This applies to the rough surfaces of raspberries, cantaloupes and strawberries. The less than 1 mm penetration depth for UV-C can affect the viability of microbial cells as reported on apples.
This agrees with results from Syamaladevi et al
who observed that higher UV-C doses were required for Penicillin expansum on rough fruit surfaces such as strawberries and raspberries compared to apples and cherries.