chemosensory perception we taste what we smell? taylor.pdf · 2017-05-24 · •triangle test...

UCD Institute of Food & Health1

Chemosensory perceptionWe taste what we smell?

Andy Taylor

Flavometrix Limited

Loughborough, UK

May 17 2017

Title is a generalisation!

UCD Institute of Food & Health 2

Difficult to differentiate apple and

onion when wearing noseclips

Key differentiator is mouthfeel

due to different particle size

Odour of cheese changes

significantly when in mouth

May 17 2017


Definition of flavour

Sound

Appearance

& colour

Taste

Smell

Mouthfeel

Texture

May 17 2017


How are the senses stimulated?

Tasty

Ortho and

retronasal

aroma routes

Taste buds on

tongue

May 17 2017


How can we measure flavour stimuli?

• Sensory is the ultimate test for acceptability

• Instrumental gives qualitative and quantitative data but not sensory impact

May 17 2017

Sensory-instrumental


Productperceptualdifferences

Quantitative data

Identifycomponents

causing change

Sensory

attributes

attributes

Instrumental

Detailed composition

Individual components

Sensory + Instrumental

May 17 2017


Measuring the flavour profile that reaches the receptors during eating

Aroma release during eating APCI-MS & PTR-MS

Tastant release during eating;

sample in mouth; off-line MS

May 17 2017


Does in-nose measurement

correlate with perception?

15.20 15.40 15.60 15.80 16.00 16.20 16.40 16.60 16.80Time0

100

%

TTR34 Unused

ANALOG

8.10e5

Height

Black line

Time-intensity sensory

perception

Red and pink

Breath by breath

aroma release

May 17 2017


Applications of science approach to real foods

May 17 2017


Effect of fat content on aroma release during eating in yogurt

0

100000

200000

300000

400000

500000

600000

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6

Time (min)

Inte

nsit

y

0% Fat

3.5% Fat

10% Fat

Each yogurt contains the

same amount of

flavour

May 17 2017


Shape of aroma release with different fat contents

0.0

20.0

40.0

60.0

80.0

100.0

120.0

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6

Time (min)

% Im

ax

0% Fat

3.5% Fat

10% Fat

Zero fat

May 17 2017


Sensory data on yogurts

• Triangle test analysis (30 panellists)

Test Assessors Perceiving Difference

Significance Positively

Sure of Choice

Unsure Of Choice

Fat free vs

Higher fat 22 < 0.0001 20 2

Fat free + -CD vs

Higher fat

15 0.0435 8 7

May 17 2017


Fat and flavoured milk

Fat content of milk• Changes partition of aromas

– Amount and rate of aroma release affected

• Changes viscosity of product• Changes mouthfeel of food• Which stimuli are significant?• Hypothesis: aroma signal most important

so if reformulation gives same aroma stimuli, perceived flavour is the same

May 17 2017


Aroma release in regular & low fat flavoured milks – same aroma content

0 4 8 12

Lipid Effect

0

25

50

75

100

Fre

qu

ency

a

-0.5 0.0 0.5 1.0 1.5

Log Lipid Effect

0

15

30

Fre

quen

cy

b

0 4 8 12

Lipid Effect

0

25

50

75

100

Fre

qu

ency

a

-0.5 0.0 0.5 1.0 1.5

Log Lipid Effect

0

15

30

Fre

quen

cy

b

Result

Most values above 0 so greater release from low

fat milks (expected)

Can calculate mean release

18 instances of log LE less than 0 were

random

May 17 2017

90 panellists

duplicate samples


Aroma release in regular & low fat flavoured milks – adjusted aroma content

-0.50 0.00 0.50

Log Lipid Effect

0

15

30

45

Fre

qu

en

cy

Result

Mean value for log LE lies at 0 – no

statistical difference in aroma release when

aroma content adjusted

May 17 2017

Shojaei et al., 2006, IJFST 41, 1192


Sensory testing – statistics

Replicate

Number

Number of

panelists

LF>RF a Significant

b

1 98 80 <0.0001

2 98 80 <0.0001

3 98 88 <0.0001

4 98 85 <0.0001

1

Replicate

Number

Number of

panelists

LF>RF

a

Significant

b

1 90 41 NS c

2 90 51 NS

3 90 44 NS

4 90 43 NS

1

Same aroma content Adjusted aroma content

Forced choice difference test, LF>RF means low fat rated as higher aroma intensity than regular fat; significance by t-test;

panelists who got it wrong were randomMay 17 2017

STUDYING TASTE-AROMA INTERACTIONS

UCD Institute of Food & Health 17May 17 2017


Chewing gum dragees: Aroma and sugar release & sensory TI

0

50

100

150

200

250

300

0 1 2 3 4 5 6

Time (min)

Inte

ns

ity

Aroma TR

Sugar

In - Mouth

Sensory TI

May 17 2017


Stick chewing gum: Aroma and sugar release & sensory TI

0

100

200

300

400

500

600

700

800

0 1 2 3 4 5 6

Time (min)

Inte

nsit

y

Aroma TR

Sensory TI

Sugar

In - Mouth

May 17 2017

Commercial applications


Taste Tech

Prolonging gum flavor

Advert April 2017

Stride gum

“Ridiculously long lasting flavor”

Cadbury Adams

2006

May 17 2017

Other interactions


ViscosityAffects taste release rather than aroma

release

EthanolComplex interactions with interfacial

layer, partition and proteins

Acid/sugar/fruit aroma

Contour plots indicate ratios of sugar

and acid that give equal flavour with

fixed aroma content

May 17 2017

BRAIN IMAGINGMEASURING INTERACTIONS AT THE COGNITIVE LEVEL

UCD Institute of Food & Health 22May 17 2017

Set-up of subjects and scanner

May 17 2017 UCD Institute of Food & Health 23

Aroma delivery during fMRI paradigm


APcI-MS

Aroma delivery

Delivery system

Interface

Time courses at 2 different voxels


-0.2

0

0.2

0.4

0.6

0 5 10 15 20

Time (s)

% s

ignal c

hange

Right anterior insula (taste)Left superior insula (aroma)

fMRI results


Cortical activation n=11

taste+aroma > unimodal aroma + unimodal taste

Future?


Current view of flavourHedonics

Developing view of flavour

Mouth to brain to gut to metabolism

May 17 2017


Acknowledgements

Flavometrix -University of NottinghamZahra Shojaei, Rob Linforth, Avinash Kant, Jim Davidson, Joanne Hort, David Cook, Tracey Hollowood, Michael Brauss, Jamie Langridge

Flavometrix works in partnership with Nichirei Corporation, Japan to solve commercial flavour problems

[email protected]

May 17 2017

mailto:[email protected]

chemosensory perception we taste what we smell? taylor.pdf · 2017-05-24 · •triangle test...

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