Research advances in non-destructive prediction technologies using VIS/NIR spectroscopy for kiwifruit property

Non-destructive prediction using VIS/NIR spectroscopy has great potential for fruit property detection. The status quo of VIS/NIR spectroscopy prediction technology for kiwifruit internal property detection was reviewed. The discussion was mainly concentrated on the VIS/NIR absorption and transport scattering properties of kiwifruit and comparative analysis of different methods of fruit sample collection, spectral data collection and calibration model development. It is concluded that the internal properties of kiwifruit collected from various orchards, by different treatments during growth, at different storage stages and at different extents of maturity, such as flesh color, firmness, dry matter content(DM), soluble solids content (SSC), sugar content and density, etc. of kiwifruits can be well predicted using 500~2500 nm VIS/NIR spectroscopy. The spectral data analysis and calibration model development technology experienced the trend from traditional numerical optimization methods to neural network(NN), wavelet transformation, genetic arithmetic and self-adaptive non-linear model pattern reorganization methods. The future research work should aim to develop the reliable, flexible and practicable calibration models. To achieve this goal, the further research should be focused on improving versatility of calibration model applied on various breeds of kiwifruits and different spectroscopic instruments, and using NIR spectroscopy to test moving kiwifruit on automatic processing line.