Summary/Reader food flavour design
By Mark Hendrik Martin de Haas
Course code: FQD-37806
Date: 11-12-2019
Location: Wageningen University and Research
This Reader is made because this course is quite new and except from lectures, lecture notes
(a small reader) and some literature, you do not have much to read up on.
So, I decided to make a Reader myself. The Reader contains information from the Lectures,
information from the course Food chemistry FCH-20806 (which was assumed knowledge),
some of the literature and the provided lecture notes.
,Contents
Guest lectures: ........................................................................................................................................ 7
Regulatory driven flavour innovation.................................................................................................. 7
Why flavours.................................................................................................................................... 7
legislation ........................................................................................................................................ 7
Natural ............................................................................................................................................. 9
Possible scenarios.......................................................................................................................... 11
Example questions......................................................................................................................... 12
Flavour encapsulation ....................................................................................................................... 12
Why do we encapsulate food flavours? ........................................................................................ 12
Main challenge .............................................................................................................................. 13
Flavour encapsulation technologies .............................................................................................. 13
Raw material...................................................................................................................................... 16
types of flavouring raw materials,................................................................................................. 17
Chemically defined flavouring substances .................................................................................... 18
Vanillin production ........................................................................................................................ 19
essential oils .................................................................................................................................. 20
Flavouring composition ................................................................................................................. 20
Flavour mixtures ............................................................................................................................ 20
Flavour mixture- interactions ........................................................................................................ 21
Lipid oxidation ....................................................................................................................................... 22
General .............................................................................................................................................. 22
Lipid oxidation: general mechanism, and flavour consequences ..................................................... 23
Reaction kinetic aspects .................................................................................................................... 26
Factors that promote lipid oxidation ................................................................................................ 26
Oxygen ........................................................................................................................................... 26
Light ............................................................................................................................................... 27
Metals ............................................................................................................................................ 27
Temperature.................................................................................................................................. 28
Water activity ................................................................................................................................ 28
Measuring methods. ......................................................................................................................... 28
Lipid oxidation in food systems ......................................................................................................... 29
Factors related to the oil phase..................................................................................................... 29
Factors related to the aqueous phase ........................................................................................... 29
Strategies to prevent lipid oxidation ................................................................................................. 30
Packaging ....................................................................................................................................... 30
, Cold-chain ...................................................................................................................................... 30
Anti-oxidants addition ................................................................................................................... 30
Consumer wish .............................................................................................................................. 30
Primary anti-oxidants .................................................................................................................... 30
Secondary anti-oxidants ................................................................................................................ 31
2 important effects of anti-oxidants ................................................................................................. 32
Polar paradox ................................................................................................................................ 32
Cutting off effect ........................................................................................................................... 33
Synergy .............................................................................................................................................. 33
Examples........................................................................................................................................ 33
Maillard ................................................................................................................................................. 35
Why does the maillard reaction make everything delicious clip(introduction): ............................... 35
Clear reaction scheme of maillard reaction ...................................................................................... 35
Step A: imine formation ................................................................................................................ 36
Step B the Amadori and Heyns rearrangement ............................................................................ 36
Step C: 1,2- or 2,3- enolization ...................................................................................................... 38
Step E: Strecker degradation ......................................................................................................... 39
Lecture ............................................................................................................................................... 40
Savoury flavour pyramid ............................................................................................................... 40
The carbon sources ....................................................................................................................... 41
The Amino group ........................................................................................................................... 41
Strecker degradation ..................................................................................................................... 41
The Sulphur sources ...................................................................................................................... 42
Meat flavour formation ................................................................................................................. 42
Reducing sugar .............................................................................................................................. 43
Reactivity ....................................................................................................................................... 43
Reaction kinetics............................................................................................................................ 44
pH .................................................................................................................................................. 44
The effects of pH ........................................................................................................................... 45
Example questions......................................................................................................................... 45
literature............................................................................................................................................ 46
A review of Maillard reaction in food and implications to kinetic modelling ............................... 46
Basic chemistry and process conditions for reaction flavours with particular focus on Maillard-
type reactions ................................................................................................................................ 49
flavour perception physiology ............................................................................................................... 57
video’s ............................................................................................................................................... 57
, intro ............................................................................................................................................... 57
Smell .............................................................................................................................................. 57
Receptor binding ........................................................................................................................... 58
Taste .............................................................................................................................................. 58
Labelled lines model ...................................................................................................................... 59
Taste cells ...................................................................................................................................... 59
Lecture ............................................................................................................................................... 59
intro ............................................................................................................................................... 59
Mechanism .................................................................................................................................... 60
Nose strength ................................................................................................................................ 60
Threshold ....................................................................................................................................... 60
Odour pattern recognition in the brain......................................................................................... 61
Taste .............................................................................................................................................. 61
Trigeminal system ......................................................................................................................... 61
Saliva.............................................................................................................................................. 61
Memory ......................................................................................................................................... 62
Oral processing behaviour and aroma release...................................................................................... 63
Velum ................................................................................................................................................ 63
Epiglottis ............................................................................................................................................ 63
pharynx .............................................................................................................................................. 63
Individual difference of consumption ............................................................................................... 64
Ways to consume food ...................................................................................................................... 65
Impact of food product composition, structure and architecture on flavour release and perception 66
General .............................................................................................................................................. 66
Lipids.................................................................................................................................................. 66
Protein ............................................................................................................................................... 67
Sugar .................................................................................................................................................. 67
Simple sugars ................................................................................................................................. 67
Polysaccharides ............................................................................................................................. 67
Consider all at once ........................................................................................................................... 67
enhance flavour perception in-mouth .............................................................................................. 68
Impact of cross-modal interactions (taste, aroma and texture) on flavour perception ....................... 70
general ............................................................................................................................................... 70
Influence of aromas on taste perception .......................................................................................... 70
Influence of taste on aroma perception ........................................................................................... 71
Influence of texture on aroma perception ........................................................................................ 71
, Influence of aroma on texture perception ........................................................................................ 72
Influence of other senses on the flavour perception ........................................................................ 72
Conclusion ......................................................................................................................................... 72
Static and dynamic sensory methods for flavour assessment .............................................................. 73
Sensory evaluation ............................................................................................................................ 73
Analytic vs hedonic ........................................................................................................................ 73
Trained panel ................................................................................................................................. 74
Discrimination sensory analysis ........................................................................................................ 74
Paired comparison test.................................................................................................................. 74
Triangle test ................................................................................................................................... 74
Application..................................................................................................................................... 75
Significance .................................................................................................................................... 75
Descriptive sensory analysis .............................................................................................................. 75
Quantitative Descriptive Analysis (QDA) ....................................................................................... 75
Dynamic sensory methods ............................................................................................................ 77
Flavour Analytics ................................................................................................................................... 81
Headspace extraction ........................................................................................................................ 81
Static headspace ............................................................................................................................ 81
Dynamic headspace....................................................................................................................... 81
Solid Micro Extraction ....................................................................................................................... 81
Stir Bar Sorbent Extraction ................................................................................................................ 82
Comparing the extraction methods .................................................................................................. 82
Partition coefficients (K) ................................................................................................................ 82
Applicability ................................................................................................................................... 82
Solvent extraction and (steam/vacuum) distillation ......................................................................... 82
Simultaneous distillation-extraction (SDE) .................................................................................... 83
Solvent-Assisted Flavour Extraction (SAFE) ................................................................................... 83
Analysis .............................................................................................................................................. 83
Gas Chromatography..................................................................................................................... 83
Mass Chromatography .................................................................................................................. 83
Identifying the key-aroma compounds ............................................................................................. 84
Aroma extract dilution analysis (AEDA) ........................................................................................ 84
Odour Threshold Values (ODT)...................................................................................................... 84
Odour Activity Value (OAV) ........................................................................................................... 84
The challenge .................................................................................................................................... 85
Improving flavour design ................................................................................................................... 85
,Enhancing or masking flavours ...................................................................................................... 85
Omission ........................................................................................................................................ 86
,Guest lectures:
Regulatory driven flavour innovation
The International Organization of the Flavour Industry (IOFI) is representing the industry that involves
flavourings worldwide. The European Flavour and Fragrance Association (EFFA) focuses on flavouring
alone, and strives to be the voice of flavour in Europe.
Innovation involves labelling. The intended use is very important. Flavours in food(digestion) is very
different from flavours in e-cigarettes(inhalation).
Why flavours?
-Sensory properties (people should like the food)
-healthy nutrition (sweetener instead of more unhealthy sugar)
-enable new food systems (make a vegan hamburger taste like hamburger)
Flavours can trigger many things
-mouth feel
-saliva production
-after taste
e.g. capsaicin and gingerol
the structure can give an indication on the on the effect of the flavouring. E.g. R1=R2=OCH3 could
trigger a tingling effect. P-CH3 substitution with a OH group shows less pungent. A long alkoxy side
chain weakens the pungency. An S is better than an O. A 5-member ring increases the feeling of
numbing, making it less pungent.
Keep in mind a flavour is experiences (sensory) when a certain receptor is triggered. A sweetener
interacts with the same receptor as sugar (often even stronger interaction). But a flavour compound
can also bind the receptor and block the trigger. This way you can block unwanted flavours.
Flavourings can be used to modify taste properties (Taste Modulation). These may be used in sugar-,
fat- and salt reduced products. E.g. chicken-containing Thai dishes lime is used to catch the fatty
notes of the chicken.
legislation
Legislation - EC Regulations on Flavourings 1334/2008
Over the world different regulations are being handled.
In the EU regulation aims at achieving 5 complementary policy objectives: 1 consumer health, 2 risk
assessment, 3 consumer interests, 4 appropriate labelling, 5 wider legitimate factors (societal,
economic, fair trade etc.)
The regulation does not cover:
Substances which have exclusively a sweet, sour of salty taste (sugars, sweeteners, salt, citric acid)
Non-compound foods and mixtures such as, fresh/dried/frozen spices and/or herbs, mixtures of tea
and mixtures of infusion
Sensory functionality
Flavourings with taste modifying properties (taste modulation), e.g. a fat replacer makes the product
taste fattier, while less fat is present. This includes: sugar-, fat- and salt reduced products.
Masking flavourings e.g. for healthy food products enriched with functional ingredients like minerals,
vitamins (these often taste bad so you want to mask them)
Flavourings that create or enhance mouthfeel
The term flavourings with modifying properties (FMPs) defines as: flavourings that can either impact
odour and/or taste to food or modify odour and/or taste of food.
Flavouring shall mean products:
(I): not intended to be consumed as such, which are added to food in order to impart or modify
odour and/or taste
,(II)-(natural) flavouring substances: a defined chemical substance with flavouring properties
-Flavour preparations (e.g. extracts, distillates): A food by appropriate physical, enzymatic or
microbiological processes, this can be done before processing (raw material) or after (ready for
consumption), by one or more of the traditional food preparation processes listed in Annex II. B
material of vegetable, animal or microbiological origin, other than food, by appropriate physical,
enzymatic or microbiological processes, the material being taken as such or prepared by one or more
of the traditional food preparation processes listed in Annex II (see Figure 1).
Figure 1: Approved Processes, Annex II
-flavour precursors (because they form the flavour components), the precursors don’t have
necessarily by itself, but can be added to food so breakdown products or the reaction with other
ingredients are flavourings.
Figure 2: Flavour precursor (Article 3.2)
-thermal process flavourings, e.g. maillard reactions, the sugar and protein produce some flavourings
under heat.
-smoke flavourings: by fractionation and purification of a condensed smoke
-other flavourings: flavouring that doesn’t fall under the conditions above
,Figure 3: Types of flavouring raw materials
e.g. Rum ether has a rum-like odour and flavour and is thus a rum substitute. It is produced by
oxidative degradation from special wood like white oak and beech. The materials typically employed
in the process are: 95% ethyl alcohol, pyroligneous acid, 93–96% sulfuric acid, manganese dioxide
and for some preparations acetic acid is used (EFSA). Nowadays, it is not common anymore and
mostly available in Czech Republic because of cultural heritage.
Food ingredient with flavouring properties shall mean: a food ingredient other than flavourings
which may be added to food for the main purpose of adding flavour to it or modifying its flavour and
which contributes significantly to the presence in food of certain naturally occurring undesirable
substances.
Source material shall mean: material of vegetable, animal, microbiological or mineral origin from
which flavourings or food ingredients with flavouring properties are produced; it may be:
(I) food;
(II) source material other than food.
Non-flavouring ingredients
-Solvents (e.g. ethanol, propylene glycol, water, triacetin..)
-Carrier (e.g. maltodextrin, modified starch..)
-Thickening agents (e.g. gum Arabic), acidity regulators (e.g. citric acid)
Natural
The term natural can be used when the ingredient comes from a ‘’natural sours’’.
This includes:
1. Flavouring preparations. This is mostly a concentrated solution/extraction made from a
natural material. This often contains much impurities. E.g. an extract from vanilla pods.
2. Natural Flavouring substances: extraction or fermentation to make a (very) pure concentrate
of the flavour molecule. (so, there are also non-natural flavouring substances)
e.g. type 2: vanillin, most vanillin is chemically synthesised. But we want natural vanillin. Using
vanillin beans is time consuming and expensive. So, we look into fermentation to form natural
vanillin.
, Figure 4: When is a product allowed to be labelled 'natural'
Chemical Abstracts Service number (CAS number), each chemical substance is described in the open
scientific appendix with a number.
The JECFA number is a numerical identifier assigned by the Joint FAO/ WHO Expert Committee on
Food Additives.
CoE number is assigned by the Council of Europe
EFSA has over 2543 flavouring substances listed. Why so many? → a little modification of a (natural)
substance can change their safety. They can have a different ADI of NOAEL.
What is natural (article 16 (2)
Natural: 1. Flavouring preparations(extraction), 2. Natural flavouring substances (extraction or
fermentation) see Figure 5
Figure 5: Obtaining ''natural'' flavour compounds
Figure 6: Article 3 Paragraph 2d flavour preparation
Allowed extraction solvents according to 2009/32/EC:
- Propane
- Butane
- Ethyl acetate
- Ethanol (becomes less popular since it is not allowed in Halal, water takes over)
- Carbon dioxide