Topic 2 (Sensory properties) Flashcards
The senses (organoleptic properties)
Sensory systems
Preferential and sensory testing panels
Changes that happen when food is cooked: texture, appearance, colour taste, sound and aroma
The importance of the senses of sight, taste, touch, smell and hearing and
how they work when making food choices
The five basic tastes recognised by receptors (sweetness, sourness, bitterness, saltiness and umami)
How to set up a testing panel
Styles and forms of rating, ranking and profiling systems with the use of appropriate descriptive terminology
What are the senses (organoleptic properties)?
- Sight
- Smell
- Sound
- Touch
- Taste
How does sight affect the food?
- The appearance (aesthetics/aesthetic qualities) of food can make it look more or less appetising. Aspects such as colour, size, shape, age, garnish and decoration will all affect how you feel about the product.
- When you cook food the method of cooking affects what it looks like (e.g. when frying, foods become golden brown, e.g. samosa; when steaming foods retain their colour, e.g. steamed vegetables).
- The size of some foods changes (e.g. cakes rise, meat and fish shrink). With age the appearance will change (e.g. red meat becomes darker, as fruit ripens it changes colour).
How does sound affect the food?
- Some food products make sounds during preparation, cooking, serving or eating.
- For example, the crackle of popcorn, the sizzle of bacon when cooking, the crunch of crisps and raw carrot when eating.
How does smell affect the food?
- You can detect volatile aromas released from foods. The aroma can stimulate the digestive juices and make the food seem more appetising.
- Some aromas are pleasant (e.g. the spiciness in a curry, bread or cakes cooking). Others are unpleasant (e.g. the burning of fat, toast burning or the cooking of sprouts).
How does taste affect the food?
- Taste buds detect four groups of flavours: bitter, sweet, sour and salt.
- Umami is often known as the fifth taste; it is a savoury taste.
- Flavour develops when the food is combined through chewing and mixing with saliva.
- The ingredients we use will allow us to detect these flavours, for example:
- sour - lemons
- sweet - sugars in recipes
- bitter - chicory and cardamom
- salt - the way we add this to recipes.
How does touch affect the food?
- The surface of the tongue is sensitive to different sensations, such as moist, dry, soft, sticky, gritty, crumbly, mushy. As we bite and chew food we can feel how hard or soft it is through our teeth and jaw. These qualities are known as ‘mouth feel’; if they are missing, food is considered to be unpalatable.
- The method of cooking combined with the working characteristics of ingredients will affect the different sensations we feel, for example potatoes will be soft if they are boiled, but have a crunchy outer if they are roasted.
How do you set up a testing panel?
It is important to use correct procedures when setting up and carrying out sensory analysis testing:
- Set up a quiet area where people will not be disturbed (do not allow testers to communicate with each other).
- Give the testers a drink of lemon-flavoured water or a piece of apple to clear the palate.
- Use small quantities of food on plain and identically sized plates/dishes
- Use same garnish or decoration.
- Try not to give too many samples at once. - Serve at the correct temperature for the product that is being tested.
- Use clean spoons or forks each time. Do NOT allow people to put dirty spoons into your dish.
- Use codes for the products to prevent the testers being influenced by the name of the product (this is known as testing blind. Do not use potentialy blased ordering such as numerical or grade ordering.
- Have any charts ready before you begin testing.
- Make sure the testers know how to fill in the charts you are using
What are the food-tasting tests?
- Ratings test
- Difference or comparison testing
(- Triangle test) - Ranking test
- Profiling tests
(- Star profile)
What do we use Food-tasting tests for?
- To evaluate product acceptability by finding out the opinions, likes and dislikes of the consumer.
What are rating tests?
- Testers give their opinion of one or more samples of food, from ‘extreme like to ‘extreme dislike’. They do not give information about specific elements of a food product
What is difference and comparison testing?
These tests are used to see whether people can tell the difference between samples, for example when:
- an ingredient or quantity of ingredient is changed
- manufacturers are copying another brand, such as brands of cheese and onion crisps or a veggie burger and a beefburger
What is an example of comparison testing?
Triangle test
- Three samples are given to the tester. Two samples are the same and the tester is asked to identify the ‘odd one out’. This test is useful if you have made small changes to a product, for instance made a curry lower in fat or used more economical ingredients (e.g. changing from using chicken breast to chicken thighs).
What is a ranking test?
- A ranking test is used to sort a variety of foods into order, for example different-flavoured crisps made by one manufacturer. A set of coded samples is presented to the tester. The tester has to rank the samples in order of either.
- a specific attribute (for example, sweetness, saltiness)
- a preference on a hedonic (enjoyment) scale or ranking.
What are profiling tests?
- Profiling tests can be used to find out what people particularly like about a food product, to help build up a profile according to a range of sensory qualities, such as saltiness, smoothness, crispness, flavour. Testers are asked to give a score out of five (where one is the least and five is the best). The scores for each quality are totalled and divided by the number of testers. This will give average scores.
What is an example of a Profiling test?
Star profile
- This type of analysis asks testers to describe the appearance, taste and texture of a food product on a star chart. When the food is tasted, the taster assesses the identified areas and marks the star diagram as required. The marks on each point are joined together to identify them clearly.
