Muscle structure responses and lysosomal cathepsins B and L in farmed Atlantic salmon (Salmo salar L.) pre- and post-rigor fillets exposed to short and long-term crowding stress

Effects of crowding on blood constituents and flesh quality variables in Atlantic salmon (Salmo salar L.)

“…In the case of the anaesthetized fish, the decrease in pH was faster than in the crowded fish. This is in agreement with (Robb 2001), who stated that there is no difference in final pH between stressed and unstressed fish of the same species in spite of presenting differences in initial post-mortem pH (Skjervold et al 2001, Bahuaud et al 2010.…”

“…In our study, initial pH was significantly lower (P < 0.05) in crowded than in anaesthetized fish (table 2). This is in accordance with a previous study where muscle pH was lower at slaughter in fish exposed to exercise, activity or stress before death (Gatica et al 2008, Bahuaud et al 2010. A lower initial pH, post mortem, is associated with more rapid and detrimental quality changes in muscle properties (Huss 1995, Einen and Thomassen 1998, Skjervold et al 2001, Toldrá 2003.…”

“…High stocking densities can be very stressful for fish a , Thomas et al 1999, Skjervold et al 2001, Bahuaud et al 2010. At slaughter, the cessation of blood circulation results in a decrease in oxygen concentration in the cell and a progressive reduction of the redox potential, leading to anaerobiosis (Toldrá 2003) and a reduction in muscle pH, due to lactic acid accumulation Thomassen 1998, Skjervold et al 2001).…”

Enhanced muscle nutrient content and flesh quality, resulting from tryptophan, is associated with anti-oxidative damage referred to the Nrf2 and TOR signalling factors in young grass carp (Ctenopharyngodon idella): Avoid tryptophan deficiency or excess

“…Cooking loss and hydroxyproline contents, to determine muscle WHC (water-holding capacity) and collagen contents, respectively, were all analyzed according to the method previously described (Kong, Tang, Lin, & Rasco, 2008). The samples of cooked meat were used for measurement of tenderness, as previously described (Bahuaud et al, 2010). Sensory tenderness was measured as described in a previous study (Reihani, Tan, Huda, & Easa, 2014) with slight modification.…”

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“…Increased muscle activity and high levels of stress before and at the time of killing are closely associated with subsequent endocrine response, usually manifested by elevated levels of so-called stress hormones -catecholamines and glucocorticoids (mainly cortisol) (Barton, 2002 (Wilkinson et al, 2008;Bahuaud et al, 2010). All these alterations may subsequently cause impaired meat quality by affecting some quality characteristics, such as freshness, colour, texture, gaping scores, water-holding capacity (percentage of drip loss) etc.…”