Sensor Fusion for Maturity Prediction of Pepper

Abstract

In order to improve the determination of pepper maturity, we examined a fusion of non-destructive sensor outputs and a fusion of destructive reference parameters. Multi-sensor models were assessed against single sensor models based on the significantly lower root mean square errors of cross validation values for all tested cultivars and all reference parameters. The fusion procedure was based on the combination of sensor outputs and the combination of reference parameters. Linear and non-linear regression methods were applied for model establishment. Through the reference parameter fusion a new combined quality index was developed in order to assess the global quality of the produce. With this new combined quality index, the comprehensive quality of the produce could be predicted as well as its maturity stage. This could support better decisions regarding harvest schedule; as the new index correlate with physical property change during growth. The sensors used in the present work were spectrophotometers at the VIS-NIR and SWIR spectral range, relaxation and ultrasonic tests, and colour measurement. The reference parameters were the following: total soluble solids, dry matter, osmotic potential, ascorbic acid, total chlorophylls, carotenoids content, coefficient of elasticity measured in compression and rupture mode.