From https://www.westonaprice.org/health-topics/food-features/broth-is-beautiful/#gsc.tab=0

Photo by Piotr Miazga on unsplash.com 

Cutting Corners

Research on gelatin came to an end in the 1950s because the food companies discovered how to induce Maillard reactions and produce meat-like flavors in the laboratory. In a General Foods Company report issued in 1947, chemists predicted that almost all natural flavors would soon be chemically synthesized. And following the Second World War, food companies also discovered monosodium glutamate (MSG), a food ingredient the Japanese had invented in 1908 to enhance food flavors, including meat-like flavors. Humans actually have receptors on the tongue for glutamate. It is the protein in food that the human body recognizes as meat. 

Any protein can be hydrolyzed to produce a base containing free glutamic acid or MSG. When the industry learned how to make the flavor of meat in the laboratory, using inexpensive proteins from grains and legumes, the door was opened to a flood of new products including bouillon cubes, dehydrated soup mixes, sauce mixes, TV dinners and condiments with a meaty taste. “Homemade” soup in most restaurants begins with a powdered soup base that comes in a package or can and almost all canned soups and stews contain MSG, often found in ingredients called hydrolyzed proteins. The fast-food industry could not exist without MSG and artificial meat flavors to make “secret” sauces and spice mixes that beguile the consumer into eating bland and tasteless food. 

Short cuts mean big profits for producers, but the consumer is short changed. When homemade stocks were pushed out by cheap substitutes, an important source of minerals disappeared from the American diet. The thickening effects of gelatin could be mimicked with emulsifiers, but the health benefits were lost. 

Most serious, however, were the problems posed by MSG, problems the industry has worked very hard to conceal from the public. In 1957, scientists found that mice became blind and obese when MSG was administered by feeding tube. In 1969, MSG-induced lesions were found in the hypothalamus region of the brain. Other studies all point in the same direction–MSG is a neurotoxic substance that causes a wide range of reactions, from temporary headaches to permanent brain damage. 

Why do consumers react to factory-produced MSG and not to naturally occurring glutamic acid found in food? One theory is that the glutamic acid produced by hydrolysis in factories contains many isomers in the right-handed form, whereas natural glutamic acid in meat and meat broths contains only the left-handed form. L-glutamic acid is a precursor to neurotransmitters, but the synthetic form, d-glutamic acid, may stimulate the nervous system in pathological ways.