Post mortem Changes

The pH of fresh fish is 6.0-6.5. The suitability limit for consurt5)tion is pH 6.8, while spoiled fish meat has a pH of 7.0 or above due to the formation of ammonia and amines (cf. 13.1.4.3.2). The specific resistance of fish muscle changes with storage duration. Soon after catching it is 440-460 ohms, after 4-days approx. 280 ohms, and after 12 days it drops to 260 ohms. The suitability limit for consumption is reached after 16 days, when the resistance is 220 ohms. 

A promising development is the gas sensor which can quickly register off-flavor substances or at least indicate an increase in volatile compounds that accompany the decrease in quality on storage. 

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Bell, L.S., Skinner, M.F., Jones, S.J. (1996). The speed of post mortem change to the human skeleton and its taphonomic significance. Forensic Science International, Vol. 82, pp. 129-140. 

Despite its characteristic symptoms and even after the exclusion of other established causes, AzD can only be reliably diagnosed by neuropathology and microscopic examination of the brain. Indeed that is how it came by its name. In 1907, a German physician, Alois Alzheimer, described two distinct post-mortem changes in the brain of a woman patient who had died with an unusual mental illness. These were the now characteristically accepted markers of the disease, namely senile plaques and neurofibrillary tangles (Fig. 18.1). 

Enzymes play a critical role in the food sciences. They are essential for life itself, and thus for food production. Their activity is responsible for many of the post-harvest and post-mortem changes in foods, thus effecting sensory attributes. In addition, enzymes are increasingly being used in the processing of foods. 

Suzuki, K. (1965) The pattern of mammalian brain gangliosides—II. Evaluation of the extraction procedures, post-mortem changes and the effect of formalin preservation, J. Neurochem. 12, 629-638. 

Kala, M., ChudziMewicz, E. The influence of post-mortem changes in biological material on interpretation of toxicological analysis results. Probl. Forensic Sci. 54, 32-59 (2003)... 

Klemin, N., and Kuhar, M, J. (1979). Post-mortem changes in high affinity choline uptake. J. Neitrochem. 32, 1487-1494,... 

Edward J (1987) Post-mortem Changes in Archaeological Bone Composition mrd Thar Effect on Paleodictary Reconstruction, PhD Dissertation, Columbia, Univ. of Missouri Rottlander R (1976) J. Archaeo. Science 3 83... 

Martinsen 0G, Grimnes S, Mirtaheri P. 2000. Non-invasive measurements of post mortem changes in dielectric properties of haddock muscle—A pilot study. / Food Eng 43,189-192. 

Guidotti A., Cheney D L., Trabucchi M., Doteuchi M., Wang C, and Hawkins R A. (1974) Focussed microwave radiation A technique to minimize post mortem changes of cyclic nucleotides, dopa and choline and to preserve brain morphology. Neuropharmacology 13, 1115-1122. 

Kraft, A. A., and Ayres, J. C. 1952. Post-mortem changes in stored meat. IV. Effect of packaging materials on keeping quality of self-service meats. Food Technol. 6, 8. 

Belle Lowe, Factors Affecting the Palatability of Poultry with Emphasis on Histological Post-Mortem Changes. 203... 

Tarr, H.L.A. (1966) Post-mortem changes in glycogen, nucleotides, sugar phosphates and sugars in fish muscles. A review. J. Food Sci. 31, 846-854. 

Recent observations by Svensson et al. (29) point toward post-mortem changes in the proteome of susceptible peptides and proteins within minutes. To prevent these alterations of the sample Svensson et al. use focused microwave irradiation to sacrifice the animals. Since focused microwave irradiation is not available in every laboratory, an alternative way to minimizing alterations is snap-freezing of the dissected tissue and defrosting only just before sample preparation starts. 

Average percentage of the total protein of a typical mammalian muscle after rigor mortis and before other post mortem changes. 

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