Changes in Content and Bioaccessibility of DHA, EPA, and
Astaxanthin During In Vitro Digestion
The data in Figure 6 unequivocally demonstrates that the emulsion
prepared by MF exhibited substantially higher levels of DHA, EPA, and
astaxanthin after undergoing digestion in both the stomach and small
intestine when compared to the emulsion prepared by HPH. This marked
difference can be attributed to the robust electrostatic repulsion
between oil droplets in the MF-prepared emulsion, which effectively
reduces the transfer of oxidation processes within the simulated
digestive tract. Additionally, the MF-prepared emulsion benefits from a
more uniform and resilient wall material, which provides superior
protection against KO degradation. Following the small intestine phase,
the digesta resulting from oil lipolysis underwent centrifugation to
separate the micelle phase, which contained the solubilized fraction of
DHA, EPA, and astaxanthin. Bioaccessibility was determined by measuring
their concentrations in both the micelle phase and the total digesta.
Figure 6D clearly illustrates that the MF-prepared emulsion exhibited
significantly higher bioaccessibility of DH5A, EPA, and astaxanthin.
This enhancement can primarily be attributed to the emulsion’s smaller
particle size, which accelerates digestion due to its greater specific
surface area. This observation aligns with previous research, such as
the study by Salvia-Trujillo et al. (2017), which demonstrated a
significant increase in carotenoid bioaccessibility with decreasing
lipid droplet size in excipient emulsions. Additionally, the MF-prepared
emulsion displayed greater stability with reduced droplet flocculation,
further amplifying the surface area of lipids exposed to lipase.