Every now and then you may see some golden brown to dark brown discoloration affecting strawberries. You have to remember strawberries are harvested and packed right in the strawberry fields, with the picker also quickly verifying the quality of the berry before placing it in the clamshell.
Although the strawberries are grown on plastic they are still exposed to the sun, as the foliage does not always offer enough protection. When the sun beats down on the exposed surfaces, the outer cells become damaged. These damaged cells will later oxidize, becoming a golden brown to dark brown discolored area. Because the damage may not always be seen in the field, the discoloration may develop after the strawberries have been packed, a condition defect.
As seen above, this is typically what you may find while inspecting strawberries. The discoloration is found on one side of the strawberry (side exposed to the sun), and near the top, or calyx end of the strawberry. This can be attributed to sunburn. But because discoloration may be caused by other factors, the USDA recommends the term “sunburn” not be used if you encounter this defect. You should describe the defect, call it “discoloration.”
Unfortunately the U.S. Grade Standards for Strawberries and the USDA’s inspection instructions do not offer a scoring guideline, only stating to score the defect when materially affecting the appearance. Not a whole lot of help. The USDA does offer a scoring guideline for flattened and discolored bruised areas, scoring as damage when exceeding an area of 1/2 inch on a 1-1/2 inch strawberry. If we are to use this as a guideline we should be able to utilize the above image (strawberry with discoloration) as a visual aid. The above image depicts an area of approximately 1/2 inch with a golden brown discoloration. Any discoloration darker than the discoloration shown above, or with a larger area affected would be scored as a defect. In other words, the above image is showing the maximum amount of discoloration allowed for a U.S. No. 1 Strawberry.
Please send me your comments, or pictures of strawberries showing various degrees of discoloration.