Tenderzyme™

Actinidin (EC 3.4.22.14) is a naturally occurring cysteine protease found in kiwifruit. The enzyme is part of the papain-like peptidase C1 family. Actinidin is the active ingredient in Tenderzyme™.

Actinidin works by selectively breaking down muscle proteins, specifically targeting the myofibrillar proteins responsible for meat toughness.

Actinidin's activity is influenced by temperature and pH, allowing processors to optimise conditions for maximum effectiveness without compromising product quality.

Actinidin is active across a wide range temperature range, from 2-4ºC up to 65ºC, with peak activity at 50ºC. This allows processors to achieve consistent, controlled results under refrigerated conditions, which allows tenderisation during marination and storage. Tenderzyme™ is fully deactivated at typical cooking temperature (>65ºC), preventing over-tenderisation and ensuring the final product maintains optimal texture.

Actinidin is stable at a pH range of 4-9, but optimal activity is found to be around pH 6.

Figure 1. Relative Activity Actinidin vs Papain.

Figure 2. Actinidin Activity vs pH on a casein substrate.

Actinidin hydrolyses both myofibrillar and connective tissue proteins, with relatively higher proteolytic activity toward collagen.

Actinidin's high specificity enables precise control over tenderisation, targeting muscle proteins while preserving the meat’s natural texture and avoiding ‘mushiness’. This precision reduces variability and minimises the risk of defects compared to other fruit proteases such as papain or bromelain.

Tenderzyme™ is typically added to a brine at 2%-4% by weight. The enzyme/brine solution is then applied at 10%-15% by weight of the meat.

Tenderzyme™ tenderises meat without compromising its natural flavour or colour. By preserving these essential sensory qualities, it enables processors to deliver premium products that stand out on both the plate and the shelf. Whereas some fruit proteases can cause excessive softening or leave citrus-like notes, actinidin preserves the meat’s authentic taste and appearance.

Tenderzyme™ delivers tenderisation across all major meat types, including beef, pork, poultry, and lamb. Its controlled action makes it suitable for a wide variety of cuts, from tougher primal cuts steaks to processed meats and value-added products.

Processing with Tenderzyme™ extends across formats such as injection, tumbling, marinades, or surface applications, giving processors flexibility to use it into with different cuts, grades, and sources of meat.

Processed without chemical modification, Tenderzyme™ can be declared as a "natural kiwifruit extract".