Experiments on Measurement Sugar Content of Fuji Apple with An Optical Fiber Sensor

Near infrared spectroscopy method with optical fiber sensor as a non destructive measurement for Fuji apples sugar content was evaluated. The objective of this research was to investigate a fiber sensing technique in interactance mode for rapid acquisition of spectral information to predict the interior quality of fruit. Three multivariate calibration techniques including partial least squares analysis(PLS)?principal component analysis(PCA) and stepwise multiple linear regression(SMLR) were used for spectral data analysis. Using PLS models, the correlation coefficient was 0 86, the standard error of calibration was 0 14 and the standard error of prediction was 0 97. Using PCA models, the correlation coefficient was 0 902, the standard error of calibration was 0 47 and the standard error of prediction was 1 27. Using SMLR models, the correlation coefficient was 0 72, the standard error of calibration was 0 72 and the standard error of prediction was 2 10. It is suggested that fiber optic sensor technique be feasible to nondestructively determinate apple sugar content in the range of 12 500～3 800 cm -1 .