Innovative Optical Sensing Precision Storage of Fruit

Company description

The PhD candidate will be part of the Division of Mechatronics, Biostatistics and Sensors (MeBioS) within the Department of Biosystems at KU Leuven. MeBioS is internationally recognised for its expertise in biosensing, postharvest technology, modelling, and precision agriculture. The group focuses on developing advanced measurement techniques and data‑driven models to better understand biological systems and improve agri‑food processes. Within this stimulating and collaborative setting, the candidate will work at the interface of plant science, engineering, and data analysis, contributing to innovative solutions for sustainable food production and storage.

This PhD position is focused on advancing non‑destructive sensing approaches to improve postharvest storage of pome fruit (apple, pear). The project aims to bridge fundamental fruit physiology, optical sensing, and applied storage technology.

Controlled atmosphere (CA) storage is widely used to extend pome fruit shelf life, yet current strategies insufficiently account for biological differences between fruit batches. Differences in fruit microstructure, particularly porosity, strongly influence gas exchange (oxygen, carbon dioxide), respiration, and susceptibility to storage disorders such as internal browning. While X-ray micro‑computed tomography (µCT) enables accurate quantification of porosity, it is not suitable for practical deployment.

Spatially resolved spectroscopy (SRS) offers a promising non‑destructive alternative to probe internal tissue structure. This project will advance SRS from laboratory validation toward application in realistic storage environments, by establishing whether porosity can be reliably measured using SRS and used as a predictor for storage behaviour and fruit quality.

• How does fruit porosity govern internal gas transport, respiration, and ethylene production?
• Can porosity be used as a robust predictor of storage potential and risk of physiological disorders?
• Which microstructural features are most relevant for explaining differences in storage behaviour?
• How can SRS signals be quantitatively linked to fruit porosity and gas exchange properties?
• To what extent can simplified, portable SRS systems provide sufficiently accurate predictions for practical use?

• Microstructural characterisation:
  Fruit porosity will be quantified using µCT at KU Leuven, enabling detailed analysis of pore structure and connectivity.
• SRS measurements:
  The same fruit batches will be measured using SRS to develop calibration models relating optical signals to porosity.
• Storage trials:
  At storage pilots as part of a large scale EU Horizon project, fruit with contrasting porosity levels will be stored under defined gas conditions. Respiration, ethylene production, and post‑storage quality (firmness, colour, disorders) will be assessed.
• Model development:
  Relationships between porosity, gas exchange, and storage outcomes will be modelled to evaluate predictive capacity.
• Technology translation:
  The project includes simplification of SRS toward handheld use, followed by validation in semi‑commercial environments.

• Fundamental insights into the role of microstructure in postharvest physiology
• Validation of porosity as a biomarker for storage optimisation
• Calibrated SRS models for non‑destructive porosity estimation
• Predictive tools linking pre‑storage measurements to storage performance
• Guidelines for deploying affordable SRS technology in practice

We seek a motivated candidate with a Master’s degree in Bioscience Engineering, Physics, Mechanical/Electrical Engineering, Applied Biology, Agricultural Engineering, Biomedical Engineering or a related field. Experience with spectroscopy, plant physiology, data analysis, or modelling is an asset. Strong analytical skills and interest in interdisciplinary research are essential.

KU Leuven offers a dynamic and inspiring environment for doctoral research at one of Europe’s top‑ranked universities. As a PhD researcher, you will receive high‑quality supervision, access to state‑of‑the‑art…