Non-destructive prediction of banana fruit quality using VIS/NIR spectroscopy

Introduction. During ripening, the pigment content, starch index and sugar content of banana fruit change, providing accurate indicators for maturity classification. However, at present, banana fruits are traded according to their color stage. This study is aimed at investigating a non-destructive, rapid instrumental method to measure fruit maturity and quality more precisely. Materials and methods. Musa cavendishii L. grown in Honduras were ripened in a commercial ripening chamber and selected at four different color stages. Visible (VIS) and near-infrared spectroscopy (NIRS) in reflectance mode were investigated for the non-destructive detection of fruit chlorophyll and sugar contents. Partial least squares regression was applied to auto-scaled spectral data. Reference analyses were performed using spectrophotometry after a diethyl ether extraction of chlorophyll and high performance liquid chromatography for individual sugar analysis. Results. Calibration models for spectral readings and laboratory destructive tests gave multivariate correlation coefficients of determination of R² > 0.70 for chlorophyll a, R2 = 0.96 with standard errors of calibration (scal) of 1.6, and standard errors of cross-validation (scval) of 1.8 for glucose; R2 = 0.94 with scal of 0.8, and scval of 0.9 for sucrose; R2 = 0.96 with scval of 2.5 and Scval of 2.7 for fructose (g·kg-1 on a dry weight basis). Conclusion. This paper shows the potential of VIS/NIRS for non-destructively predicting the maturity and quality of whole banana fruit based on determining fruit chlorophyll and sugar contents.