[Show abstract][Hide abstract] ABSTRACT: The effect of bleeding on white muscle quality in amberjack and red sea bream was evaluated by measuring ATP-related compounds,
volatile basic nitrogen (VBN), and the trimethylamine (TMA) content. The freshness was evaluated by the K value, and the degree of spoilage was elucidated by VBN and TMA. ATP was rapidly converted to ADP and AMP in the muscle and
IMP was the main product of ATP degradation during iced storage. For both species, the IMP content was higher in the muscles
of fish that were bled than in those unbled during iced storage. Conversely, the K value and the levels of hypoxanthine (Hx) and VBN were higher in the muscle tissue of unbled fish than in the bled tissue
of both species. Similarly, the TMA content was higher in the unbled muscle tissues of both species after a week of storage.
No preview · Article · Mar 2010 · Fisheries Science
[Show abstract][Hide abstract] ABSTRACT: Cathepsin L, one of the cysteine proteases found in fish muscle, is considered to be the main cause of post-mortem autolysis
of fish muscle. We have determined the presence of cathepsin L in the membranes of red blood cells of carp, amberjack, and
red sea bream and measured its activity. Immunoblotting of an extract of the red blood cell membranes from these three fish
species using human anti-cathepsin L antibody revealed the presence of cathepsin L of different molecular masses. The molecular
masses of cathepsin L was estimated to be 120 and 85kDa in the amberjack and 75 and 70kDa in the carp. These proteins have
higher molecular masses than the mature form of cathepsin L, suggesting that they are precursor forms. In contrast, the protein
in the red sea bream was estimated to have a molecular mass of 30kDa, suggesting that this cathepsin L is a mature form.
The specific activity of cathepsin L was highest in the red blood cell membranes of the amberjack, followed by the carp and
the red sea bream in descending order.
No preview · Article · Jan 2009 · Fisheries Science