The senses and sensory evaluation

Question 0

When can sensory evaluation be used?

Answer 0

Can apply to fragrance, nappy, deodorant and car industry.

Question 1

What is the definition of sensory science?

Answer 1

Scientific discipline used to evoke, measure, analyse and interpret reactions to those characteristics of foods and materials as they are perceived by the senses of sight, smell, taste, touch and hearing.

Question 2

What are our sensors.?

Answer 2

• eyes, ears, tongue and nose
  1. First you see it
  2. Then you smell if it is quite volatile
  3. Then you consume it
• this is carried by nerves to the brain (a split second) and then you recognise what it is.
• you normally make a second decision whether you like/dislike

Question 3

What are the general categories of sensory evaluation?

Answer 3

Objective and subjective

Question 4

What is objective sensory evaluation?

Answer 4

• measures the attributes of the food
• you need someone who is sensitive to those attributes therefore, use selected assessors because everyone has different sensitivity levels.
• when selecting sensitive people, you get about 10/100 people to do the best job

Question 5

What is subjective sensory evaluations?

Answer 5

• measures consumer acceptance and preference, need to know whether they like it or not
• measuring the person rather than the product, if we are doing that then we are trying to represent the population
• usually consists of a big panel

Question 6

When eating what two experiences occur?

Answer 6

• determine the attributes (sweet or not)

- whether we like or dislike

Question 7

What is the process of eating something, what receptors are used?

Answer 7

• vision: appearance (identify colour, translucency and gloss)
• Gustafson: taste receptors on tongue (sweet, bitter, acid, salt, umami)
• olfaction: smell (LMW molecules are volatile)
• somesthesis: what do you feel? Surface structure. Muscles in face feedback to the brain about how much effort it’s putting in which detects how hard/soft food is.
• kinaesthesis: internal structure. How much effort you’ve got to add to pull food apart.
• audition: what do you hear?
• nociception: perception of pain
• thermoception: determines the temperature of the food, there are also chemical compounds that can stimulate the temperature receptors.

All those sensations together are what we call texture perception.

Question 8

Do people differ in sensitivity to the same compounds?

Answer 8

Yes

Question 9

Why do people vary in their sensitivity?

Answer 9

• being able to detect, recognise, notice differences and terminal threshold
• everyone has a detection threshold but is very individual to you

Question 10

What is detection threshold?

Answer 10

Lowest stimulus capable of producing a sensation

Question 11

What is recognition threshold?

Answer 11

Level of stimulus at which it can be recognised and identified e.g. Can recognise whether it is bitter / sweet

Question 12

What is just noticeable difference?

Answer 12

Extent of change in stimulus necessary to produce a noticeable difference

Question 13

What is terminal threshold?

Answer 13

Level of stimulus above which there is no increase in perceived intensity