Tadlock said her bag was randomly searched as she went through customs in Minneapolis.
"He asked me if my trip to France was expensive". She said the agent gave her a $500 fine instead.
She says she understands why the rules are in place, but says, "the apple is from Delta and. that [is] the most important part to take away from this". She wasn't hungry at the time and placed it in her bag.
U.S. Customs recalled in a statement that all agriculture items must be declared as penalties are as high as $1,000.
She says she's frustrated and feels Delta shouldn't have handed out apples.
"I understand the laws and the department of agriculture doesn't want certain insects in the US", said Tadlock.
U.S. Customs has warnings at the entry point and on the declaration form that tells travelers they must declare fruit that is brought into the country.
When contacted by USA TODAY, a Delta spokesperson would not comment specifically on the incident but said the company encourage its customers "to adhere to Customs and Border Protection policies and requirements".
Tadlock told the television station that she plans to fight the fine in court, saying that she was upset that an innocent mistake could lead to such a large fine and the loss of her Global Entry Status. Tadlock says that is tough to swallow.
Tadlock made a decision to fight the fine in court and will bring the case before a judge.
"It is very unfortunate some body needed to experience that and also be treated as a criminal over a parcel of fruit", she informed KDVR.