Kiwifruit ripeness is hard to judge by eye: the fruit changes little in appearance as it ripens, and the skin says almost nothing about what is happening in the flesh. The DA-Meter® handheld for kiwifruit measures the ripening stage in a few seconds by placing the instrument on the fruit, without cutting or damaging it. It works on both green-fleshed and gold-fleshed kiwifruit.
How the kiwifruit version works
The DA-Meter® measures how the flesh beneath the skin absorbs light and calculates the DA Index®, a value linked to chlorophyll content that changes steadily as the fruit ripens. In gold-fleshed kiwifruit, the loss of chlorophyll goes hand in hand with the colour change of the flesh, so the index tracks the approach of harvest very closely.
The kiwifruit version has a contact reading head with a 9 mm support and works on two wavelengths specific to gold and green kiwifruit. The method was developed by Prof. Costa at the University of Bologna and has been applied to kiwifruit in several scientific studies.
Why measure kiwifruit ripeness
- Decide when to harvest.A sample of fruit is measured at regular intervals and picked when the index reaches the reference value for that variety.
- Plan the harvest block by block.Different orchards, exposures and rootstocks ripen at different times: measuring them tells you where to start.
- Separate lots for storage.Kiwifruit can stay in cold storage for many months. Knowing which lots are further ahead lets you send them to market first and store the ones that are behind for longer.
- Check quality in the packhouse and in distribution, with an objective, repeatable measurement.
- Trial new varieties, following the same fruit throughout the season.
A support to traditional checks
For kiwifruit, sugar content, dry matter and flesh firmness are usually measured. These are useful but destructive measurements, and therefore limited to a few fruit. The DA-Meter® lets you measure many fruit, always the same ones, and understand the ripening trend over time. Destructive checks can then be concentrated at the moment they are really needed.
How to use it
- Mark a few representative fruit in each orchard block.
- Place the reading head on the fruit, usually on two opposite sides.
- The value appears on the display and is saved in memory.
- Repeat the measurement every week and compare the data on a computer, also with the ItsRipe software.
Data from the measuring campaigns
Every year Sinteleia measures several kiwifruit cultivars to test the instrument in the field and follow how ripening changes from one season to the next.
Frequently asked questions
Does it work on both green and gold kiwifruit?
Yes. The instrument uses two wavelengths specific to the two types.
Can I use the kiwifruit version on other fruit?
The kiwifruit version is calibrated for kiwifruit. There is a standard version for apples, pears and stone fruit, and a dedicated version for cherries. If you need a single laboratory instrument for several species, have a look at the MultiMeter.
Does the measurement damage the fruit?
No. It is an optical measurement that leaves no marks.
Is it used on the vine or in storage?
Both. It is portable and battery-powered.
How do I request a quote?
Fill in the form below with your kiwifruit varieties and intended use.
(product code: FRM01AP)
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