Page 388 - IJB-10-6

International Journal of Bioprinting Innovative manufacturing of ω-3-enriched chocolate

particle formation is observed on the surface of the ω-3- deformation vibration of C–OH, possibly involving the
SA-coated chocolate. These results indicate that the mixing symmetric stretching vibration of O–C–O. Additionally,
44
and coating processes were successfully achieved. Scanning in the ω-3-SA microparticles group, the characteristic peak
electron microscopy (SEM) images of ω-3-loaded SA of SA at 1597 cm shifted to 1652 cm (Figure 6). This
−1
−1
microparticles (Figure 5) revealed that microparticles were shift might be attributed to the interaction between SA
successfully produced; particle sizes of 0.5 µm were noted. and ω-3. However, these characteristic peaks of SA were
The chocolate samples could not be imaged using SEM not observed in the ω-3-SA MP-coated chocolate group,
because of they were melting under electron gun. possibly due to the lower level of SA MP-coating. Quispe-
Chambilla et al. also reported that the regions associated
3.3. Analysis of physicochemical properties with the peaks 2924 and 2853 cm can be assigned to
−1
Fourier transform infrared (FTIR) analysis is a chemical the functional group −CH in the vibrational mode of
characterization method that provides information on the symmetric and asymmetric stretching. Lipids and
2
40
functional groups within a material, which involves the carbohydrates in dark chocolate would be linked to this
assessment of molecular vibrations generated in response 45 −1
to the absorption of infrared radiation. It is important to finding. A band was noted around 3009 cm (Figure 6),
41
note that each bond in a molecule has a distinct natural which can be assigned to the stretching vibration of cis-
vibrational frequency, meaning that certain infrared olefinic double bonds (=C–H) of polyunsaturated fatty
40,46
radiation frequencies are absorbed by certain bonds inside acids (PUFA) ; a greater intensity was noted for the ω-3-
the molecule. When materials containing an electric mixed and ω-3-SA-coated chocolate samples due to the
dipole interact with infrared radiation, the molecule presence of polyunsaturated acids.
absorbs energy and causes the bonds to oscillate. As a 3.4. Moisture content and water activity
result, the oscillation modifies the net dipole moment of Moisture content is an important characteristic that affects
the molecule for absorbing infrared energy. 41,42 Figure 6 the texture, rheological properties, crystallization, and shelf
displays the FTIR spectra of ω-3-mixed chocolate, ω-3- life of a chocolate product. The ω-3-coated and mixed
47
SA microparticles, ω-3-SA MP-coated chocolate, pure chocolate samples were characterized by significantly
chocolate, SA, and commercial ω-3 itself. Characteristic higher levels of moisture compared to the pure chocolate
peaks of commercial ω-3 were observed at 1743 cm sample; the moisture content of the samples was 2.25 ±
−1
(carbonyl stretching, C=O) and 2852 cm (symmetric 0.06% (pure chocolate), 3.17 ± 0.08% (coated chocolate),
−1
C–H stretching). As noted in the FTIR spectra, all groups and 5.56 ± 0.60% (mixed chocolate). Erunsal et al.
47
containing commercial ω-3 exhibited these characteristic reported that the moisture content of chocolate samples
peaks, suggesting the successful incorporation of ω-3 increased proportionally with the ratio of carob extract.
into the chocolate. For SA, the broad spectral bands
43
in the range of 1600–1610 cm were indicative of the Water activity (aw) values of chocolate samples ranged
−1
asymmetric stretching of O–C–O carboxylate groups; the from 0.43 to 0.59 (Table 1); this value is within the acceptable
bands between 1400 and 1428 cm were attributed to the limit (< 1%). It should be noted that the presented results
−1

Figure 5. Scanning electron microscopy (SEM) images of ω-3 loaded sodium alginate (SA) microparticles. (A) Magnification: 500 X Scale bar: 20 µm (B)
Magnification:10 KX, Scale bar: 2 µm.

Volume 10 Issue 6 (2024) 380 doi: 10.36922/ijb.3969