Verification of Cooking Endpoint Temperatures in Beef by Immunoassay of Lactate Dehydrogenase Isozyme 5

• Published in: Journal of food science Vol. 68; no. 6; pp. 2076 - 2079
• Main Authors: Miller, D.R, Keeton, J.T, Acuff, G.R, Prochaska, J.F
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.08.2003; Wiley Subscription Services, Inc
• Subjects: Beef; Cooking; cooking endpoint temperature; Escherichia coli; Food safety; Food science; ground beef; Immunoassay; immunoassays; isozymes; lactate dehydrogenase; Temperature; thermal death
• ISSN: 0022-1147; 1750-3841
• DOI: 10.1111/j.1365-2621.2003.tb07021.x

Ground beef Semimembranosus muscle was inoculated with Escherichia coli, and aliquots were left raw or cooked to 1 of 24 time/temperature combinations. Samples were analyzed by aerobic plate counts for surviving bacteria, total extractable protein, and immunoblot quantification of lactate dehydrogenase isozyme 5 (LDH5). Bacterial thermal death curves exhibited a consistent log decline with increasing temperature and cooking times at a given temperature, which were paralleled by decreases in LDH5 at 61 °C and above. Total protein exhibited a linear time/temperature decline. Immunologic analysis of LDH5 may be suitable for development into a rapid assay method for the verification in beef of cooking endpoint temperatures from 61 °C to 69 °C.