Table 1 Partial summary for the impact of different exogenous proteases on meat tenderness
Classification | Sources | Name | Characteristics and tenderising effects | References |
|---|---|---|---|---|
Plant-derived enzyme |  | Papain | Broad range of substrate specificity, and high inactivation temperature (90 °C) and optimal temperature (65 °C) High proteolysis ability to myofibrillar protein The proteolysis ability to connective tissue is relatively weaker than bromelain/ficin Significant tenderising effect, but easy to produce paste and overly soft texture | Abdel-Naeem & Mohamed 2016; Bekhit et al. 2014; Maqsood et al. 2018 |
Plant-derived enzyme |  | Bromelain | Optimum proteolytic activity (pH 5–7, 50 °C) Proteolysis activity: stem-derived < fruit-derived Lower selectivity to actin than papain Higher levels of hydrolysis in myofibrillar and sarcoplasmic proteins and better flavor than papain | |
Plant-derived enzyme | Â | Ficin | Broad range of substrate specificity and optimum pH is dependent on substrate concentration Higher degradation to collagen than matrix substrate | Maqsood et al. 2018 |
Plant-derived enzyme | Actinidia arguta | Actinidin | Optimal activity at 58–62 °C and low influence on sensory The hydrolysability to beef: commercial actinidin > other plant-derived enzymes Effectively tenderise tissue and decompose actomyosin | |
Plant-derived enzyme | Ginger rhizome | Zingibain | Higher specificity to collagen than actomyosin Degradation on Troponin-T, α-actinin and desmin Decrease in shear force and increase in MFI Reduction in myofibrillar fragment length | Cruz et al. 2020; Tsai et al. 2012 |
Microbe-derived enzymes | Alkalophilic Bacillus YaB | Alkaline elastase | Optimum activity (pH 5.5–6.0, 10–50 °C) The dissociation amount of elastic tissue is much higher than that of papain and bromelain Low hydrolysis activity to MP at low pH; mild tenderisation Combination with papain to avoid over-tenderisation | Yeh et al. 2002 |
Microbe-derived enzymes | Clostridium histolyticum | Collagenase | Collagen solubility: collagenase > papain, bromelain, ficin Low proteolysis to salt-soluble protein | Foegeding & Larick 1986 |
Microbe-derived enzymes | Rhizomucor miehei | Aspartic protease | Broad range of substrate specificity Positive correlation with tenderness under a certain range of concentration and optimum activity at 50 °C PSE texture under exorbitant concentration | Sun et al. 2018 |
Animal-derived enzymes | Â | Placental protease | Hydrolyse collagen, and target connective tissue | Phillips et al. 2000 |
Animal-derived enzymes | Â | Porcine pancreatin | Degrade myosin, stretch sarcomere length and decompose collagen fibres | Pietrasik et al. 2010 |