The fridge does not ruin a tomato, but it does mute one

There is a short answer about refrigerating tomatoes and a useful one, and they are not the same. What follows is the useful one.

What flavour in a tomato consists of

Sweetness and acidity come from sugars and acids, and both survive refrigeration essentially unchanged. Almost everything else people describe as tomato flavour comes from volatile aroma compounds detected through the nose. Those compounds are produced continuously by enzymes in the fruit, which means the supply depends on the fruit still working.

A tomato that stops producing them still tastes sweet and acidic while smelling of very little. That is exactly the profile people describe when they complain that supermarket tomatoes taste of nothing.

What the cold does

Chilling slows and in some cases suppresses the enzymes responsible for making those volatile compounds. Research on this has found that the reduction is not fully reversed when the fruit is returned to room temperature. Genes involved in aroma production appear to be affected, which is why the loss can outlast the chilling itself.

The effect depends on temperature and duration, with colder and longer producing more loss. It also causes textural changes, as cell membranes are damaged and the flesh becomes mealy rather than juicy.

Where the advice becomes complicated

A fully ripe tomato has already produced most of its aroma compounds, so it has less to lose from a short spell in the cold. An under-ripe tomato is still developing, and chilling can arrest that development permanently.

Checked against the record, the practical implication is to ripen on the counter and refrigerate only when the alternative is throwing the fruit away. Cut tomatoes are a different matter, since food safety considerations apply once the flesh is exposed. A blanket rule in either direction misses the point, which is that ripeness determines how much the cold costs you.

Where the rule came from

Domestic refrigeration spread rapidly in the twentieth century, accompanied by general advice to refrigerate perishable foods. That advice was sound for most items and was applied to produce without much differentiation between types. Chilling injury in tropical and subtropical crops was known in commercial horticulture long before it reached home kitchens.

Trace it back and the counter-campaign among cooks and food writers then produced an absolute prohibition, which overshoots in the other direction.

Both the original advice and the reaction to it are generalisations covering a situation that varies by fruit.

Other produce that dislikes cold

Bananas, avocados, basil, and several tropical fruits show chilling injury of various kinds, from blackened skins to arrested ripening. Potatoes stored very cold convert starch to sugar, which changes how they behave when fried and can darken the result. Onions and garlic keep better dry and ventilated than cold, where they take up moisture and sprout.

The common thread is that crops from warm climates generally handle refrigeration badly, which is a useful rule of thumb. Crops from cool climates, including most leafy vegetables and root crops, are usually happier cold.

A claim being badly sourced does not make its opposite true.

Getting more out of a tomato

Warming a cold tomato before eating recovers some aroma perception, since volatile compounds are released more readily at higher temperatures. Salting cut tomatoes and leaving them briefly draws out liquid and concentrates what flavour is present. Cooking is a good route for tomatoes that have lost their aroma, since heat generates new compounds through browning and concentration.

Buying from a source that ripens on the plant matters far more than any storage decision at home. Storage is damage limitation, and the interesting variable was decided before the fruit reached the shop.

The takeaway

The sugar survives the fridge and the smell does not, which is why the tomato still looks exactly like a tomato.

Ask who gained from the claim being repeated. That usually explains the rest.