Rapid Analysis of Sugarcane with High Extraneous Matter by Near-Infrared Spectroscopy

Efficient analysis of sugar cane quality is critical for the global sugar industry, which is valued at approximately $78 billion annually. Near-infrared (NIR) spectroscopy is a rapid, nondestructive alternative for analyzing multiple quality parameters of sugar cane. However, sugar cane with large amounts of extraneous matter (EM)─soil, green and brown leaves, roots, and tops─presents a unique challenge to NIR analysis due to the increased scattering and absorption from the EM, which is becoming increasingly relevant as climate change intensifies rainfall patterns, mechanical harvesting replaces manual methods, and environmental regulations promote green cane harvesting. This study evaluates the potential of NIR spectroscopy as a rapid, nondestructive alternative for analyzing multiple quality parameters of sugar cane with high EM values. Samples of shredded cane, pressed cane, and pressed juice were collected from three Louisiana (LA) sugar factories. Partial least squares regression models with k-fold cross-validation were developed to relate NIR spectra to reference values. The models demonstrated that pressed juice and pressed cane samples yielded the most accurate predictions of Brix, pol, and moisture, outperforming shredded cane samples. These findings support the practical implementation of NIR spectroscopy for the rapid and accurate determination of multiple quality parameters, from sugar cane with high EM.