Food Flavour Design
2024 - 2025
MFT Year 1
,Learning Outcomes:
After successful completion of this course students are expected to be able to:
• Create formulations and design processing conditions to generate flavours during food thermal treatment via
Maillard reaction and explain the flavour formation via fermentation;
• Design strategies to delay the formation of off-flavours (lipid oxidation);
• Explain the chemistry of flavour compounds and their interaction with food matrices, to formulate flavour solutions
and to assess those in different matrices;
• Explain how the taste receptors work, where they are located and their effect in our body (brain and gut);
• Explain the effect of oral behaviour on flavour perception and the emotional reward which is created during eating;
• Explain the impact of flavour molecules on sensorial perception and the role of product architecture on flavour
perception and how taste, texture, colour, flavour can influence each other (cross-modal interaction), and apply
this knowledge to propose strategies to improve taste perception in re-formulated products.
,Chapter 1.1: Lipid Oxidation in a multiphase food system
and strategies for prevention
The oxidation reaction, is a complex chemical reaction that happens in wine, tea, coffee where the
starting point are the phenolic compounds (primary substrates for oxidation) that degrade into
aldehydes, ketones, organic acids, amongst other. This chemical phenomena (oxidation reaction)
changes the chemical and sensory profile of wines. The formation of aldehydes and ketones can have
either positive or negative effects depending on the food product.
Lipid oxidation:
• Decreases shelf-life
• Decreases nutritional value
• Colour change
• Causes the formation of volatile compounds such as hexanal, associated with unpleasant off-flavours
- Reaction that takes place:
Volatile compounds (e.g. hexanal) are responsible for off-flavors (0.5 pt).
Initiation: Hydrogen abstraction between two double bonds or next to a double to form alkyl radical (0.5 pt, i.e. 0.25
pt for mentioning hydrogen abstraction and 0.25 pt for mentioning the correct position).
Propagation: Reaction of alkyl radical with oxygen to form peroxyl radical (0.5 pt) --> Reaction with another
unsaturated fatty acid to from a hydroperoxide and a new alkyl radical (0.5 pt).
Degradation of hydroperoxide --> Formation of alkoxyl radical (0.5 pt) followed by scission of the molecule to
form volatile molecules (0.5 pt).
Food lipids:
• Lipids are most commonly define as a wide variety of compounds, which are insoluble in water and soluble
in organic solvents (e.g. chloroform, ether, ...)
• Except for short-chain-fatty acids (FA), that are soluble in both organic solvents AND water
• 95% of food lipids are triacylglycerols non-polar lipid molecules consisting of a glycerol backbone on which
three FAs are esterified
• Food products also contains minor lipid species, including polar lipids such as phospholipids.
• Phospholipids contain a glycerol backbone on which two FAs and one polar phospho-group are esterified. Due
to their structure, phospholipids are amphiphilic molecules that can be used as emulsifiers in food products.
Triglycerides are the main constituent of oils and fats (~95- 99%). Other minor lipid compounds can be found in fats
and oils, that either derive from the degradation of other lipids through hydrolysis and/or oxidation or are
initially present, such as sterols, tocopherols, or phospholipids.
, Lipid functions:
Biological/physiological role:
1. Structural role: Cell membranes; a phospholipid bilayer in which sterols and glycolipids can be incorporated.
2. Functional role: Precursors of hormones, vitamins and molecules involved in the regulation of inflammation.
3. Energy storage: In the adipose tissue
Role in foods:
1. Texture: creaminess, viscosity
2. Surface-active properties
3. Flavour
4. Nutritional value: Caloric density, Essential fatty acids, Vitamins, etc.
5. Technological role: used as frying oil (op te bakken (ex. olijf olie) of the frituren (ex. zonnebloem olie)
Fatty acids:
• Hydrocarbon molecules with a carboxyl terminal. (COOH - CH2-......-CH3)
• Can be free,
• Most of the time, they are esterified to other molecules to form e.g. triglycerides, phospholipids, cholesteryl esters
• Saturated (no double bonds)
• monounsaturated (one double bond)
• Polyunsaturated (two or more double bonds)
• In nature, double bonds are usually in cis configuration (i.e. the hydrogen atoms bonds to the carbons on the
double bonds stick out on the same side of the molecule), as they are produced through enzymatic pathway that
specifically introduce cis double bonds in the molecules.
• During food processing (e.g. hydrogenation), the double bond configuration may change to a trans
configuration (i.e. the hydrogen atoms on the carbon of the double bonds stick out on opposite side from the
molecule) this is sterically more favourable for the producers for certain food products.
• When a fatty acid contains more than one double bond, double bonds are always in nature methylene
interrupted, forming a 1,4-pentadiene motif (motif “double bond - single bond - single bond – double bond”; see
- -
-
-
linoleic acid structure). ...
Nomenclature of fatty acids:
1. The systemic name determined by the chemical structure
2. The common name, most commonly used
3. The short notation. In the short notation of a fatty acid, the first number refers to the number of carbons and
the second number to the number of double bonds (e.g. 0 for saturated fatty acids, 1 for monounsaturated
fatty acids, ...).
Unsaturated fatty acids ω/ n- or Δ nomenclature:
• ω or n- nomenclature: Indicates the position of the first double bond from the methyl terminal
• Δ nomenclature: Indicates the position of the first double bond from the carboxy terminal.
2024 - 2025
MFT Year 1
,Learning Outcomes:
After successful completion of this course students are expected to be able to:
• Create formulations and design processing conditions to generate flavours during food thermal treatment via
Maillard reaction and explain the flavour formation via fermentation;
• Design strategies to delay the formation of off-flavours (lipid oxidation);
• Explain the chemistry of flavour compounds and their interaction with food matrices, to formulate flavour solutions
and to assess those in different matrices;
• Explain how the taste receptors work, where they are located and their effect in our body (brain and gut);
• Explain the effect of oral behaviour on flavour perception and the emotional reward which is created during eating;
• Explain the impact of flavour molecules on sensorial perception and the role of product architecture on flavour
perception and how taste, texture, colour, flavour can influence each other (cross-modal interaction), and apply
this knowledge to propose strategies to improve taste perception in re-formulated products.
,Chapter 1.1: Lipid Oxidation in a multiphase food system
and strategies for prevention
The oxidation reaction, is a complex chemical reaction that happens in wine, tea, coffee where the
starting point are the phenolic compounds (primary substrates for oxidation) that degrade into
aldehydes, ketones, organic acids, amongst other. This chemical phenomena (oxidation reaction)
changes the chemical and sensory profile of wines. The formation of aldehydes and ketones can have
either positive or negative effects depending on the food product.
Lipid oxidation:
• Decreases shelf-life
• Decreases nutritional value
• Colour change
• Causes the formation of volatile compounds such as hexanal, associated with unpleasant off-flavours
- Reaction that takes place:
Volatile compounds (e.g. hexanal) are responsible for off-flavors (0.5 pt).
Initiation: Hydrogen abstraction between two double bonds or next to a double to form alkyl radical (0.5 pt, i.e. 0.25
pt for mentioning hydrogen abstraction and 0.25 pt for mentioning the correct position).
Propagation: Reaction of alkyl radical with oxygen to form peroxyl radical (0.5 pt) --> Reaction with another
unsaturated fatty acid to from a hydroperoxide and a new alkyl radical (0.5 pt).
Degradation of hydroperoxide --> Formation of alkoxyl radical (0.5 pt) followed by scission of the molecule to
form volatile molecules (0.5 pt).
Food lipids:
• Lipids are most commonly define as a wide variety of compounds, which are insoluble in water and soluble
in organic solvents (e.g. chloroform, ether, ...)
• Except for short-chain-fatty acids (FA), that are soluble in both organic solvents AND water
• 95% of food lipids are triacylglycerols non-polar lipid molecules consisting of a glycerol backbone on which
three FAs are esterified
• Food products also contains minor lipid species, including polar lipids such as phospholipids.
• Phospholipids contain a glycerol backbone on which two FAs and one polar phospho-group are esterified. Due
to their structure, phospholipids are amphiphilic molecules that can be used as emulsifiers in food products.
Triglycerides are the main constituent of oils and fats (~95- 99%). Other minor lipid compounds can be found in fats
and oils, that either derive from the degradation of other lipids through hydrolysis and/or oxidation or are
initially present, such as sterols, tocopherols, or phospholipids.
, Lipid functions:
Biological/physiological role:
1. Structural role: Cell membranes; a phospholipid bilayer in which sterols and glycolipids can be incorporated.
2. Functional role: Precursors of hormones, vitamins and molecules involved in the regulation of inflammation.
3. Energy storage: In the adipose tissue
Role in foods:
1. Texture: creaminess, viscosity
2. Surface-active properties
3. Flavour
4. Nutritional value: Caloric density, Essential fatty acids, Vitamins, etc.
5. Technological role: used as frying oil (op te bakken (ex. olijf olie) of the frituren (ex. zonnebloem olie)
Fatty acids:
• Hydrocarbon molecules with a carboxyl terminal. (COOH - CH2-......-CH3)
• Can be free,
• Most of the time, they are esterified to other molecules to form e.g. triglycerides, phospholipids, cholesteryl esters
• Saturated (no double bonds)
• monounsaturated (one double bond)
• Polyunsaturated (two or more double bonds)
• In nature, double bonds are usually in cis configuration (i.e. the hydrogen atoms bonds to the carbons on the
double bonds stick out on the same side of the molecule), as they are produced through enzymatic pathway that
specifically introduce cis double bonds in the molecules.
• During food processing (e.g. hydrogenation), the double bond configuration may change to a trans
configuration (i.e. the hydrogen atoms on the carbon of the double bonds stick out on opposite side from the
molecule) this is sterically more favourable for the producers for certain food products.
• When a fatty acid contains more than one double bond, double bonds are always in nature methylene
interrupted, forming a 1,4-pentadiene motif (motif “double bond - single bond - single bond – double bond”; see
- -
-
-
linoleic acid structure). ...
Nomenclature of fatty acids:
1. The systemic name determined by the chemical structure
2. The common name, most commonly used
3. The short notation. In the short notation of a fatty acid, the first number refers to the number of carbons and
the second number to the number of double bonds (e.g. 0 for saturated fatty acids, 1 for monounsaturated
fatty acids, ...).
Unsaturated fatty acids ω/ n- or Δ nomenclature:
• ω or n- nomenclature: Indicates the position of the first double bond from the methyl terminal
• Δ nomenclature: Indicates the position of the first double bond from the carboxy terminal.
