Lynne Wong's PhD thesis

where ׳D sF , ׳D sp , ׳D rF and ׳D rf are the dry mass fractions of stalk fibre, stalk pith, rind
fibre and rind fines, m st is the estimated Brix-free water value of the sugar cane stalk, m sF ,
m sp , m rF and m rf are the measured Brix-free water of stalk fibre, stalk pith, rind fibre and
rind fines.
The two mass fractions (fibre and fines) in dry leaf and green leaf, and the four mass
fractions in cane stalk, i.e. rind fibre and fines, and stalk fibre and pith, were calculated for
the four cane varieties harvested in 2003 and the R 570 harvested in 2001, from Tables 3.8
and 3.11 for cane aged 52 weeks. With the corresponding component Brix-free water
values obtained experimentally and tabulated in Tables 4.17, 4.18, 4.20 and 4.21, those of
the reconstituted dry leaf, green leaf and cane stalk aged 52 weeks can be predicted (Table
4.26).
Similarly, mass fractions data for samples aged 44 and 36 weeks were calculated using
data in Tables 3.9, 3.10 and 3.11, and with the corresponding constituent Brix-free water
values obtained experimentally and tabulated in Tables 4.17, 4.18, 4.20 and 4.21
respectively, those of the reconstituted dry cane leaf, green cane leaf and cane stalk aged
44 and 36 weeks can be predicted (Tables 4.27 and 4.28).
In Tables 4.26 – 4.28, all the measured Brix-free water values had 1.1 units added in order
to correct for the residual moisture content in the test fibre samples prior to the Brix-free
water determination. (Refer to Section 4.4.6 for a discussion of this point.)
Results from Tables 4.26 – 4.28 show that:
- If the reconstituted cane stalk aged 52 weeks is considered, the Brix-free water
values of the four cane varieties (Table 4.26) average 16.03% and vary from 15.13
to 16.95%, which is much lower than the traditionally accepted value of 25% for
Brix-free water of cane stalk (Section 2.2).
- Brix-free water values for reconstituted dry leaves of four cane varieties
investigated aged 52 weeks, i.e. R 579, R 570 harvested in 2003 and in 2001,
M 1557/70 and M 1400/86 are 17.10, 16.99, 15.99, 15.08 and 15.61% respectively.
From Chapter 2 Section 2.2.2.6, Brix-free water values of dry leaves of the four
main cane varieties cultivated in Mauritius, i.e. M 695/69, M 3035/66, R 570 and
M 1658/78 were found to be 25.6, 28.5, 28.7 and 27.8% respectively.