Evaluation of Near Infrared Spectroscopy for Sugarcane Quality Determination in Western Kenya

Abstract

In Kenya, sugar is produced exclusively from sugarcane cultivated in Nyanza, parts of Rift Valley counties, Western Kenya and coastal region. Since the industry inception in early 1900s, farmer payments for delivered milling sugarcane has been based on tonnage delivered, with no consideration for quality of cane. However, in early 2000s, Kenya, attempted to put in place structures for paying farmers based on quality as measured by sucrose content amongst other factors. An effective, fast and accurate method of determining such quality has been missing, thus delaying implementation. Near Infrared (NIR) spectroscopy has been suggested as an accurate, non destructive and high-speed method for estimating the quality of milling cane. This research evaluated performance of a Matrix-F FT NIR spectrophotometer for estimation of cane quality in Nzoia Sugar Company, western Kenya. A total of 688 milling cane samples were obtained from randomly selected trucks delivering cane to the factory using a core sampler. The samples were finely shredded and analyzed by a method combining wet disintegration and core press as the primary measurements and NIR. The NIR spectrometer was calibrated using OPUS Lab Chemometrics software for pol, brix, fibre, moisture in cane . Results from wet chemistry were linearly regressed against the NIR results. The R² values were 0.9787, 0.9503, 0.8432 and 0.8725 for brix, pol, moisture and fibre, respectively. The results demonstrate that NIR spectroscopic analysis is an acceptable method for use in Kenya for quality based cane payment system.

Keywords: NIR spectroscopy, sugarcane quality, Kenya.