LLOYD AUGUSTUS HALL Biography - Famous Scientists


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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.                                         
Lloyd Hall was born in Elgin, Illinois. His father was a Baptist minister, Lloyd's           
grandfather was one of the first black preachers at the church his father                   
ministered. After attending high school in Aurora, Illinois, he earned a                     
bachelor's degree in chemistry from Northwestern University.                                 
With the onset of the United States' involvement in World War I, he was                     
commissioned as a lieutenant and explosives inspector in the Ordnance Department.           
However, he found himself at the receiving end of a variety of discriminatory               
practices in the military and requested transfer. Over the next nine years, he               
worked for several chemical laboratories, frequently as a consultant, until in               
1925 he was hired by Griffith Laboratories, where he would do most of his work               
in food science.                                                                             
Hall devoted much of his efforts to the technologies behind curing meat,                     
particularly to improving a curing salt marketed by Griffith Laboratories known             
as flash-drying. This product originated with German chemist Karl Max Seifert,               
developer of a process whereby solutions of sodium chloride 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                         
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. 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 anticaking 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, helping to advance an idea that had been                 
around for several years.                                                                   
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.