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Autoxidation of fatty materials in emulsion. II. Factors affecting the histidine‐catalyzed autoxidation of emulsified methyl linoleate
Author(s) -
Coleman J. E.,
Hampson J. W.,
Saunders D. H.
Publication year - 1964
Publication title -
journal of the american oil chemists' society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 117
eISSN - 1558-9331
pISSN - 0003-021X
DOI - 10.1007/bf02654811
Subject(s) - autoxidation , chemistry , histidine , emulsion , catalysis , organic chemistry , sodium , oxygen , ionic bonding , ion , enzyme
Abstract Several factors which affect autoxidation of methyl linoleate in emulsion have been examined. Data are presented which indicate: 1) In the presence of histidine, the ionic (anionic) emulsifiers examined promote autoxidation of emulsified methyl linoleate, but nonionic emulsifiers do not. 2) The concentration of an emulsifier affects the rate of oxygen absorption. 3) Inorganic salts (0.1 M or less) such as sodium chloride, sodium acetate and sodium sulfate affect oxygen absorption of emulsified methyl linoleate prepared with either ionic or nonionic emulsifiers. In histidine‐catalyzed autoxidation there is a suppressing effect in the case of the ionic and a promotional effect in the case of the nonionic. In uncatalyzed autoxidation, these salts have a promotional effect in ionic emulsions and none in nonionic emulsions. 4) Sodium phosphate buffers completely suppress autoxidation due to histidine catalysis, but do not suppress the normal uncatalyzed autoxidation of emulsified methyl linoleate. 5) The pro‐oxidative effects of histidine and histidine‐metal ion complexes on emulsified unsaturated materials is not limited to polyolefins but also includes mono‐olefinic compounds.