Lynne Wong's PhD thesis

The main difference in the two sets of results are that the former were obtained by
the devised method of Brix-free water determination with a blank incorporated,
while the latter, by Mangion and Player’s (1991) method. The other difference
being in the state of the dry leaves used. In the former, Brix-free water values were
determined on the fibre and fines fractions of dry leaves and values were used to
estimate those of the dry leaves reconstituted form these fractions while in the
latter, Brix-free water values were determined on the intact whole dry leaves.
- For the reconstituted dry leaf, green leaf and cane stalk, the Brix-free water values
(corrected for residual moisture) do not vary much with age nor with variety. At
52, 44 and 36 weeks, the dry leaf of the four cane varieties has an average Brix-free
water value of 16.15, 16.57 and 16.41%, green leaf, 15.26, 14.89 and 14.95% and
cane stalk 16.03, 15.40 and 15.66%, respectively. If these values are taken together
with the corresponding Brix-free water values of 16.06, 16.42 and 15.66%
(corrected for residual moisture content) shown in Table 4.19 for intact cane tops
aged 52, 44 and 36 weeks respectively, it would mean that the Brix-free water
values of these different parts of the sugar cane plant, i.e. dry leaf, green leaf, cane
tops and cane stalk, are all about 15-16%. Only those of fibres differ from those of
fines or pith as seen previously.
When the moisture content of any of these parts of sugar cane plant is below the Brix-free
water value of 15%, the press juice in contact with it will have inflated analyte results,
which will affect the cane payment system. However, of these four different parts of sugar
cane plant, only dry leaves can have moisture level below 15%.
Re-examination of the results obtained from the survey of moisture in dry trash (see
Section 2.2.3), most of the dry trash samples had a low moisture content below the Brixfree
water value of 15%. Tables 2.16 – 2.19 show that 51.6, 64.3, 26.7 and 59.1% of the
192, 98, 60 and 22 samples respectively contain less than 15% moisture.