Rapid Analysis of Sugar Products by near Infra

The NIRSystems 6500 spectrophotometer has been used to study analytes in bagasse, shredded cane, direct analysis of cane extracts (DAC), mixed juice, molasses and raw sugar. Analytes included pol, brix, dry solids, moisture, sucrose, glucose, fructose, invert, ethanol, colour, ash and starch. Although Near Infra Red (NIR) is a secondary technique, relying on conventional laboratory procedures for calibration, the indirect technique was able to produce a surprisingly good estimate for many of the analytes tested. The results suggest that NIR could not replace conventional procedures where high accuracy is required (e.g. cane payment, factory balances and raw sugar sales). NIR is however able to produce results for multicomponents extremely rapidly and precisely, and therefore does appear to have a role to play in monitoring field and factory environments. Statistical comparisons between laboratory results and NIR are given for all analytes tested. NIR estimates for analytes in shredded cane and mixed juice from the 6500 spectrophotometer are compared with those obtained from a filter instrument. Possible applications for NIR are also suggested.