Spectral Imaging Supports Study on Natural Chitosan Coatings to Protect Oranges 

A sustainable alternative to fungicides powered by Videometer’s imaging technology 

Every year, citrus producers face major postharvest losses due to fungal infections caused by Penicillium digitatum and Penicillium italicum, the pathogens responsible for green and blue mold on oranges. Traditional fungicide-based treatments are increasingly challenged by fungicide resistance, stricter regulations, and growing consumer demand for residue-free fruit. 

A new peer-reviewed study published in Postharvest Biology and Technology by researchers from Marche Polytechnic University, University of California Davis, and the Federal University of Paraná demonstrates that chitosan, a naturally derived biopolymer, can be a powerful and sustainable alternative to synthetic fungicides in managing postharvest citrus diseases. 

VideometerLab4: enabling non-destructive fungal detection and quantification 

To evaluate the effectiveness of chitosan coatings, the research team used the VideometerLab Spectral Imaging Technology. 

Our flagship system captures 19 spectral images across a spectral range of 365–970 nm, enabling detailed, non-destructive analysis of the fruit surface. With the VideometerLab Software and, specifically, the normalized Canonical Discriminant Analysis (nCDA), the researchers were able to accurately distinguish healthy from infected areas on orange peels, even before visual symptoms appeared. 

This capability allowed for early, objective quantification of infection development and the precise evaluation of chitosan’s antifungal effectiveness. 

“The absence of infection signals in chitosan-treated fruit, confirmed by Videometer’s spectral analysis, provided visual and quantitative proof of protection against Penicillium,” the authors note. 

Key findings from the study 

• Chitosan coatings (1–2%) effectively inhibited fungal growth, even in fungicide-resistant strains of P. digitatum and P. italicum. 

• Oranges treated with chitosan and wax coatings showed the lowest infection incidence and superior shelf-life performance. 

• The VideometerLab instrument clearly visualized and quantified infection progression, validating chitosan’s protective effect. 

• The chitosan and wax combination also minimized weight loss and maintained the fruit’s visual appeal during storage. 

These results position chitosan as a safe, natural, and cost-effective strategy for postharvest protection and highlight Videometer’s role in enabling advanced quality and disease monitoring. 

Advancing sustainable postharvest research with multispectral imaging 

By combining chitosan’s antimicrobial properties with Videometer’s spectral imaging technology, the study sets a new standard for non-invasive fruit quality assessment and postharvest disease detection. 

Videometer’s spectral imaging tools are used in research and industry for: 

• Early detection of fungal infections on fruit and vegetables 

• Quantitative analysis of coating performance 

• Shelf-life and quality monitoring 

• Objective color and surface evaluation 

This work reinforces the value of spectral imaging in agricultural innovation, supporting a shift toward sustainable, data-driven postharvest management.

About the study

Chitosan inhibits the growth of Penicillium digitatum and Penicillium italicum and protects oranges from green and blue mold during postharvest.

Authors: Simone Piancatelli, Adrian O. Sbodio, Thomas Bruno Michelon, Muyun Tsen, Mary Carmen Carranza-Rodriguez, Elia Gutierrez-Baeza, Gianfranco Romanazzi, Barbara Blanco-Ulate.