Sensory and instrumental research · PDF fileSensory and instrumental research methods....

Department of Food Science, Sensory Science

Wender BredieDepartment of Food Science, KU-LIFE

SAAFoST – ESN lecture evening“Future directions for Sensory and Consumer Science”Pretoria, SA, 15 April 2008

Sensory and instrumental research methods


Wender Bredie, ESN, Pretoria, SA, 15 April 2008 2

Sensory evaluation

The application of analytical and affective sensory evaluation techniques ........ to correlate human reactions to foods with analytical measurements of food and food components



Classical sensory methodology

"Objective" methods "Subjective" methods Laboratory panel, focus groups Consumer panels

CONSUMER TESTAffective and cognitive testsQualitative and quantitative methods

DESCRIPTIVE TESTQUALITY TEST

DISCRIMINATIVE TEST

Does the difference have any meaning for the consumer?

What characterises the difference and how much?

Is there a difference between products?



Descriptive analysis

Texture profile

1940

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2010

Spectrum QDA

Free-Choice Profiling

Hybrid methods

Progressive profiling

Time-intensity

Flavour profile method (A.D. Little)

High time-resolved Low time-resolved

Flash profile

Various ISO standardsand national standards



Applications of descriptive analysis

Main fields of applications• Quality control• Product research and development• Calibration of sensors/instruments• Preference mapping



Sensory – Instrumental relationships

INSTRUMENT SENSORS

HUMAN SENSORS

AND SENSORY/CONSUMERPERCEPTION DATA

CHEMICAL/PHYSICALPHENOMENA AND DATA



Instrumental product analysis

• Volatile compounds• GC-MS (DHA, SPME-MS, …)• GCO

• Non-volatile compounds• HPLC-DAD; LC-MS/MS; MIMS; Electrodes• Taste dilution analysis (TDA)

• Release of volatile compounds• PTR-MS; APCI-MS; Gas sensors

• Artificial mouth systems

• Correlation to sensory perception• Descriptive analysis; Time-Intensity



Instrumental in vivo studies

• Brown, W., et al.• Taylor, A., et al.• Prinz, J., et al.• Delahunty, C., et al.• Haahr, A.-M., et al.• …



Instruments for sensory stimulation

Sense of smell – olfactometerSense of taste – gustometerSense of hearing – audiometerSense of touch – tactilometer



Instruments for sensory stimulation

Studies odour/taste perception• Intensity, pleasantness, memory, mixtures

Cross-modal interactions• Odour - taste interactions• Texture - odour/taste interactions

Adaptation / cross adaptation• Product optimisation• Structure-activity relationships

Sensory - physiological studies• EEG, EDA, heart rate, EMG, ...



Applications of descriptive analysis

Methodological aspects• Focus on immediate sensory attributes• Focus on the five senses• Standardisation of test conditions• Removal of contexts



Immediate sensory responses

Does descriptive analysis describe perceptible product quality well?



Sensory product quality

• Evaluation of composite attributes (harmony, complexity, …)

• Feelings of hunger, desires, satiety, satisfaction, ...• Evaluate more complex stimuli (meals)• Explore sensory perception in contexts/situations• Observe responses



Observational methods

Observe sensory induced behavior • Postures, gestures• Facial expressions• Movements• Social interactions

Studying• Acceptance• Choice behaviour• Preference/aversion formation• Eating behaviour



Helene Hausner, PhD-Student

To investigate early establishment of food preferences. Emphasis is on how early feeding with breast or formula milk affects childhood food preferences and acceptance of novel foods

Early predictors of food preferences



Study design

The study comprises 2 parts1. Flavour exposure via breast milk 2. Exposure to flavour during complementary feeding

days1 29 50

Preference testing

Mother consume hummus, home

Infant consume potato purée, home

Part 1 Part 2

Habitual diet, home



Observational laboratory, OBSENSE



Nutritional meals

VR1 receptorNa+

Neurotransmitters (Substance P)

Pain

DigestionGI tract

Intestinalcell Capsaicin

Absorption

Capsaicin-albumin Portalblood

Adrenalgland

catecholaminesAdrenaline, noradrenaline

Adipocyt

Liver

LipolysisGlycogenolysis

Lipolysis

Substrates

Muscles

Trigeminal stimuli

Heat

http://www.chilli.dk/side1.htm



Do spicy meals affect appetite and food intake?

Method40 subjectsFixed meal ±hot spices 9-point category scale: mood, appetite, liking, desiressour, bitter, sweet, salty, fat, hot

Results• Hot spices no effect on food intake• Food intake affected by meal type• Liking positively correlated to food intake• Desire for sweet increased by chilli; mustard decreased desire for

salty

Reinbach, H.C, (2008). PhD thesis, KU-LIFE

Meal 2: ± horseradishMeal 1: ± chilli

pepper

Meal 3: ± ginger

Meal 5: ± wasabi Meal 4: ±

mustard

1041-1042 KJ 989.7- 1040 KJ1956-1996 KJ

1986-2056 KJ1494.7 KJ

Chili Horseradish Ginger Mustard Wasabi0

100

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700

To

tal fo

od

in

take

(g

)

Meal

Men Women



Sensory evaluation in restaurants• Expectation/Surprise• Esthetics• Contexts and situations• Interior designs• Whole meal experience

• Techniques for food preparations• Food physics and chemistry

Molecular gastronomy



Future …

• Study more complex systems• Instruments for understanding perception• Sensory - physiology relationships• Dynamics in preferences and desires• Exploring situations and information• Gastronomy for health

Sensory and instrumental research · PDF fileSensory and instrumental research methods....

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