Midterm 1.7 Sensory Evaluation Part 1

Question 1

Sensory evaluation definition

Answer 1

Scientific discipline used to evoke, measure, analyze and interpret responses or reactions to products as perceived via 5 senses

Not just for food products but cosmetics, clothing…etc

Question 2

To evoke
Strategies

Answer 2

Minimize biasing factors through specific preparation and serving of samples

1) individual booths
2) random labelling
3) define orders to participants
4) standardize temp, volume and spacing in time

Question 3

To measure

Answer 3

Quantitative science where numerical data is collected to establish relationships between product characteristics and human perception

Concerned with accuracy/validity, sensitivity, precision and avoiding false-positives

Screen and trained panelists

Question 4

To analyze

Answer 4

Some variation cannot be controlled (mood, motivation, past history, familiarity)

Good experimental design and stat analysis are necessary for drawing sensible and real conclusions

Question 5

To interpret
Factors

Answer 5

Data only useful when interpreted in context of hypotheses, background and implications for decisions/actions to be taken

Limitations of procedure, risks, liabilities, contextual framework, appropriate interpretation of results, reasonable course of action

Question 6

Historical triggers of sensory eval

Answer 6

1950’s food acceptance for US army

War on Hunger and Food from the Sea programs in 1970’s

Industrial revolution and competition

Question 7

Why do sensory evaluation

Answer 7

Chain of perception, multi-sensory experience cannot be measured by a machine

Development, risk reduction, competition, improvements, quality testing

Question 8

Human senses involved in sensory evaluation (7)

Answer 8

Vision - visual
Olfaction - sound
Audition - sound
Gustation - taste
Tactile - touch
Chemesthesis - chemical response such as drying
Kinesthetic - bounce back, ∆ body movement

Question 9

Taste qualities

Answer 9

Sweet, salty, sour, bitter, umami, astringent, metallic taste

Question 10

Compounds associated with bitter taste

Answer 10

phenylthiocarbamide 6-n-propyl-2-thiouracil
Some people can’t taste bitter

Question 11

Circumvallate papillae

Answer 11

outer grooves of tongue (100s of buds per groove) posterior portion of tongue

Question 12

Fungiform papillae

Answer 12

anterior portion of tongue
10 buds per papillae

Question 13

Filiform papillae

Answer 13

No taste buds
Provide mechanical resistance to hold food in mouth longer

Question 14

Foliate papillae

Answer 14

parallel grooves on outside of tongue
10 taste buds per groove

Question 15

Ion channel tastes

Answer 15

salt and sour use ion channel mechanism

Na entering taste receptor cells triggers cell membrane potential

Sour receptors respond to protons entering cell, and stimulates ion channels to open
- Acid Sensitive Ion Channels (ASIC)
- Potassium conductance channel

Question 16

GPCR taste receptors

Answer 16

T1R - umami and sweet
T2R - bitter taste

Question 17

Adaptation

Answer 17

decrease in responsiveness under conditions of constant stimulation

Question 18

Mixture inhibition

Mixture suppression

Answer 18

Inhibition: mixture of different tastes can partially inhibit or mask interactions
Ex. Inhibition of sour with sweet in wine (creates balance)

Suppression: one or more component reduces impact
ex. suppression of bitter quinine taste with aspartame, sucrose doesn’t have this effect

Question 19

Most important area of sensory testing environment

Answer 19

Booth area more important than waiting room or orientation area

Taste perception is dependent on environment (keep it professional, neutral and organized)

Question 20

Test protocol considerations

Answer 20

sample serving, size, temp
containers, carriers (edible or not)
palate cleansing
swallow/expectoration
panelist instructions
randomization and blind labelling