Submitted To :
Submitted By :
Mr. Manish Kumar
Deptt of food tech
B.Tech (6 sem)
What is it ?
Need of E nose
o Electronic noses are engineered to
mimic the mammalian olfactory system.
o Instrument designed to allow repeatable
identifications and classifications of
o Determines the various characteristics
properties of the odour while
eliminating operator fatigue.
Refers to the capability of reproducing human senses using sensor arrays and pattern
What is it ?
A device intended to detect odors or flavors.
Consist of :-
an array of electronic sensors used for
a neural network mechanism used for
Biological Nose E-Nose
Olfactory epithelium Sensors
Binding with proteins Interaction
Enzymatic proteins Reaction
Cell membrane depolarized Signal
Nerve impulses Circuitry and neural network
Comparison of e-nose with
o Each and every part of the electronic nose is similar
to human nose.
o Comparison Table:
The need of an e-nose
o The human sniffers are costly when compared to electronic nose.
o Speedy, reliable new technology of the gas sensors are used in the
o Detection of hazardous or poisonous gas is not possible with a human
o An e-nose also overcomes other problems associated with the human
o For the confirmation of the values obtained from a sniffer the result
obtained from the sniffer has to be compared with some other sniffer’s
o There lies a great chances of difference in the values got by each
WORKING OF E-NOSE
o An air sample is pulled by a vacuum pump.
o It is led through a tube into a small chamber consisting of electronic
o A transient response is produced as the volatile organic compounds in the
sample interact with the surface of the sensor’s active material.
o A steady state response is reached within few minutes.
o This response is then sent to a signal processing unit.
o A washing gas such as an alcohol vapour is applied to the array for a few
seconds to a minute.
o This is done to remove the odorant mixture from the surface and bulk of
the sensor's active material.
o Finally, the reference gas is again applied to the array, to prepare it for a
new measurement cycle.
o A variety of basic sensors can be used according to the nose strategy
o Each sensor in the array has different characteristics.
o The pattern of response across all the sensors in the array is used to identify
and/or characterize the odour.
Working principle of an e-nose
Electronic noses include three major parts:
I. a sample delivery system
II. a detection system
III. a computing system
I. Sample delivery system
o Enables the generation of the
headspace (volatile compounds)
of a sample.
o The system then injects this
headspace into the detection
system of the e-nose.
II. Detection system
o Consists of a sensor set, is the "reactive" part of the instrument.
o Adsorption of volatile compounds on the sensor surface causes a
physical change of the sensor; they experience a change of electrical
o A specific response is recorded by the electronic interface transforming the
signal into a digital value.
o Recorded data are then computed based on statistical models.
III. Computing system
o Works to combine the
responses of all of the
Applications of E-nose
The applications(current) of an electronic nose
Medical diagnosis and health monitoring
Application in food industry
Detection of explosives
In research and development industries
In quality control laboratories
In process and production department
In Food Industry
1. Dairy Applications
2. Meat and Poultry Applications
3. Fruit and Vegetable Applications
4. Grains and Beans Applications
5. Beverage Applications
Grains and Beans
CPS (chemical parameter spectrometry) – contains 4
Odor of classes of good ,moldy , weakly oats was predicted
classify grains contaminated with alfatoxins.
Sample of dilute vapor is pyrolysed on heated
catalyst of platinum.
Then passed through 4 amperometric sensors of diff
Each sample was measured with 4 sensors at 4 diff temp
generating 16 signals.
Signals are finally treated with ANN (artificial neural network)
Beer : Aroma scan A20S with 20 CP is used
Spanish wine makers monitored lot-to lot variation in
ingredients and detected microbial contamination early using
Enose 4048 system with 12 CP and Aroma scan A20S with
20 CP are used.
Sensors arrays have been used to determine the role
of fatty acid in aroma profiles of swiss cheese.
An “electronic nose” is a system originally created to mimic the function of an
Offers a cheap and non destructive instrument that (if properly programmed and
automated) can be operated by non specialists.
Since the whole process is automatic, the cost of each measurement is very low.
Finally, the measurement cycle should be faster in order to increase throughput.
However, this analytical instrument is more a “multi-sensor array technology”
than a real “nose”.
Whatever the sensor technology, it is still far from the sensitivity and selectivity
of a mammalian nose.
Therefore, its aim is not to totally replace either the human nose or other
o in field of crime prevention and
o detection of harmful bacteria
o detection of drug odours etc.
The possible and future applications of an electronic nose
FLGEN KOREL .& MURAT BALABAN -Uses of
electronic nose in food industry.
Elizabeth A. Baldwin . Jinhe Bai -Electronic
tongue and nose : application for food and
Juan , E.Susana- quality control through
electronic nose sysytem.
Rod goodman- The Electronic nose – from chips