Meat Tenderising
How to Turn an 8-year-old Cow into ‘Fillet’ Steak Quality
Meat tenderising using a Minimal of Actinidin – Between 2-4% of total brine weight.
The meat industry estimates that up to 90% of animal carcass weight is NOT graded prime tender meat. A large number of animals go to slaughter at an older age, devaluing the quality.
This presents a great opportunity for processing plants to add value to their meat cuts. A proteolytic enzyme naturally breaks down those long protein chains like collagen. Using the protease Actinidin found in kiwifruit extracts, it is possible to achieve a controlled breakdown of the connective proteins in meat, improving the customer experience. Best of all, your bottom line grows proportionally as your product improves.
You may have experienced the problem first hand as your guests dig in and take their first bite. The news isn’t good. Like a dog pulling a tube sock from your clenched fist, your guests tug and strain. “I’ve had beef jerky more tender than this steak.” The problem is failure to properly tenderise the meat before cooking. You may thank collagen for the trauma. These long strands of protein hold meat together and act as a binding agent.
Think of your consumers. Who doesn’t prefer a more flavourful, juicy, tender cut?

Kiwifruit Extract KEP40
The Shortest Distance Between Pork and Pulled-Pork, Lamb and Pulled Lamb, or Beef and Pulled Beef.
Why Actinidin?
Seeing the research has prompted several food industry giants to promote Kiwifruit extracts for tenderising. Comparing Actinidin with other enzyme products such as papain, bromelain, or bacterial proteases, it is apparent that Actinidin offers:
- An improvement for all types of meat (beef, pork, lamb, poultry and fish)
- Increased operational flexibility
- Stability in freezer storage; injected meat portions can be stored frozen then thawed and tempered for subsequent consumption
- Actinidin leaves no taste influence or off-colour
- Significant improvement in tenderness (based on European studies)
- Better control. You don’t end up with mushy meat because Actinidin deactivates at the optimum temperature!!

Using Kiwifruit Extract (KEP40) in Commercial Meat Processing
Financial Advantages using a 2% to 4% Brine Solution
- Your product quality will improve 20% to 40%
- Your bottom line will improve significantly, plus 60% to 100%
Cooking Regimes
Kiwifruit Extract KEP40 is most effective when mixed in a brine solution and applied with multi-needle injectors then tumbled for uniform distribution and even texturing. Small meat portions are best prepared in the same way prior to cutting into smaller portions. Small portions are best finished using a sous-vide cooking regime.
Large meat portions (1.5 – 3.0kg) such as corned beef, beef roast and whole poultry are tenderised as the temperature of the portion rises from chilled to the target cook temperature. Cook time for such portions are 1 – 2 hours; Actinidin activity will increase with temperature, optimal at 55° – 60°C and deactivate at 65°C preventing over-tenderising or mushy meat.
Small meat portions such as beef steaks and poultry thighs typically require short cook times that are insufficient to achieve full tenderising. Trials have demonstrated that a pre-cook at 50°- 55°C for 30 – 40 minutes achieves effective tenderising. This pre-cook stage is the basis for a widely-used method known as sous-vide (see below).
Kiwifruit Extract (KEP40) in Brine Solutions
KiwiEnzyme and several ingredient companies have undertaken extensive trials of kiwifruit extract for tenderising cow and bull beef. Kiwifruit Extract KEP40 is dissolved in a brine solution and injected. The meat is then tumbled.
Product from these trials has been evaluated by both quantitative measurements (tenderometer) and by sensory panel. The overall assessment has shown improvements in:
- Tenderness
- Juiciness
- Flavour
The colour of the meat when stored chilled, uncooked, retains a more natural red appearance.
Brine Solution and Marinades
Kiwifruit Extract KEP40 is easily blended with your existing brine mixture or marinade recipe.
The enzyme activity remains constant in salty mixtures.
Typical brine consists of sodium chloride, sodium tripolyphosphate and sodium hexametaphosphate yet each company has their own formula based on the desired flavour profile. Brine is generally 10% of the weight of water with 2-4% being KEP40.
Salt content of the brine solution influences the flavour profile of the meat and it is important to balance salt content with other flavour enhancers and water retention aids to control excessive saltiness or drying.



Sous-vide
Sous-vide is ideally suited to Kiwifruit Extract KEP40 brine injection for tenderising small meat portions. This is popular with retail, fast food or airline companies where quantities of meat are partially prepared in advance.
- Portions are cooked in sealed pouches or containers at 55° – 60°C for periods up to 60 minutes.
- Temperature can be increased to 70°C to terminate the enzyme and pasteurise the portion controlling bacterial growth.
- Cooked meat can be stored and refrigerated in a sealed state.
- Steak portions can be seared either before or after Sous-vide to achieve desired Maillard reactions on the meat surface.
Sous-vide process avoids the high cook temperatures that cause the structural proteins in the meat to toughen. The bulk temperature is the same as the target cooking temperature. The shape and size of the portion does not affect the outcome.
Using Sous-vide preparation, Actinidin has sufficient time to achieve the optimal tenderising outcome.
Combining the benefits of Kiwifruit Extract KEP40 tenderising with Sous-vide cooking is ideally suited to large scale food services which require reproducable quality meat products at a competitive cost.

Product Description
Description: An extract of New Zealand kiwifruit with standardised activity level of the proteolytic enzyme Actinidin.
Appearance: Cream-coloured free-flowing powder.
Particle Size: Less than 850 Microns.
Solubility in Water: Readily soluble.
Packaging: 10kg net weight, PE liner in metallised PES bags, vacuumed packed with cardboard outer.
Shelf Life: Stable for minimum of 24 months at ambient temperatures. Once opened, product must be protected from moisture.
