NEAR-INFRARED SPECTROSCOPY (NIRS) RESEARCH IN THE SOUTH-AFRICAN SUGAR-INDUSTRY

Sugar industries worldwide have increasing interest in the potential o f near infra-red (NIR) analysis for cane and beet sugar quality testin g, downstream sugar byproduct analysis, cane nutrition, soil fertility monitoring and screening for resistance to pests and diseases. In Sou th Africa during the past decade, NIR spectrophotometers have been use d to improve fertilizer use efficiency of sugarcane by matching the cr op's nitrogen (N) requirement and soil N requirement to soil N mineral ising potential and plant N status. Major benefits have been substanti al savings in N fertilizer and reduction in the risks of environmental pollution. Recent developments include use of scanning NIR instrument s for determining various constituents in cane juice, shredded cane, b agasse, raw sugar, and molasses. The use of NIR on shredded cane has b een proposed as an alternative to direct analysis of individual cane c onsignments (DAC). Global calibrations developed for mixed cane juice and molasses constituents for daily process control management of raw sugar factories are also currently under investigation. Possible new a pplications of NIR include partitioning the N pool in the cane plant, estimating photosynthesis, predicting yield potential, screening for p est and disease resistance and measuring the sustainability potential of soils.