How to reduce the bitter
The bitterness is caused by curcurbitacins and can be removed by blanching or degorging using salt.
1) To blanch, cut in half, remove seeds, and parboil for a few minutes; or 2) To degorge, make slits in fruit or cut into slices, remove seeds, sprinkle with salt and leave 10 minutes before squeezing out the juice and rinsing.