Food, Expectations, Colour and Appearance

John Hutchings

Department of Colour ScienceUniversity of Leeds, UK

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

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 pressureX

poisonous food colour

paints textiles plasticsfoods

why are foods different?

man made pigments are closely controlled

in natural foods light absorbers and scatterers have:

evolved with climate

coevolved with vision

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

our natural foods have also coevolved with insect and animal vision

insect vision

300 400 500 600 700nmanimal vision

human 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 dependencex x

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 andscatterers

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 arising from sensory input:

visually assessed safetyvisually assessed identificationvisually assessed usefulness visually assessed pleasantnessvisually assessed satisfaction

EXPECTATIONS – two types:

based on belief

based on our senses

appearance driven expectations control our responses:

along the whole supply chain from field to kitchen

the plate of food

the store façade

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

60mm

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

e.g. tomato soup

orange juice

1

2

3

4

5

6

7

0% 20% 40% 60% 80% 100%

Concentration

Pref

eren

ce S

cale

Population I Population II

so, EXPECTATIONS

lead to commercial EXPLOITATION

which lead to ETHICS

aged brown beef illuminated by red light looks red

is it unethical to display food to best advantage?

red light

steak

beef display in the store

colour in food marketing and ethics

Bright, high contrast colours for childrenso let’s use bright colours to market to 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)

Logical? – discuss.

Ethical? – discuss.

Cadbury pushing chocolate for free sports kit.

BUT, the buyer is to blame for buying it.

MEASUREMENT AND SPECIFICATION

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 )

specification )

communication )

sensory panel aid

consumer understanding

anywhere along the supply chain

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 applicationscolour 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

RY

R+ SY + S

R+ SSY + SS

6

34

5

1

2

analysis of the eating/drinking environment

combination of existing colour impact methods

semantic scaling

Paul Green-Armytage

Shigenobu

Kobayashi

SOFT

HARD

WARM COOL

1.a room

2. add room divisions -concrete

3. plaster the concrete-whiteneutral lighting

4a. add furniture - wood

5a.add warm

lighting 5b.add cool lighting6.paint room

warm colour

4b. add furniture- metal

size

situation

decoration

lighting

colour

table top quality

design of eating/drinking spaces

headline physical properties:

headline expectations:

intimacy

elegance

impact

comfort

satisfaction

using semantic scaling to understand

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

direction change in significanceof change elegance (%)

enclosed-in open air in open air decreases 5silent-noisy noisy decreases 1

dark-light dark increases 5illumination (uneven-even) uneven increases 5

colourfulness (low-high) high increases 1colours (soft-hard) soft increases 5

plain-decorated decorated increases 1texture variation (low-high) high increases 0.1

decoration (aged-new) new increases 1clean-dirty dirty decreases 0.1

tabletop (rudimentary-sophisticated) sophisticated increases 1

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