Main causes of damage in packaged fruit and vegetables are fungal infections, the most important of them being the green rot (Penicillium digitatum) causing 55-80% of the losses. Other rots (i.e., blue, black, acid and grey rots) can also be damaging. Fungal induced decay starts in the area between the soft part of the fruit/vegetable and its skin and destroys its cellular structure but cannot be detected visually in the packaging line. Due to the under skin- nature of the rot process, a single undetected damaged fruit or vegetable can ruin the whole package with severe economic losses. Fruit/vegetable decay can be detected at its early stage by measuring the frequency displacement of the nuclear magnetic resonance (NMR) proton line using NMR technology, which this project proposes to develop.
The objective of this project is to develop and test innovative low cost nuclear magnetic resonance (NMR) techniques and fruit handling mechanisms for testing the quality level of horti-fruit products in the selection and packaging line. It is expected to reduce the shortcomings of quality control methods based on visual or manual inspection of fruit. Specifically, a prototype system (QTEPACK) will be developed consisting of: a) an NMR component (a magnet, a spectrometer and an electronic unit to process electromagnetic signals), b) a high-precision fruit handling mechanical unit to ensure efficient scanning of the fruit and c) a computer based fruit selection system correlating NMR electromagnetic signals with fruit quality. The above components of the QTEPACK prototype will be integrated into an autonomous control system for food packaging. The efficiency and reliability of the QTEPACK system will be evaluated by the end users in an orange packaging line. The result to be expected from future industrial applications of the new QTEPACK system is a 40% increase in the detection of damaged items in fruit and vegetable batches prior to the packaging step.
The project expects to achieve the following goals:
- Quality determination of organic materials from electromagnetic signals
- Definition of a new methodology to identify the NMR trace of fungus. The signal owing to the quality of the organic material needs to be isolated from other factors such as geometrical shape of the item, position or traces of non critical substances.
- Innovative magnet solutions for industrial environments
- New low cost NMR magnets compatible with technical, industrial, and commercial requirements
- Development of innovative shimming strategies and testing procedures to achieve an high homogeneity field magnetically shielded from the environment
- Localised and non-destructive magnetic recognition
- A new spectrometer based on low-cost magnets will be designed and built. Specific sensors and advanced signal processing algorithms will be developed.
- Complete surface characterisation of the horti-fruit products
- Design and manufacture of a new mechanical system to feed the fruit into the NMR based QC system. The handling strategy together with the mechanical system will be used for fast 3D scanning of fruits.
- Advanced simulation software
- Use of advanced computational tools to study the parameters of the individual QTEPACK modules, providing a fast way to test alternative designs. Two design and evaluation stages are required: the characterisation of each specific unit (magnet and sensor array) and the validation of the computer simulations.
- Integration of the Innovative QC Methodology into Existing Fruit Selection and Packaging Systems
The prototype QTEPACK system will be integrated into existing fruit packaging machines manufactured by DAUMAR. Comparisons with existing QC systems will be performed from the technical point of view (processing & selection, compatibility) as well as the human one (working conditions & environmental).
Applications: The new NMR based quality control mechanisms will be implemented into existing fruit and vegetable weighting and packaging machines developed by the project partners. Spin-off applications of the NMR quality control methods developed in this project include the quality control of a wide range of horti-fruit products, as well as other products such as rubber tires, cloths, plastic, composite components, ceramic parts, etc. and other food, biological and medical products.