Effect of Pre‐irradiation Heating Temperatures, Irradiation Level, and Storage Time at 34° F on the Free Amino Acid Composition of Beef^a,b

Abstract

SUMMARY Slices of fresh beef were heated to 130, 150, and 1.95°F, then irradiated at 0.1 and 5.0 megarads, and stored at 34°F for periods up to 60 days. Unheated and unirradiated beef was subjected to the same variables. No free lysine, lysine, or tryptophan was found. Heating to 150°F inhibited the release of amino acids from the parent protein. Histidine and tyrosine were observed in quantitative amounts, but only traces of alanine, glycine, leueine, threonine, and valine were observed at 60 days. Heating to 150°F completely inhibited the appearance of aspartic acid, glutamic acid, serine, methionine, and phenylalanine. Methionine and valine were affected by radiation at both levels. Serine, phenylalanine, histidine, glycine, glutamic acid, aspartic acid, and alanine were affected only at the 5.0‐megarad level. Storage generally resulted in increasing quantities of the free amino acids except for arginine and proline.

Free Amino Acid Content of Chicken Muscle from Broilers and Hens

“…These expected increases are generally in agreement with previous reports by Ginger et al ( 1954), Colombo and Gervasini ( 19.54 ;1955a,b ;1956), Niewiarowicz (1956, and Thompson et al (1961).…”

“…The exact role played by these enzymes in the increase in tenderness associated with aging meat is rather obscure (Whitaker, 1959). Classical approaches to get evidence on the effect of cathepsin in the proteolytic aging process have yielded negative or, at best, inconclusive results (Wierbicki et al, 1954). The increases in nonprotein nitrogen that should occur during proteolysis or autolysis have not always been found, though increases in free amino acids have been reported (Locker, 1960).…”

Free amino acids, sugars, and organic acids in aqueous beef extract

“…Their relationship to tenderness of beef has also been considered (Field and Chang, 1969;Locker, 1960;Ma et al, 1961;Parrish et al, 1969). Moreover, these same water soluble, low molecular weight compounds have been reported in studies on an index of incipient spoilage, the effects of heat and irradiation on proteolysis, and the variation of composition among different tissues from the same animal (Gardner and Stewart, 1966;Thompson et al, 1961;Walker, 1952). Numerous other studies have indi-Food Sciences Laboratory, U. S. Army Natick Laboratories.…”

Water‐Soluble Flavor and Odor Precursors of Meat. I. Qualitative Study of Certain Amino Acids, Carbohydrates, Non‐Amino Acid Nitrogen Compounds, and Phosphoric Acid Esters of Beef, Pork, and Lamba

“…Several investigators have reported on the free organic constituents of meat (Greenwood et al, 1951;Walker, 1952;Wood, 1956;Wood and Bender, 1957;Bender et nl., 1958;Ma et al, 1961;Thompson et al, 1961 ;Kijrmendy and Gantner, 1962) but there is a general lack of agreement on the exact constituents present in water-extracts of meat, and the concurrent study of free amino acids in meat from the three most popular species of red meat ania Contribution from the Missouri Agricultural Experiment Station. Journal Series Number 2592. mals has not been reported.…”