Total sugar and maturity evaluation of intact watermelon using near infrared spectroscopy

In this study, a near infrared spectroscopy (700-1100 nm) measurement technique was used to evaluate the internal quality of watermelons non-destructively. A spectrometer and near infrared ray emitting diode were designed and developed to evaluate the internal quality parameters such as total sugar content and maturity of intact watermelons. A relationship was found between the maturity of intact watermelon and the diffuse transmittance spectra. The total sugar content was calculated from the second derivative spectral values at four selected wavelengths. The verification correlation coefficient and standard error of prediction values were 0.81 and 0.42 Brix% respectively.