FFD
Personal Notes
01 NOVEMBER 2022
WUR
Konstantina Moustaka
,Table of Contents
Lipid Oxidation ........................................................................................................................................ 3
Food Lipids .......................................................................................................................................... 3
Lipid Oxidation and General Mechanisms and Flavour Consequences .............................................. 3
Initiation .......................................................................................................................................... 4
Propagation ..................................................................................................................................... 4
Termination..................................................................................................................................... 5
Decomposition of Hydroperoxides ................................................................................................. 5
Kinetic Aspects ................................................................................................................................ 6
Factors Promoting Lipid Oxidation.................................................................................................. 6
Measurement Methods to Monitor Lipid Oxidation .......................................................................... 8
Lipid oxidation in a multiphase food system (emulsions)............................................................... 8
Factors related to the oil phase ...................................................................................................... 8
Factors related to the aqueous phase ............................................................................................ 9
Factors related to the interface ...................................................................................................... 9
Strategies to prevent lipid oxidation ................................................................................................ 10
Antioxidant Efficiency= matrix-dependent ................................................................................... 10
Antioxidant Synergy ...................................................................................................................... 11
Accelerated Shelf-life Testing ........................................................................................................... 11
Maillard Reaction .................................................................................................................................. 12
Maillard reaction in meat ................................................................................................................. 12
Sugar Reactivity................................................................................................................................. 13
How sugars react w/ the a.a. ........................................................................................................ 13
Maillard Kinetics................................................................................................................................ 16
Zero order kinetics ........................................................................................................................ 16
Determination of Ea ...................................................................................................................... 17
pH Influence on Maillard Kinetics and Flavour Generation .......................................................... 18
Oil Oxidation in Maillard ................................................................................................................... 19
Fermentation ........................................................................................................................................ 20
Types of Fermentation ...................................................................................................................... 20
Pathways ........................................................................................................................................... 20
Malolactic Fermentation............................................................................................................... 21
Citrate Metabolism ....................................................................................................................... 21
Microbial Flavour Compounds .......................................................................................................... 21
Flavour Implications .............................................................................................................................. 23
Proteins ......................................................................................................................................... 23
1
, Fat ................................................................................................................................................. 24
Sugar/ salt ..................................................................................................................................... 24
Physics behind Flavours .................................................................................................................... 25
LogP ............................................................................................................................................... 25
OAV ............................................................................................................................................... 25
Effect of Viscosity .............................................................................................................................. 25
Effect of hardness and chewing pattern ........................................................................................... 26
Effect of contrast in flavour perception ............................................................................................ 26
Impact of cross-modal interactions on flavour perception .............................................................. 27
Composition of Flavourings .............................................................................................................. 27
Importance of Flavour Perception .................................................................................................... 27
Selection of Compounds ................................................................................................................... 28
Legal Aspects..................................................................................................................................... 28
Physical Formats ............................................................................................................................... 29
Liquid ............................................................................................................................................. 29
Dry ................................................................................................................................................. 29
Drying technologies ...................................................................................................................... 29
Taste and Odour Receptors .............................................................................................................. 30
How do we Smell?......................................................................................................................... 30
Odour/ Olfactory Reception ......................................................................................................... 30
Taste Perception ........................................................................................................................... 31
Oral Physiological Processes during Food Consumption .............................................................. 32
Static & Dynamic Sensory Methods for Flavour Assessment ............................................................... 34
Isolation of flavour compounds ........................................................................................................ 35
Machines ....................................................................................................................................... 37
Manipulation and Improvement of Flavour Quality ......................................................................... 38
2
, Lipid Oxidation
Food Lipids
Soluble in organic solvents Non-polar→Triacylglycerols Saturated fa→ No double bonds
Liquid at room T→ Oil (Glycerol backbone connected to 3 Unsaturated fa→ double bonds
Solid at room T→ Fat fatty acids) usually in cis form, may change to
Polar→ Phospholipids (Glycerol trans through hydrogenation.
backbone connected to 2 fa and More sensitive to lipid oxidation.
one phosphate group-lecithin) EPA & DHA→ long
(Amphiphilic=used as emulsifiers) polyunsaturated omega-3 fa
Lipid Function→ precursors of hormones, liposoluble vitamins, pro-inflammatory molecules, energy
storage, structural as cell membranes, texture, surface active properties, flavour, nutritional value,
technological role.
Lipid Oxidation and General Mechanisms and Flavour Consequences
Hydrolysis→ In the presence of water the triglyceride is broken down into its constituents
and is catalysed by alkali, acids, and enzymes (lipases).
Oxidation→ Degradation reaction btw an unsaturated fa and oxygen. Stimulated by light
(photo-oxidation) or enzymes (enzymatic oxidation). Autooxidation though more
problematic in food systems.
Lipid autooxidation is divided into 3 steps;
1/ Initiation in which, light, metals, and reactive oxygen species (ROS) catalyse the formation of an
alkyl radical (L•) by hydrogen abstraction from an unsaturated fa (LH); 2/ Propagation in which the
alkyl radical reacts very quickly with oxygen present to form a peroxyl radical (LOO•). This peroxyl
radical will further react another unsaturated fa (LH) to form a hydroperoxide (primary lipid oxidation)
along with a new alkyl radical (L•) generating a propagation circle of reactions; 3/ Termination during
which non-radical secondary oxidation products are formed (secondary lipid oxidation).
3
Personal Notes
01 NOVEMBER 2022
WUR
Konstantina Moustaka
,Table of Contents
Lipid Oxidation ........................................................................................................................................ 3
Food Lipids .......................................................................................................................................... 3
Lipid Oxidation and General Mechanisms and Flavour Consequences .............................................. 3
Initiation .......................................................................................................................................... 4
Propagation ..................................................................................................................................... 4
Termination..................................................................................................................................... 5
Decomposition of Hydroperoxides ................................................................................................. 5
Kinetic Aspects ................................................................................................................................ 6
Factors Promoting Lipid Oxidation.................................................................................................. 6
Measurement Methods to Monitor Lipid Oxidation .......................................................................... 8
Lipid oxidation in a multiphase food system (emulsions)............................................................... 8
Factors related to the oil phase ...................................................................................................... 8
Factors related to the aqueous phase ............................................................................................ 9
Factors related to the interface ...................................................................................................... 9
Strategies to prevent lipid oxidation ................................................................................................ 10
Antioxidant Efficiency= matrix-dependent ................................................................................... 10
Antioxidant Synergy ...................................................................................................................... 11
Accelerated Shelf-life Testing ........................................................................................................... 11
Maillard Reaction .................................................................................................................................. 12
Maillard reaction in meat ................................................................................................................. 12
Sugar Reactivity................................................................................................................................. 13
How sugars react w/ the a.a. ........................................................................................................ 13
Maillard Kinetics................................................................................................................................ 16
Zero order kinetics ........................................................................................................................ 16
Determination of Ea ...................................................................................................................... 17
pH Influence on Maillard Kinetics and Flavour Generation .......................................................... 18
Oil Oxidation in Maillard ................................................................................................................... 19
Fermentation ........................................................................................................................................ 20
Types of Fermentation ...................................................................................................................... 20
Pathways ........................................................................................................................................... 20
Malolactic Fermentation............................................................................................................... 21
Citrate Metabolism ....................................................................................................................... 21
Microbial Flavour Compounds .......................................................................................................... 21
Flavour Implications .............................................................................................................................. 23
Proteins ......................................................................................................................................... 23
1
, Fat ................................................................................................................................................. 24
Sugar/ salt ..................................................................................................................................... 24
Physics behind Flavours .................................................................................................................... 25
LogP ............................................................................................................................................... 25
OAV ............................................................................................................................................... 25
Effect of Viscosity .............................................................................................................................. 25
Effect of hardness and chewing pattern ........................................................................................... 26
Effect of contrast in flavour perception ............................................................................................ 26
Impact of cross-modal interactions on flavour perception .............................................................. 27
Composition of Flavourings .............................................................................................................. 27
Importance of Flavour Perception .................................................................................................... 27
Selection of Compounds ................................................................................................................... 28
Legal Aspects..................................................................................................................................... 28
Physical Formats ............................................................................................................................... 29
Liquid ............................................................................................................................................. 29
Dry ................................................................................................................................................. 29
Drying technologies ...................................................................................................................... 29
Taste and Odour Receptors .............................................................................................................. 30
How do we Smell?......................................................................................................................... 30
Odour/ Olfactory Reception ......................................................................................................... 30
Taste Perception ........................................................................................................................... 31
Oral Physiological Processes during Food Consumption .............................................................. 32
Static & Dynamic Sensory Methods for Flavour Assessment ............................................................... 34
Isolation of flavour compounds ........................................................................................................ 35
Machines ....................................................................................................................................... 37
Manipulation and Improvement of Flavour Quality ......................................................................... 38
2
, Lipid Oxidation
Food Lipids
Soluble in organic solvents Non-polar→Triacylglycerols Saturated fa→ No double bonds
Liquid at room T→ Oil (Glycerol backbone connected to 3 Unsaturated fa→ double bonds
Solid at room T→ Fat fatty acids) usually in cis form, may change to
Polar→ Phospholipids (Glycerol trans through hydrogenation.
backbone connected to 2 fa and More sensitive to lipid oxidation.
one phosphate group-lecithin) EPA & DHA→ long
(Amphiphilic=used as emulsifiers) polyunsaturated omega-3 fa
Lipid Function→ precursors of hormones, liposoluble vitamins, pro-inflammatory molecules, energy
storage, structural as cell membranes, texture, surface active properties, flavour, nutritional value,
technological role.
Lipid Oxidation and General Mechanisms and Flavour Consequences
Hydrolysis→ In the presence of water the triglyceride is broken down into its constituents
and is catalysed by alkali, acids, and enzymes (lipases).
Oxidation→ Degradation reaction btw an unsaturated fa and oxygen. Stimulated by light
(photo-oxidation) or enzymes (enzymatic oxidation). Autooxidation though more
problematic in food systems.
Lipid autooxidation is divided into 3 steps;
1/ Initiation in which, light, metals, and reactive oxygen species (ROS) catalyse the formation of an
alkyl radical (L•) by hydrogen abstraction from an unsaturated fa (LH); 2/ Propagation in which the
alkyl radical reacts very quickly with oxygen present to form a peroxyl radical (LOO•). This peroxyl
radical will further react another unsaturated fa (LH) to form a hydroperoxide (primary lipid oxidation)
along with a new alkyl radical (L•) generating a propagation circle of reactions; 3/ Termination during
which non-radical secondary oxidation products are formed (secondary lipid oxidation).
3
