How do apples bruise on the inside?

Factual Questions
1

Occasionally I’ll quarter an apple and discover brown areas inside, far below the skin. Sometimes the brown is touching the core, sometimes not. It’s the same color and consistency as bruises that you find right under the skin, but I don’t know if the interior brown areas are technically bruises or not.

So:

  1. Are these bruises? If not, what are they?
  2. Where do the bruises come from? How do they bruise on the inside if the exterior is fine?
2

It comes from people talking rudely about apples. It hurts their feelings deep inside. There’s been a lot of that recently, in the wake of a famous baby being named Apple. Comedians and social commentators groused about the name, and many apples were hurt deeply. :stuck_out_tongue:

3

I suspect the brrowing on the inside is due to fungal or bacterial infection but I could be wrong. External brusing is caused by damage to cells, which split open and release enzymes that catalyse oxidation of phenols which go brown. Whether this is a deliberate ploy on the part of the fruit as a defense, or just accidental I don’t know.

4

here is some good pictures of apple problems with discussion http://res2.agr.ca/parc-crapac/pubs/phhandbook/a_disor_e.htm#internal

here are some chemical experiments you can do on apple bruising! http://ag.udel.edu/other_websites/foodworkshop/WSFWorkshop/Enzymatic%20Browning%20(Ch1).htm

5

Thanks for that link, scm1001. The “internal breakdown of Spartan apples” section didn’t seem quite right – the discoloration I see starts further inside than the skin – but Braeburn Browning Disorder is probably what I’ve encountered. What with me eating Braeburns for the most part.

Further info, with pictures that resemble what I’ve seen: http://www.hortnet.co.nz/publications/hortfacts/hf205018.htm

And the money quote: