Interfacial and emulsifying properties of sucrose ester vs tween
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Transcript of Interfacial and emulsifying properties of sucrose ester vs tween
Interfacial and emulsifying properties of sucrose ester in coconut milk
emulsion in comparasion with tween
Suwimon Ariyaprakai, Tanachote Limpachoti, Pasawadee Pradipasena
-Thailand-
IntroductionCoconut Milk Food emulsion
Improve stability??
Adding additional surfactant
Example of surfactant:1. Tweens2. Sodium dodecyl
sulfate3. Sucrose esters
Aim of reasearch:Understanding the relationship between interfacial properties and stability of coconut milk emulsions after addition of sucrose ester and tween 60.
Comparasion structure of sucrose monostearate and ethoxylated sorbitan monostearate (tween 60)
• Comparative interfacial properties and emulsifier properties between SE and TW
• Difference between carbohydrate and ethoxylate headgroups
Material and Methods
Material: Sucrose ester (50-53% sucrose monostrearate, 18-
20% sucrose disterate, 12-14% sucrose dipalmitate, 5-10% sucrose alkylate) Mitsubishi Kagaku Food Corp.
Tween 60 (Polyoxyethylene sorbitan monostearate) Sigma
Coconut oil & Soybean oil Tropicana OilGround coconut meat purchased locally
Material and Methods (continued)
Coconut Milk Emulsion Preparation
Minced ground coconut meat(1)
mixed
Distilled water (2)
Pressed & filtered
Coconut milk
Solid residue
mixed
Distilled waterOr
Surfactant aqueous solution (0.25 wt%)
Homogenized(11.200 rpm, 3 min)
Sodium azide 0.02 wt%
1. Coconut milk (B)2. Coconut milk (SE)3. Coconut milk (TW)
Measurement• Coconut oil-water interfacial tension
measurement digital tensiometer at 25o C• Measurement of emulsion properties Droplet size measurement Laser diffraction particle size
analyzer Zeta-potential measurementParticle electrophoresis
instrument Optical MicroscopyStandard optical microscope Visual appearance and creaming index measurement photo
• Coconut milk emulsion stability Emulsion stability against pH and salt concentration Emulsion thermal stability
Material and Methods (continued)
Coconut oil-water interfacial behavior
• Minimum interfacial tension SE < 2 mN/mto small better ability than TW in reducing oil-water interfacial tension
• Minimum interfacial tension TW 8 mN/m
All types of emulsions appeared as white creamy emulsions
Emulsion thermal stability
• All types of emulsions appeared coagulated white solid particles denatured proteins (lesser in 100 C)
• Extra population of emulsion population
• SE surfactant more heat stable than TW surfactant
No oil layer on SE coconut milk
Particle size TW<SE<kontrol
• solid substance in optical micrographs
• SE and TW still small droplets but control became large coalesced oil drops
SE emulsifier revealing good emulsion stability
Emulsion thermal stability (continued)
Emulsion thermal stability (continued)
Emulsion thermal stability (continued)
Presence sucrose made coconut milk SE most stable after freeze thaw
Emulsion thermal stability (continued)
Emulsion stability against pH and salt concentrations
Emulsion stability on pH (continued)
Zero droplet charge flocculated
Emulsion stability on pH (continued)
Higest creaming index at pH 4, because zero droplet charged
Creaming index SE lowest beneficial as creaming stabilizer
Emulsion stability on pH and salt (continued)
Emulsion sensitive with salt
Conclusion
• SE slightly better in lowering interfacial tension between coconut oil and water interface
• SE were more thermally stable than TW