Triglycerides Flashcards
Triglycerides with high melting points are _______ at room temperature
Solid = they form fats
Triglycerides with low melting points are ________ at room temperature
Liquid = they form oils
What is the melting point of triglycerides dependent on?
Fatty acids and the crystal structure of the triglyceride
How does the length of the fatty acid chain affect melting point and why?
The longer the chain the higher the melting point because there are more intermolecular bonds between the fatty acids to break
How does the number of carbon double bonds affect melting point and why?
The more double bonds the lower the melting point because the triglyceride has decreased stability due to the kink created
What are the three polymorphic forms of triglycerides?
Alpha, Beta’, Beta
What does polymorphic mean?
They exist in more than on crystalline form
Which polymorphic form cools the quickest and which polymorphic form cools the slowest ?
Cools quickest = alpha
Cools slowest = beta
Which polymorphic form is the most stable and which polymorphic form is the least stable?
Most stable = beta
Least stable = alpha
How are alpha triglycerides used?
Limited food application
How are beta’ triglycerides used?
Form some plastic fats = margarine
How are beta triglycerides used?
Form large crystals = cocoa butter
How many polymorphic states does cocoa butter have and which has the desired properties?
6 states
Type 5 has the desired properties
What is tempering in chocolate making?
Controlled crystallisation used to induce the desired form of cocoa butter
What three states are lipids present in?
Solid = short chain fatty acids Plastic = mix of solid and liquid Liquid = long chain fatty acids
