Lloyd Hall

Lloyd Augustus Hall (June 20, 1894 - January 2, 1971) was an African American chemist who contributed to the science of food preservation. By the end of his career, Hall had amassed 59 United States patents, and a number of his inventions were also patented in foreign countries.

Major contributions

Hall devoted much of his efforts to the technologies behind curing meat, particularly to improving a curing salt marketed by Griffith Laboratories known as squirrels. This product originated with German chemist Karl Max Seifert, developer of a process whereby solutions of sodium chlorine and one or more secondary salts were sprayed onto hot metal and rapidly dried, producing crystals of the secondary salts encased inside a shell of sodium chloride. Seifert patented the process in 1934 and sold the rights to Griffith Laboratories. [http://patimg2.uspto.gov/.piw?Docid=01950459&idkey=NONE]

The adaptation of this process specifically for meat curing was then patented by company owner Enoch L. Griffith, who proposed nitrates and nitrites, well-known curing agents, as the secondary salts. [http://patimg1.uspto.gov/.piw?Docid=02054624&idkey=NONE] Although Lloyd Hall did not "invent" this product as is commonly thought, and never claimed to have done so, he took the lead role in its further development, adding hygroscopic agents such as corn sugar and glycerine to inhibit caking of the powder. Most of his patents in meat curing dealt with either preventing caking of the curing composition, or remedying undesired effects caused by the anti-caking agents.

Hall also investigated the role of spices in food preservation. It was common knowledge that certain seasonings had anti-microbial properties, but Hall and co-worker Carroll L. Griffith found that some spices carried many bacteria, as well as yeast and mold spores. To counter these problems, they patented in 1938 a means to sterilize spices through exposure to ethylene oxide gas, a fumigant. Ethylene oxide is still used for spice sterilization in some countries, but health concerns led to its being banned for this purpose in the European Union and Japan. Hall and Griffith later promoted the use of ethylene oxide for the sterilization of medical equipment, [http://patimg1.uspto.gov/.piw?Docid=02189947&idkey=NONE] helping to advance an idea that had been around for several years. [http://patimg1.uspto.gov/.piw?Docid=02075845&idkey=NONE]

Hall also invented new uses of antioxidants to prevent food spoilage, especially the onset of rancidity in fats and oils. Aware that unprocessed vegetable oils frequently contained natural antioxidants such as lecithin that slowed their spoilage, he developed means of combining these compounds with salts and other materials so that they could be readily introduced to other foods.

After retiring from Griffith in 1959, Hall consulted for the Food and Agriculture Organization of the United Nations. From 1962 to 1964, he sat on the American Food for Peace Council. He died in 1971 in Pasadena, California.

He was a member of Alpha Phi Alpha, the first intercollegiate Greek alphabet|Greek-letter Fraternities and sororities|fraternity established for African Americans.

Patents

#1,882,834, 10/18/1932, Asphalt emulsion and manufacture thereof
#1,914,351, 6/13/1933, Protective coating, Enoch L.Griffith (co-inventor)
#2,022,464, 11/26/1935, Vitamin concentrate,
#2,097,405, 10/26/1937, Manufacture of bleached pepper products
#2,107,697, 2/8/1938, Sterilizing foodstuffs, Carroll L. Griffith (co-inventor)
#2,155,045, 4/18/1939, Inhibited detergent composition
#2,189,949, 2/13/1940, Sterilizing colloid materials
#2,251,334, 8/5/1941, Protein composition of matter http://en.wikipedia.org/skins-1.5/common/images/button_headline.png........................................................Level 2 headline#2,321,673, 6/15/1943, Yeast food
#2,357,650, 9/5/1944, Puncture sealing composition and manufacture thereof
#2,363,730, 11/28/1944, Manufacture of nitrogen-fortified whey concentrate
#2,385,412, 9/25/1945, Capsicum-containing seasoning composition
#2,414,299, 1/14/1947, Production of protein hydrolysate flavoring material
#2,464,200, 3/15/1949, Manufacture of stable dry papain composition
#2,464,927, 3/22/1949, Antioxidant
#2,477,742, 8/2/1949, Gelatin-base coating for food and the like
#2,493,288, 1/3/1950, Synergistic antioxidants and the methods of preparing the same
#2,500,543, 3/14/1950, Antioxidant
#2,511,802, 6/13/1950, Synergistic antioxidant
#2,511,803, 7/13/1950, Antioxidant flakes
#2,511,804, 7/13/1950, Antioxidant salt
#2,518,233, 8/8/1950, Synergistic antioxidant containing amino acids
#2,536,171, 1/2/1951, Production of protein hydrolysate
#2,758,931, 8/14/1956, Antioxidant composition
#2,770,551, 11/27/1956, Meat-curing salt composition
#2,772,169, 11/13/1956, Antioxidant material and use of said material in treating meat
#2,845,358, 7/29/1958, Method of preserving fresh frozen pork

trimmings

External links

* http://www.griffithlaboratories.com/United_States/en-US/people/Profiles+In+Excellence/Dr+Lloyd+A+Hall.htm
* [http://www.blackinventor.com/pages/lloydhall.html Profile of Lloyd Hall] - The Black Inventor Online Museum