A Multispectral Framework for the Detection of Calcium Carbide-Induced Ripening and Shelf-Life Estimation in Climacteric Fruits

2026-08-13

AI Summary

This study addresses the health risks associated with arsenic and phosphorus residues from industrial-grade calcium carbide used to ripen climacteric fruits, necessitating non-destructive methods to identify ripening treatments and assess maturity and shelf life. The authors propose a novel non-invasive framework based on visible–near-infrared multispectral imaging (410–940 nm, 18 bands), integrating innovative features such as spectral intensity ratios, inter-method variance, and environmental temperature–humidity data. By combining principal component analysis (PCA) for dimensionality reduction with an XGBoost regression model, the approach simultaneously achieves, for the first time, identification of calcium carbide-induced ripening, estimation of maturity percentage, and prediction of remaining shelf life. Experimental results demonstrate classification accuracies of 95% for mangoes and 81% for bananas, with the first 5–7 principal components retaining over 90% of the total variance, confirming the method’s efficacy and innovation.

Abstract

Significant health risks are associated with the illegal, yet commonly practiced use of industrial-grade Calcium Carbide (CaC2) for ripening climacteric fruits like mango and banana, which leaves behind trace residues of arsenic and phosphorus. To address this, the proposed study explores a novel, non-invasive multispectral framework for distinguishing safely ripened fruits (naturally ripened and ethephon-induced) from calcium carbide-ripened samples, while also estimating their ripening progression (in percentage) and remaining shelf life (in days). The spectral profiles of mango (Mangifera indica) and banana (Musa acuminata) at 18 discrete wavelengths in the visible-near infrared (NIR) range (410 nm - 940 nm) are studied using the AS7265x spectral triad sensor. CaC2-treated samples exhibit sharper spectral intensity drops in the visible region, consistent with accelerated chlorophyll degradation and carotenoid development. To characterize these physiological changes, the feature engineering strategy integrates inter-method spectral variance, intensity ratios at distinct wavelengths, and environmental parameters including temperature and humidity. Dimensionality reduction using Principal Component Analysis (PCA) retains >90% of spectral variance within the first 5-7 components. The resulting feature set is used to train three independent eXtreme Gradient Boosting (XGBoost)-based learning algorithms for ripening method classification, along with quantitative estimation of remaining shelf life and ripening progression. A classification accuracy of 95% along with carbide class recall of 0.67 is observed for mango samples, while the model achieves an accuracy of 81% and carbide class recall of 0.74 for banana. This instrumentation and data-driven approach demonstrates the effectiveness of the proposed non-invasive framework.

Problem

• Calcium Carbide
• Climacteric Fruits
• Ripening Detection
• Shelf-Life Estimation
• Food Safety

Innovation

• multispectral sensing
• calcium carbide detection
• non-invasive fruit ripening assessment
• XGBoost
• shelf-life estimation