Instrumental Detection of Boar Taint: Advantages and ... · friendly production, in particular on alternatives to the castration of pigs and on alternatives to the dehorning of cattle”

Instrumental Detection of Boar Taint:Advantages and Disadvantages of the Existing

Methods

Professor Olena Doran University of the West of England, Bristol, UK

TRAINING SCHOOLSensory evaluation of boar taint: Methods for assessor selection, good sensory practice

and performance evaluation

Boar Taint

An offensive odour in the meat of

5-10% of uncastrated male pigs

Is mainly due to excessive

accumulation of skatole and

androstenone in pig adipose

tissue

Threshold levels differ between countries Skatole: 0.20-0.25 µg/g of fat

Androstenone: 0.5 - 1.0 µg/g of fat

EU position

EU Directive on castration without anesthesia

during the first week of life (2001/93/EC)

Plan to voluntarily end surgical castration

(EU SANCO, 2010)

European Partnership on Alternatives to

Surgical Castration of Pigs Established

(hedhttp://ec.europa.eu/food/animal/welfar)

Potential solutions

• Alternatives to surgical castration to

prevent boar taint

• Technologies for rapid detection

of boar taint

• Effective meat processing technologies

Prevention of

Boar Taint

Surgical

Castration

Immunocastration

Management/Diet

Genetic

selection

Semen Sorting

Slaughtering at

Lower weight

“There are no harmonised methods of consistently

identifying carcases with boar taint in commercial

slaughter houses. Investigation of possible

processing techniques to reduce the offensive

properties of boar taint is hampered by the lack of

such methods to asses levels of the compounds

contributing to the phenomenon”(The EFSA Journal, European Food Safety Authority, 2004)

Recent initiatives

EU ALCASDE Project “Study on the improved methods for animal-

friendly production, in particular on alternatives to the castration of

pigs and on alternatives to the dehorning of cattle”

EU: Health and Consumers Directorate General Tender “Study on

rapid detection methods for boar taint used or being developed at

slaughter plants in the European Union”

“UK/China partnership for innovative technologies”.

EU COST ACTION (CA15215) Innovative Approaches for

Pork Production with Entire Males (IPEMA)

Detection of Skatole and Indole

Colorimetric method

Gas Chromatography

(GC)

High Performance

Liquid Chromatography

(HPLC)

Mass-Spectrometry

” Bio-sensors

Detection of Androstenone

Gas Chromatography

(GC)

Mass-Spectrometry

Immunoassay/

Radioimmunoassay

Colorimetricmethod

Bio-sensors

Methods to be discussed

Colorimetric method

Gas chromatography (GC)

High Performance Liquid Chromatography

(HPLC)

Mass-spectrometry

Immunoassay/radio immunoassay

Bio-sensors


Colorimetric method



(HPLC)

Mass-spectrometry


Bio-sensors

Principle of Colorimetric Method

Image from:

https://www.google.co.uk/search?biw=911&bih=449&tbm=isch&sa=1&ei=XmC4W4nbCIvAgAam877QCw&q=colo

rimeter+principle&oq=colorimeter+principle&gs_

Colorimetric method Quantification of skatole equivalent in adipose tissue

(Mortensen and Sorensen 1984)

Determination of total 16-androstenes in fat (Squires, 1990)

Implemented in Danish slaughter houses for detection of

skatole (automated system) in 1990s

https://www.google.co.uk/search?q=danish+slaughterhouse+boa

r+taint+detection

Colorimetric Method

Advantages

• On-line method for skatole

• Simple

• Capacity: 200 samples/h

• Limit of detection: 0.03 µg/g

“skatole equivalent”

• Time between sampling and

results: 20 min

• High correlation with sensory and

HPLC results

Challenges

• Specificity issues:

-“skatole equivalent”

- total 16-androstene steroids

• Requires extraction stage

• Analysis Time?

• Existing on-line method does not

detect androstenone

• Interference of cholesterol with

androstenone detection


Colorimetric method



(HPLC)

Mass-spectrometry


Bio-sensors

Principle of Gas Chromatography

https://www.youtube.com/watch?v=NUVbIClAYUY

Gas Chromatography Detection of androstenone of skatole in adipose tissue

(Claus, 1970)

Analysis of skatole concentration in backfat (Vold, 1970)

Coupling of Chromatography with:

-Mass-Spectrometry,MS

(Garcia-Regueiro and Rius, 1995, Schreurs et al., 2007;

Verplanken et al, 2016)

-Flame Ionisation Detector, FID

(Hansson et al., 1980;Porter et al., 1989)

-Nitrogen-phosphorus detector, NPD

(Peleran and Bories, 1985; Zaboloysky et al., 1995)

Gas Chromatography

Advantages

• Sensitive

• Short analysis time for skatole

(around 10 min) after samples

preparation

• Simultaneous detection of boar

taint compounds (when coupled

with mass spectrometry)

• Can be portable (when coupled

with mass spectrometry)

Challenges

• Time-consuming samples

preparation stage

• Expensive

• Portable GC-MS does not achieve

threshold detection of boar taint

compounds

• Laboratory method


Colorimetric method



(HPLC)

Mass-spectrometry


Bio-sensors

Principle of High Performance Liquid

Chromatography (HPLC)

http://www.waters.com/waters/en_

GB/How-Does-High-Performance-Liquid-Chromatography

-Work%3F/nav.htm?cid=10049055&locale=en_GB

http://www.waters.com/waters/en_

HPLC Detection and quantification of skatole and indole

Coupling of HPLC with:

• UV-detector (Garcia-Regueiro and Diaz, 1989)

• Fluorescent detector, FL

(Givis et al., 1991; Hansen-Moller, 1992, Garcia-Regueiro and Rius, 1998)

• Mass-spectrometry (Bekaert et al. 2012)

HPLC-FL method for androstenone detection

(Claus et al., 1997)

HPLC

Advantages

• High sensitivity

• High specificity

• High reproducibility

• Potential of simultaneous

detection of skatole, androstenone

and indole

Challenges

• Samples preparation stage

• Laboratory-based method

• Expensive

• Long analysis time


Colorimetric method



(HPLC)

Mass-spectrometry


Bio-sensors

Principle of Mass-Spectrometry

https://chem.libretexts.org/Textbook_Maps/Analytical_Chemistry/Supplemental_Modules_(Analytical_Chemistry)

Mass-Spectrometry

Detection and quantification of androstenone

(in combination with separation methods e.g. liquid or gas

chromatography)

(Garcia-Regueiro and Diaz, 1989;Schilt et al, 1989;

Verheyden et al., 2007; Verplanken et al., 2016)

Detection of indolic compounds

(Zamaratskaia and Jastrebova, 2006)

Simultaneous measurement of all the boar taint

compounds(Verheyden et al., 2007)

Mass-Spectrometry

Advantages

• Enhancing specificity of

detection

• High sensitivity

• Possibility of simultaneous

analysis of boar taint

compounds

Challenges

• Used as a part of a complex

approach together with separation

methods

• Expensive

• Require specialised staff

• Long analysis time


Colorimetric method



(HPLC)

Mass-spectrometry


Bio-sensors

Immunoassay

• The analyte reacts with specific antibody

• The complex is detected and quantified by a range of approaches

(e.g. radioactive isotopes, enzymes)

https://www.bio-rad-antibodies.com/elisa-types-direct-indirect-

sandwich-competition-elisa-formats.html

Immunoassays

Detection and quantification of androstenone(Kaufmann and Schubert, 1986; Claus, Mahler and Munster, 1988, Tuomola et al.,

2002)

- enzyme immunoassay

- radioimmunoassay

- fluoroimmunoassay

Limited information on the use of immunoassays for

analysis of skatole (Tuomola et al., 2000)

Immunoassay

Advantages

• Easy to perform

• Accurate and sensitive

(radioimmunoassay)

Challenges

• Selectivity/Antibody specificity

• The use of radioactive isotopes:

- Require specialised laboratories

- Not suitable for the use in

abattoirs

- Expensive


Colorimetric method



(HPLC)

Mass-spectrometry


Bio-sensors

http://www.biosensores.com/EN/biosensores_afinidad_molecular.php

Bio-sensors based on the use of insects

Wasps can be conditioned to respond to low, medium

and high concentration of indole, skatole and androstenone

in boar fat

(D.Olson, F. Wackers, H.-E.Haugen, 2012)

https://www.google.co.uk/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwjAoLnDtYPSAhXLuxQKHeuNDS8QjRwIBw&url=https%3A%2F%2Fcedarcirclefarm.org%2Ftips%2Fentry%2Fbeneficial-insect-parasitic-wasp&psig=AFQjCNEJskN__BweAhAG2fwJMLSMte8tDw&ust=1486743558425183

https://www.google.co.uk/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwjAoLnDtYPSAhXLuxQKHeuNDS8QjRwIBw&url=https%3A%2F%2Fcedarcirclefarm.org%2Ftips%2Fentry%2Fbeneficial-insect-parasitic-wasp&psig=AFQjCNEJskN__BweAhAG2fwJMLSMte8tDw&ust=1486743558425183

Types of

bio-sensors

Bioluminescent

Bacteria-based

biosensors

Nano particles-

based sensors

Gas sensors

Optical

biosensors

Electrochemical

biosensors

Gas Sensors

https://www.google.co.uk/imgres?imgurl=http%3A%2F%2Fwww.bdi.ie%2Fimages%2Fresearchphotos%2Frp4.jpg&imgrefurl=http%3A%2F%2Fwww.bdi.ie%2Fresearch%2Fcc4_sig_amp.html&docid=JLB8YSa3evMFlM&tbnid=8dsuVjdgb2CGjM%3A&vet=1&w=860&h=400&bih=673&biw=1326&ved=0ahUKEwjZ9-btw4XSAhWhB8AKHQ51BbA4rAIQMwg3KDUwNQ&iact=c&ictx=1

https://www.google.co.uk/imgres?imgurl=http%3A%2F%2Fwww.bdi.ie%2Fimages%2Fresearchphotos%2Frp4.jpg&imgrefurl=http%3A%2F%2Fwww.bdi.ie%2Fresearch%2Fcc4_sig_amp.html&docid=JLB8YSa3evMFlM&tbnid=8dsuVjdgb2CGjM%3A&vet=1&w=860&h=400&bih=673&biw=1326&ved=0ahUKEwjZ9-btw4XSAhWhB8AKHQ51BbA4rAIQMwg3KDUwNQ&iact=c&ictx=1

Screen-printed Electrodes(Prof. John Hart and his group, UWE)

•Rapid

•Multi-analyte capability

•Inexpensive fabrication

Technology for Boar Taint (Inventors: J. Hart, A. Crew, O. Doran, N. McGuire, UWE)

• Simultaneous analysis of skatole and androstenone

• Can be extended to analysis of other compounds

• Cost effective

• Does not require sample preparation

• Displays results within seconds as numbers

• Can be portable

• Can apply to analysis of boar taint in:

?

Challenges

• Incorporating in abattoir setting

• Different needs and specifications for small and

large abattoirs (e.g. hand-held or stationary device)

• Analysis time – to reduce further?

• Potential to use multiple equipment units to speed

up the analysis

• Cost will depend on the scale of production

Conclusions

EU legislations and initiatives emphasise the need in on-

line detection of boar taint

There is a number of instrumental methods for boar taint

compounds detection but not for on-line measurement

(except of colorimetric detection of skatole)

A number of technologies for on-line boar taint detection

are at various stages of development. Evaluation in

industrial setting is essential.

Harmonization of existing methods for boar taint detection

is required

4. ReferencesAmpuero, S.K., Verkuylen, B., Dahlmans, H., Hortos, M., García-Regueiro, J.A., Dahl, E., Odresen, O., Feitsma, H., Mathur, P.K.,

Harlizius, B., 2011. Inter-laboratory comparison of methods to measure androstenone in pork fat. Animal, 5(10): 1-9.

Bekaert, K. (2013). Chemical and sensory detection of boar taint. Doctor in Veterinary Science, Ghent University.

G.Backus, 2017. Human nose scoring System for boar taint. Prague. Cost IPEMA (February 2017). http://www.ca-ipema.eu/meat-quality

Haugen, J. E., C. Brunius and G. Zamaratskaia (2012). "Review of analytical methods to measure boar taint compounds in porcine adipose tissue: The need for harmonised methods." Meat Science 90(1): 9-19.

Haugen, J.E., Panella-Riera, N., de la Calle, B. 2013. D1.1. Method survey. Boarcheck project. D1.1 Method survey

Keller, A., Zhuang, H., Chi, Q., Vosshall, L. B., & Matsunami, H. (2007). Genetic variation in a human odorant receptor alters odourperception. Nature, 449(7161), 468–472.

Liu, X., H. Schmidt and D. Mörlein (2016). "Feasibility of boar taint classification using a portable Raman device." Meat Science 116: 133-139.

Mathur PK, Napel J ten, Crump RE, Mulder HA, Knol EF. Genetic relationship between boar taint compounds, human nose scores, and reproduction traits in pigs. J Anim Sci. 2013;91(9):4080–9. DOI: 10.2527/jas.2013-6478.

Mathur, P. K., J. ten Napel, S. Bloemhof, L. Heres, E. F. Knol and H. A. Mulder (2012). "A human nose scoring system for boar taint and its relationship with androstenone and skatole." Meat Science 91(4): 414-422.

Sorensen, K. M., C. Westley, R. Goodacre and S. B. Engelsen (2015). "Simultaneous quantification of the boar-taint compoundsskatole and androstenone by surface-enhanced Raman scattering (SERS) and multivariate data analysis " Analytical and Bioanalytical chemistry: 10.

Trautmann, J., J. Gertheiss, M. Wicke and D. Mörlein (2014). "How olfactory acuity affects the sensory assessment of boar fat: A proposal for quantification." Meat Science 98(2): 255-262.

Wang, Q., S. Ding, K. Hamouche and C. Yu (2014). Evaluating meat quality using Ramman Spectroscopy. Proceedings International Converence of Agricultural Engineering, Zurich.

5. Linkshttp://www.ca-ipema.eu/oeiras-presentations

http://www.ca-ipema.eu/oeiras-presentations

Maria Font i Furnols

IRTA- Monells

Consumer studies and alignment consumer acceptance and panelist

Training school “Sensory evaluation of boar taint: methods for assessor selection, good sensory practice and performance

evaluation

IPEMA- CA15215

Innovative approaches in pork production with entire males

SENSORY ANALYSIS

SENSORY EVALUATION IS A SCIENTIFIC

DISCIPLINE USED TO EVOKE, MEASURE,

ANALYSE AND INTERPRET HUMAN

REACTIONS AND SENSATIONS TO THOSE

CHARACTERISTICS OF FOODS,

BEVERAGES AND MATERIALS AS THEY ARE

PERCEIVED BY THE SENSES OF SIGHT,

SMELL, TASTE, TOUCH AND HEARING

(IFT Sensory Evaluation, 1975)

SENSORY ANALYSIS: IMPORTANT CONCEPTS

ANALYTICAL SENSORY ANALYSIS VS. CONSUMER STUDIES

Selected and trained people (panelists)

Evaluations totally OBJECTIVES and reproducible

They do not use hedonic works or preference

Comparable to a laboratory equipment

Comparison between sensory and instrumental analyses

VerificationReadjustment

CALIBRATION

SELECTION

Completion of the methodology:- references- sample preparation- ...

Training of the group:- use of scales- definition of attributes- ...

Recruitment:

- availability

- interest & motivation

- …

Time T Time T

- New accessories- Replace part of old or broken pieces

- Experience- Replacement of tasters

Previous information:- characteristics- price

- ...

OBJECTIVE AND REPEATABLE

MEASURE

SENSORY ANALYSIS: IMPORTANT CONCEPTS

ANALYTICAL SENSORY ANALYSIS VS. CONSUMER STUDIES

They represent a specific population

Their evaluations are SUBJETIVES

The use words like good, bad, satisfaction,…

Selected and trained people (panelists)

Evaluations totally OBJECTIVES and reproducible

They do not use hedonic works or preference

Comparable to a laboratory equipment

Example of the difference between tasters and consumers

Fictitious study about different alcoholic drinks

Russianconsumers

Cubanconsumers

Spanishconsumers

Scottishpanel

Russianpanel

Cubanpanel

Spanishpanel

Whisky

Vodka

Rum

Wine

Prefer

Prefer

Prefer

Prefer

Sweettaste

3/10

1/10

5/10

2/10

Intensity

Subjective measurement,

indicates preference or acceptability

Objective measurement, neverindicates preference

Scottishconsumers

Consumerbehaviour

Psychologicalfactors

Lifestyle andvalues

Expectations

Risk

Attitude

Socio-culturaleffect

Beliefs

Moral and affectivecomponent

Origin

Sensoryfactors

Visualappearance

In-mouthtexture

Flavour

Odour

Marketingfactors

Price

Brand

Availability

Label

Individual Product-specific

Environmental

Font-i-Furnols & Guerrero, 2012

DESIGN OF SENSORY STUDIES

• PRODUCT / MUSCLE EVALUATED

TYPE OF PRODUCT

N=50

Font-i-Furnols, 2012


• METHODOLOGY USED IN SAMPLE PREPARATION


TÍTOL DEL

POWER POINT.

PRESENTACIÓ

COOKING METHOD & TEMPERATURE

Dry-heat

Stewed +

oven

Marinated &

Stewed +

oven

Microwave

Hotwire

Melting

Boiling -75º

Boiling- 25º

Un/pumped

Fry-Grill

Oven

Hot plate

70 & 80ºC

65ºC

72.5ºC

80ºC

SM - LD

68 & 80ºC

Sir

ete

t a

l

19

97

McC

au

ley e

t a

l.1

99

7W

hittin

gto

n e

t a

l. 2

01

1P

resta

te

t a

l.

20

02

Woo

d e

t a

l.

Nute

et a

l.,

19

95

Ag

erh

em

,

To

rnb

erg

,

19

95


• METHODOLOGY TO DETERMINE BOAR TAINT COMPOUNDS

• TYPE OF SAMPLES (SEX, AND & SKA LEVELS,…)

• QUESTIONNAIRE: ATTRIBUTES AND SCALE

• SENSITIVITY TO ANDROSTENONE



SENSITIVITY TO ANDROSTENONE

Different methods to determine consumer sensitivity:


• METHODOLOGY TO DETERMINE BOAR TAINT COMPOUNDS

• TYPE OF SAMPLES (SEX, AND & SKA LEVELS,…)

• QUESTIONNAIRE: ATTRIBUTES AND SCALE

• SENSITIVITY TO ANDROSTENONE



• PRESENTATION OF RESULTS AND DATA ANALYSIS

• CONSUMER’S PROFILE

• INFORMATION PROVIDED TO THE CONSUMERS

• TEST LOCATION: home test, hall test

-Controlled conditions

-Less consumers and samples

-All the questionnaires recovered

-Less similar to consumption reality

-High variability in pork preparation

-Need of more consumers & samples

-Low-medium % returned questionnaires

-Conditions close to consumption reality

What is the best? Depends on the objectives of the study

Comparison, cross-cultural studies,…at same conditions

Enhance the problem

‘Real’ situation

HOME TEST HALL TEST

TEST LOCATION: HOME TEST vs HALL TEST

SENSORY STUDIES ON BOAR TAINT:

SENSITIVITY OF THE CONSUMERS

CONSUMERS + TRAINED PANEL

Sensitivity to Androstenone

Germany: Highly sensitives Midly sensitives Insensitives

. Men 15.6 14.7 69.7

. Women 19.3 14.7 65.9

. Total 17.6 14.7 67.7

Spain: Highly sensitives Midly sensitives Insensitives

. Men 23.7 16.6 59.7

. Women 37.3 14.6 48.1

. Total 30.9 15.5 53.6

(Weiler et al., 2000)

ODOUR Highly sensitive Less sensitive/insensitive Sign. of sensitivity

Spain

Low 4.10a 4.15 NS

Medium 3.78b 4.22 **

High 3.75b 4.12 ***

FLAVOUR Highly sensitive Less sensitive/insensitive Sign. of sensitivity

Germany

Low 4.68a 4.75 NS

Medium 4.41ab 4.62 NS

High 4.17b 4.66 ***

(Weiler et al., 2000)1: Dislike extremely7: Like extremely

AND Flavour Odour

Like 3.75a 3.35a

Indifferent 3.35b 3.06b

Dislike 3.39b 2.94b

1: Dislike extremely7: Like extremely

35 EM, 23 CM, 36 IM and 24 FE Pi x (DU x LR). Slaughtering: 180 days, same age Efficacy vaccine, 100%

# Loins defrozen (24 h at 4ºC)

SAMPLE PREPARATION - panellists

ANALYTICAL SENSORY ANALYSIS: METHODOLOGY

Font i Furnols et al. (2009)

• Cooked inside glass tubes

• Convection oven, 10 minutes at 180ºC

SAMPLE PREPARATION - panellists



EXPERIMENTAL DESIGN• 8 trained panellists

• 24 sessions (4 samples/session, one of each typee)

• Order of presentation different for each panellist to avoid first sample

and carry over effect)

ODOUR

Androstenone

Skatole

Sweet

Grilled

FLAVOUR

Androstenone

Skatole

Sweet

Metallic

TEXTURE

Hardness

Juiciness


0

2.5

5

O Androstenon

O Escatol

O Dulce

O Tostado

F Androstenon

F Escatol

F Dulce

F Metálico

T Dureza

T Jugosidad

Castrados Inmunocastrados Enteros Hembras

a

a

O skatole

O sweet

O grilled

F androstenone

F skatole

F sweet

F metallic

T hardness

T juiciness

O androstenone

Immunocastrated malesCastrated males Entire male Females

ANALYTICAL SENSORY ANALYSIS: RESULTS


CONCLUSIONS

The meat from immunocastrated males is sensory different

from those of entire males, but it is not different from those of

castrated males and females.

The meat from entire males is characterized by an odour and

flavour of androstenone and skatole

ANALYTICAL SENSORY ANALYSIS: RESULTS


# Loin defrost 24 h at a temperature of 4ºC

SAMPLE PREPARATION - consumers

CONSUMERS: METHODOLOGY


Cook: 180ºC

10 minutes

Convection oven (FAGOR)

SAMPLE PREPARATION - consumers



EXPERIMENTAL DESIGN• Controlled conditions at IRTA-Monells (Hall test)

• 20 sessions of 10 consumers

• Ordre of presentation of the samples different for each consumer

(in order to avoid first sample and carry-over effect)

• 4 samples/consumer 80 samples, 20/sex type

• 201 representative consumers (gender, age)

97104201Total (n)

48.351.7100.0Total (%)

18.616.417.461-77 years old

35.130.832.841-60 years old

32.033.732.816-40 years old

14.419.216.918-25 years old

Age WomenMenGlobal

%



QUESTIONNAIRE

I like it extremely . . . . . . . . . . . . . . . . . . . . . . . . ___________________

I like it a lot . . . . . . .. . . . . . . . . . . . . . . . . . . . . . ___________________

I like it . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . ___________________

I like it slightly . . . . . . . . . . . . . . . . . . . . . . . . . . ___________________

I dislike it slightly . . . . . . . . . . . . . . . . . . . . . . . ____________________

I dislike it . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ____________________

I dislike it a lot . . . . . . . . . . . . . . . . . . . . . . . . . . ____________________

I dislike it extremely . . . .. . . . . . . . . . . . . . . . . . ____________________

Sample Nº:_________ ODOUR FLAVOUR OBSERVATIONS

9

8

7

6

4

3

2

1


6.2a5.8b6.4a6.4a201Flavour

6.2a5.5b6.2a6.2a201Odour

Only entire males with < 1 μg/g of androstenone

6.2a5.7b6.4a6.4a201Flavour

6.2a5.4b6.2a6.2a201Odour

All the animals

FEEMIMCMN

6.2ab5.9b6.4a6.4a201Flavour

6.25.86.26.2201Odour

Only entire males with < 0.5 μg/g of androstenone

1 N=171 for EM; 2 N=82 for EM

CONSUMERS: RESULTS


SENSIBILITY TO ANDROSTENONE SMELL• Consumers’ sensitivity test to pure androstenone smell

Highly sensitive

Less sensitive/insensitive

6- Extremely strong

5- Very strong

4- Strong

3- Weak

2- Very weak

1- Extremely weak

0- No odour percetion

Total (n) Sensitive (%)Less sensitive/insensitive

(%)

Men 104 36.5 63.5

Women 97 53.6 46.4


ODOUR ACCEPTABILITY

4

5

6

7

CM IM EM FE

Oo

du

rsco

re

a a

b

a

Global

a a

b

a

Sensitive Less sensitive/insensitive

CONSUMERS: RESULTS

a a

b

a

aa

b

a

4

5

6

7

CM IM EM FE

Fla

vour

score

s

Global Sensitive Less sensitive/insensitive

FLAVOUR ACCEPTABILITY

CONSUMERS: RESULTS

This study shows that:

Consumers’ acceptability of pork depends on the sex of the

animals: consumers prefer the odour and the flavour of pork from

females, surgically castrated males and immunocastrated males

compared with those from entire males.

The acceptability of pork by consumers sensitive to

androstenone is more affected by the sex of the animal for

consumers sensitive to androstenone than for consumers less

sensitive or insensitve to this compound.

Pork from entire males is less preferred than those from

surgically castrated males, immunocastrated males and females,

also if the levels of androstenone are low.

CONSUMERS: CONCLUSIONS


CORRELATIONS: PANEL-CONSUMERS-CHEMICAL

OAnd OSka FAnd FSka And Ska

Flavour

accept

O Skatole 0.68 -

F Androstenone 0.91 0.61 -

F Skatole 0.80 0.67 0.75 -

Androstenone 0.88 0.59 0.95 0.73 -

Skatole 0.57 0.53 0.56 0.65 0.53 -

Flavour accept -0.46 -0.22 -0.42 -0.42 -0.42 -0.26 -

Odour accept -0.50 -0.26 -0.49 -0.44 -0.49 -0.35 0.77


F_OGen M_Ogen M_FLGen Cons_Od Cons_Flav Hot Iron

Andros 0.18 0.35 0.32 0.19 0.30

Skatole 0.28 0.30 0.32 0.12 0.36

F_OGen 0.35 0.36 0.15 0.35

M_Ogen 0.35 0.21 0.20 0.42

M_FLGen 0.21 0.19 0.36

Cons_Od 0.68 0.13

Consumer: 1(good) – 6 (bad)

FAT

MUSCLE

Aluwé et al 2012Consumer: 1(good) – 6 (bad)

Denmark France Italy Poland Total

N 109 128 121 118 476

Age (years)

<25 5.7 21.8 13.2 22.9 16.4

25-44 29.8 49.2 43.0 22.9 36.7

45-59 43.3 18.8 24.0 33.9 29.3

>60 21.2 10.2 19.8 20.3 17.6

All women Aluwé et al 2018

CAMPIG PROJECT

METHODOLOGY – SAMPLE PREPARATION

Tint= 80ºC, 10-12 min

Aluwé et al 2018

Each consumer:- 1 pair castrate-castrate- 4 pairs boar-castrate/castrate-boar

PREFERENCE:Which product do you like more with respect to the smell?Which product do you like better in terms of taste?

METHODOLOGY – DESIGN & QUESTIONNAIRE

Meat patties 20 % fatAndrostenone from 0.5 to 2 ppmSkatole from 0.10 to 0.40 ppm

Aluwé et al 2018

AND sensitivity

SKA sensitivity No Yes Very Total

Overall No 30.0 9.2 1.3 40.5

n=476 Yes 35.7 16.0 7.8 59.5

Total 65.8 25.2 9.0 100.0

METHODOLOGY – SENSITIVITY

Low AND (0.5 ppm)High AND (5 ppm)SKA (1 ppm)

Aluwé et al 2018

MAPSConsumer dissatifactionby AND, SKA and SENS

A map for Odour and onefor Flavour

Each stakeholder can use the map to decide whereto cut.

Aluwé et al 2018

Aluwé et al 2018Campig Report, 2012

• The preference for the boar patties decreased with increasing SKA content. At low SKA content, the preference for the boar meat patties also decreased with increasing AND level, the more so in the subpopulation of consumers that are especially for consumers sensitive to AND

• It was not possible to determine a clear preference/rejection threshold for AND and SKA as the decrease in liking or preference was gradual. Any sorting limit therefore depends on the risk the stakeholders are willing to take.

CAMPIG: CONCLUSIONS

Christensen et al., 2018


Model 1

Critical: random consumer effect 90th percentile in the estimated population consumer likingPopulation-average: consumer population averaged on the probability scaleTypical: random consumer effect =0

Model 2


Estimated binary distribution of SKA and AND on original scale and log10 scale. Each dot entire male, and the curves are density contours for the estimatedbivariate normal distribution

Model 3


Estimated % of discarded EM pigs as function of sorting limits for SKA and AND

Effect of sorting limits on the risk of dislike in % for EM pigs; the estimated riskof dislike for CM coincides with 9% contour


6.2% of EM

Maria Font i [email protected]

http://irtanet/IC/ImatgeCorp/Image Library/LOGOS/Logos_jpg_i altres_formats/IRTA/català/IRTA+DESCRIPTOR_QUADRE_NEGRE_CAT.jpg

1

Human nose methods, main characteristics, advantages-

disadvantages

Dra. Núria Panella-Riera

([email protected])

October, 8th, 2018

http://www.ca-ipema.eu/

mailto:[email protected]

2 Bekaert, K. (2013)

There is a need of accurate measurements of boar taint compounds

for research purposes ...To detect tainted

meat before it reaches

consumers

...to identify and understand factors

affecting variations in androstenone and skatole levels, ...

...to develop methods to reduce boar taintº

Why do we need to determine boar taint?

...to develop methods mask boar taint

3

Detection methods applied in the abattoir.

Carcass free of boar taint

Boar tainted carcasses

Carcass identification according to boar

taint level

Method to classify carcasses according to

boar taint

How are they commercialised?

4

Table of contents:

1. Human Nose methods. Main characteristics

2. Type of Human nose methods

3. On-line methods

4. At-line methods

5. Main steps for training the assessors

6. Survey about the situation of rapid methods for boar taint (May 2013)

7. Final remarks



3. On-line methods

4. At-line methods



7. Final remarks

5 Mathur et al., 2012

Consist of identifying boar tainted carcasses with sensory assessment.

Assessors smell fat carcasses right after heating it.

It requires intensive training of the assessors.

Despite the limitations of a sensory methodology used at the slaughter line, this method is currently used as a routine method in different European countries (i.e. The Netherlands, Germany, Belgium, Denmark, France, and Spain).

Human nose methodology. Main characteristics.

6 Backus et al., 2017

Low cost method with high throughput.

It is a method that helps in making progress.

i.e. feedback information for suppliers

Practicable for…

… slaughter line detection

… breeding purposes

… method that fulfils requirements of Dutch-German retailers



https://www.q-s.de/documentcenter/dc-slaughtering-deboning.html


Companies that slaughter entire males or cannot exclude this possibility in the future must have procedures in place to ensure reliable detection of carcasses with potential boar taint. Where detection is via sense of smell, the following criteria must at least be met:

8

CONS

It is required a training of the assessors, and to keep them trained.

Rotation of the assessors (i.e. 20 min intervals) is needed to avoid fatigue.

It is important to “believe” in this method (assessors and management team motivated).

It needs strategic decisions from the meat company: How do we include this information on the production line? What do we do with the tainted carcasses?

PROS

Immediate response.

Correlated to the sensory perception of the consumer.


9

The industry needs a balance of ...

... risk of costumer complaints (too low

sensitivity)...

... pork industry cost due to too many false positives (too low

specificity).

...against...


10

Table of contents:



3. On-line methods

4. At-line methods



7. Final remarks

11

At-line: analysis in separate laboratory. The sample is extracted from the carcass and sent to an in-house laboratory where it is analysed.

SamplingTransport and

logistics sampleAnalysis

PLC, database &

report

On line: measurement at the slaughter line. The method can be implemented directly at the slaughter line without physically removing a sub-sample.

Local

heatingAssessment

PLC, database &

report

PLC: Programable logical controllers

Nielsen et al, K. (2013)

Type of Human Nose methods

12

Sample location(fat)

Heating Routine use

Use slaughterline

Samples per hour

1 Neck Soldering iron Yes No 550

2 Neck Boiling water Yes No 40

3 Neck Gas powered torch heated plate

Yes Yes 600

4 Long.dorsi Boiling water No No 5

5 Neck Microwave Yes No 30

BOARCHECK project, 2012 ( a DK, DE, NL, FR, BE i ES)

Important reported method details from the questionnaires on sensory methods.



On-line (at slaughter line) At-line: at the laboratory



Flaming soldering iron

In slaughter line

At slaughter speed

250-300 samples during 30

min.

Team of trained panellists

Electric soldering iron

In a separated room (“laboratory”) with good ventilation

At own speed

max. 100 samples

Team of trained panellists

On-line: at slaughter line At-line: at the laboratory


15

Table of contents:



3. On-line methods

4. At-line methods


6. Survey about the situation of rapid methods for

boar taint (May 2013)

7. Final remarks

16

Human nose applied in a Dutch company (2012)

Simple identification of

tainted carcasses

Type of Human Nose methods: on-line.

17

Human nose methodology applied in an Spanish abattoir (450 carcass/h; 2014)


18

Human nose applied in a Spanish company (600 carcass/h; 2018)


19 Boars heading 2018


20

On line test for the human nose method in a Spanish company (2014).Steps: 1. bone dust removal, 2. heat/melt fat, 3. sniffing carcass.


21

Type of Human Nose methods: on-line. Tools.

22


23


24 Nielsen et al, K. (2013)

It is important to register individual animal ID, sex of the animal and sample ID.

Sample should be representative of the entire animal

It is important to ensure the reproducibility between different assessors on an adequate level and to ensure that the analytical results do not “drift” from day to day.

Type of Human Nose methods: on-line. Requirements.

25 Nielsen et al, K. (2013)

Type of Human Nose methods: on-line. Requirements.

26

Table of contents:



3. On-line methods

4. At-line methods



7. Final remarks

27

Type of Human Nose methods: at-line.

28

How do we perform fat sampling?


29

Remarks regarding the fat collection:

Amount of fat available (preferably, several small pieces so that each assessor smell a new piece/avoid utilization of re-heat the same piece)

Fat temperature: at room temperature or warm (approx. 36 ºC)


30

For the sensory evaluation

1. Skewer the samples (with forceps)

2. Heat the sample by rubbing a hot iron (~240 ºC) until it appears white, glassy/shinny, blistery, sweaty.

3. Sniff the fat sample about 3 cm from the nostrils.

4. After each evaluation theheated part should be cut off (so that each assessor evaluate a freshly cut surface).

Trautman et al., 2016


31

Type of Human Nose methods: at-line. Tools.

32

Type of Human Nose methods: at-line. Tools.

33

Analysis in separate laboratory: The sample is extracted from the carcass and sent to an in-house laboratory where it is analysed.

SamplingTransport and

logistics sampleAnalysis

PLC, database &

report

PLC: Programable logical controllers


It is important to register individual animal id; sex of the animal, sample ID (pre-marked disposable vials),

Sample should be representative of the entire animal,

Preferably, use of disposable items to minimize cleaning and cross-contamination,


34

Analysis in separate laboratory:



35

Table of contents:



3. On-line methods

4. At-line methods



7. Final remarks

36

Main steps for training the assessors

Preparation of smell strips:

1. Preparation of the solutions of androstenone and skatole standards

2. Preparation of smell strips

37

Main steps for training assessors

First stage: Selection of assessors

1. Sensitivity test for androstenone and skatole (smell strips)


38

SESSIÓ 1 . 1.1. Olor sexual: compostos responsables

To ensure the constant release of the composites of the paper strips, it is recommended to …

save for 7 days max. use 4 times max.

(according to measurements made in the head space)


First stage: Selection of assessors

1. Sensitivity test for androstenone and skatole (smell strips)


39

There is a need for intensive training of the assessors

Assessors should be motivated to be part of the SMELLING TEAM

Recruitment and selection of assessors to be part of the SMELL MASTER TEAM

1st/ Announcement of an informative session for all the staff

2nd/ Informative session to motivate volunteers

3rd/ Presentation of volunteers

4rt/ Sensitivity test for androstenona and skatole to built the SMELL MASTER TEAM

5th/ Training process (in the laboratory and on line)

6th/ Start to smell carcasses

40


Second stage: Training with smell strips (laboratory)

Example of tests:

1. Odour discrimination test (triangle tests for androstenone and skatole)

2. Odour threshold test, Odour identification tests

3. Pair test , triangular tests, ranking test


Third stage: Training with fat with different levels of boar taint. Example of tests:1. Odour threshold test, Compounds identification test2. Pair test, triangular tests, ranking test 3. Familiarization with the procedure (environment,

speed,...)4. On line test next to a experienced assessor

41Ampuero, et al 2011; Haugen et al., 2012

There is a need

of a reference

method

Attention on the methodology used for the chemical analyses of Androstenone and Skatole levels. There has been used different extraction methodologies

60 %

40 %

ug/g adipose tissue

ug/g pure fat

Androstenone 1

≡1.7

Skatole 1 1.6

Indole 1 1.2


Third stage: Training with fat with different levels of boar taint

42

Table of contents:



3. On-line methods

4. At-line methods



7. Final remarks

43

Survey in slaughterhouses 35 abattoirs (31 from EU) in 10 different countries (8 in the EU) .

(EU: Belgium, Denmark, France, Germany, Netherlands, Spain, United kingdom;

Third countries: Canada, New Zealand, Norway)

Among the 31 abattoirs,

1. 24 slaughtered entire male pigs or were planning to do so during the following years

2. Only Belgium was slaughtering immunocastrated pigs.

3. 12 abattoirs (BE, DK, FR, DE i NL) had a boar taint detection method (4 with a Human nose under development)

http://www.ca-ipema.eu/meat-quality Projecte BOARCHECK, 2012 ( a DK, DE, NL, FR, BE i ES)

Survey about the situation of rapid methods for boar taint (May 2013)

http://www.ca-ipema.eu/meat-quality

44

/.../

4. Nine abattoirs had a method based on sensory analyses, 1 with a chemical analyses of skatole.

5. The abattoirs with a method to determine boar taint, assessed all the entire male pigs.

6. Scores given for the boar taint:

2 levels (YES/NO) in 6 companies

More than 2 levels in 3 abattoirs

7. Costs related to the detection (answers from 3 companies)

Initial investment: median 10000 € (3600 – 12000)

Operational cost: Median 1.5 €/boar slaughtered (0.20 – 2.68 €)

http://www.ca-ipema.eu/meat-quality Projecte BOARCHECK, 2012 ( a DK, DE, NL, FR, BE i ES)



45http://www.ca-ipema.eu/meat-quality Projecte BOARCHECK, 2012 ( a DK, DE, NL, FR, BE i ES)

Method performance traits Requeriments

Method capacity

Capacity/analysis pr hr 100-800 carcass

Analysis speed pr sample 4-40 seg

Sampling time pr sample 0.5-20 min

Result reporting

At-line method < 30 min

On-line method <1 min

Costs

Running cost pr carcass < 2 eur

Method performance



46

Table of contents:



3. On-line methods

4. At-line methods



7. Final remarks

47

Nowadays, there is not a dedicated on- or at-line instrumental measurement system available for sorting of boar tainted carcasses that measures both androstenone and skatole.

Different sensory methods have been developed and are functioning in abattoirs, either on-line or at line. Whatever the case, the performance of these systems need validation.

If sensory methods are used for boar taint detection, there is a need of a good program for the training of the assessors and plan to keep them trained.

Therefore, there is still need in a fully validated and a reliable on-line test for use in abattoirs to remove tainted meat.

Final remarks

48

Muchas gracias Moltes gràcies

48

Thank you very much

49

References of interest

Ampuero, S.K., Verkuylen, B., Dahlmans, H., Hortos, M., García-Regueiro, J.A., Dahl, E., Odresen, O., Feitsma, H., Mathur, P.K., Harlizius, B., 2011. Inter-laboratory comparison of methods to measure androstenone in pork fat. Animal, 5(10): 1-9.

Bekaert, K. (2013). Chemical and sensory detection of boar taint. Doctor in Veterinary Science, Ghent University.

G.Backus, 2017. Human nose scoring System for boar taint. Prague. Cost IPEMA (February 2017). http://www.ca-ipema.eu/meat-quality

Haugen, J. E., C. Brunius and G. Zamaratskaia (2012). "Review of analytical methods to measure boar taint compounds in porcine adipose tissue: The need for harmonised methods." Meat Science 90(1): 9-19.

Haugen, J.E., Panella-Riera, N., de la Calle, B. 2013. D1.1. Method survey. Boarcheck project. D1.1 Method survey

Keller, A., Zhuang, H., Chi, Q., Vosshall, L. B., & Matsunami, H. (2007). Genetic variation in a human odorant receptor alters odourperception. Nature, 449(7161), 468–472.

Liu, X., H. Schmidt and D. Mörlein (2016). "Feasibility of boar taint classification using a portable Raman device." Meat Science 116: 133-139.

Mathur PK, Napel J ten, Crump RE, Mulder HA, Knol EF. Genetic relationship between boar taint compounds, human nose scores, and reproduction traits in pigs. J Anim Sci. 2013;91(9):4080–9. DOI: 10.2527/jas.2013-6478.

Mathur, P. K., J. ten Napel, S. Bloemhof, L. Heres, E. F. Knol and H. A. Mulder (2012). "A human nose scoring system for boar taint and its relationship with androstenone and skatole." Meat Science 91(4): 414-422.

Sorensen, K. M., C. Westley, R. Goodacre and S. B. Engelsen (2015). "Simultaneous quantification of the boar-taint compoundsskatole and androstenone by surface-enhanced Raman scattering (SERS) and multivariate data analysis " Analytical and Bioanalytical chemistry: 10.

Trautmann, J., J. Gertheiss, M. Wicke and D. Mörlein (2014). "How olfactory acuity affects the sensory assessment of boar fat: A proposal for quantification." Meat Science 98(2): 255-262.

Wang, Q., S. Ding, K. Hamouche and C. Yu (2014). Evaluating meat quality using Ramman Spectroscopy. Proceedings International Converence of Agricultural Engineering, Zurich.

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5. Links of interests





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