Head Retention in Fruit beers

[Donny]

Recently i made a golden ale but added some mango and lime to the secondary to add some fruit flavors and aromas to it.

I added lime by soaking the zest in vodka for a few days and then chucked it all into the fermenter, the mango was pulsed into mush.

I opened one this eve to have a taste see but even tho there is nice carbonation there is 0% head retention. Even on a heavy pour. Is it possible that the citrus fruits are affecting the head retention?   

[oblivious]

It could be the papain in the mango breaking down head developing polypeptides

[Donny]

Cheers for the info. I'll have to look into it more now that you've givien me something to research.