Although it has been known forsome

Although it has been known forsome time that metal-promoted decompositionof hydropcroxides is an importantreaction in the oxidation of foodlipids, the understanding of the factorsthat affect meral-hydroperoxide interactionsis still incomplete. One of themajor factors influencing the ability oftransition metals to decompose lipidhydroperoxides and thus acceleratelipid oxidation is physical location. Thisis especially true in mulriphase foodssuch as emulsions. Emulsions can becharacterized as having several distinctphysical environments including thelipid phase, the droplets' interfacialmembrane, and the aqueous phase. lnemulsion systems, the reactantsinvolved in lipid oxidation can partitioninto these different environments, e.g.,transition metals in the aqueous phaseand emulsion droplet surface and surface-active lipid hydroperoxide at thedroplet interface (Figure 2). This reviewwill discuss how conditions thatincrease contact between transitionmetals and lipid hydroperoxides in oilin-water emulsions will generallyincrease lipid oxidation. Conversely, thereactivity of metals can be decreased byphysically separating them from thelipid and droplet membrane, one of themechanisms by which chela tors andmetal-binding proteins inhibit oxidation

Although it has been known for
some time that metal-promoted decomposition
of hydropcroxides is an important
reaction in. The oxidation of food
lipids the understanding, of the factors
that affect meral-hydroperoxide interactions
is still, incomplete. One of the
major factors influencing the ability of
transition metals to decompose lipid
hydroperoxides and thus accelerate
.Lipid oxidation is physical location. This
is especially true in mulriphase foods
such as emulsions. Emulsions can be
characterized. As having several distinct
physical environments including the
lipid, phase the droplets' interfacial
membrane and the,, Aqueous phase. Ln
emulsion, systems the reactants
involved in lipid oxidation can partition
into these, different environments. E.g,
.Transition metals in the aqueous phase
and emulsion droplet surface and surface -
active lipid hydroperoxide at the
droplet. Interface (Figure 2). This review
will discuss how conditions that
increase contact between transition
metals and lipid. Hydroperoxides in oilin -
water emulsions will generally
increase lipid oxidation. Conversely the
reactivity, of metals can. Be decreased by
.Physically separating them from the
lipid and droplet membrane one of, the
mechanisms by which chela tors and
metal-binding. Proteins inhibit oxidation.