Lipid Modification, Interesterification and Fractionation Flashcards
what is fractionation
the process of producing clear oils
- oil is cooled to ~7.2 degrees to allow high MP TGs to crystallise out
- high MP TGs are also removed by filtration
what are the advantages and disadvantages of chemical interesterification
advantages
low processing cost (batch reactor)
high processing loss (oil saponification)
highly reproducible and easily controlled
disadvantages
low oxidative stability (tocopherol loss)
high levels of reaction byproducts (eg. glycerols)
flavour reversion problem
what are the advantages and disadvantages of enzymatic interesterifiction
advantages minimum processing loss no flavour no change in oxidative stability low levels of reaction byproducts
disadvantages
more complex operation and control
high processing cost (continuous plug flow reactor)
what is interesterification
heating lipids with alkali metals or sodium methoxide
what is blending
mixing different base stocks- like partially or fully hydrogenated oils, interesterified oils and fats, fractionated or winterised oils- to obtain a specific composition, consistency and stability in a final product
what are the uses of the acyl exchange reaction
TG enrichment
To produce products that are unobtainable by chemical means
what is the acyl exchange reaction
lipases catalyse hydrolysis of lipids
synthesis of acyl glycerols from glycerol and fatty acids
what are the advantages of interesterification
increasingly used as an alternative to fractionation and hydrogenation
produces low/no trans fat
what are the disadvantages of interesterification
high cost
what is the process of interesterification
lipid- dryer- reactor- cooler- mixed- separator- bleacher- filter- interesterified oil
what are the best choices of catalysts for interesterifcation
heat with sodium methoxide at 80-100 degrees
heat with metallic sodium ay 100-200 degrees
which types of lipid is interesterification used for?
soybean oil
cotton oil
lard
