Lecture 6 - Sensory Evaluation

Question 1

What is sensory evaluation?

Answer 1

• Assessment of all qualities of a food item as perceived by the human senses (5 basic senses)
• Human senses includes:
• Physical:
○ Sight – colour, size, shape, texture etc. (green bananas: probably not ripe yet - sour)
○ Feel – texture, mouthfeel, warm cold, pain, etc.
○ Hearing – e.g. sound made by chewing or breaking the food before it goes in the mouth; fizzing of carbonated drinks
• Chemical:
○ Taste – sweet, sour, salty, bitter etc.
○ Smell - odour

Question 2

Steps of Sensory Evaluation

Answer 2

Sensory evaluation is a scientific method: (must be quantified into numbers for analysis)
	• Identification of the issue.
	• Statement of hypothesis.
	• Experimental design.
	• Data collection and analysis.
	• Conclusion.

Question 3

What are character notes?

Answer 3

Sensory attributes that describe the character of a food. (unique flavour that makes the food what it is )

It includes: Appearance and Flavour (Taste/Aroma/Texture)

Question 4

Food colourants

Answer 4

Dyes: Water soluble
Lakes: Insoluble

In emulsion: if colour is added to the dispersed phase (colour will not be observed)

If colour is added to the continuous phase (colour will be observed)

Question 5

Is denatured protein still contain its nutritional value?

Answer 5

shape of the protein is altered

Can still benefit from the protein if the amino acid residue is not destroyed from the denaturation process

Question 6

What is flavour?

Answer 6

Taste and Aroma

Question 7

What is taste?

Answer 7

A chemical sense produced by tastants detected by taste buds on the tongue

Question 8

What is mouthfeel?

Answer 8

• Perceived by the epithelial lining of the oral cavity.

* Includes tactile sensation and thermal response/temperature

Question 9

What is hardness?

Answer 9

amount of force required to compress the food between teeth.

Question 10

What is cohesiveness?

Answer 10

degree to which food will deform or compress between the teeth before it breaks.

Question 11

What is sensory viscosity?

Answer 11

force required to draw a fluid food from a spoon across the tongue at steady rate.

Question 12

What is chewiness?

Answer 12

length of time in seconds required to chew a food sample at a steady rate (one chew per second) with constant force

Question 13

What is springiness?

Answer 13

ability of the food to return to its original shape after being compressed

Question 14

What is the detection threshold?

Answer 14

concentration of stimulant at the point it is detected.

Question 15

What is the recognition threshold?

Answer 15

concentration of stimulant at the point it is recognized.

Question 16

What is the difference threshold?

Answer 16

change in concentration of stimulant at the point a different level of stimulus is perceived

Question 17

What is the terminal threshold?

Answer 17

maximum amount of stimulant that consumers can detect. Any increase in intensity cannot be detected without the use of reference standards.

Question 18

What is the triangle test?

Answer 18

Which one is different out of three items. (whether panellists are able to consistently identify the product that is different)

Question 19

What is the difference from control test?

Answer 19

Panellists are given two samples, control and sample, to rate the level of difference.

Question 20

What is the duo-trio test?

Answer 20

Panelists are asked to identify which sample is the same as the control out of three samples (2 controls and 1 sample)

Question 21

Quantitative descriptive analysis

Answer 21

Spiderweb plot