Table 1. Some studies showing the effects of post-mortem aging/storage conditions on endogenous proteases in meat from different animal sources

Source	Muscle type	Post-mortem storage conditions	Results	References
Beef	Longissimus muscle	14 d at 1°C	- m-Calpain activity remained nearly constant- μ-Calpain activity decreased gradually	Koohmaraie et al. (1987)
	Semimembranosus and Longissimus lumborum steaks muscles	84 d at −75°C	- Only 5.4% of the initial μ-calpain activity remained in bovine Semimembranosus muscles after 2 d of post-mortem aging- m-Calpain was activated in most bovine Semimembranosus and Longissimus lumborum steaks muscles by the 14 d of aging- The procaspase-3 activity was noticed in the bovine muscles up to 7 d of storage	Colle and Doumit (2017)
	Longissimus thoracis	7 d at 4°C	- Active caspase-3-isoforms and their levels decreased with post-mortem aging	Huang et al. (2016)
	Semimembranosus, Longissimus lumborum, Longissimus thoracic, Psoas major, and Triceps brachii	7 d at 4°C	- No autolysis of m-calpain was noticed during the aging period	Camou et al. (2007)
Pork	Longissimus muscle	5 d at different temperatures (2°C, 15°C, 25°C, and 30°C)	- μ-Calpain was activated earlier than m-calpains at all temperatures- Autolyzed m-calpain was reported after 5 d at 2°C storage temperature- The activity of calpastatin and myofibril particle size decreased with increasing incubation time (2 h post-mortem to 120 h post-mortem) and temperatures (2°C to 30°C)	Pomponio and Ertbjerg (2012)
	Longissimus dorsi	1 d post-mortem storage (4°C and 25 °C)	- μ-Calpain activity was undetected after 1 d post-mortem storage	Xu et al. (2012)
	Longissimus muscle	192 h after slaughter (temperature not mentioned)	- Caspase 3/7 and caspase 9 exhibited the highest activities at 2 h post-mortem, and their activities decreased with post-mortem time	Kemp et al. (2006)
Lamb	Longissimus, Semimembranosus and Infraspinatus muscles	21 d post-mortem storage at 4°C	- The activity of caspase 9 was observed to decline faster in contrast to caspase 3/7 in lamb Longissimus, Semimembranosus and Infraspinatus muscles during post-mortem storage	Kemp et al. (2009)
Goat	Biceps femoris	96 h post-mortem storage at 4°C	- The optimised μ-calpain mediated aging was achieved after 48 to 72 h post-mortem storage	Biswas et al. (2016)
Chicken	Chicken Pectoralis superficialis muscle	72 h post-mortem storage at 4°C	- After 6 h post-mortem, μ-calpain activity in the chicken Pectoralis superficialis muscle was hardly detectable	Lee et al. (2008)