1. Sensory Testing/Evaluation
Sensory evaluation is a scientific discipline that analyses and measures human responses to the composition of food and drink, e.g. appearance, touch, odour, texture, temperature and taste
Can be used in design process to:
compare similarities/differences in a range of dishes/products
evaluate a range of existing dishes/food products
analyse food samples for improvements
gauge responses to a dish/product, e.g. acceptable v unacceptable
explore specific characteristics of an ingredient or dish/food product
check whether a final dish/food product meets its original specification
provide objective and subjective feedback data to enable informed decisions to be made

2. Sensory Evaluation/Testing
How To Perform Sensory Evaluation
1. Decide on the type of test you want to perform.
Preference test - asks whether people like or dislike a product, e.g. hedonic scale
Discrimination test - asks people to describe a particular attribute of a product, e.g. paired comparison test.
2. Find a clear area to hold the sensory test.  Try to make sure that it is away from noise and cooking smells which may distract the people taking part in the test.
3. Place as many samples in serving containers as there are people taking part in the test. Code each sample with a random number, letter or symbol.
4. Check that you have enough glasses of water for the people taking part.
5. Make sure the people taking part know what is expected from them.
6. Ask each person to taste one sample at a time, and record their responses. Allow time between samples so that tasters can record their opinions.
A typical tasting kit could contain:
serving spoons
teaspoons
small, plain white pots, cups and plates
paper towel
rubbish bags
cutlery
labels
pens

3. Types of tests Tests Hedonic Scoring Paired comparison (preference)
There is a set of standard tests which can be used by industry.  These are laid down by British Standard (BS5929).
Preference Tests - these supply information about people's likes and dislikes of a product. They are not intended to evaluate specific characteristics, such as crunchiness or smoothness.  They are subjective tests and include pair comparison, hedonic and scoring.
Discrimination Tests - these aim to evaluate specific attributes, i.e. characteristics of products (crunchiness).  They are objective tests and include pair comparison, duo trio and triangle
Tests
Hedonic
Scoring
Paired comparison (preference)
Paired comparison (discrimination)
Triangle
Duo-trio
Ranking
Star diagram/chart

4. Hedonic
1. Prepare the food samples. 2. Ask each taster to taste each sample in turn and tick a box, from '1 Dislike Very Much' to '5. Like Very Much‘ to indicate their preference. This is a 5-point-scale. Sometime a 9-point-scale is used. 3. The taster may also wish to make remarks about the products’ appearance, taste, odour and texture. 4. Analyse the results. Which sample received the highest/lowest scores? Which sample was preferred?

5. Paired comparison (preference)
1. Prepare two samples of the dish you wish to test.
2. Ask each taster which dish they prefer.
3. Record the response from the tasters.

6. Scoring
1. Food samples are scored on a scale, between dislike and like.
2. Allow tasters to evaluate samples and score (place in order of
preference).
3. Record their responses.

7. Triangular 1. Prepare three food samples, two of which are the same.
2. Arrange the samples in a triangle.
3. Ask the tasters to decide which of the samples is the odd one out.
4. Record the responses from the tasters.

8. Duo-Trio 1. Prepare three food samples, two of which are the same.
2. Using one of the two identical samples as a control, as the tasters
to decide which of the other two remaining samples is the same
as the control.
3. Record the tasters’ responses.

9. Ranking 1. Decide on the attribute to be ranked, e.g. crunchiness.
2. Allow tasters to evaluate samples and place them in rank order
according to the presence or absence of the attribute from ‘very’ to
‘not at all’.
3. Record the responses.

10. Paired comparison (discrimination)
1. Prepare two different samples of the food product you wish to test. 2. Compare one attribute, e.g. which one is smoother? 3. Record the response from the tasters.

11. Star charts/diagrams
This type of test allows the intensity of the sensory attributes of a single food dish, or range of food dishes, to be recorded. The test is not intended to model general attributes such as 'nutrition', 'cost' or 'appearance', as they are more complex and are better dealt with in other ways. 1. Choose 8 attributes that describe the characteristics of the product, e.g. crunchy, spicy, savoury or smooth. 2. Taste the food sample. Decide on the intensity for each attribute, using a scale from 0 to 10 (the higher the number, the greater the intensity). 3. Use the information to draw a star chart/diagram of the product's attributes. Note: Multiple products can be overlaid on the same chart, indicating sensory differences/similarities. Although the worksheet or template can be used to compare 1-5 dishes/products, they can also be used to gather information from 1 or more tasters about the same product.

12. The senses and food
© British Nutrition Foundation 2010

13. Which senses do we use? A range of senses are used when eating food.
These senses are:
sight;
smell;
hearing;
taste;
touch.
A combination of these senses enables you to evaluate a food.
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14. Appearance
The size, shape, colour, temperature and surface texture all play an important part in helping to determine your first reaction to a food.
Often if a food does not look appetising, then you will not eat it.
Appearance is therefore vitally important if you want your food to be eaten and enjoyed.
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15. Appearance Useful words to describe appearance: stringy firm dry
heavy flaky crumbly
flat crisp lumpy
fizzy fluffy smooth
crystalline hard mushy
cuboid sticky fragile
dull
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16. ? Appearance What words would you use to describe these foods?
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17. Odour
The nose detects volatile aromas released from food. An odour may be described by association with a particular food, e.g. herby, cheesy, fishy. The intensity can also be recorded.
Odour and taste work together to produce flavour. This is the reason why people with a blocked nose find it difficult to determine the flavours of foods.
© British Nutrition Foundation 2010

18. Odour Useful words to describe odour: aromatic pungent spicy
floral bland tainted
perfumed rancid savoury
rotten tart citrus
acrid strong mild
musty weak scented
fragrant
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19. ? Odour What words would you use to describe these foods?
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20. Sound
The sounds of food being prepared, cooked, served and eaten all help to influence our preferences.
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21. ? Sound What words would you use to describe these foods?
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22. Taste The tongue can detect five basic tastes: bitter; salt; sour;
sweet;
umami.
Taste may be described by association with a particular food, e.g. meaty, minty or fruity.
The intensity can also be recorded, e.g. mild or strong Cheddar.
© British Nutrition Foundation 2010

23. What is umami?
Umami is a savoury taste, often known as the fifth taste. It is a subtle taste and blends well with other tastes. Most people do not recognise the taste unless attention is especially drawn towards it.
After eating Cheddar cheese or tomatoes, there may be a ‘savoury’ taste lingering - this is umami.
Have you tasted umami?
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24. How was it discovered?
Umami was discovered by Dr Kikunae Ikeda, from Tokyo Imperial University, Japan, in 1908.
He undertook research into Dashi, a traditional Japanese stock made from kombu (kelp). His research lead to describing the savoury taste as ‘umami’.
He was sure that this taste was held in common by other foods with a savoury flavour, including those used in Western meals such as tomatoes and meat. Upon investigation it was discovered that these foods also had ‘umami’.
Dr Kikunae Ikeda
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25. What is dashi?
Dashi is a traditional stock used in Japanese cooking. It has been used for over 1,000 years.
Dashi is made from dried kombu (kelp), katsuobushi (dried bonito – fish) or dried shiitake mushrooms.
Dashi means ‘boiled extract’.
Dried kombu
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26. How is dashi made?
Japanese stock, dashi, is the key element of the authentic Japanese cuisine. The recipe is simple and quick!
Ingredients
4cm x 4cm dried kombu (kelp) 600ml water 8g bonito flakes
Method
1. Make a few slits in the kombu and cook it in the water on a medium heat.
2. Remove the kelp just before it boils and add the bonito flakes.
3. Bring to the boil and strain.
kombu
bonito flakes
Kombu dashi, made without the bonito flakes, is vegetarian.
Vegetarian dashi can be made by soaking 2-3 dried shiitake mushrooms in 600ml for 1 hour. Drain and use.
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27. Umami in Japanese cuisine
Japanese miso soup
Clear Japanese soup with shrimp
Nishime
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28. Umami in Japanese cuisine
Spinach in dashi sauce
Thinly sliced beef, potato and vegetable stew
Savoury egg custard
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29. Umami in Japanese cuisine
Here are four traditional Japanese foods which have an umami taste.
Sea Vegetables – Wakame and Nori
Fresh tuna
Shittake mushroom
Bonito
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30. Umami around the world
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31. Familiar foods with a umami taste
These are foods which all have an umami taste:
tomatoes;
cured pork, e.g. ham, sausage, bacon;
Cheddar cheese;
Parmesan;
meat, e.g. beef;
anchovies;
yeast extract.
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32. Cooking and umami
Several chefs around the world feature the umami taste in their cooking.
In the UK, Heston Blumenthal uses umami-rich Japanese ingredients in Western style preparation in order to deliver a umami hit. Other chefs include Claude Bosi and Sat Bains.
However, the umami taste can be delivered using familiar foods, such as yeast extract, Parmensan cheese, ketchup and tomatoes.
A umami-rich food is pizza – featuring tomatoes, Parmensan cheese and anchovies.
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33. Taste Useful words to describe taste: sweet cool bitter umami
zesty warm hot tangy
sour sharp rich salty
bland rancid tart acidic
strong citrus mild savoury
spicy tainted weak
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34. ? Taste What words would you use to describe these foods?
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35. Texture Texture can be assessed through touch.
When food is placed in the mouth, the surface of the tongue and other sensitive skin reacts to the feel of the surface of the food. The sensation is also known as mouth-feel.
Different sensations are felt as the food is chewed. The resistance to chewing also affects texture, e.g. chewiness, springiness.
The viscosity is also a factor, e.g. runny, thick.
The mouth also detects temperature, which plays an important stimulus, e.g. cold icecream, warm bread, hot soup.
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36. Texture Useful words to describe texture: brittle rubbery short gritty
clammy close stodgy bubbly
sandy tacky tender waxy
open soft firm flaky
crisp fluffy dry crumbly
lumpy smooth hard mushy
sticky chalky grainy fibrous
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37. ? Texture What words would you use to describe these foods?
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38. Other factors
Although the senses play an important role in determining our food preferences, and helping us to evaluate food, other factors are also involved.
These include:
previous experiences with food;
hunger and satiety;
mood;
where you eat, e.g. home, canteen, picnic;
beliefs and values, e.g. religion, culture and tradition.
social aspects, e.g. special occasions, events.
© British Nutrition Foundation 2010

39. Using your senses The senses help to:
develop personal food preferences (likes/dislikes);
evaluate foods, either through preference or discrimination tests.
© British Nutrition Foundation 2010