Kiwifruit Well-Known for Meat Tenderizing in New Zealand

  • Chefs in New Zealand for decades have been placing kiwifruit on top of meat to improve tenderness
  • Tenderizing effects of kiwifruit enzyme can be exploited for all meat types
  • Better meat tenderization control than other fruit protease enzymes
  • No adverse flavours or colour changes 

Sous Vide

  • Sous vide provides benefits of low cooking loss, quality improvement and long shelf-life of cooked meat
  • Sous vide is ideal application for utilizing benefits of kiwifruit enzyme in fruit extract form
  • Kiwifruit enzyme provides following benefits to meat:
    • Improved tenderness
    • increased pullness
    • Some increase in juiciness
    • No effect on flavour or colour
    • Unaffected by presence of salts
  • Potential to improve value of meat by 8-10 times using kiwifruit extract high in protease enzyme


Sous Vide with Kiwifruit Enzyme

pdf download icon 72pxStudy conducted by Danish Meat Research Institute

Download: Injection of marinade with actinidin increases tenderness of porcine M biceps femoris and affects myofibrils and connective tissue

Sensory attributes of pulled pork with different kiwifruit extract concentration, cooked at 56°C for one hour, followed by holding times at 80°C, compared to reference with no kiwifruit extract added.

kiwifruit extract sous vide meat actinidin

  • Increased tenderness
  • Increase in pullness
  • Some increase in meat juiciness 


Injected and Tumbled Meats

  • Excellent opportunity to incorporate kiwifruit extract, high in enzyme (actinidin), into injected or tumbled meats
  • Actinidin is highly active at pH 5.5-8, the typical pH of most meat products
  • Apply kiwifruit extract (actinidin) with injected solution or in marinade solution for tumbled meat
  • For both injected and tumbled meats, actinidin will be exposed to meat cells, digesting meat proteins, converting tough meat into high-quality tender meats
  • No adverse flavour or colour changes
  • Natural, clean-label, non-GMO, improving meat quality and adding-value 


Injected Meat with KEP40

Sensory scores of hardness and juiciness of beef flank with no injection, injection of water, or 0.5% and 1.0% injection of kiwifruit extract KEP40.

injected meat KEP40P actinidin

KEP40 kiwifruit extract improved meat tenderness and increased meat juiciness compared to untreated beef flank and beef flank injected with water.


Marinade Sauces

  • Opportunity to include kiwifruit extract (with actinidin enzyme) into marinade sauces
  • Especially applicable for targeting consumers seeking marinade sauce made with ingredients that are clean-label, natural and non-GMO
  • Safely allows marinade sauce to qualify for Non- GMO Project seal
  • Actinidin is active and stable in typical salt concentrations of marinade sauces 


Study: Actinidin has broader applications in meat

pdf download icon 72pxStudy by Ha et al. (2012), Food Chemistry 134: 95-105

Download: Characterisation of commercial papain, bromelain, actinidin and zingibain protease preparations and their activities toward meat proteins

  • Actindin has advantage over other fruit proteases such as papain and bromelain, as less aggressive in action, so demonstrates mild tenderizing effects, even at high concentrations
  • Mild tenderization prevents meat surface mushiness
  • Relatively low inactivation temperature compared to papain and bromelain also enables easier control of tenderization process without overcooking 


Study: Injection of marinade with actinidin increases meat tenderness

pdf download icon 72pxStudy by Christensen et al. (2009), J. Sci. Food Agric. 89: 1607-1614

Download: Injection of marinade with actinidin increases tenderness of porcine M biceps femoris and affects myofibrils and connective tissue

  • Actindin increased tenderness of pork M. biceps femoris
  • Flavour and juiciness were unaffected by actinidin
  • Pork injected with actinidin reached similar tenderness in 2 days, compared to controls without kiwifruit enzyme that took 9 days
  • Pork with actinidin had increased degradation of desmin and heat-soluble collagen
  • Myofibrillar particle size decreased with increasing actinidin concentration 


Study: Pre-rigor infusion of kiwifruit juice increases quality of lamb

pdf download icon 72pxMaster thesis by Han (2008), Lincoln University, New Zealand

Download: The Effect of Pre-Rigor Infusion of Lamb With Kiwifruit Juice on Meat Quality

  • Lamb infused with actindin was most tender compared with lamb infused with water or no infusion
  • More myofibrillar proteins were degraded in lamb infused with actinidin
  • Slight positive effects in lamb redness and decreased lipid oxidation were attributed to kiwifruit antioxidants
  • Infused kiwifruit did not alter the flavour of lamb 


Study: Actinidin improves tenderness of steaks

pdf download icon 72pxStudy by Lewis et al. (1988), J. Food Biochem. 12: 147-158

Download: Application of Actinidin From Kiwifruit to Meat Tenderization and Characterization of Beef Muscle Protein Hydrolysis

  • Broiled bovine semitendinosus steaks treated with actinidin had improved sensory tenderness compared to steaks with no treatment
  • Actindin did not over-tenderize at the meat surface, whereas papain created mushy meat surface
  • Lack of over-tender mushiness in steaks using actinidin was due to less hydrolysis of myofibrillar proteins compared to papain 

Meat Tenderising – FAQs

Can Kiwifruit Extract P40 be used in meat tenderising without needle injection?

Effective tenderizing requires uniform distribution of the enzyme solution into all muscle layers. Tumbling will assist this process, but tumbling without injection will require longer process times and can result in loss of texture and variable tenderizing.

What is the typical dose rate of Kiwifruit Extract P40?

Kiwifruit Extract P40 is typically dosed at 0.5% - 2.0% by weight in a brine solution. The enzyme/brine solution is injected at 10% - 15% by weight of the meat.

Is it necessary to use a brine with Kiwifruit Extract P40?

The primary purpose of the brine is to provide effective water holding in the meat thereby ensuring that the enzyme performs its tenderizing action on the meat fibres in an optimal way. Tenderising solutions increase the water content of the meat which would be lost during subsequent handling without a suitable brine.

Additional benefits of the brine are enhanced flavour and juiciness of the cooked meat.

Alternative water-binding agents such as Carrageenan Gum have been used as partial replacements for salts but these can result in undesirable textural qualities in the meat.

What brine should be used?

Salt brines are typically a mixture of sodium chloride and sodium tripolyphosphate.

Brines available from food ingredient suppliers will be compatible with Kiwifruit Extract P40.

How stable is Kiwifruit Extract P40 in the brine solution?

Kiwifruit Extract P40 has demonstrated stability in high salt brine solutions (15% by weight) with no loss of activity after 3 hours at 7°C. 

Will the substitution of brine with Carrageenan Gum affect enzyme activity?

Kiwifruit Extract P40 has demonstrated no loss of activity when Carrageenan Gum at up to 2% by weight was added to the brine solution.

Is Kiwifruit Extract P40 easy to dissolve in the brine solution?

Kiwifruit Extract P40 is readily soluble at the recommended use rates. The solution does require continuous agitation during the powder addition. Blending the brine salt mix with Kiwifruit Extract P40 prior to dissolving in water assists the dispersion and dissolution.

Will the tenderizing effect operate if the treated meat portion has been stored frozen or chilled for extended periods?

TBA - anecdotal evidence says yes but the loss (of tenderising efficacy) if any have not been quantified.

Dose the injected Kiwifruit Extract P40 / brine solution pose any food safety risks?

TBA – microbiological data from trials to date says no, provided equipment is properly sanitized. Kiwifruit Extract P40 undergoes full microbiological testing prior to release.





Category: Standardised Actinidin Powder, Meat Tenderising, Meat Tenderizing, Digestive Health, Prebiotic