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Journal of Tea Science Research 2013, Vol.3, No.1, 1-6
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Table 2 Solidfat content of cocoa butter and enzymatically interesterified sample
SFC (percent)
Samples
5
℃
10
℃
15
℃
20
℃
25
℃
30
℃
35
℃
40
℃
CB
96.1±0.10 94.8±0.10 88.5±0.30 78.6±0.30
26.9±0.30 8.49±0.02 0.76±0.03 0
EIS
34.0±0.10 29.9±0.30 23.9±0.20 18.5±0.30
9.91±0.02 3.57±0.03 0.37±0.01 0
Note: EIS: enzymatically interesterified sample; CB: cocoa butter
Langevelde et al., 2001; Guthrie et al., 2005;
Lonchampt and Hartel, 2006; Smith et al., 2007). Yet,
in the case of the CB chocolate, bloom development
was higher than EI chocolate samples. This is perhaps
due to the more complex crystalline forms
(polymorphic structures) provided by modified oil
(EIS) in the chocolate sample (Osborn and Akoh,
2002). This result is similar to that of Sonwai and
Rousseau (2006), who reported that addition of cocoa
butter equivalent to chocolate formulation delays
bloom development by 1~2 weeks. Our finding is also
in agreement with Osborn and Akoh (2002). They
studied the effect of enzymatically modified beef
tallow, as cocoa butter substitute, on fat bloom rate in
dark chocolate and have found that the fat bloom rates
were lower in chocolate prepared with modified beef
tallow compared with chocolate prepared with CB.
Figure 2 Bloom development on the surface of dark chocolate
samples containing cocoa butter and cocoa butter blending with
10, 15 and 20 percent of enzymatically modified sample
Note: Each value represents the mean ± S.D. of triplicate
measurements
The polymorphism patterns of CB, EICH, CB and EI
chocolate samples are shown in Table 3. According to
the results obtained, a single strong spacing was found
in CB at 4.59 Å, which indicates the formation of
β-polymorph. In the literature, two different
β-polymorphs (V and VI) have been reported with
different m.p. and XRD patterns. Since fat bloom
formation is linked to transformation of CB from β-V
to β-VI, determining the structures of these crystalline
forms is very important.
Some studies have demonstrated that depending on
the CB origin, β-V and β-VI show different XRD
patterns (Langevelde et al., 2001). A comparison of
the XRD patterns of CB from various origins with our
sample (Figure 3) reveals that XRD characteristics of
our sample is closer to that of CB originated from
Bahaia. This is while the iodine value (34.90) is closer
to that of the CB obtained from Malaysia (33.9). Our
CB samples also shows XRD patterns which look
much like that of β-VI (Figure 1), while its melting
point (31.43
℃
) was closer to β-V (30.8~33.8
℃
), as
reported by Chapman et al. (1971) and Wille and
Lutton (2001). Malssen et al. (1996) also observed
that in some CB samples originated from twelve
different countries, XRD patterns of β-phase are closer
to those of β-VI but their m.p. resembled that of β-V.
They concluded that phase V and VI should be
regarded as two sub phases of β. In comparison, we
concluded that there is probably one new crystalline
form in CB with the behavioral characteristics
between β-V and β-VI.
Figure 3 X-ray diffraction patterns of cocoa butters from
different origins (A) (langevelde et al., 2001), CB sample
(malasian CB) was used in this study (B)
According to the results shown in Table 3, a very
strong spacing at 4.13 Å and a medium spacing at
3.74 Å were found in EIS, which indicate the
formation of β′-polymorph in this sample. Moreover,
according to some literatures, many vegetable oils or