Gravimetric and Spectrophotometric Determination of Surface Wax Content in Maize Kernels

Abstract

There are several methods available to determine wax content in maize kernel. These methods are based on gravimetric, spectrophotometric, and chromatographic analyses. This study aims to determine the surface wax content on maize kernel with different reference methods and develop NIR (Near Infrared Reflectance Spectroscopy) calibration models based on those reference methods. In this study, samples from 250 different maize genotypes were used. Surface wax content in the samples was determined by gravimetric and UV-Spectrophotometric methods. The results of each reference method were used to develop NIR prediction models for surface wax content in kernel samples. Our results suggest that there is a medium-level correlation (r=0.708) between the data obtained from spectrophotometric and gravimetric methods. Also, significant differences were observed between the wax content obtained from reference methods. It has been found that the NIR calibration model (RMSE =4.381, R2 =0.143, r =0,378, RPD =1.08) based on the gravimetric method had lower estimation power than the NIR calibration model (RMSEC =7.257, R2 =0.221, r =0.471, RPD =1.34) based on the UV spectroscopic method.