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Effects of droplet size on the oxidative stability of oil‐in‐water emulsions
Author(s) -
Nakaya Kyoko,
Ushio Hideki,
Matsukawa Shingo,
Shimizu Masataka,
Ohshima Toshiaki
Publication year - 2005
Publication title -
lipids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.601
H-Index - 120
eISSN - 1558-9307
pISSN - 0024-4201
DOI - 10.1007/s11745-005-1410-4
Subject(s) - emulsion , chemistry , particle size , hexanal , chromatography , oil droplet , repeatability , analytical chemistry (journal) , oxidative phosphorylation , organic chemistry , biochemistry
The effects of droplet size and emulsifiers on oxidative stability of polyunsaturated TAG in oil‐in‐water (o/w) emulsions with droplet sizes of 0.806±0.0690, 3.28±0.0660, or 10.7±0.106 μm (mean ± SD) were investigated. Hydroperoxide contents in the emulsion with a mean droplet size of 0.831 μm were significantly lower than those in the emulsion with a mean droplet size of 12.8 μm for up to 120 h of oxidation time. Residual oxygen contents in the headspace air of the vials containing an o/w emulsion with a mean droplet size of 0.831 μm were lower compared with those of the emulsion with a mean droplet size of 12.8 μm. Hexanal developed from soybean oil TAG o/w emulsions with smaller droplet size showed significantly lower residual oxygen contents than those of the larger droplet size emulsions. Consequently, oxidative stability of TAG in o/w emulsions could be controlled by the size of oil droplet even though the origins of TAG were different. Spin‐spin relaxation time of protons of acyl residues on TAG in o/w emulsions measured by 1 H NMR suggested that motional frequency of some acyl residues was shorter in o/w emulsions with a smaller droplet size. The effect of the wedge associated with hydrophobic acyl residues of emulsifiers was proposed as a possible mechanism to explain differences in oxidative stability between o/w emulsions with different droplet sizes.