An Evaluation of Simple Methods for Following Rigor Development in Fish

Abstract

Measurements obtained with a simple rigorometer (muscle tension measuring device) were found to correlate well with measurements of the relative ATP/IMP content ratio (258/250 nm absorbance ratio of perchloric extracts), muscle pH, and visual measurements of stiffness in wholt fish (tilapia, Areochromis aureus) during rigor development. These simple tests yielded measurements which clearly differentiated the effects of ante-mortem stress on the rate of onset of rigor mortis and associated biochemical changes in the fish muscle.

Influence of Slaughtering Method on Some Aspects of Quality of Gilthead Seabream and Smoked Rainbow Trout

“…Considering that the ATP/IMP ratio is a useful indicator of the amount of stress exposure just prior to death (Korhonen et al, 1990) and since an ATP/IMP ratio 1.15-1.25 is typical of 'unstressed' fish, our results confirm that electrical stunning is a less stressful slaughtering method than bleeding or simple anoxia, as described by Lines and colleagues (2003). Erikson and colleagues (1999) showed that the bleeding procedure applied to Atlantic salmon did not dominate over the total pre-slaughter handling stress since the bleeding per se does not have adverse effects on flesh freshness resulting from excessive handling stress.…”

Effect of trawling with traditional and ‘T90’ trawl codends on fish size and on different quality parameters of cod Gadus morhua and haddock Melanogrammus aeglefinus

“…, and Cl -, whereas blood pH decreases [11]. The more strenuous the stress-related activity the fish are subjected to, the more rapid the muscle ATP depletion [7,10] and severe muscle activity causes early rigor mortis onset [10,14]. Cole et al [7] showed that in terms of low initial flesh pH (7.1), high blood lactate and depleted ATP stores, handlining of blue cod Parapercis colias was the most fatiguing capture method when compared with commercial potting, modified potting and rested harvested fish.…”

“…In many cases, the cause of death is anoxia where fish are left in the open air on the deck. The catching process leads to elevated levels of plasma cortisol [9,10], glucose [11], lactate, [11][12][13][14] haematocrit, Na ? , K ?…”

The Influence of Ca²⁺ Concentration around Myofibrillar Mg²⁺-ATPase on the Speed and Pattern of Rigor Mortis in Fish Species or Cultured and Wild Fish

“…This result suggests that the contractile percentage in pillar form muscle observed in rigor mortis from four parameters is better than the other methods of measuring the rigor value2) and the degree of sag. 11) In regard to the difference in muscular contraction progress among fish species and between cultured and wild fish of the same species, the relative activity of myofibrillar Mg2+-ATPase in ordinary muscle did not influence the difference (Fig. 6); however, from the relationship between Call concentration and superprecipitation reaction of ac tomyosin it was found that the progress of superprecipita tion reaction of actomyosin changed remarkably in the four parameters of progression speed, progression pat tern, and time and level taken to reach the peak by very small differences in Ca2+ concentration.…”

“…However, the tension also has a defect for measur ing multiple muscle samples at the same time, because a muscle sample requires a particular measuring apparatus, although tension can be measured by various methods. [11][12][13][14] Therefore it is necessary to develop a new method which measures the changes of rigor mortis on an equal plane with tension. In addition, the method must be simple in operation, and capable of measuring multiple muscle sam ples at the same time.…”