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AIC 2010 Color and Food, Mar del Plata, Argentina 12-15 October 2010

Food, Expectations, Colour and Appearance John Hutchings Department of Colour Science University of Leeds, UK

congratulations to

GRUPO ARGENTINO DEL COLOR organisers of the first international conference on food colour

four points: 1. study of the colour of food is different from study of colour in all other mass marketed materials 2. first, think “appearance” of food not “colour” 3. think “expectations” – they drive behaviour 4. all aspects of food del campo a la mesa can be specified and driving forces identified

four stories: 1. the evolution of food colour – leads to a look at colour and diet 2. leads to the story of appearance expectations halo effects commercial exploitation 3. leads to population differences ethics 4. quantification – all appearance properties food, packaging and restaurant design can be measured and/or specified

colour itself is important because natural colorants keep us healthy


lowers blood pressure

poisonous food colour

study of food colour is different from the study of the colour of other mass marketed materials

paints textiles plastics foods man made pigments are closely controlled

in natural foods light absorbers and scatterers have: evolved with climate coevolved with vision

why are foods different?

our natural foods have also coevolved with insect and animal vision insect vision 300





animal vision hence, the “appearance� of the natural world was optimised for insect and animal vision in terms of wavelength dependence angle dependence (gloss) surface irregularity or roughness dependence (surface texture) internal diffusion dependence (translucency, opacity)



uv signals and polarisation dependence human vision

so, human beings live in a natural world that has been optimised in terms of: visual structure wavelength dependence (colour), angle dependence (gloss) surface texture, internal diffusion dependence (translucency) therefore, think “appearance” not “colour” study of colour in foods is different because: 1. evolution has resulted in uncontrolled light absorbers and scatterers 2. natural variation across surface and in depth 3. foods are naturally variable in colour, translucency, gloss and surface texture – processing can affect all attributes.

CARE with sensory assessment, theoretical treatment and appearance instrumentation. In other materials each attribute of appearance (colour, translucency, surface texture, gloss) can be treated as independent variables but in foods they cannot foods change on cooking and processing not only in colour but in other appearance attributes that is, we must consider food appearance not just colour.

examples of interactions: the visually perceived quality of: fish and meat depends on colour and translucency chocolate depends on colour and gloss breakfast cereals depends on colour, colour distribution and surface texture drinks depend on colour and translucency therefore, we must consider colour AND appearance appearance consists of visual structure, variation of colour, translucency, gloss and surface texture, temporal properties (i.e. how these change with time or processing).

total appearance = interaction of appearance with human reactions i.e. total appearance of any food/scene comprises two parts: the scene the elements of the scene the design the illumination the viewer individual visual characteristics upbringing, psychology, preferences immediate environment e.g. appetite, needs, health total appearance results in sensory, emotional, intellectual images and EXPECTATIONS.

EXPECTATIONS – two types: based on belief based on our senses

EXPECTATIONS arising from sensory input: visually assessed safety visually assessed identification visually assessed usefulness visually assessed pleasantness visually assessed satisfaction

appearance driven expectations control our responses: along the whole supply chain from field to kitchen the plate of food the store faรงade the store environment the food package the food on the store shelf the restaurant environment BUT, responses are influenced by halo effects

halo effect types: colour/flavour/aroma interactions subject’s attitudes subject’s immediate environment size market effect – regional.

expectations, a commercial example


size,shape,colour,translucency,gloss,surface texture = an orange.

expectations of the orange

colour = contains antioxidants, vitamins therefore this is good for me! gloss = sprayed with wax to keep moisture in colour uniformity = sprayed with insecticide, herbicide therefore this is bad for me!

commercial exploitation 1

commercial exploitation 2

the halo effect is very powerful therefore, when testing specifically for FLAVOUR, the sample must be hidden.

halo effect applies to humans humans are different there are differences between populations orange juice e.g. tomato soup Preference Scale

7 6 5 4 3 2 1 0% Population I



Population II





so, EXPECTATIONS lead to commercial EXPLOITATION which lead to ETHICS

colour in food marketing and ethics beef display in the store red light

steak aged brown beef illuminated by red light looks red is it unethical to display food to best advantage?

so let’s use contrast bright colours to market to children Bright, high colours for children

dark colours, sophisticated surface textures and design for adults

colour in food marketing changes have occurred brash, bold and high contrast rules for all marketing

such brash, bold and high contrast colours are used to attract children to adult products

high fat margarines - purple, bubblegum flavoured (Crosse & Blackwell) - hot pink and bright blue (Con Agra) high fat, high sugar ketchup - purple (Heinz) - Squirt Blastin’ Green (Heinz) high fat snacks - neon orange Cheetos (Frito-Lay)

Cadbury pushing chocolate for free sports kit. BUT, the buyer is to blame for buying it. Logical? – discuss. Ethical? – discuss.


MEASUREMENT/SPECIFICATION OF COLOUR AND APPEARANCE PROPERTIES the food industry requires: 1. measurement/specification of material properties (i.e. visual structure, colour, translucency, gloss, surface texture, change with time) 2. measurement/specification of design and expectations properties of: e.g. packaging, restaurants and stores

1. measurement/specification of material properties (i.e. visual structure, colour, translucency, gloss, surface texture, change with time) uses for all foods: monitoring






anywhere along the supply chain

sensory panel aid consumer understanding

conventional measurement methods have severe limitations calibrated digital colour measurement can be used for measurement of all appearance properties

sensory applications – two examples time lapse recording creation of colour or appearance charts

creation of colour calibrated printed charts for panel use

prototype comparative colour scale for panel use

food sensory applications colour calibrated imaging used for: • • • • • •

sample changes with time develop comparative scales for panels creation of virtual products panel on-screen scoring of products communication and archiving e.g. connecting grower and processor portable system e.g. in field, in store

Y + SS R+ SS Y+S R+ S



6 5 4 3 2 1

analysis of the eating/drinking environment combination of

existing colour impact methods semantic scaling

Paul Green-Armytage

Shigenobu Kobayashi


5a.add warm lighting

5b.add cool lighting

6.paint room warm colour

4a. add furniture - wood

3. plaster the concrete-white neutral lighting

1.a room WARM


4b. add furniture- metal


2. add room divisions concrete

using semantic scaling to understand design of eating/drinking spaces headline physical properties: size situation decoration lighting

headline expectations: intimacy elegance impact



table top quality


Effect of physical environment on the image of elegance and its significance. direction of change

change in significance elegance (%)

enclosed-in open air silent-noisy

in open air noisy

decreases decreases

5 1

dark-light illumination (uneven-even)

dark uneven

increases increases

5 5

colourfulness (low-high) colours (soft-hard)

high soft

increases increases

1 5

plain-decorated texture variation (low-high)

decorated high

increases increases

1 0.1

decoration (aged-new) clean-dirty

new dirty

increases decreases

1 0.1

tabletop (rudimentary-sophisticated)




analysis and specification of design (e.g. of restaurants and stores) is based on the principles of total appearance we interact with a scene in terms of five elements: 1. our perceptions of the physical properties of the environment (e.g. proportions, decoration, temperature) 2. the psychophysical effects of our perceptions of the physical properties (e.g. intimacy, smartness, comfort, privacy) 3. the expectations we have as individuals (e.g. safety, usefulness, satisfaction) 4. impact of the scene (e.g. in terms of warm/cool and hard/soft – impact of colours, materials, design, lighting etc can be specified separately) 5. the psychological effect on us as individuals (e.g. makes us feel happy, lonely)

In summary, the story of food colour and appearance involves: a story of vision, evolution and of our survival as humans a story of appearance, total appearance and expectations a story of halo effects and population differences a story of commercial exploitation and ethics a story of the eating environment a story that for completion and understanding requires disciplined assessment and measurement

References •

John Hutchings, Food colour and appearance, 2nd edition, Gaithersburg, MD, Aspen 1999

D B MacDougall, editor, Colour in food, improving quality, Cambridge, Woodhead Publishing 2002

John Hutchings, Expectations and the food industry - the impact of color and appearance, New York, Kluwer/Plenum Publishers 2003, hard and soft back

John Hutchings, Li-Chen Ou and M Ronnier Luo, Quantification of scene appearance - a valid design tool? Color Research and Application, 2011 forthcoming