it means that basically the texture is the same
all the way around the fruit and vegetables
because all the water is being held in really small crystals
and it's not breaking any of the tissue walls or the fibre.
So when you defrost it, it's going to be
a better eating experience.
Now, here is a perfect example of two of my punnets of berries,
one that hasn't been frozen correctly.
And you're starting to see a lot of these ice crystals form
in this punnet, whilst this one has been stored correctly
at a constant negative 20 degree temperature.
There are no ice crystals in here.
All of the water is attached to the flesh inside the fruit.
Now, compared to fresh
frozen fruits and vegetables are always picked
at its most mature state.
So is there a difference in nutritional value
between fresh, frozen and can produce?
Well, the answer is not really.
And especially if you're going to cook the fruits and vegetables
before you eat it,
you're pretty much going to obtain
all the nutritional value you can
from each of these ingredients.
Now, there is a difference between price
availability and shelf-life
of these three different types of produce.
So here are my tips for how I feed my family.
Canned tomatoes, it's a no brainer.
I mean, if you're going to have a salad, of course,
get the fresh one because you want the texture,
you want the vibrancy.
But if you're going to cook it down in a pasta then
canned tomatoes does the trick.
It's cheap, but it's also picked at a more riper stage.
Now, canned pineapples are really good option
because pineapples are often very fibrous.
There's a lot of string in there,
and so when it's canned, it doesn't actually break down that much.
And so it doesn't turn to mush.
And so if you're going to cut it up, put it in a pizza,
put it in a soup or in a granola,
you still going to get that textural bite.
And most of the time, let's face it,
we're not going to need a whole pineapple for a meal.
Now, frozen berries are such a great option if you're baking
or going to cook it down anyway.
But my kids actually eat frozen berries
every morning with their cereal.
And I'll tell you why frozen berries
can often be a better option than fresh.
Because if you look at this strawberry right here,
this one is a fresh strawberry, but this is a frozen one.
Now, you can see here
that the strawberry has been picked backwards.
It's a little bit green and it's a little bit white
whilst the frozen strawberry has been picked
at it's optimal moment where it's fully mature.
And you can tell with the colour difference,
one's full red and one's a little bit white.
And that means that when this strawberry goes into the cereal,
it's going to be more sweet
than this fresh one.
Now, with the cost-of-living crisis becoming harder
and prices going up,
if you still want to eat a nutritious diet
filled with fruits and vegetables,
you can do so by eating fresh, canned and frozen.