This document discusses computer-aided sensory evaluation tools for beverages. It describes electronic nose (e-nose) and electronic tongue (e-tongue) systems that can mimic and measure some human sensory functions like smell and taste. The e-nose uses sensor arrays and pattern recognition to detect volatile compounds. The e-tongue uses sensor arrays and electrochemical cells to analyze soluble compounds. Both tools generate data that requires multivariate analysis. The document also discusses the Compusense Five sensory evaluation software that facilitates planning, conducting, and analyzing sensory tests.

1. FST 519: Sensory Evaluation of Foods
Assignment on: “Computer-Aided Sensory
Evaluation of Beverages”
Submitted To: Dr. Anil Kumar
Chauhan Sir
Submitted By: Jagriti Bhasin
ID: 19412FST008
Enrol. No.:416758
M.Sc. Food Science and
Technology (3rd Sem)
Departmentof dairyscienceandfoodtechnology
Instituteof agriculturalsciences
Banarashinduuniversity

2. CONTENTS
 Sensory Evaluation
 Human Senses
 Human Senses V/S Computer
 Computer-Aided Sensory Evaluation
 E-Nose
• Working principle of E-Nose
• Commonly used sensors in E-Nose
• Data Analysis For E-Nose
• Applications Of E-Nose
 E-Tongue
• Working of E-Tongue
• Equipments
• Applications of E-Tongue
 Compusense Five
• Features of Compusense Five Software
 References

3. SENSORY EVALUATION
 Sensory evaluation is a scientific discipline that analyses and measures
human responses to the composition and nature of foods and drink.
 Sensory evaluation does not just deal with "likes and dislikes,“ “OK or
not OK” but the process scientifically elicits, measures, analyses and
interprets psychological and / or physiological responses to physical
stimuli produced by a food product.
 It is a scientific discipline used to evoke, measure, analyze and interpret
reactions to those characteristics of food and materials as they are
perceived by senses of sight, smell, taste, touch and hearing.

4. HUMAN SENSES
•‘Sense’ may be described as the physiological perception of a stimuli.
•There are 5 senses in human beings:
1) Sight : Ability of the eye and brain to detect electromagnetic
waves within the visible range of light and interpret the image.
2) Hearing : Sense of sound. When vibrations propagating through
a medium (e.g. air) are detected by the brain, sound is perceived.
3) Touch : Sense of pressure perception, mostly in the skin /
tongue.
4) Taste
5) Smell

5. HUMAN SENSES V/S COMPUTER
Human
Senses
Sight
Hearing
Taste
Smell
Touch
Computer
Colour
Detector
Sound
Detector
E-Tongue
E-Nose
Texture
Detectors

6. COMPUTER-AIDED SENSORY EVALUATION
There are specially designed
hardware and softwares for sensory
evaluation of beverages and other
food products:
E- Nose
E- Tongue
Compusense Five
E-Nose E-Tongue

7. E- Nose
 The electronic nose is a device that detects the smell more effectively then the
human sense of smell.
 An electronic nose consists of a mechanism for chemical detection. The electronic
nose is an intelligent sensing device that uses an array of gas sensors which are
overlapping selectively along with a pattern reorganization component.
 The smells are composed of molecules, which has a specific size and shape. Each
of these molecules has a corresponding sized and shaped receptor in the human
nose.
 When a specific receptor receives a molecule it sends a signal to the brain and
brain identifies the smell associated with the particular molecule.
 The electronic noses work in a similar manner of human. The electronic nose uses
sensors as the receptor.
 When a specific sensor receives the molecules, it transmits the signal to a program
for processing, rather than to the brain.

9. Working Principle of E-Nose
 The electronic nose was developed in
order to mimic human olfaction whose
functions are non separate mechanism ,
i.e. the smell or flavor is perceived as a
global finger print.
 Essentially the instrument consists of
sensor array, pattern reorganization
modules, and headspace sampling, to
generate signal pattern that are used for
characterizing smells.
 The electronic nose consists of three major
parts which are detecting system,
computing system, sample delivery system.
Fig 1: Working of E-Nose

10.  The sample delivery system: The sample delivery system enables the
generation of headspace of sample or volatile compounds which is a fraction
analyzed. The system then sends this head space into the detection system
of the electronic nose.
 The detection system: The detection system which consists of a group of
sensors is the reactive part of the instrument. When in contact with volatile
compounds at that time the sensors reacts causing changes in electrical
characteristics.
 The Computing system: In most electronic noses each sensor is sensitive
to all molecules in their specific way. However in bioelectric noses the
receptor proteins which respond to specific smell molecules are used. Most
of electronic noses use sensor arrays that react to volatile compounds.
Whenever the sensors sense any smell , a specific response is recorded that
signal is transmitted into the digital value.

12. Commonly used Sensors in E-Nose
Metal Oxide semiconductor sensor:
This is used for switching or amplifying electronic signals. The Working principle of
MOSFET is that molecules entering into the sensor area will be charged positively or
negatively which have directly effect on the electric field inside MOSFET.
Metal Oxide sensors: (MOS)
This sensor is based on adsorption of gas molecules to provoke change in conductivity.
This conductivity change is the measure of the amount of volatile organic compounds
adsorbed.
Piezoelectric sensors:
The adsorption of gas onto the surface of the polymer leads to change in mass on the
sensor surface. This is turn produce a change in the resonant frequency of the crystal.
Quartz crystal microbalance:
This is a way of measuring mass per unit area by measuring the change in frequency of
crystal resonator. This can be stored in a data base.
Conducting polymers:
Conductive polymer gas sensors operate based on changed in electrical resistance caused
by adsorption of gases onto the sensor surface.

13. Data Analysis for E-Nose
The digital output generated by electronic nose sensors
has to be analyzed and interpreted in order to provide.
There are three main types of commercially available
techniques.
• Graphical analysis
• Multivariate data analysis
• Network analysis
The choice of method utilized depends on available input
data from sensors.
The simplest form of a data reduction is a graphical
analysis useful for comparing samples or comparing
smells identification elements of unknown analysts
relative to those of known sources in reference libraries.
Fig 2

14. Applications of E-Nose
 Medical diagnostics and health monitoring
 Environmental monitoring
 Application in food industry
 Detection of explosive
 Space applications (NASA)
 Research and development industries
 Quality control laboratories
 The process and production department
 Detection of drug smells
 Detection of harmful bacteria

15. E-Tongue
 An Electronic Tongue is an instrument which comprises of electrochemical cell,
sensor array and appropriate pattern recognition system, capable of recognizing
simple or complex soluble nonvolatile molecules which forms a taste of a sample.
 The sensor array consists of broadly tuned (non-specific) potentiometric metal based
electrodes that are treated with a variety of common anion of a salt in solution –
chemical materials.
 A taste sensor with global selectivity is composed of several kinds of lipid/polymer
membranes for transforming information of taste substances into an electric signal.
 The output of this electronic tongue shows different patterns for chemical substances
which have different taste qualities, such as saltiness and sourness.
 The taste of foodstuffs such as beer, sake, coffee, mineral water, milk and vegetables
can be discussed quantitatively using the electronic tongue, which provides the
objective scale for the human sensory expression.
 Such devices have been mainly used in the field of food analysis: for classification of
wine, beer, tea and herbal products, tomato samples, coffee, and milk.

16. Working of E-Tongue
 The electronic tongue initially developed by the
University of Texas consists of a light source, a
sensor array and a detector.
 The light source shines onto chemically adapted
polymer beads arranged on a small silicon wafer,
which is known as a sensor chip.
 These beads change colour on the basis of the
presence and quantity of specific chemicals.
 The change in colour is captured by a digital
camera and the resulting signal converted into
data using a video capture board and a computer
as shown in Figure 3.
Fig 3: Working of E-Tongue

17. The technology can be applied to the measurement of a range of chemical
compounds, from the simple, such as calcium carbonate in water, through to
complex organic compounds, such as haemoglobin in blood and proteins in
food.
Moreover, it is helpful in discriminating mixtures of analytes, toxins and/or
bacteria in medical, food/beverage and environmental solutions.
Vusion, Inc. is developing a chemical analyzer and sensor cartridge, based upon
the electronic tongue technology of University of Texas, that can instantly
analyze complex chemical solutions.
The analyzer consists of a customized housing into which the sensor cartridge
can be placed and exposed to liquid chemicals within a process plant.

18. Equipment
 Two electronic tongue systems are commercially available: the taste sensing
system SA402B (Insent Inc., Atsugi-chi, Japan) and the ASTREE e-tongue (Alpha
M.O.S, Toulouse, France). Both measure changes in electronic potential while
investigating liquid samples but the underlying sensor technologies are different.
 The taste sensing system SA402B is equipped with lipid membrane sensors 45-49
whereas the ASTREE uses chemical field effect transistor technology.
 In addition other taste sensing systems are under development as for example a
Voltametric electronic tongue . To date several studies have been performed using
electronic tongues. The electronic tongue made of following parts.
 Working Electrode :The working electrode is an innert material such as Gold,
Platinum, Glassy Carbon, iridium and rhodium etc. In these cases, the working
electrode serves as a surface on which the electrochemical takes place. It
places where redox reaction occur. Surface area should very less (few mm2)
to limit current flow

19.  Reference Electrode: An Ag/ AgCl reference electrode is
used in measuring the working electrode potential. A reference
electrode should have a constant electrochemical potential as
long as no current flows through it.
 Auxillary electrode: A stainless steel counter electrode is a
conductor that completes the cell circuit. It is generally inert
conductor.
The current flow into the solution via the working electrode
leaves the solution via the counter electrode. It does not role in
the redox reaction.
A relay box is used, enabling the working electrodes to be
connected consecutively to form four standard three electrode
configurations. The potential pulses/steps are applied by a
potentiostat which is controlled by a PC. The PC is used to set
and control the pulses, measure and store current responses
and to operate the relay box. The set-up is illustrated in Figure
4.
Fig 4: E-Tongue equipment

20. Applications of E-Tongue
 Analyze flavor ageing in beverages (for instance fruit juice,
alcoholic or non alcoholic drinks, flavored milks...)
 Quantify bitterness or “spicy level” of drinks or dissolved
compounds (e.g. bitterness measurement and prediction of
teas)
 Quantify taste masking efficiency of formulations (tablets,
syrups, powders, capsules, lozenges...)
 Analyze medicines stability in terms of taste
 Benchmark target products.
 Monitor environmental parameters.
 Monitor biological and biochemical processes.

21. COMPUSENSE FIVE
Compusense five is sensory
evaluation software that allows
you to conduct a comprehensive
test, right from the planning
stage through to analyzing and
reporting your results.
Simply install it on your local
area network to start running test
that yield reliable repeatable
results.

22. Features of Compusense Five Software
 Question types include line scale, category/hedonic, keypad, ranking,
multiple choice, standard descriptor (choose all that apply), triangle,
duo-trio, R-index, paired comparison, comment. Labeled Magnitude
Scale, and Time Intensity. Use these questions and customize them to
suit your needs.
 Flexible question designs with options such as attribute definition pop-
up boxes, the ability to hide question responses, and to force an
answer before moving to the next question.
 Add graphic images, videos, and sound files to your test. Give verbal
instructions to your panelists.

23.  Create custom templates! Customize and re-use
questionnaires, individual questions, attributes and all text
screens (such as Welcome texts, Instruction texts, and
Thank-you texts).
 Add breaks to a test. You can use a time delay, partially
present a test or allow panelists to stop and restart a test.
 Use Branching to guide panelists through a series of
questions while skipping others depending upon their
response to key questions such as product usage.

24. References
 https://www2.slideshare.net/omar-alajil/computer-aided-sensory-
evaluation?qid=ca286a4c-128f-4197-b1ca-
eb7377fb9d54&v=&b=&from_search=1
 https://globalresearchonline.net/journalcontents/volume5issue2/Article-
017.pdf
 https://en.wikipedia.org/wiki/Electronic_tongue
 https://www.elprocus.com/electronic-nose-work/