Lynne Wong's PhD thesis

filter paper, rejecting the first few mL of the filtrate. The Brix of the filtrate together with
the original 10° Brix sucrose solution were determined in triplicate.
The Brix-free water in the dry leaf was then calculated from the following equation
(Mangion and Player, 1991):
Brix - free
⎡ Mass of sucrose solution ⎤ ⎡
water in dry leaf = 100 ⎢
⎥ ⎢1
−
⎣ Mass of dry leaf sample ⎦ ⎣
Brix before contacting ⎤
Brix after contacting
⎥
⎦
2.2.2 Results and discussion
The average results for Trials I - III, with green and dry trash are shown in Tables 2.9 –
2.11, and the results of Trial IV with bagasse are presented in Table 2.12. Values of CCS
were computed by using the Australian method of calculation (Anon., 1984) described in
Section 2.1.4.
The effect on press juice and cane qualities due to the additions of green leaves, dry leaves
and bagasse was assessed from the data presented in Tables 2.9 – 2.12, and the average
values are compiled in Table 2.13.
The increase of non-sucrose in press juice, taken as Brix minus Clerget sucrose, due to the
addition of EM was also calculated, and the percentage increase or decrease presented in
Table 2.13.
2.2.2.1 Glucose/fructose ratio in green and dry leaves
The green leaves used in Trial I, in contrast to those that were used in Trials II – IV,
contained very little glucose but had a relatively high fructose concentration as shown by
the constant amount of glucose with increased addition of green leaves while the fructose
content increased significantly. The low glucose in these green leaves indicates
leuconostoc growth and formation of dextran, which is a polymer of glucose. This
explains the decrease in G/F ratio, from 0.96 to 0.53, with the addition of the first 5%
green leaves, and to 0.34% with a further 5% addition, representing decreases of 0.43 and
0.19 units respectively. This concurs with Legendre's finding (1991) that green (but not
dry) leaves reduced the G/F ratio. He also reported that a G/F ratio of < 1.6, might give
rise to false low pol. The aforesaid, however, does not apply to the green leaves used in
Trials II – IV in which both glucose and fructose contents rose with increasing additions of
green leaves, with the result that the G/F ratio remained more or less constant at 0.87 and
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