When I buy a package of strawberries and put them in the fridge, they start to go bad within two days.
When I buy strawberries, chop them up, and put them in a fruit salad, they seem immune to rot. I’ve seen them last up to seven days when they’re combined with other fruit.
I get similar results with grapes and raspberries.
Explain.
Do you wash your strawberries before you put them into a fruit salad? That can have the effect of removing some of the mold spores. There may also be enzymes in the other fruits that create a hostile environment for the spores, inhibiting their growth.
I’ve seen mold on pineapple chunks, for instance, but not before they were several weeks old.
I could be the acid from the other fruits acting as a preservative.
How are they packaged when you put them in the fridge. You want lots of air to be able to get at them. If they are handpacked into pints or quarts with a piece of cellophane over the top, that’ll ruin them in a hurry and you should keep it off. If they are in clamshells, they should be okay, but it wouldn’t hurt to open the top. Oh, and are they getting moldy or are they getting damp and squishy?
Do you put anything in the fruit salad other than pieces of fruit? For example, lemon juice or sugar? Both are mild preservatives.