Impact of emulsifier microenvironments on acid–base equilibrium and activity of antioxidants

Effects of emulsifier hydrophile–lipophile balance and emulsifier concentration on the distributions of gallic acid, propyl gallate, and α-tocopherol in corn oil emulsions

“…The first qualitative theory attempting to predict the antioxidant efficiency, the ''polar paradox'', was formulated by Porter [10,11] as early as 1980, who stated that AOs added to oil-in-water emulsions exhibit different effectiveness compared to when included in bulk oils because of the existing differences in the physical nature of the two systems. Subsequently, different researchers [8,[12][13][14][15] confirmed that lipophilic antioxidants inhibit lipid oxidation more efficiently than hydrophilic antioxidants in emulsions because they are primarily located in the interfacial regions of emulsions. In contrast, in bulk oils, polar (hydrophilic) antioxidants would be adsorbed in the air-oil interface and would be more efficient in inhibiting lipid oxidation than the lipophilic counterparts.…”

Antioxidant activities of corn fiber and wheat bran and derived extracts

“…Ferulic acid acts as a radical scavenger and displays antioxidant activity in lipid containing foods (Oehlke, Heins, Stöckmann, & Schwarz, 2010). The antioxidative capacity of ferulic acid is based on its ability to easily abstract a hydrogen atom to form a resonance stabilized phenoxyl radical which is unable to initiate or propagate a radical chain reaction (Graf, 1992).…”

Effects of acidity and emulsifier concentration on the distribution of vitamin C in a model food emulsion

“…Several researchers approached the problem of determining the antioxidant distribution in emulsions using a combination of ultracentrifugation techniques followed by determination of analyte concentrations by employing different analytical tools in combination with mathematical models to determine the distribution of molecules of interest in a variety of emulsified systems . The methods, however, do not provide the percentage of antioxidant in the interfacial region and the obtained results can be biased because the emulsion is broken previous to any measurement …”