SENSORY EVALUATION TECHNIQUES

Food and Society Lesson 92011-2012

Lesson’s objective

Define the term “sensory evaluation”

Explain the processes involved in “sensory evaluation” tests

Create a sensory evaluation criteria for the selected dish of the region

Prepare a sensory evaluation checklist for the dishes of your assigned region

What is the purpose of a “sensory evaluation” ?

•Establishes the value of a commodity

•Evaluates options to select items

•Characterizes and examines the quality of food and beverages

•Used as tool in quality control , product development and research

THE CHAIN OF SENSORY PERCEPTION

STIMULUS HITS THE SENSE ORGAN AND IS CONVERTED TO A NERVE THAT

TRAVELS TO THE BRAIN

WITH PREVIOUS EXPERIENCES IN MEMORY, THE BRAIN THEN

INTERPRETS,ORGANIZES AND INTEGRATES INCOMING SENSATIONS

TO PERCEPTIONS

RESPONSE IS FORMULATES BASED ON SUBJECT’S PERCEPTION

THE PROCESS OF EVALUATION

DEFINITION OF THE

PROBLEM

TEST DESIGN

INSTRUMEN-TATION

INTERPRE-TATION

OF RESULTS

SENSORY ATTRIBUTES

Appearance Odour/Aroma/

fragrance Consistency and

Texture Flavour (aromatics,

chemical feelings and taste

APPEARANCE

Colour

Hue valueChroma of

colour

Size and Shape

Length thickness

WidthGeometric

shapeBig, small

Surface texture

Dullness or shininess

Roughness or evennessWet or dry

Soft or hardCrisp or tough

Clarity

Haze of transparent

liquid or solids

Presence or absence of

visible particles

Carbonation

Degree of effervescen

ceObserves on

pouring

ODOR AROMA FRAGRANCE

Amount of volatiles

that enters the nose

and perceived

by the olfactory organ

Aromatics are

volatiles that are

perceived by the

olfactory system from a

substance the mouth

Volatiles is affected by

the temperature and the nature of

the product

CONSISTENCY AND TEXTUREPerceived by the sensors in the mouth other than the taste and

chemical feelingsViscosity

Rate of a liquid’s flow under some

force or gravity

Consistency

UniformityStability

regularity

Texture

ThicknessRunninessMouth feel

COMPONENTS OF CONSISTENCY AND TEXTURE

Mechanical Properties Reaction to stress

Firmness and hardness force to attain given deformation

Cohesiveness degree to which sample deforms e.g.

cohesive, chewy ,stiff , viscous Adhesiveness

force required to remove substance from a given surface e.g. Sticky , gluey, messy, drag

COMPONENTS OF CONSISTENCY AND TEXTURE

Densenesscompactness of cross section e.g. Dense/heavy, airy/fluffy/light, airy/light, fullness/flimsy

Springinessrate of return to original shape e.g. springy/rubbery,springy,resilient(tensile and compression)cushy(compression)

COMPONENTS OF CONSISTENCY AND TEXTURE

Geometrical Properties-Perception of particles

Smoothness

•absence of particles

Gritty

•small, hard particles

Grainy

•small part

Chalky/powdery

•Fine particle, film

Fibrous

•Long, stringy particles

Lumpy/bumpy

•Large even particles or protrusions

COMPONENTS OF CONSISTENCY AND TEXTURE

Moisture properties-Perception of water, oil and fat

Moistness-amount of wetness, oiliness present Juicy Oily Greasy Wets down Amount of liquid fat Amount of solid fat

FLAVORSum of perceptions resulting from simulation of the sense ends that

are grouped together

The aromatics

Olfactory perceptions caused by volatile substances released from a product in the mouth via the posterior nares

The taste

Gustatory perceptions

(salty,sweet,sour,

bitter)caused by soluble

substances in the mouth

The chemical feeling factors that stimulate nerve ends in

the soft membranes of the buccal and nasal cavities (astringency ,

spice heat, cooling, bite,

mettalic flavor, umami taste)

Noise Noise produced

during the mastication of foods

Crispy Crunchy Squeak

Characteristics of Human Subjects as Instruments

Variable over time

Very variable amongst themselves

Highly prone to bias

What is the importance of using rating scales in the evaluation?

Lessens subjectivity

Gives a definite value for the criteria being

evaluated

Makes evaluation truthful and exact

RATING SCALES

Like extremely

Like very much

Like moderately

Like slightly Neither like nor dislike

Dislike slightly

Dislike Moderately

Dislike very much

Dislike extremely

HEDONIC RATING-concerned with pleasure of eating

STATISTICAL MEASUREMENT Assignment of numbers to objects

or events in a systematic fashion Four levels of measurement scales

are commonly distinguished: Nominal Ordinal Interval Ratio

NOMINAL SCALE List of categories to which

objects can be classified

Data are reflects the classification of objects into different categories Satisfied, not satisfied Good , very good Acceptable, unacceptable

ORDINAL SCALE

Assigns values to objects based on their ranking with respect to one another

For scale of 0-10 to indicate degree of acceptability in some condition, from 0 (not acceptable ) to 10 (highly acceptable )

Seatwork /Assignment

Make your criteria for sensory evaluation Refer to the characteristic of the cuisine and presentation

Assign a rating scale for the checklist

SCENARIO You school is coming up with the Culinary

Skills Competition. Being one of the officers of the HRM Club, you were task to chair the committee on the Global Cuisine Challenge- the game which aims to identify the best team to produce and present the most authentic cuisine from a selected region from Asia and the Pacific Rim to Americas and Europe. More so, you are to head the board of judges in the evaluation of the food and drink to be presented. Your club adviser told you to get ready with your evaluation tools. Since a debriefing is expected, you have to be ready to present a report on your evaluation.

Identify an appropriate rating scale with criteria and value to determine the acceptability and quality of food and drink by constructing a sensory evaluation checklist (e.g. role of the five senses, primary tastes and taste sensitivity, importance of smell, detection and perception of flavour and texture)to determine the acceptability of food and drink in a given region. Use hedonic, numeric criteria and values for your rating scale. (10.3.2)

Evaluate the inter-relationship between food and beverage and the five senses by comparing the regional food and beverage items that the contestants have prepared, taking note of the primary tastes and taste sensitivity of each dish, the importance of smell in the detection and perception of flavour and texture. (10.3.1)

Apply various sensory evaluation techniques to access the acceptability and quality of food and drink by recording and analyzing results of the evaluation checklist, assessing and interpreting sensory perceptions, and presenting results for the food and beverage items presented. (10.3.3)

Present and interpret the results of the assessment through a critique of each regional food and drink presented. (10.3.4)

Define evaluation techniques and criteria for evaluation of the food and drink experience by making reasoned judgement based on available information and coming up with recommendations for improvement for the regional food and beverage items presented. (10. 4.1)

Evaluate different food and drink experiences by justifying the nature of food and drink experience,

Justify the outcomes of the evaluation by appraising the acceptability and quality of food and drink in a chosen region. (10.4.3)

Make valid recommendations for improvement in the quality of food and drink presented. (10.4.4)

GRADING: Pass All criteria identified in the

assignments are met. Merit Must firstly achieve all conditions

for a Pass. Effective judgement has been made and

complex problems with more than one variable have been expressed (M1)

Relevant theories and techniques have been applied and a range of sources of information has been used (M2)

The appropriate structure and approach has been used and there is a coherent, logical development of principles/concepts for the intended audience (M3)

GRADING: Must firstly achieve all conditions for a

Merit.

The validity of results has been evaluated using defined criteria. ( D1)

Substantial activities, projects or investigations have been planned, managed and organized and activities have been managed ( D2)

Convergent and lateral thinking have been applied. ( D3)

SUBMISSION DATE

12TH WEEK1ST 2.5 HOURS CHECKING

FINAL SUBMISSION 1800 HRS

SAMPLE EVALUATION CHECKLIST DESSERT

CREPE SUZETTE

CRITERIA 1Unaccept-

able

2Needs

improve-ment

3acceptable

4Very

accept-able

5Excellent quality

APPEARANCE

Crepe should be brown toffee color

Crepe should be thin and folded

Zest of orange should be visible