That statement had nothing to do with the investigation, it was a chance to play up her constituency - this is what politicians do.

Here, let me translate for you:

"I, as a representative of a majority African American district, am making the public and my voters aware that I am involved in a popular issue that they will remember. I can also tie this to the real concern of food deserts because Whole Foods is a grocery store, and it allows me to find relevancy even if only marginally."