Lynne Wong's PhD thesis

Table 4.4. Results of the determination of Brix-free water on re-generated samples.
Sample
Brix-free water % on sample
Original
Re-generated
Stalk fibre 10.3 12.8
Stalk pith 9.0 15.8
Rind fibre 12.8 15.4
Rind fines 7.4 18.2
Dry leaf fibre 15.8 18.1
Dry leaf fines 15.3 19.4
4.4.4 Homogeneity of fibre samples
When the samples analysed previously (Table 4.3) were examined closely, it was evident
that the fibre/fines separation was not perfect; discrepancy could arise due to the
heterogeneous nature of the samples since the results obtained so far indicated that the
finer fractions of a cane component have higher Brix-free water values than the coarser
fibre fractions. It was therefore decided to sieve all samples through a 1.18 mm sieve as
described in Section 3.4.3.1. The fraction retained on the sieve will be termed ‘fibre’ and
that which passed through the sieve, as ‘fines’, or ‘pith’ in the case of stalk fines. Samples
of rind, stalk, top and green leaf fibres were separately sieved through a 1.18 mm sieve,
and 4 x 6 g of each were weighed out in four bottles for triplicate determinations of Brixfree
water content. The fourth replicate was used for the blank determination. Drying was
effected in a vacuum oven at 65 °C under 875 mbar vacuum overnight for 16 hours. The
triplicate results obtained for each cane component appeared consistent except for that of
stalk fibre (Table 4.5).
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