ASSESSING THE PROCESSABILITY OF SUGARCANE VARIETIES
The Sugar Milling Research Institute (SMRI) is developing methods to characterise the processability of sugarcane, particularly pre-release varieties from the South African Sugarcane Research Institute’s (SASRI) breeding programme. The pith/fibre ratio and colour are presently used to characterise the processability of sugarcane; however, further parameters are required to obtain a better understanding of how a particular variety would behave during processing, particularly in the front end of the factory. A number of methods have been investigated; these include the use of a stereomicroscope to identify pith and fibre, an impact test method and a percolation test method. Each method is described and test results obtained on selected varieties are given. The suitability and feasibility of each of the different methods is discussed.
Characterisation of cane varieties based on sugar processing parameters.
Cane varieties that form part of the South African Sugarcane Research Institute’s (SASRI) variety trial programme were used in these investigations. More than 30 varieties were tested including factors such as seven geographical locations, age, ratoon number and whether rainfed or irrigated. Juices were extracted from shredded clean fresh stalks, and analysed for brix, colour, phosphate, silica, potassium, sodium, calcium, magnesium, and conductivity ash. The shredded cane was analysed for pith and fibre content. The paper collates data from these investigations with data from SASRI to attempt to characterise varieties suitable for both agricultural (i.e. yield and sucrose content) and processing (i.e. colour) requirements. The results of these investigations are presented and the impacts of the different factors discussed.
The effect of cane variety and other agricultural factors on juice composition.
Juice extracts from clean, fresh cane stalks from nineteen runs of the 1999 South African Sugar Association Experiment Station varietal trial program have been used. Twenty-six varieties from seven geographical locations in South Africa were involved. In addition, factors such as cane age, ratoon number, burnt or trashed, rainfed or irrigated were available. The extracts were analysed for brix, colour, phosphates, silica, gums, calcium , potassium and sulphated ash. The paper presents these results and discusses the impact of the factors, particularly variety and location. The concentration of gums, which influences processing and sugar quality, is shown to be highly dependent on location and on variety, while colour is predominantly a varietal effect.