Stangle: Impossible burgers are made of what?

Dr. James Stangle,
DVM, Milesville, SD

The impossible whopper is being advertised by Burger King as a plant based alternative to the whopper. When food manufacturers started talking about making artificial meat, I, too, thought it would be impossible to make a hamburger cheaply enough to make it competitive. You see, I assumed that they would have to buy the individual amino acids (the building blocks for protein) and chemically string them together in the proper order, then remove the reagents (chemicals needed to cause the chain reactions) and then add something to give it the right textures

​The impossible whopper (made by Impossible Foods) bypassed all of those steps. Let’s compare the two. The impossible whopper patty is made from 24 ingredients. The most important ingredient is soy protein. The whopper patty has just one ingredient. That would be beef.

​The impossible whopper has 630 calories, mostly from the added oils. The whopper has 660 calories. So, about 5% less calories, this is not a huge improvement.

The impossible whopper has 25 grams of protein. The whopper has 28 grams. Seems pretty equal, only 11% less protein in the impossible whopper. However, not all proteins are created equal. There are 20 amino acids. Nine of which are essential, meaning your body cannot make them so they are required in the diet. Each of those essential amino acids must meet a certain level to make a complete protein profile. If any essential amino acid does not hit the required amount, it is said to be rate limiting. As an analogy, picture nine chains connected in a line. All of the chains need to lift 100 pounds to carry the load. If one chain can only support 50 pounds, it doesn’t matter how much the others can support. The 50 pound chain is the rate limiting chain.

​As an extreme example, bovine gelatin, aka Jell-O, is 100% protein; however, it completely lacks the essential amino acid histidine. Therefore, its value as a protein is zero. In beef the rate limiting amino acid is tryptophan, which is at 79% of the required level. In soy protein, the rate limiting amino acid is methionine, which is at 41% of the required level. So, to compare the impossible whopper with the whopper, you have to take 0.41 x 25 grams of protein and compare it to 0.79 x 28 grams of protein. The impossible whopper has 10 grams of usable protein and the whopper has 22 grams of usable protein. So you would have to eat two and a quarter impossible whoppers to get the same protein in one whopper.

​Now, let’s compare the estrogen hormone in an impossible whopper to the whopper made from hormone implanted beef. The impossible whopper has 44 mg of estrogen and the whopper has 2.5 ng of estrogen. Now let me refresh your metric system. There are 1 million nanograms (ng) in one milligram (mg). That means an impossible whopper has 18 million times as much estrogen as a regular whopper. Just six glasses of soy milk per day has enough estrogen to grow boobs on a male. That’s the equivalent of eating four impossible whoppers per day. You would have to eat 880 pounds of beef from an implanted steer to equal the amount of estrogen in one birth control pill.

There is one ingredient in the impossible whopper that bears mentioning. Beefs red color comes from hemoglobin, the oxygen binding protein in blood, and myoglobin, the molecule that takes the oxygen away from the hemoglobin. To get the same red color in an impossible whopper, they used leghemoglobin. This is the cool part. Leghemoglobin is made by the bacteria, Rhizobium. Rhizobium is the crucial bacterium that lives in the nodules of the roots of legumes like soybeans. Rhizobium has an enzyme that can take nitrogen from the air and turn it into fertilizer, which the plant can use. The bacterial enzyme that binds the nitrogen is damaged by the presence of oxygen so the bacterium makes the leghemoglobin to bind oxygen to keep it out of the way. To make enough leghemoglobin to add to the impossible whopper, scientists spliced the gene for leghemoglobin into yeast. They can grow the yeast easily and separate the leghemoglobin and add it to the impossible whopper. So the impossible whopper is technically a genetically modified organism (GMO). Don’t get me wrong, I think it’s cool. I’m all in favor of GMO’s. More should be done with them to improve our food supply. Currently, the only GMO protein that is legal in the US is a GMO salmon that is engineered to grow twice as fast. Unfortunately, the production and sale of it in the US is blocked by Senator, Lisa Murkowsky (R. Alaska). No doubt to protect Alaska’s salmon industry. Scientists have made a GMO milk cow which is modified to be polled (hornless) yet neither its meat nor milk is allowed to enter the food supply. What’s funny about the impossible whopper being a GMO is that the people most likely to eat it are the ones most likely to be against GMO’s.

​So when you watch the next Burger King commercial and you see the guy dressed as a cowboy eating an impossible whopper saying, “Well, I’m a darn fool”. “Just say, yep!” There is another word for really big lie. It is called a whopper. Here’s to hoping that the impossible whopper is a possible flopper.