mongondryp technical analysis for food products

8/13/2019 MongondryP Technical Analysis for Food Products

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Technical analysis forfood products

Philippe Mongondry

[email protected]

29 June 2011, Maribor


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Many analytical chemical and physical techniques:

Electro-analysisQtyof ions GravimetryFat or water content

El

ectrophoresisseparationAtomic spectrometrytrace element

Molecular spectrometryemission (Fluo); diffusion (Raman) absorption (UV, IR RMN)

Mass Spectrometry Radiometry (14C) origin & date

X ray diffusion structural ID RheometryFlow & structure

Sensory analysis Chromatography


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Techniques for food products: what for?

Quality control

Quantification of nutr iments, vitamins

of compoundsIdentification of contamination

Determination of ingredients

Authentication of origin of the product


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Physical and chemical analysis

Spectroscopy (UV visible IR)

Chromatography

SNIF NMR and Mass spectrometry

Concepts and Basis

Sensory analysis


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Matter

Spectroscopy

and interactions


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From atom to complex molecules


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Biological Molecules

Thousands of different molecules per cell, fast Renew

Complex system

Biological specificity with 'allowed' movement and

conformation

E(link etc...)reactions, biological and thermodynamic

parameters

Particularity :

transformation of light energy (chlorophyll)

LipidsGlucide

Proteins

Nucleic acid


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electromagnetic radiancedomain Phenomena Frequency (Hz) Wave length

RadiofrequencyNuclear Magnetic Resonance

Nuclear Quadrupole Resonance106to 108 300 to 3 m

Micro-ondesElectronic paramagnetic Resonance

molecular rotations spectrum1010to 1012 300 to 0.3 mm

Infrared molecular vibrations 1012to 31014 300 to 0,8 m

Visible and ultraviolet Electronic Transitions (external e-) 31014

to 1016

800 to 10 nmX Rays Electronic Transitions (core e-) 31016to 1019 10 to 0.03 nm

Rays nuclear Transitions 1019to 10220.03 to 0.003

nm

Spectroscopic principles


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Transmission and reflection = nothing


Absorption of energy

UV absorption spectrum

Emission of large spectrum of photons (energy)


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I

I

Large spectre of thesource

Spectrale composition

of transmise light

Polychromatic radiation

Abs

Construction of absorption spectrum



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Spectroscopy UV-visible

Quantitative method,

Kinetic of reaction

Absorption of UV by unsaturated bondsO

OH

NH2

O

ONO

YES

YES

YES


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Principe:Molecule under infrared radiation: vibration and rotationSymmetrical

stretching

Antisymmetrical

stretching

Scissoring

Rocking Wagging

Twisting

http://fr.wikipedia.org/wiki/Spectroscopie_infrarouge

Infrared Spectroscopy
http://en.wikipedia.org/wiki/File:Twisting.gifhttp://en.wikipedia.org/wiki/File:Wagging.gifhttp://en.wikipedia.org/wiki/File:Modo_rotacao.gifhttp://en.wikipedia.org/wiki/File:Scissoring.gifhttp://en.wikipedia.org/wiki/File:Asymmetrical_stretching.gifhttp://en.wikipedia.org/wiki/File:Symmetrical_stretching.gif


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Fourier Transform InfraRed Spectroscopy

Fingerprint of molecule

spectrometer FTIR

Used for samples :

Gaz, liquid or solid in powder


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Separation & Identification

Chromatography or HPLC

Extraction and preparationin liquid media


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Chromatography or HPLC

High Performance Liquid Chromatography

Different Types

Partition chromatography

Normal-phase chromatography

Reversed-phase chromatography (RPC) Size-exclusion chromatography (SEC)

Ion-exchange chromatography

Bio-affinity chromatography

SEC


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Chromatogram of

pesticide in cow milk

Identification of

polyphenols in wine


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SNIF NMR Site-Specific Natural Isotope Fractionation Nuclear Magnetic Resonance

Based on the absorption of deuterium in plants (Glucose or ethanol)

Irregular distribution of De on the Earth due to rotation

Addition of different type of sugar in Tequilas


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Mass Spectrometry

Main steps of the measurement

Unknown sample

Determination of the molecular

weight of big molecules (proteins)

Quick Identif ication based ondatabases

Aims


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IdentificationReconstruction by affini ty of pieces

Depend on posi tion of the picks and ratio m/Z

Mass Spectrometry

Coupling HPLC-MS

Coupling techniques is powerful !!


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Sensory analysis

What consumer understand from different information we give him ?

What consumer looks for ?

How improve his loyalty ?

How his sensory experiments is influenced by the information he has ?

What is important in his purchase behavior ?

What does he discern in products ?

How to measure the sensory performance of products ?

What is the impact of a new process or technology on his fondness ?


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Sensory analysis

How objectively measure the tasting and thesensorial characteristics of food products?

Habits

Culture

Personality

Current mood

Physiology (allergy)

Time of the day

place

With who

how

Why what

Sensorial characteristics

Nutriments

Packaging

Factors which influence the choice of a food product ( Gains, 1994)

Consumer Context product


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Definition:

Evaluation of organolepticpropertiesof a food product by human senses

based on experimental designand statistical analysis(combination of

inferences or deductive reasoningand insight or specific cause and effect)

Sensory analysis of Food products

ICS 67.240 Sensory analysis

(ISO standard)Glossary


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Sensory analysis

How objectively measure the tasting and the sensorial characteristics of food products?

dif ferences preferences Evocations Motivations

3 categories: Effective, affective and perception analysis

Descriptive

Test

Hedonic

Test

Qualitative

Test

Trained panel Naive consumers


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Study consumer behavior and motivation

to get a better understanding of his reactions

Sensory analysis

Aims: Identify all reactions, all opinions that consumer have

Example : Reaction in front of the product

Label, design

Information

Price

Association of these different attributes

Which cap do you prefer ??


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Thank you for your attention

It is time for sensoryanalysis

[email protected]

mongondryp technical analysis for food products

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