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.