Enzyme treatment is a product decision, not a standard machine
A kiwifruit line can be discussed without an enzyme step, and this site does not include enzyme dosing as a standard equipment module. Food-grade pectinases and other enzymes can change extraction, viscosity, cloud stability and clarity. Those changes may be useful in a selected juice process and undesirable in a puree where body and cloud are part of the product. The project should therefore start with the target ingredient, not with a generic enzyme recommendation.
- State whether the product is cloudy puree, cloudy juice or a separated liquid.
- Describe any enzyme step already used upstream and provide the supplier specification.
- Keep enzyme supply, dosing, inactivation and labelling responsibilities explicit.
Start with the product you intend to sell
A cloudy puree and a clarified juice are different products even when they begin with the same fruit. Puree may depend on suspended solids, fibre and a particular mouthfeel; a clear juice may value yield and clarity. Enzyme treatment can shift the balance between pectin, water and particles, so it should be tested against the intended product. A treatment that improves drainage in one route can reduce the body expected in another.
- Provide a reference sample and the acceptance observations for colour, body and particles.
- Separate a yield objective from a texture or clarity objective.
- Avoid assuming that an enzyme step is transferable between puree and juice.
Browning is a reaction, not a colour setting
Polyphenol oxidase (PPO) is present in kiwifruit and can contribute to browning when tissue is damaged and oxygen is available. Practical control starts with the process: limit unnecessary tissue damage, reduce open exposure, and manage time and temperature through the route. Ascorbic acid has been reported to delay enzymatic browning in kiwifruit, but the literature does not establish one universal dose for every puree. Any antioxidant or inhibitor addition belongs to the product specification, local labelling review and a representative trial.
- Distinguish enzymatic browning from heat-related colour loss or storage change.
- Map where fruit is cut, crushed, pumped or left open to air.
- Treat an additive as a product decision, not an equipment feature.
Thermal treatment can protect or change the target
Heat can inactivate enzymes and reduce microbial risk, but it can also alter green colour and the balance of fresh, fruity and cooked notes. Published work on kiwifruit puree and juice reports differences between heating methods, product fractions and varieties. That is why this site does not publish a universal temperature and hold time. The treatment objective, product properties, package and validation work must be reviewed together, with colour and aroma assessed using a consistent sample and method.
- Provide viscosity, particles, acidity and inlet temperature for the actual product.
- Agree the treatment objective and who validates the operating conditions.
- Include a sensory and colour reference in the product assessment.
Define the enzyme boundary in the quotation
If an enzyme step is required, write it into the project as a defined boundary. Identify who supplies the enzyme, its food-grade specification and addition point. Define contact time, temperature, pH, inactivation or removal, and the cleaning procedure for the addition and holding section. State how residues or labelling are handled. If the equipment supplier does not provide the enzyme or the validation, say so rather than leaving the buyer to infer it from a process flow.
- Name the addition point and the equipment that contacts the enzyme.
- State the inactivation or removal step and its verification.
- Separate equipment supply from enzyme supply, process validation and labelling.
Send the fruit, product and route together
A useful enzyme or colour discussion includes the fruit cultivar and condition, the target product, the existing process and the intended package. Describe any current enzyme use and the result it gives. Include a reference sample if colour, aroma or body is important. With those inputs, the equipment and validation boundaries can be reviewed without inventing a dose, a heat schedule or a shelf-life claim.
- Cultivar, maturity and incoming condition.
- Target product, reference sample and assessment method.
- Existing enzyme, thermal and packaging steps, including who owns each one.
TECHNICAL REFERENCES
Sources and boundaries.
These references are provided for technical orientation. They do not establish a machine rating, a validated process or a performance guarantee for your fruit, product or installation.
- Journal of Food Science · Polyphenol oxidase of kiwifruit (1985)Reports kiwifruit PPO extraction and the delay of enzymatic browning by ascorbic acid in that study. Not a universal dosage or process recommendation.Published 1985 · accessed 25 October 2026
- Innovative Food Science & Emerging Technologies · Microwaves and conventional thermal treatment of kiwifruit puree (2013)Compares enzyme activity and antioxidant capacity after thermal treatments. Used as background on product-specific thermal effects.Published 2013 · accessed 25 October 2026
- LWT · Columella, aroma and thermally treated kiwifruit juice (2022)Shows that fruit fraction, variety and heating affect aroma-active compounds. Supports a sample-based flavour assessment rather than a universal schedule.Published 2022 · accessed 25 October 2026
- International Journal of Molecular Sciences · Celluclast and gold kiwifruit pectin (2011)Examines enzymatic modification of gold kiwifruit pectin. Illustrates why an enzyme step can change product functionality and requires a product-specific trial.Published 2011 · accessed 25 October 2026
