One of the darlings of food tech, the Impossible Burger, is being questioned by the F.D.A. because of its "secret sauce", soy leghemoglobin. The agency is concerned because it hasn't been consumed by humans before for a length of time, and may be an allergen, reported the NYT. Soy leghemoglobina is a substance found in the roots of soybean plants that the Impossible Foods makes in its laboratory. 

The burgers are still safe to consume, it's more a matter of testing the new ingredient for longer before resubmitting their application to the FDA. 

A bit of background on the burger that "bleeds" - Impossible Foods spent five years engineering a plant-based alternative that mimics the look, smell, texture and taste of beef. In fact, the company objects to you calling it a veggie burger. The burger's main ingredients are water, wheat protein, coconut oil, potato protein and leghemoglobin.

Impossible Foods says it is better for your body and the environment than actual meat. The company claims creating their burger requires just a quarter of the water needed for beef, but delivers comparable protein and iron with no cholesterol, hormones or antibiotics. There is big money behind this effort. Khosla Ventures, Bill Gates, Google Ventures (GOOG - Get Report)  Horizons Ventures, UBS (UBS - Get Report)  and Viking Global Investors are all investors in Impossible Foods. David Lee is Impossible Foods CFO and COO, he spoke with TheStreet's Sarah Solomon and told her the company is already working on plant based fish and chicken alternatives. 

Watch More with TheStreet:

This article was written by a staff member of TheStreet.