Interestification of Lipids Flashcards
What is interesterification?
The process of rearranging fatty acids on the glycerol backbone and between triglyceride molecules
What properties of the triglyceride does interesterification change?
Melting point
Crystal structure
Texture
What property of the triglyceride does interestification improve?
Makes the triglyceride more plastic
Describe the interesterification process.
- Lipid sourced
- Lipid dried
- Catalyst added
- Reaction occur inside a reactor = fatty acids removed from the glycerol backbone
- Lipid is cooled = fatty acids randomly reattach to the glycerol backbone
- Hot water mixed in
- Separator
- Citrate added
- Bleached
- Filtered
- Interestified oil produced
Why is hot water added during interesterification?
Fatty acids that have not attached to a glycerol backbone dissolve in the water and are removed
Why is citrate added during interesterification?
It binds to the catalyst so that it can be removed
How does lards structure change when it is interesterified?
From beta to beta’
What reaction occurs when enzymes are used in interesterification?
Acyl exchange reaction = lipase catalyses the transfer of acyl residues between acyl glycerols and fatty acids
How is lipase used in interesterification?
Lipase can selectively remove fatty acids so that new desired fatty acids are added in the reactor and attach to the glycerol backbone during cooling
What are the advantages of interesterification?
Few by products are produced
No trans fatty acids are produced
What are the disadvantages of interesterification?
High cost due to loss of lipids
What is fractionating?
The separation of triglycerides from lipids on the basis of melting point
What does fractionating produce?
Lipids with specific melting properties
How does fractionation occur?
- Oil is cooled to 72 degree allowing triglycerides with high melting points to crystallise and be filtered out
- The resulting oil stays clear when cooled
What fractions are removed during fractionation?
High melting point fractions = saturated triglycerids
Low melting point fractions = unsaturated di- and triglycerides
