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Lloyd Augustus Hall ( June 20, 1894 - January 2, 1971) was an African-American chemist who greatly advanced the science of food preservation. By the end of his career, Hall had amassed over 100 patents, and many of the preservation techniques and chemical preservatives he invented are still in use today.1 Early life
Lloyd Hall was born in Elgin, Illinois. His father was a Baptist minister. After attending high school in Aurora, Illinois, he earned a bachelors 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 make his major contributions to food science.
2 Major works
Hall devoted much of his efforts to the technologies behind curing meat. While the use of saltFor other meanings of the word salt see salt (disambiguation In chemistry, a salt is a composed of positively charged cations and negatively charged anions, so that the product is neutral and without a net charge. They are typically the product of a chemis such as sodium chlorideProperties General Name Sodium chloride Chemical formula Na Cl Appearance White or clear solid CAS-number 7647-14-5 Physical Formula weight 58. 4 amu Melting point 1074 K (801 °C) Boiling point 1738 K (1465 °C) Density 2. 2 ×103 kg/ m3 Crystal structure f and sodium nitrateProperties General Name Sodium nitrate Chemical formula Na NO Appearance White solid Physical Formula weight 85. 0 amu Melting point 580 K (307 °C) Boiling point decomposes at 653 K (380 °C) Density 2. 3 ×103 kg/ m3 Crystal structure ? Solubility 92 g in in food preservation is ancient, prior to his work, it was poorly understood and was frequently a hit-or-miss process balanced between ineffective preservation and negative impact on flavor. Hall developed a process whereby solutions of sodium chloride, sodium nitrate, and sodium nitriteSodium nitrite also called nitrous acid, sodium salt is a food additive with chemical formula which serves a useful dual purpose in the food industry since it both fixes the color of preserved fish and meats and also prevents growth of the bacteria which were sprayed onto hot metal and rapidly dried, producing crystals of the nitrates and nitrites encased inside a shell of sodium chloride. These flash-dried salt crystals proved effective at reliably preserving meat without adversely affecting taste. Hall also pioneered the use of glycerineGlycerine, Glycerin or Glycerol (CHO is an alcohol (hence the name glycerol with three hydroxyl groups (OH): H H H CH-OH | | | | H C C C H or CH-OH | | | | OH OH OH CH-OH Other synonyms of glycerine are 1,2,3-propanetriol; D-glycerol; L-glycerol (although to stabilize salts in meat, allowing the preservatives to remain within the meat rather than forming a crust on the outside.
He also investigated the role of spiceFor information on the spice from Frank Herbert's Dune universe, see melange. Spices are strongly flavored or aromatic parts of plants used in small quantities in food as a preservative, or flavouring in cooking. Spices are distinguished from other plants in food preservation. It was commonly held that seasonings were effective preservatives, but Hall found that rather than preserving food, they generally only covered up the taste of spoilage. In fact, seasonings frequently accelerated spoilage because they contained bacteria and moldThis article is about the fungi. See also the manufacturing process molding. Mold or mould also refers to soil or earth, particularly soil that is loose and suitable for planting. Mold is also a town in Flintshire, in Wales. Note that in British English m spores. To counter these problems, Hall developed a means to sterilize spices through exposure to ethylene oxide gas. Later, he promoted this same method for the sterilization of medical equipment, and it has become a standard method for sterilizing medical supplies made of plastic or other materials that could be damaged by the high temperatures used in other sterilization techniques.
Hall introduced the use of antioxidants to prevent food spoilage, especially the onset of rancidity in fats and oils. Upon determining 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.
