Figure 1 . Heat capacity of samples as a function of temperature
Although there are no general statements on heat capacity changes, the
heat capacity of the samples increased steadily with rise in
temperature. The heat capacity shows a linear relationship with
temperature over the range of (190 to 300) K as shown in equations (2),
(3) and (4), respectively.
\(BA:\ C_{p}\left(\text{J.\ }K^{-1}g^{-1}\right)=0.2422+0.0028\ T\ \left(K\right)\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ (2)\)
\(BCN:\ C_{p}\left(\text{J.\ }K^{-1}g^{-1}\right)=0.1889+0.0032\ T\ \left(K\right)\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ (3)\)
\(GA:\ C_{p}\left(\text{J.\ }K^{-1}g^{-1}\right)=0.1845+0.0034\ T\ \left(K\right)\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ (4)\)
The heat capacity of GA samples was shown to be the highest. The low
heat capacity observed for BCN samples maybe due to the stress imposed
by the free cyanide during microbial proliferation which in turn could
affect the biomass structural integrity compared to GA samples.
Furthermore, BA samples recorded the lowest heat capacity when compared
with all other samples studied. This was expected since Beta
vulgaris contains approximately 9.56 % carbohydrate that served as an
energy and/or carbon source for the F. oxysporum used
[34,
35]. The higher values of heat capacity
in BCN samples when compared to BA samples, could be directly related to
the microorganism’s ability to utilise cyanide as a carbon source to
supplement carbohydrates in B. vulgaris agro-industrial waste.
Since there is no other reports on heat capacities of microbial dried
biomass in literature particularly for fungi, comparing the heat
capacity of Fusarium oxysporum with Saccharomyces
cerevisiae showed that from the results obtained, GA samples were
comparatively similar to those reported by Battley
[17].
Table 3 compares the values of specific heat capacities of starch and/or
glucose samples reported by previous authors. At temperature range of
(200 to 300) K, our result is closer to the Boerio-Goates report
[14] especially GA sample. All the
specific heat capacity reported by
[17] were higher than our findings
while [16] is lower than our reports
for BCN and GA samples. Generally, our report can be seen within the
reported heat capacity for starch in literature.
Table 3: Comparison of specific heat capacities
(\(\text{J\ }K^{-1}g^{-1}\)) for organic samples