What goes on a supermarket orange

First things first: nothing described here is illegal or dangerous. Every
treatment a conventional orange receives is authorised, has maximum residue limits and is monitored.
Anyone eating supermarket oranges is running no risk at all.

That said, it’s worth knowing what happens between the tree and the shelf, because there are
six or seven steps and each leaves something behind. It’s the only way to understand
why an orange in January and one in August aren’t alike, and why on some you can zest the peel and on
others you can’t.

The full journey

2. The washing, which sounds harmless

It’s the step that triggers the next two, so it’s worth understanding first.

The fruit goes into a line of brushes with water that takes off soil, residues of field treatments
and leaves. So far so good. The side effect is that it also strips away its natural waxy
layer, the one the tree itself made to protect it.

A washed, bare orange loses water fast and is vulnerable to fungus. Hence the need to replace that
protection artificially.

3. Degreening: colour without ripeness

This is the one that surprises people most. In October, when the fruit already has enough sugar but
the skin is still green — because there have been no cold nights — it goes into chambers with a low
concentration of ethylene, the same hormone plants produce naturally.

The ethylene breaks down the chlorophyll in the skin and, as the green disappears, the orange
underneath shows through. In two or three days the fruit comes out looking as though it’s at its
peak.

What it doesn’t do is ripen the fruit. The sugar doesn’t rise, the acidity doesn’t
fall, the flavour doesn’t improve. It only changes the colour. That’s why the colour of an orange
tells you nothing about what’s inside, and why there can be flawless-looking oranges in October that
turn out disappointing. It’s set out in
how to tell whether an orange is any good.

4. The post-harvest fungicide

The treatment people know least about, and the only one that leaves a measurable residue.

What it’s for

Against two particular fungi — the Penicillium moulds, that green and blue growth that
appears on a soft spot — which can take out a whole pallet during storage. One infected fruit infects
the ones around it, and in a cold store with thousands of kilos that’s a huge loss.

How it’s applied

By shower, by bath or mixed into the wax of the next step, which carries it. The commonest ones on
citrus are imazalil, thiabendazole and
orthophenylphenol.

What it means for you

That the residue stays in the skin, which is where it has to work. The flesh is
practically free of it, so peeling and eating poses no problem at all. What you shouldn’t do is zest
that peel for a cake, and that’s where the warning in so many recipes comes from: «use an untreated
lemon».

That’s why on citrus it’s compulsory to declare the post-harvest treatment on the
label or the shelf sign. That line of small print saying «treated with» is there by law, precisely so
you know whether the peel is usable.

5. The waxing

The protection the washing removed is put back, with authorised edible waxes: carnauba, beeswax,
shellac, resins. They slow water loss, seal tiny wounds and give the characteristic shelf shine.

They’re safe and have been used for decades. The practical detail is that they don’t come
off with water — that’s what they’re for — so they seal the skin and with it the essential
oils, which are what carry the aroma. It’s set out in full in
why our fruit isn’t waxed.

6. The grading

A machine sorts the fruit by size and weight, and discards anything outside the commercial norm:
small pieces, large ones, ones with rubs, with branch marks, with slightly irregular skin. None of
that affects the inside, but it doesn’t fit a tray.

It’s why every orange on the shelf is identical, and also why a huge amount of perfectly good crop
is lost along the way.

7. And the cold store, which adds nothing but takes away

The last step doesn’t put anything on the fruit: it takes something off.

Kept between 3 and 8 degrees with controlled humidity, an orange lasts months. What it can’t do is
improve: citrus doesn’t ripen once it’s cut. And while it waits, it transpires. Every
week in store takes a little weight off it, and that weight is juice.

Hence an August orange weighing less than it looks and giving less juice than expected, however
flawless it seems. Why there’s nothing else in summer is in
why there are no oranges in August.

Which of all this happens to our fruit

And that isn’t to our credit: it’s the consequence of selling direct. A packhouse
supplying a supermarket chain can’t afford to skip any of it, because its fruit has to survive a long
journey and arrive uniform. We skip all seven steps because the box is filled after your order comes
in.

The trade-off is a catalogue that empties for four months a year and fruit that needs keeping with
a little more care. That’s the deal, and it’s explained in
From tree to table.

One thing worth being clear about

There’s a widespread misconception worth undoing: none of this has anything to do with the
fruit being «artificial» or «injected». Not one of the seven steps puts anything inside the
orange. They all act on the skin or in the air of a chamber.

What they do determine is something else, less dramatic but more real: how much time can
pass between the cutting and your kitchen. That’s the variable that explains the flavour. A
cold-store orange with seven impeccable treatments tastes of less than one with none, cut two days
ago — and it isn’t because of the treatments: it’s because of the months.

So the argument isn’t «theirs has things on it and ours doesn’t». It’s that
season and distance govern everything else.

How to choose better on the shelf

Most of the year fruit gets bought where it can be, so these are the three things worth looking
at:

• The treatment line. If it says «treated with», the peel isn’t for zesting. If it
  says nothing at all, that’s unusual on citrus: ask.
• The origin and the month. In August, Spain means cold store; South Africa or
  Argentina means their season, and a sea voyage.
• The weight. Two of the same size, keep the heavier. That difference is juice.