Effects of chilling rate on progression of rigor mortis in postmortem lamb meat

Effect of chilling rate on heat shock proteins abundance, myofibrils degradation and caspase‐3 activity in postmortem muscles

“…Yan et al . (2022) observed that VFC treatments could improve the meat tenderness than conventional chilling (4 °C), which was consistent with our results. The mechanism may be because the low temperature (very fast chilling) could promote the release of Ca 2+ from sarcoplasm and the formation of the super‐contracted state of sarcomeres, leading to the increase of MFI value (Yan et al ., 2022).…”

“…Another study showed that the fast chilled muscles presented a slower rate of pH values decline than control group, and the pH values of fast chilled muscles recorded more than 6.0 and even up to 6.4 within 5 h after slaughter (Li et al ., 2012). In addition, our previous study found that VFC treatment could delay the rate of pH decline compared with 4 °C chilling (Yan et al ., 2022). Therefore, HSP90 abundance in the control group decreased significantly than VFC‐II group at 1 h postmortem as a result of the difference in pH values due to the different chilling rate.…”

“…The results indicated that increasing of chilling rate for lamb muscle may inhibit the activation of caspase‐3 activity in postmortem muscle. Our previous study has found that VFC treatment can delay the reduction in ATP concentration reduction and glycolysis rate in lamb muscle after slaughter (Yan et al ., 2022). Thus, this observation may be due to the fact that VFC treatments can effectively inhibit the activities of enzyme and delay the process of physiological/biochemical changes in postmortem muscle.…”

“…The sarcoplasmic proteins and myofibrillar proteins were prepared according to the procedure of previous literature by Yan et al . (2022). 1 g muscle sample was to add he chilled extraction buffer of 0.1 mM Tris and 10 mM DTT (pH 8.3) containing protease inhibitor (Roche, Mannheim, Germany).…”

“…Moreover, several studies have reported that very fast chilling has a positive effect on meat tenderness (Li et al ., 2012; Sikes et al ., 2017). It could be due to the changes in the rate of pH‐temperature decline (Thompson, 2002), massive release of Ca 2+ (Yan et al ., 2022), physical damage of the myofibrils (Li et al ., 2012) and weakening of actomyosin cross‐bridges (Warner et al ., 2015) of postmortem muscles during very fast chilling. Although these mechanisms of very fast chilling have been explored well, the exact molecular mechanisms are still unknown.…”