Enhanced Oxidative Stability in MF-Prepared Emulsions
The Peroxide Value (POV) and Acid Value (AV) are critical indicators for
assessing the quantity of hydroperoxide (the primary oxidation product
in fats and oils) and the degree of oil hydrolysis, respectively.
Monitoring these indices is crucial for maintaining food quality and
safety. The results regarding POV and AV of emulsions after one month of
storage at 25°C are depicted in Figure 2. Notably, MF-prepared emulsions
consistently exhibited significantly lower POV and AV values (p< 0.05) compared to HPH-prepared emulsions. at the beginning
of the storage period (day 0) with values of 3.70±0.03 vs. 4.05±0.36 mg
POV/kg oil and 18.50±3.54 vs. 6.49±1.31 mg AV/kg oil for MF and HPH,
respectively. Similarly, after one month of storage (25℃), the values
remained lower for MF-prepared emulsions, with values of 18.27±0.92vs. 7.59±0.94 mg POV/kg oil and 49.54±2.96 vs. 16.35±1.41
mg AV/kg oil for MF and HPH, respectively.
Figure 2 illustrates that the POV and AV of HPH-prepared emulsions
exhibited a faster rate of increase compared to MF-prepared samples
during the storage period. Several key mechanisms contribute to the
superior oxidative stability observed in MF-prepared emulsions. Firstly,
MF-prepared emulsions feature smaller droplet sizes and a more uniform
distribution of droplets. This results in a higher surface
area-to-volume ratio, facilitating greater interaction between the oil
phase and the aqueous phase. This increased interfacial area enhances
the encapsulation of pro-oxidants within the smaller oil droplets,
reducing their contact with the bulk aqueous phase and, consequently,
diminishing the initiation of oxidation reactions. Moreover, MF-prepared
emulsions exhibit a remarkable resistance to aggregation. Aggregation
can lead to localized areas of high oil concentration, making them
particularly susceptible to oxidation. By preventing aggregation, MF
emulsions hinder the propagation of oxidation reactions from one droplet
to another. This isolation of oxidation events within individual
droplets significantly contributes to the overall oxidative stability.
Lastly, the uniform distribution of smaller oil droplets in MF-prepared
emulsions ensures an even dispersion of oil throughout the emulsion.
This uniformity minimizes the potential for localized oxidation events
and further enhances the overall oxidative stability of the emulsion.
The data presented in Figure 2 undeniably support the assertion that
MF-prepared emulsions exhibit a substantial advantage in terms of
oxidative stability compared to their HPH counterparts. These findings
underscore the potential of MF-prepared emulsions to more effectively
protect KO and other sensitive compounds during storage.