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Effect of prerigor pressurization on postmortem biochemical changes in beef muscle

Prerigor pressurization of bovine semimembranosus muscle at 103.5
MNm⁻² (15,000 psi) for two min at 35°C significantly decreased
(P<0.01) muscle pH, and significantly (P<0.01) increased the rate of
glycogen degradation during the first 4 hr postmortem.
Glycogen levels of pressurized muscle were significantly
(P<0.01) lower than those of the control at 1, 2 and 4 hr postmortem.
Glucose concentrations were significantly (P<0.01) higher in the
treated muscle than in the control at all sampling periods. Until 4
hr postmortem the level of glucose-6-phosphosphate was higher in
pressure-treated muscle than in the control. Lactate content
increased rapidly after pressurization (1 hr postmortem), resulting in
an immediate drop in pH; however, there was no significant difference
between control and treated muscles at 24 hr. Pressurized muscle
showed a significant (P<0.01) increase in lactate dehydrogenase
activity over that of the control muscle at 1 hr but not at 24 hr.
Pressurization accelerated catabolism of both creatine phosphate
and adenosine triphosphate which resulted in a higher ATP turnover
value than that of the control. R-values (a measure of metabolic
rate) were significantly correlated (r=-0.95) with degradation of ATP. CPK activity was significantly higher (P<0.01) in pressurized muscle
than in the control at 1 hr postmortem but not at 24 hr.
Concentrations of ATP, adenosine diphosphate (ADP), adenosine
monophosphate (AMP), inosine monophosphate (IMP), bases and
nucleosides (adenosine, adenine, inosine, hypoxanthine) and
nicotinamide adenine dinucleotide (NAD) were determined by high
pressure liquid chromatography. Pressurization completely depleted
the ATP supply and increased the IMP concentration at 1, 4 and 24 hr
postmortem. At 24 hr postmortem, control samples had more ADP whereas
the AMP concentration was higher in the pressurized samples at 1 hr
postmortem but not at 24 hr. Concentrations of bases and nucleoside
metabolites and NAD did not differ between treatments. / Graduation date: 1984

Identiferoai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/26189
Date30 June 1983
CreatorsElkhalifa, Elamin Abdalla
ContributorsAnglemier, A. F.
Source SetsOregon State University
Languageen_US
Detected LanguageEnglish
TypeThesis/Dissertation

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