Actinidin &
Actinizyme®
kiwifruit-powered support for collagen, plant protein digestion & muscle performance.
Actinizyme® leverages a unique combination of actinidin (a protease unique to kiwifruit), whole-fruit fibre and phytonutrients to turbo-charge plant protein and collagen digestion, improve amino acid availability and support muscle growth and recovery in high-protein diets.
what is ACTINIDIN?
Actinidin is a cysteine protease found at high levels in green kiwifruit, where it can account for up to around 40% of the fruit’s soluble protein.
It belongs to the same broad family as papain and bromelain but has distinct substrate preferences, targeting peptide bonds that are relatively resistant to common gastric and pancreatic proteases.
By cutting protein chains at additional sites, actinidin complements pepsin, trypsin and chymotrypsin to achieve a more complete breakdown of complex dietary proteins.
This is particularly helpful for structurally dense proteins and proteins encapsulated within plant cell walls, supporting more efficient release of muscle building amino acids.
How actinidin supports
plant protein &
collagen for muscle
growth.
Proteins must be digested into small peptides and amino acids before they can be absorbed and used for muscle building, tissue repair and metabolic functions.
Actinidin accelerates this process in the stomach by helping to unfold and hydrolyse tough proteins that otherwise digest slowly, supporting quicker amino acid delivery to the bloodstream.
Research shows that actinidin:
- Leads to faster amino acid appearance in the bloodstream following protein rich meals.
- Supports more efficient use of protein for muscle building, recovery and adaptation to training.
actinidin
& plant proteins.
Plant proteins are often embedded in fibres and plant cell walls made of cellulose, hemicellulose and pectin that human enzymes cannot fully dismantle.
Actinidin helps expose and hydrolyse these encapsulated proteins.
Actinidin has demonstrated activity on pea, soy, almond, quinoa and wheat gluten, increasing the rate and extent of plant protein hydrolysis versus gastric enzymes alone.
This can narrow the digestibility gap, supporting better amino acid delivery and muscle relevant protein quality in plant forward diets.
HYDROLYSES
PROTEINS.
improveS
PLANT PROTEIN
EFFICACY.
SUPPORTS
AMINO ACIDS.
WHAT IS
Actinizyme®?
Actinizyme is a non GMO, freeze-dried green kiwifruit powder from New Zealand, standardised to a high, consistent level of actinidin activity for use in supplements and functional foods.
It delivers actinidin in its natural whole fruit matrix, alongside kiwifruit fibre, polyphenols, vitamin C, vitamin E and potassium, providing a holistic, performance-oriented protein support ingredient.
- Skinless, seedless whole fruit powder for consistent composition and enzyme activity.
- Standardised actinidin content to ensure reliable protein digestion and amino acid release support.
- Fruit based format that fits clean label, high protein and sports nutrition formulations.
Because it uses whole kiwifruit rather than isolated enzyme extracts, Actinizyme offers both enzyme driven protein benefits and the broader whole fruit complex effects of kiwifruit bioactives.
Actinizyme®
& collagen products.
Collagen peptides and collagen enriched products are popular for beauty, joint and recovery support, and are increasingly used in performance and sports stacks.
Actinidin has been shown to effectively hydrolyse collagen like substrates, indicating it can further break down collagen peptides beyond the action of standard gastric enzymes.
By delivering a high, standardised level of actinidin in a whole kiwifruit matrix, Actinizyme provides targeted support for collagen powders, ready to mix drinks and collagen fortified functional foods.
Including Actinizyme alongside collagen can help:
- Promote more thorough breakdown of collagen peptides into smaller fragments and amino acids.
- Support faster amino acid availability from collagen containing products to complement muscle and recovery goals.
The tropical fruity flavour of Actinizyme provides a clear, kiwifruit-style fruit note that helps mask earthy or beany protein-notes, works well with other tropical flavours, and supports a simple smoothie-style taste in powder blends.
Actinidin vs. other
proteolytic enzymeS.
Actinidin is often compared with papain (papaya) and bromelain (pineapple), but its source, matrix and substrate profile make it particularly attractive for digestive health applications.
Everyday benefits
of actinidin-rich
Actinizyme®.
When formulated into capsules, chewables, powders or synbiotic products, Actinizyme can help a wide range of users get more out of the protein they consume.
- Protein users: Support more efficient use of plant and collagen proteins in shakes and blends.
- Active individuals & athletes: Help optimise amino acid delivery from high protein diets to support muscle building and recovery.
- Performance focused consumers: Integrate Actinizyme into pre and post workout products to complement training and protein strategies.
By uniting actinidin’s targeted protease activity with the broader bioactives of green kiwifruit, Actinizyme offers a differentiated, food based solution for modern, protein heavy, muscle focused lifestyles.
where actinidin comes from.
Actinidin is a cysteine protease made by kiwifruit (Actinidia), and the amount depends heavily on the variety. In one laboratory comparison, an extract from Hayward green kiwifruit carried about 28 U/mL of actinidin activity, against about 8 U/mL for SunGold gold kiwifruit.
The enzyme is small: about 220 amino acids and 23.5 kDa. It belongs to the papain-like family of plant proteases, alongside papain from papaya latex and bromelain from pineapple.
That variety gap explains why the human studies below use green kiwifruit as the actinidin source and a gold variety (Hort16A), with little protease activity, as the comparator. It also means a kiwifruit powder is only an actinidin ingredient if its enzyme activity is measured and standardised. Actinizyme is specified at above 100,000 U/g actinidin activity. Actazin, our kiwifruit powder built for bowel regularity, is specified above 25,000 U/g.
actinidin vs papain and bromelain.
The three enzymes are close relatives, so the differences sit in the details, not the mechanism. Published values from one comparison of the three:
| Actinidin | Papain | Bromelain | |
|---|---|---|---|
| Typical source | Kiwifruit (green varieties highest) | Papaya latex | Pineapple stem and fruit |
| Amino acids | 220 | 212 | 285 |
| Molecular weight | 23.5 kDa | 23.4 kDa | 23.4 to 35.7 kDa |
| Reported active pH range | 4 to 10 | 5 to 7 | 4.6 to 9.5 |
| Catalytic efficiency on milk proteins (in vitro) | Highest | Middle | Lowest |
In simulated gastric digestion of gluten, actinidin broke down gliadin at about 0.8% per minute, roughly double the average of papain, bromelain and a commercial enzyme (about 0.4% per minute).
Those are test-tube results with commercial enzyme preparations. We know of no human trial that compares actinidin head to head with papain or bromelain, so any claim that it digests protein better in people than they do goes beyond the data.
what the evidence actually shows.
The mechanism is well supported. The human evidence is real but small.
- Laboratory: in a simulated stomach, actinidin improved digestion of casein, soy protein and beef muscle beyond pepsin alone. In a 2022 digestion model it sped gastric breakdown of pea protein, tofu and almonds, while quinoa showed only small effects.
- Animals: in rats and pigs, dietary actinidin increased gastric digestion of proteins such as beef muscle and gluten, and sped stomach emptying. In pigs, over 44% more digested protein reached the small intestine at 5 hours.
- People, amino acids: 12 healthy adults aged 60 to 85 ate 2 kiwifruit daily for 14 days, then a meal with 100 g of beef, in a randomised, double-blind crossover. Blood levels of branched-chain amino acids and leucine were higher at 40 and 60 minutes after green kiwifruit than after gold. Total amino acids absorbed did not differ, and neither did whole-body protein kinetics.
- People, comfort: in 10 healthy men eating 400 g of lean steak, gastric emptying and transit did not differ between green and gold kiwifruit, but bloating ratings were lower with green (p<0.028). It was a small pilot.
Read fairly: actinidin changes how fast amino acids appear, in small studies that used whole kiwifruit rather than isolated enzyme. No study cited here measured muscle gain, so keep muscle claims modest and build around digestive comfort and protein handling.
how Actinizyme puts actinidin to work.
Actinizyme is a freeze-dried whole green kiwifruit powder from New Zealand, standardised to above 100,000 U/g actinidin activity. Anagenix positions it at 200 mg per serving alongside 20 to 30 g of protein, for protein powders, sachets, chewables, capsules, ready-to-drink beverages and bars.
Anagenix’s own user tests give early signals on comfort. In a UK test, 21 regular protein-powder users took 600 mg of Actinizyme once daily for 2 weeks and scored their symptoms against their own baseline. Average scores fell 37% for bloating and gas, 34% for abdominal pain and 29% for reflux. A separate NZ group of 13 people over 4 weeks recorded a 17% fall in bloating and gas scores.
These are small, self-reported questionnaire studies with no placebo group and a higher dose than the 200 mg positioning, so treat them as formulation signals, not clinical proof.
For the mechanism and study list, see the science of Actinizyme. Manufacturers can find supply partners on the Anagenix distributor page or contact us about samples.
actinidin questions, answered.
What is actinidin?
Actinidin is a protein-digesting enzyme (a cysteine protease) found in kiwifruit, most abundantly in green varieties. In laboratory and animal studies it breaks dietary protein into smaller pieces and adds to the action of pepsin.
Which foods contain actinidin?
Kiwifruit. Green kiwifruit carries more activity than gold varieties, which contain it at lower levels (in one study the gold extract measured about 28% of the green). Papaya and pineapple contain related enzymes, papain and bromelain, not actinidin.
Is actinidin the same as bromelain or papain?
No. All three are plant cysteine proteases from the same family, but they come from different fruits and differ in size, pH range and substrate preference. Actinidin comes from kiwifruit, bromelain from pineapple and papain from papaya.
Can actinidin be used in a supplement?
Yes, usually inside a kiwifruit powder. Actinizyme is a whole green kiwifruit powder standardised for actinidin activity, supplied to supplement and food manufacturers rather than sold directly to consumers.
Is actinidin a kiwifruit allergen?
Actinidin is recognised as one of the major kiwifruit allergens (Act d 1). People with a kiwifruit allergy should avoid kiwifruit-derived ingredients, and manufacturers should check allergen labelling rules in their target markets.
