RESEARCH RESULTS
Kiwi - NIR measured on skin or flesh
In GreenCHAINge fruit & vegetables, non-destructive measurement techniques are explored and developed. The general aim is to measure quality aspects non-destructively, objectively, repeatable and reliably. One of those measurement methods is by using NIR. In this subproject, NIR measurements of kiwi are explored.
Objective
To measure the quality of kiwifruit with near-infrared spectroscopy (NIR), it is important to know if the NIR measurement can be done on the skin of the kiwi or if the flesh needs to be visible before a proper measurement can be done.
Experiment and Results
More than 350 kiwifruits were stored at 20 °C. The kiwis were measured using a SCIO portable NIR (reflectance mode) spectrometer. Each kiwi was measured with and without skin. Firmness, determined with a penetrometer, and Brix measurements were taken as reference (ground truth).
The prediction (R2) of the Brix and Firmness was improved by removal of the skin. The skin of kiwi suppresses reliable non-destructive measurements of internal quality characteristics like Brix and firmness.
Conclusion
The SCIO portable NIR can better predict firmness and brix based on measurements on the flesh than measurements on the skin.
More information?
This project was commissioned and funded by ABB, Expertisebureau HDG, Fruitbedrijf Pronk, Fruitmasters Holland, Hillfresh, Total Produce and Univeg, and cofunded by Top Sector for Horticulture & Starting Materials.
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FreshKnowledge Team