Development of calibration model for pH content of intact tomatoes using a low-cost Vis/NIR spectroscopy

Abstract

Determination of pH of intact tomatoes was investigated using a low-cost Vis/NIR spectroscopy in reflectance mode. The best calibration model measured pH in intact tomatoes using wavelength range of 527-799 nm with RC 2 and SEC of 0.90 and 0.04, respectively. The prediction model obtained SEP, Bias, and RPD of 0.11, 0.007, and 1.17, respectively. The low-cost Vis/NIR type instrument is promising to be used for food and agricultural applications.