We have quantified obse
rved diffe
rences in the mic
rost
ructu
re and
rheology of c
reaming emulsionsstabilized by p
rotein and low molecula
r weight su
rfactants. In this study, we made two sets of emulsionsf
rom a single pa
rent emulsion, which diffe
red only in thei
r inte
rfacial composition (i.e., eithe
r p
roteino
r su
rfactant). The p
rotein studied was whey p
rotein isolate. The
![](/images/gifcha<font color=)
rs/zeta.gif" BORDER=0 > potential of the su
rfactant-stabilizedemulsion was cont
rolled by mixing anionic (SDS) and nonionic (B
rij 35) su
rfactants to match the
![](/images/gifcha<font color=)
rs/zeta.gif" BORDER=0 >potential of the p
rotein-stabilized emulsion. Despite this, ult
rasonic c
reaming measu
rements andconfocal mic
roscopy showed that the st
ructu
res within the c
ream laye
rs we
re diffe
rent between thetwo sets of emulsions. The p
rotein-stabilized emulsions appea
red to slow o
r a
rrest the packing withinthe c
ream, leading to a lowe
r density netwo
rk of emulsion d
roplets, whe
reas the su
rfactant emulsiond
roplets
rea
rranged mo
re quickly into a well-packed, concent
rated c
ream laye
r. Rheological analysisof the c
reams showed that despite the p
rotein-stabilized emulsions having a lowe
r dispe
rsed phasevolume f
raction, thei
r elastic modulus was app
roximately 30 times g
reate
r than that of a compa
rablesu
rfactant-stabilized emulsion. These diffe
rences we
re caused by the ability of the p
rotein to fo
rm ahighly viscoelastic inte
rfacial netwo
rk a
round the d
roplets which may include inte
rmolecula
r covalentc
ross-links. At close
range the adhesive natu
re of the inte
raction between the laye
rs cont
ributes tothe mic
rost
ructu
re and
rheology of concent
rated emulsions. This is the fi
rst time that such well-defined emulsion systems have been studied in detail both noninvasively to look at the impact onc
reaming and also invasively to look at the impact on bulk
rheological p
rope
rties.