Integrated Studies on the Freshness of Rainbow Trout (Oncorhynchus Mykiss Walbaum) Postmortem During Chilled and Frozen Storage

Abstract

Rainbow trout were killed by two methods, asphyxiation and clubbing. The concentration of ATP in specimens of skeletal muscle taken immediately after death was significantly (P<0.01) higher in clubbed (4.41 ± 0.86 μmol/g) than in asphyxiated (2.00 ± 0.69 μmol/g) fish. The shear force (Warner‐Bratzler) required to cut the muscle was higher (P<0.05) in clubbed (8.33 ± 0.61 N) than in asphyxiated (6.85 ± 0.98 N) fish. Changes in the concentration of adenine nucleotides and in shear force were measured at intervals during storage at 3C and ‐ 30C. The K value was calculated and was found to be correlated inversely with changes in shear force, Torrymeter readings and sensory assessment. There were no significant differences in the concentrations of ATP and metabolites between muscle sites. There were no differences in shear force measurements between the locations sampled nor between muscle taken from the right and left sides of the fish.

Comparative studies of quality changes in white and dark muscles from common carp (Cyprinus carpio) during refrigerated (4 °C) storage

“…() reported that IMP in crucian carp ( Carassius auratus ) reached a maximum in 4 h postmortem. Similar result was found by Wills & Proctor () in rainbow trout in 3 h stored at 3 °C. Therefore, the value of IMP in AP white muscle we detected on the 2nd day was possibly not the actual maximum attained during chilled storage.…”

Physical, chemical and microbiological quality of fillets and mechanically separated meat, and sensory evaluation of fillets of Nile Tilapia treated with homeopathic product

“…Fish products provide important components of the human diet (Watterson et al, 2012), but are highly perishable products, as their quality and freshness deteriorate quickly after death (Medina et al, 2009). The results of physical, chemical, and microbiological analysis in addition to sensory evaluations provide the necessary information to measure the quality and freshness of fish muscle (Wills et al, 2004). The current investigation evaluated physical, chemical, and microbiological quality of fillets and mechanically separated meat (MSM) and rated sensory evaluation of fillets of Tilapia that consumed Homeopatila 100 ® .…”

Effects of Salt Concentration on Biogenic Amine Formation and Quality Changes in Grass Carp (Ctenopharyngodon idellus) Fillets Stored at 4 and 20°C

“…ATP degradation is one of the most important postmortem biochemical changes in the muscle of fish. The sequence of nucleotide degradation in teleost fish muscle is as follows: ATP -» adenosine diphosphate -» adenosine monophosphate -» IMP -» HxR -> Hx (30). Figure 3A through 3F illustrates the pattern of nucleotide degradation in the muscle of variously brined grass carp fillets stored at 20 and 4°C.…”

“…However, for cazon fish muscle (20) and black skipjack muscle (18,20) significantly lower values of ATP were obtained. Factors such as exhaustion, starvation, hunting, and manner of death (20,30) may contribute to the different initial values of ATP. The ATP of CK and Tl rapidly decreased to values lower than 0.1 pmol/g after 48 h of storage at 20°C, whereas T2 decreased to 0.30 pmol/g during the same storage period.…”