Cane Testing Service

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Cane Testing Service

The Cane Testing Service (CTS) provides a specialist service under contract to individual Mill Group Boards to determine the quality of individual grower cane deliveries to the mill for cane payment purposes. This analytical chemistry service assesses the recoverable value content in cane delivered to the mill by growers, providing a neutral and objective basis on which to calculate recoverable value payment by miller to grower. The CTS also provides a technical audit of the distribution between millers and growers ensuring fair and equitable division of proceeds. Click here to contact a Cane Testing Service Centre.

Historically the measure of quality for cane payment purposes in the South African sugar industry has been the sucrose content of the cane, but as of 1 April 2000, the start of the new sugar season, payment for sugar cane is on basis of its Recoverable Value (RV) content.

The recoverable value is a measure of the value of the sugar and molasses that will be recovered from the sugar cane delivered by the individual grower and is calculated as follows:

RV % cane  = S - dN - cF
where  S  = sucrose % cane
N  = non-sucrose % cane 
F  = fibre % cane 
and d  = the relative value of sucrose which each unit of non-sucrose diverts from sugar production to molasses  
c  = the loss of sucrose from sugar production per unit of fibre 

The factors d and c are calculated for each season and currently are approximately 0,4 and 0,02 respectively.

The recoverable value basis of cane payment provides the necessary incentives for improving still further the quality of the sugar cane delivered to the mill and this together with local area agreements between growers and millers regarding issues that impact on cane quality will lead to improved efficiencies all round.

The CTS operation at the mill is equipped to sample and analyse individual cane consignments using the Direct Analysis of Cane (DAC) system as described in the Laboratory Manual for South African Sugar Factories. The analytical procedures provide the sucrose, non-sucrose and fibre per cent cane data necessary for individual consignment RV calculation.

However, in parallel with the individual consignment analysis, the CTS also determines the total sucrose, non-sucrose and fibre contained in the mixed juice and final bagasse (the so-called mill balance measure) which is the master measure of the total input into the mill.

The individual cane consignment stream (DAC) as well as the mill balance stream (mixed juice and final bagasse) are both analysed in parallel over the week and at the end of the week a reconciliation takes place such that all the individual consignment (DAC) analyses for sucrose, non-sucrose and fibre are adjusted such that the summations for each component equals that determined from the mill balance. Thereafter the RV % cane for the individual cane consignment is calculated from the adjusted DAC data.

This parallel measure of total sucrose, non-sucrose and fibre (and thus RV) entering the mill over the week makes for a powerful means of control as any deviation in one is immediately evident in a change in the normal relationship between the two measures (DAC and mill balance).

The mill balance measure is also used by the miller as the measure of the input to the factory and mill recoveries and efficiencies are calculated from this input.

In common with many sugar cane producing industries, a system of relative payment is applied in the South African sugar industry.

Details regarding the sampling and analytical procedures employed in the cane testing operation in South Africa are to be found in the Laboratory Manual for South African Sugar Factories (4th edition) copies of which can be purchased from the

South African Sugar Technologists' Association
SASRI
Private Bag X021
Mount Edgecombe
4300