Pineapple juice deffo works in that it makes cum taste "better". make sure your properly hydrated...... dehydrated guys produce thicker/lumpier cum , with a stronger "bleachy-salty" taste , not pleasant...... Much better when the guy is properly hydrated.
As for making yourself have "more" cum , i do not know. Eating well , 5 a day n lots of protein n water will not do any harm though.
All i can say is that diet n hydration makes a big difference to the overall "palatability" .
Unhealthy guys with a bad diet full of junk , it shows in their "cum"