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

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

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

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?

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.

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.

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.

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.

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.

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.

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.

The senses and food © British Nutrition Foundation 2010

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. © British Nutrition Foundation 2010

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. © British Nutrition Foundation 2010

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 © British Nutrition Foundation 2010

? Appearance What words would you use to describe these foods? © British Nutrition Foundation 2010

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

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 © British Nutrition Foundation 2010

? Odour What words would you use to describe these foods? © British Nutrition Foundation 2010

Sound The sounds of food being prepared, cooked, served and eaten all help to influence our preferences. © British Nutrition Foundation 2010

? Sound What words would you use to describe these foods? © British Nutrition Foundation 2010

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

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? © British Nutrition Foundation 2010

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 © British Nutrition Foundation 2010

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 © British Nutrition Foundation 2010

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. © British Nutrition Foundation 2010

Umami in Japanese cuisine Japanese miso soup Clear Japanese soup with shrimp Nishime © British Nutrition Foundation 2010

Umami in Japanese cuisine Spinach in dashi sauce Thinly sliced beef, potato and vegetable stew Savoury egg custard © British Nutrition Foundation 2010

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 © British Nutrition Foundation 2010

Umami around the world © British Nutrition Foundation 2010

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. © British Nutrition Foundation 2010

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. © British Nutrition Foundation 2010

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 © British Nutrition Foundation 2010

? Taste What words would you use to describe these foods? © British Nutrition Foundation 2010

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. © British Nutrition Foundation 2010

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 © British Nutrition Foundation 2010

? Texture What words would you use to describe these foods? © British Nutrition Foundation 2010

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

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