With Bitter Pit being a virtual free-from defect, there has been some confusion over the years when it comes to correctly identifying this defect. Does anyone have some good guidance or some pictures I can post on this site, to help everyone identify Bitter Pit?
Thanks.
6 Comments on “Apples- Bitter Pit”
A special thanks to a reader who sent me a few pictures of Bitter Pit. Also from the UC Davis web site I found the following information, describing the cause of Bitter Pit. (http://postharvest.ucdavis.edu/Produce/Disorders/
apple/pdapbit.shtml)
“Physiology:
Initiation of symptoms may begin four to six weeks after petal fall when affected tissues have a higher rate of respiration and ethylene production. This is a period of greater protein and pectin synthesis with greater migration of organic ions into the affected areas. Affected areas retain starch grains not seen in healthy tissue. A mineral imbalance in the apple flesh develops with low levels of calcium and relatively high concentrations of potassium and magnesium. Low levels of calcium impair the selective permeability of cell membranes leading to cell injury and necrosis. Other explanations for the cause of bitter pit include the dissolution of the middle lamellae by oxalic and succinic acid, and changes in proton secretion and potassium permeability.”
If we are unsure if it is Bitter Pit, we just describe the defect as sunken discolored areas. I wish there were better pictures around, showing the defect as it really appears.
We have found Bitter Pit showing up on Granny Smiths and Golden Delicious varieties more than others. Is this common for these varieties? Have you noticed Bitter Pit looks different on apples from different countries? I wonder why???
The trade (primarily overseas) uses the term “lenticelosis” for defect that gets commonly scored as bitter pit. This defect is found primarily in royal gala and Fuji apples. It looks similar to bitter pit except it usually only affects the surface of the apple.
How much bitter pit is needed to be scored?
Bitter pit is scored as damage (against U.S. Extra Fancy, U.S. Fancy and U.S. No.1 )when 1 or more spots is present…..in essence a free from defect. It would be scored as serious damage when bitter pit is thinly scattered affecting more than 10% of the surface.