Citation:
Haiqing Yang1, Boyan Kuang, Abdul M. Mouazen. Size estimation of tomato fruits based on spectroscopic analysis. Advanced Materials Research, 2011, volume 225-226, Issue 1-2, pp1254-1257
Special issue: Advanced Research on Automation, Communication, Architectonics and Materials
Abstract:
This study used visible and near-infrared (VIS-NIR) spectroscopy for size
estimation of tomato fruits of three cultivars. A mobile, fibre-type, VIS-NIR
spectrophotometer (AgroSpec, Tec 5, Germany) with spectral range of 350-2200 nm,
was used to measure reflectance spectra of on-vine tomatoes growing from July to
September 2010. Spectra were divided into a calibration set (75%) and an
independent validation set (25%). A partial least squares regression (PLSR) with
leave-one-out cross validation was adopted to establish calibration models
between fruit diameter and spectra. Furthermore, the latent variables (LVs)
obtained from PLS regression was used as input to back-propagation artificial
neural network (BPANN) analysis. Result shows that the prediction of PLSR model
can produce good performance with coefficient of determination (R2) of 0.82,
root-mean-square error of prediction (RMSEP) of 4.87 mm and residual prediction
deviation (RPD) of 2.35. Compared to the PLSR model, the PLS-BPANN model
provides considerably higher prediction performance with R2 of 0.88, RMSEP of
3.98 mm and RPD of 2.89. It is concluded that VIS-NIR spectroscopy coupled with
PLS-BPANN can be adopted successfully for size estimation of tomato fruits.