Parts of the berries on my red raspberries are white in color. Why?
A raspberry fruit (berry) is composed of over 50 drupelets. The white colored drupelets are likely due to sunscald or white drupelet disorder. Sunscald and white drupelet disorder are physiological disorders caused by sun exposure (solar injury) and excessive temperatures. Berries with full exposure to direct afternoon sun are most susceptible to sunscald and/or white drupelet disorder. However, high temperatures also appear to be involved as berries shaded by the leaf canopy may also develop white drupelets.
Watering the raspberry planting on a weekly basis (in hot, dry weather) may reduce the incidence of sunscald and/or white drupelet disorder.
Raspberries with white drupelets aren’t very attractive, but are edible. Berries with brown (rotting) drupelets, should be picked and discarded.