Lynne Wong's PhD thesis

5.6.4.5 Calculated EMC values of reconstituted R 570
In a similar way to the work done on corn stover by Igathinathane et al. (2005), as
described in 4.7.4, the EMC of sugar cane stalk could be estimated from the dry mass
fraction of cane stalk fibre, stalk pith, rind fibre and rind fines, and their observed EMC.
Thus:
M st = D′ sF M sF + D′ sp M sp + D′ rF M rF + D′ rf M rf
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 EMC of the sugar cane stalk, and M sF , M sp , M rF and M rf
are the measured EMC of stalk fibre, stalk pith, rind fibre and rind fines respectively.
From Table 4.25, the average mass fractions of these four components from the three
replicates of R 570 aged 52 weeks were calculated to be 0.169, 0.244, 0.347 and 0.240
respectively. Their respective measured EMC’s at various water activities at 30, 45, 55
and 60 °C were extracted from Tables 5.8 – 5.11 to enable the calculation of the EMC
values of reconstituted R 570 cane stalk aged 52 weeks (Table 5.29).
Similarly, from Table 4.27, the average mass fractions of the four components from the
three replicates of R 570 aged 36 weeks were found to be 0.120, 0.216, 0.399 and 0.265
respectively for stalk fibre, stalk pith, rind fibre and rind fines. Their respective measured
EMC’s at various water activities at 30, 45, 55 and 60 °C are extracted from Tables 5.8 –
5.11. EMC values of reconstituted R 570 aged 36 weeks were thus calculated (Table 5.30).
In a similar manner, EMC of reconstituted dry leaf and green leaf aged 52 and 36 weeks
were predicted from their respective mass fractions (fibre and fines) and their experimental
EMC values (Tables 5.31 – 5.32). From Table 4.25, the mass fractions of dry leaf fibre
and fines were calculated to be 0.579 and 0.421 for 52 weeks sample, and those of the
green leaf fibre and fines were 0.371 and 0.329.
For 36 weeks sample, the mass fractions of dry leaf fibre and fines were 0.631 and 0.369,
and of the green leaf fibre and fines, 0.701 and 0.299 (Table 4.27).
Since the Hailwood-Horrobin isotherm and GAB models were found to describe the
sorption behaviour of the fibres of sugar cane components well, these models were fitted to
the calculated EMC data for reconstituted cane stalk, dry leaf and green leaf to determine
whether they fitted these data too.
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