The DA-Meter® handheld is a portable fruit ripeness meter that shows the ripening stage of a fruit in a few seconds, without cutting or damaging it. Simply place the reading head on the skin: the instrument measures the DA Index® and immediately shows the value on the display. The same fruit can therefore be measured several times, on the tree, in the packhouse, in cold storage or at the point of sale.
The standard version is designed for the most widely grown fruit species: apples, pears, peaches, plums and apricots.
How the DA-Meter® ripeness meter works
As the fruit ripens, the chlorophyll just beneath the skin decreases. The DA-Meter® measures how much light the flesh absorbs at specific wavelengths and calculates the DA Index® (Index of Absorbance Difference, IADin the literature). A high value means more chlorophyll and therefore a less ripe fruit. As ripening progresses, the index falls.
The method was developed by Prof. Costa and his team at the University of Bologna. Since then it has been validated in many independent scientific studies published by universities and research centres in several countries.
The standard version has a contact reading head with a 13 mm support and works on a single wavelength optimised for medium and large fruit.
Why measure fruit ripeness
The DA-Meter® is mainly used to:
- Choose the right harvest time, by measuring a sample of fruit in the weeks before harvest and following the trend of the index.
- Check the uniformity of a batch, to separate lots that are further ahead in ripening from those that are behind.
- Assess the storage potential of lots, i.e. decide which fruit to send to market straight away and which to keep in long-term cold storage.
- Check quality on arrival and at the point of sale, with an objective measurement instead of a visual judgement.
- Develop growing protocolsfor new varieties and species, in research and field trials.
Traditional methods such as flesh firmness, sugar content or the starch test require destroying the fruit and only give information on a small sample. With the DA-Meter® you can measure dozens of fruit in a few minutes, always the same ones, and see how ripening changes from week to week.
How it is used in the field and in storage
- Switch on the instrument and select the species or measuring protocol.
- Place the reading head on the skin, usually on two opposite sides of the fruit.
- The DA Index® value appears on the display and is saved in memory.
- At the end of the day the data are downloaded to a computer and analysed, also with the ItsRipe software, to compare orchard blocks, varieties and seasons.
Reference values by cultivar
Every year Sinteleia runs measuring campaigns on different cultivars to test the instrument and its field applications. The DA Index® value that corresponds to harvest varies from variety to variety and from one season to the next. That is why it is best to build your own reference curve, measuring the same fruit for a few weeks.
Who uses the DA-Meter®
The meter is used by fruit growers, field technicians, cooperatives and producer organisations, packing and storage houses, retail chains and research centres.
Frequently asked questions
Does the DA-Meter® damage the fruit?
No. The measurement is optical and leaves no marks, so the fruit can stay on the tree and be measured again in the following days.
Which fruit does the standard version work on?
Apples, pears, peaches, plums and apricots. There are dedicated versions for cherries and kiwifruit, with a 9 mm reading head. Trials on other species are under way.
How long does a measurement take?
A few seconds per fruit.
Do I need a computer to use it?
No, the instrument is self-contained and shows the value on the display. A computer is only needed to store and analyse the data.
How do I request a quote?
Fill in the form below with the species, varieties and the number of fruit you usually measure. We will get back to you with the most suitable configuration.
(product code: FRM01F)
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