After my second attempt at making a ginger mousse with gelatin and finding that it fails, I've discovered that fresh ginger contains a protease. I knew that pineapple does, and that it complicates making pineapple jelly, but I didn't realise that ginger does too.

Is there an authoritatively sourced and fairly complete list of fruits etc. which require cooking when making jellies? (Note that I'm not asking for a bunch of answers consisting of a single fruit, and such answers will likely be downvoted). Or is there some quick and simple way to tell whether a fruit contains proteases?

  • @SAJ14SAJ, I'm not promising downvotes: I realise that I'm treading close to a "list question" (although I hope I'm on the right side of the line), and I'm trying to pre-empt the kind of answers that are the reason that list questions have a bad reputation and that will almost certainly end up at -3 or below. May 4, 2013 at 23:19

1 Answer 1


Enzymes which degrade proteins, called proteases, are found in many fruits. There is no simple test for it other than holding some in your mouth and seeing if it "eats" your flesh away after a few minutes

Commercial test are not practical or portable as they require maceration, heating, centrifuging and using florescent dye markers. Or just make some in gelatine and see what happens :-)

A quick list would be:

  • Fig - Ficin
  • Ginger - zingipain
  • Kiwi fruit - Actinidin
  • Papaya (Pawpaw) - Papain
  • Pineapple - Bromelain

Also to a lesser extent

  • Banana
  • Guava
  • Mango

It is in many other fruits, but at levels where they will not be a problem, of course at different levels depending on the specific fruit variety etc.

  • Is there maybe a food you could easily tell if it eats at, rather than using your mouth?
    – Cascabel
    May 7, 2013 at 2:21
  • @Jefromi it will "eat" most meat proteins, but the effect is subtle, so using your mouth is the only way I know you will detect it. Similar to how a strong soap/akaline makes your skin feel very smooth, but you can't see any difference
    – TFD
    May 7, 2013 at 3:14
  • What's an example of a non-protein-degrading protease?
    – Nick T
    Sep 26, 2014 at 18:23
  • @NickT none, by definition. If you wanted to only point out the unlucky choice of words: I edited the sentence.
    – rumtscho
    Sep 26, 2014 at 22:25
  • @TFD +1 for the "eats your flesh away" test. While I knew about the protease in pineapple, and have always noticed the feeling strongly with fresh pineapple, I never connected the two and just assumed that it's the pineapple's acidity. Your explanation makes much more sense.
    – rumtscho
    Sep 26, 2014 at 22:26

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