Laboratory analysis of soluble solids content in sugarcane juice from direct and shredded extraction methods using NIR spectrometer

Most stakeholders, including farmers and sugar millers, are interested in sugarcane quality to plan for harvesting season. However, the impact of different juice extraction methods on juice quality is not clearly understood. While individual factories measure soluble solids content (SSC) to gauge sugar content before harvest, the extraction method significantly affects the measurement. This study was performed to determine and compare the SSC in sugarcane juice extracted by the direct extraction method (DEM) and shredded extraction method (SEM), and to develop a calibration model to monitor SSC in juice using NIR measurement to support harvest planning. A total of 156 sugarcane samples were collected, and the juice was extracted using both DEM and SEM. Their spectra data were acquired using NIR spectrometer (400–2500 nm) and uniformly divided into calibration and validation sets. The models were developed using PLS regression. Calibration models developed from short and long wavelengths showed significant prediction, with RMSEP values of 0.27 °Brix and 0.11 °Brix for independent samples, and biases of 0.05 °Brix and 0.00 °Brix for DEM and SEM, respectively. These results indicate that the choice of juice extraction methods can significantly influence predictions of sugarcane maturity based on SSC levels. Therefore, farmers and sugar millers should consider their extraction methods when monitoring and predicting sugarcane harvest maturity. Juice differences extracted by the DEM and SEM • Juice extraction methods affect SSC quantity in juice. • Either DEM or SEM can be used for SSC determination of sugarcane harvest maturity. • NIR spectrometer is feasible in predicting SSC in juice extracted from sugarcane. • Farmers and sugar millers should consider extraction methods during maturity tests.