topic e_chemical reactions of fragrances and flavours Flashcards
3 chemical reactions of fragrances and flavours
- ester hydrolysis to form acid
- aldol reaction/condensation (between 2 carbonyl compounds)
- acetal formation (aldehyde + alcohol)
why does ester hydrolysis not affect lavender fragrance oil ?
linalyl acetate undergoes ester hydrolysis to form linalool but linalool is also a component in lavender oil so this does not undercut the fragrance
components in lavender fragrance oil
● linalyl acetate
● linalool
components in orange fragrance oil
● beta-pinene
● limonene
components in mint fragrance oil
● menthol
components in lemongrass fragrance oil
● neral
● citral
what is the potential impact of ester hydrolysis of fragrance and flavour?
loss of valuable odour
how does aldol condensation affect vanillin (1) ? and how (4) ?
what can a formulator do to avoid this ? (1)
aldol condensation of vanillin produces a brown colour
● every aldol condensation of vanillin with other carbonyl compounds in formulation adds one double bond
● contributes to conjugated pi electron system
● creates unwanted byproduct with maximum absorbance wavelength in visible light region
● produces brown colour
formulator can use the alternative Ultravanil which replaces the aldehyde group with methyl group so it does not undergo aldol condensation
what is the potential impact of acetal formation on fragrances and flavours?
loss of valuable odour
what causes acetal formation ?
fragrant aldehyde reacts with glycerine in soap
what is the potential impact of aldol condensation on fragrances and flavours
change in colour and smell
what type of fragrance compounds are unstable in acid
ester (acid hydrolysis)
base (protonation)
what types of fragrance compounds are unstable in basic conditions
ester (base hydrolysis)
aldehyde (aldol condensation)
acid (deprotonation)
what type of fragrance compound is unstable in soap and why
aldehydes will form acetal (odourless) when rxt with glycerine in soap
