Note: Descriptions are shown in the official language in which they were submitted.
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DETECTION OF BODY ODOUR USING A VISUAL INDICATOR STRIP
Field of the Invention
This invention relates to a method of body odour detection and more precisely
a system that detects
carboxylic compounds found within body odour.
Background of the Invention
The term "body odour" herein refers to a scent generated in various parts and
zones of the human body,
most commonly axilla (underarm), perineum, and perianal areas. Human body
odour is a perceived
unpleasant scent primarily caused by skin gland excretions and bacterial
activity near the regions of those
glands. Two major types of skin glands are sweat glands and sebaceous glands.
The sebaceous glands
secrete sebum, an oily and waxy matter consisting of triglycerides, wax, and
squalene. Sebum is
odourless; however, bacterial breakdown of its compounds can produce minor
odours.
There are two kinds of sweat glands: eccrine sweat glands, which are
distributed throughout the body,
and apocrine sweat glands, which are mainly situated in axilla, perineum, and
perianal areas (Turkington
etal., 2007). It is largely the result of the apocrine sweat gland excretions
that causes body odours. These
glands secrete organic compounds metabolized by the skin flora, thereby
producing odorous substances.
Human body odour mainly arises from areas where apocrine sweat glands are
prominent, namely the
axilla, areola, anal, genital, and navel areas.
The skin flora plays an essential role in the formation of human body odour.
Bacteria residing in the axilla
metabolize compounds secreted by the apocrine sweat glands. The microflora in
the axilla mainly
comprises of various species of Corynebacterium (Bojar etal., 2004). These
bacteria manufacture lipases
that metabolize lipids in the perspiration to smaller fatty acids, molecules
that give body odours their
characteristic smell. A major representative of this group of bacteria is
Corynebacterium jeikeium, which
resides in the moist environment of the axilla. It lacks fatty acid synthase,
explaining its lipid dependence
and high activity in the lipid-rich habitat (Barzantny et al., 2012). These
lipophilic bacteria are involved in
the formation of human body odour through four major routes and mechanisms:
1.
Biotransformation of steroids. Bacterial enzymes convert steroid precursors
into 16-androstenes
which contribute to human malodour (Gower etal., 1994) .
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2. Cleavage of glutamine sites by aminoacylases. Glutamine conjugates
released by apocrine sweat
glands are cleaved by aminoacylases to produce short volatile fatty acids. A
major component of
the human axillary odour is (E)-3-methyl-2-hexenoic acid (3M2H) which is
produced through
aminoacylase activity (Zeng et al., 1991).
3. Cleavage of glycine-cysteine-(S)-conjugates by metallopeptidases and C-S
lyases. Various
enzymes are involved in cleaving glycine-cysteine conjugates released by
apocrine sweat glands
to produce volatile thiols (Hasegawa etal., 2004).
4. Metabolism of long chain fatty acids (LCFAs). The surface of skin and
sweat glands contain a wide
range of lipids. Cotynebacterium show strong lipase activity which generates
free fatty acids from
the skin lipids. Through the actions of fatty acid metabolic enzymes, these
LCFAs are subsequently
degraded to form short volatile fatty acids, which contribute to human
malodour (James etal.,
2004) .
Other lipophilic bacteria such as Propionibacterium acnes utilize lipids to
form propionic acid, a major
constituent of perspiration. The actions of Staphylococcus epidermis cause the
formation of isovaleric
acid, another source of body odour (Ara etal., 2006). Both propionibacteria
and staphylococci species are
colonized in sebaceous glands (Barzantny, Brune, & Tauch, 2012) .
Human body odour consists of various odour components. The environment of the
human axilla is mainly
characterized by fluids containing cholesterol, steroid derivatives, and a
wide range of lipids (Barzantny,
Brune, & Tauch, 2012) . These compounds are metabolized by the skin flora and
give rise to a
characteristic body odour. The three major product groups that cause human
malodour, in order of odour
contribution, are:
1. Short volatile fatty acids
2. 16-androstenes and odoriferous steroid derivatives
3. Volatile thiols
The most common of these substances present in the human body odour are shown
in the table below
(Zeng etal., 1991).
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Acids Carbonyls Alcohol Steroids
n-hexanoic g-C8-lactone Phenol 17-oxo-5a-androsten-3-y1
sulfate
2-methylhexanoic g-C9-lactone Tetradecanol cholesterol
3-methylhexanoic g-C10-lactone n-hexadecanol squalene
4-ethylpentanoic 5a-androst-16-en-3a-ol
(Z)-3-methyl-2- 5a-androst-16-en-3-one
hexanoic
2-ethylhexanoic
n-ethylheptanoic
2-methylheptanoic
(E)-3-methyl-2-
hexanoic
n-octanoic
2-methyloctanoic
4-ethylheptanoic
n-nonanoic
2-methylnonanoic
4-ethyloctanoic
n-decanoic
2-methyldecanoic
4-ethylnonanoic
9-decenoic
n-undecanoic
4-ethyldecanoic
Detection of Body Odour: Description of Prior Art and Research
In recent years, considerable efforts have been made in understanding human
body odour formation. This
emerging field of biotechnological research described above has major
implications in the cosmetic and
deodorant industry. These industries are particularly interested in developing
deodorants that target
bacteria present in the axilla (ie. Corynebacterium) and their respective
enzymes, which are involved in
the metabolic formation of odorous compounds (Barzantny et al., 2012). To gain
useful insight into body
odour control, various technologies have been developed to detect and
determine the compounds giving
rise to the characteristic body odour.
A study by Gallagher et al. (2008) applied two techniques to analyze volatile
organic compounds (VOC)
from the human axilla region using gas chromatography/mass spectrometry
(GC/MS) and gas
chromatography with flame photometric detection. Sampling of VOC profiles were
performed using solid-
phase micro-extraction (SPME), a technique that uses fibres to collect skin
metabolites, and solvent
extraction, a technique that dissolves skin lipids and organic acids in a
suitable solvent. Once sampling
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was performed, GC/MS was performed in tandem to separate volatile compounds
and identify them.
Flame photometric detection was employed to detect sulphur compounds that
would not be detectable
using conventional GC.
An emerging technology uses a modified electronic nose (E-nose) to detect and
classify human axillary
body odour (Wongchoosuk et al., 2009) . Metal oxide sensors are used to detect
volatile organic
compounds and computer software and algorithms are used to classify such
compounds. Wongchoosuk
etal. (2009) developed an E-nose specific for human body odours by
implementing a humidity correction
algorithm which takes into account the variations of moisture in human
perspiration.
Other applications of the electronic nose have been employed to detect human
body odour. A common
steroid present in skin odour, 5a-androst-16-en-3-one, was tested using
various metal oxide sensors (Di
Natale etal., 2000). An electronic nose, designed for detecting humans buried
in rubble, senses VOCs
found in body odour (Teo et al., 2002) .
Yet another novel approach for detecting odours and VOCs uses thin films of
chemically responsive dyes
in colorimetric sensor arrays. Called an Optoelectronic Nose, this technology
uses dyes that respond to
organic compounds and change colour according to sensitivity. Each odorant
produces a unique array of
colours which can be then used for the classification of compounds (Suslick,
2004).
PCT International Public No. WO 05/039656 to Macdonald etal. (2005) describes
the use of an odour-
controlling article which includes a visual indicator device for monitoring
odour absorption. The visual
indicator agent changes colour in response to the odour. This is a very
generic invention in which a wide
range of odour compounds can be detected with the use of different indicating
agents. The application of
this invention is specifically aimed to control and determine the levels of
the odours. The fact that there is
no surface contact with the odour compounds makes the invention unusable for
detecting body odour. In
this sense, this invention is deficient in that it can only be applied to
situations that result in high levels of
odour. Furthermore, this invention requires the use of an odour-absorbing
agent, which attracts odour
compounds onto its surface. The present invention eliminates the need for an
odour-absorbing agent
because direct contact of the material is sufficient for the attraction and
adherence of odour compounds.
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US Patent 7,608,459 to Yabuki et al. (2009) describes a method for determining
body odour by detecting a
substance that contains a 3-mercapto alcohol derivative. The inventors
developed this invention with the
idea that the main component responsible for apocrine odour is alcohol
compounds having thiol groups.
However, as seen above, the major odour-causing components are short volatile
fatty acids, produced
from fatty acid metabolism by the skin microflora. There are deficiencies in
this invention because it
requires sophisticated methods, such as Gas Chromatography, to quantitatively
measure the odorous
substance.
US Patent 4,777,143 to Price etal. (1988) describes a method for detecting the
presence of carboxylic
acids in a specimen. The specimen is reacted with a metal salt, forming a
complex that can be
colorimetrically detected. However, this invention is only feasible for the
detection of the specified
carboxylic acids. To detect other carboxylic acids, such as those present in
body odour, further tests that
determine which metal ion and organic solvent to use are required. Thus, this
invention is too time-
consuming and research intensive to be employed in situations where a more
facile manner is needed,
such as in personalized medicine and personalized hygiene.
US Patent 2010/0021341 to Newell (2010) describes a device specifically
designed for hunters to detect
human body odour. It comprises of a dry reactive chemical powder as an
indicator which is housed inside
a two-sided detecting packet. Although this device serves the purpose of
detecting body odour, the
deficiency therein is that it reaches a saturation limit where the reaction
stops. It is also highly ineffective
since the body odour compounds are not in direct contact with the reagent.
The prior art and research shows various applications for detecting body
odour. Despite the heightened
importance of the recent advances in the detection of body odour, a simple and
effective way to detect
body odour does not exist. These applications are very time-consuming,
expensive to perform, and not
portable. The lack of accessibility to the general public and ease of these
technologies makes them very
difficult for everyday use. As well, technologies such as the E-nose or Gas
Chromatography require expert
knowledge and aid to use them.
Advantages of the Present Invention
With an increase in hygiene consciousness among the general public, there are
growing concerns in
regards to body odour. The ability to self-identify and detect one's own body
odour has become an
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important practice. The presence of body odour has potentially consequential
effects on an individual's
social and psychosocial behaviour. It is important for individuals to be aware
of the degree of their own
body odour in order to take appropriate measures. Thus, the inventors of the
present invention found a
growing need to develop a simple and effective system for to detect and
qualitatively measure body
odour.
Since body odour largely constitutes of volatile organic fatty acids, it is
prudent that the approach to
detecting body odour includes the detection of carboxylic acids. There are
various ways of detecting
carboxylic acid groups. The present invention describes the use of a reaction
between acriflavine and
sodium nitrite. Aqueous sodium nitrite is exposed to carboxylic acid compounds
which are then reacted
with acriflavine to produce a violet colour. This reaction is highly specific
to carboxylic acids, making it
advantageous to use it for the purpose of the present invention (Johar et aL,
1971) .
Some of the novel aspects of the present invention are the use of a strip to
detect the intensity of body
odour, the use of a colorimetric reaction to detect carboxylic compounds in
body odour, the use of visual
indicating reagents to qualitatively assess the intensity of body odour, and
the use of a simple and fast
body odour detection method/the efficiency of this body odour detection
method. The major advantage
of the present invention is its ease of accessibility and use to the general
public. The invention uses a fast,
inexpensive, and portable method to detect body odour. It provides a
qualitative assessment of the
intensity of body odour and can be used as a personal hygiene check,
especially by those people who are
challenged or limited in their gustatory or olfactory senses.
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References
Ara, K., Hama, M., Akiba, S., Koike, K., Okisaka, K., Hagura, T., Tomita, F.
(2006). Foot odor due to
microbial metabolism and its control. Canadian Journal of Microbiology, 52(4),
357-364. doi:
10.1139/W05-130
Barzantny, H., Brune, I., & Tauch, A. (2012). Molecular basis of human body
odour formation: Insights
deduced from corynebacterial genome sequences. International Journal of
Cosmetic Science, 34(1), 2-
11. doi: 10.111161468-2494.2011.00669.x
Barzantny, H., Schroeder, J., Strotmeier, J., Fredrich, E., Brune, I., &
Tauch, A. (2012). The transcriptional
regulatory network of Corynebacterium jeikeium K411 and its interaction with
metabolic routes
contributing to human body odor formation. Journal of Biotechnology, 159(3),
235-248. doi:
10.1016/Mbiotec.2012.01.021
Bojar, R., Tue, C., & Holland, K. (2004). The effect of lipids on the
adherence of axillary aerobic coryneform
bacteria. Letters in Applied Microbiology, 38(6), 470-475. doi: 10.111141472-
765X.2004.01522.x
Di Natale, C., Macagnano, A., Paolesse, R., Tarizzo, E., Mantini, A., &
D'Amico, A. (2000). Human skin odor
analysis by means of an electronic nose. Sensors and Actuators B-Chemical,
65(1-3), 216-219. doi:
10.1016/S0925-4005(99)00313-5
Gallagher, M., Wysocki, J., Leyden, J. J., Spielman, A. I., Sun, X., & Preti,
G. (2008). Analyses of volatile
organic compounds from human skin. British Journal of Dermatology, /59(4), 780-
791. doi:
10.1111/0365-2133.2008.08748.x
Gower, D., Holland, K., Mallet, A., Rennie, P., & Watkins, W. (1994).
Comparison of 16-androstene steroid
concentrations in sterile apocrine sweat and axillary secretions -
interconversions of 16-androstenes
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by the axillary microflora - a mechanism for axillary odor production in man.
Journal of Steroid
Biochemistry and Molecular Biology, 48(4), 409-418. doi: 10.1016/0960-
0760(94)90082-5
Hasegawa, Y., Yabuki, M., & Matsukane, M. (2004). Identification of new
odoriferous compounds in
human axillary sweat. Chemistry & Biodiversity, /(12), 2042-2050. doi:
10.1002/cbdv.200490157
James, A., Casey, J., Hyliands, D., & Mycock, G. (2004). Fatty acid metabolism
by cutaneous bacteria and
its role in axillary malodour. World Journal of Microbiology & Biotechnology,
20(8), 787-793. doi:
10.1007/s11274-004-5843-8
Johar, G. S., Agarwala, U., & Sodhi, H. S. (1971). New methods for detection
of carboxylic acid groups in
organic compounds, with acriflavine. Talanta, /8(10) doi: 10.1016/0039-
9140(71)80177-7
Suslick, K. (2004). An optoelectronic nose: "Seeing" smells by means of
colorimetric sensor arrays. MRS
Bulletin, 29(10), 720-725. doi: 10.1557/mrs2004.209
Teo, A., Garg, H., & Puthusserypady, S. (2002). Detection of humans buried in
rubble: An electronic nose
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disorders (3rd ed). New York: Facts on
File. pp 363. ISBN 978-0-8160-6403-8.
Wongchoosuk, C., Lutz, M., & Kerdcharoen, T. (2009). Detection and
classification of human body odor
using an electronic nose. Sensors, 9(9), 7234-7249. doi: 10.3390/s90907234
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Zeng, X., Leyden, J., Lawley, H., Sawano, K., Nohara, I., & Preti, G. (1991).
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Summary of the Invention
Personal hygiene is an increasingly important aspect among individuals of the
general public. Many
consumers remain uncertain about their odour because they become desensitized
to their own scent. The
application of the present invention allows individuals to feel more confident
because it serves as a
personal check for body odour. In many parts of the world where water deficit
is both an environmental
and social constraint, bathing and/or showering of the body is not readily
practiced. To date, there does
not exist a simple, easy and effective way of detecting body odour. The
invention presented forth solves
this problem, providing an effective system for detecting body odour in a
qualitative manner. The easy
detection method provided in the present invention serves several purposes.
Firstly, it allows the
consumer to measure their body odour at any convenient time and place.
Secondly, the straightforward
method to using the present invention allows for ease of use and portability.
Thirdly, the present
invention provides a qualitative measurement of the intensity of the body
odour at the applied body area.
Most importantly, the consumer's qualitative assessment enables appropriate
decision-making in terms
of body odour control and prevention.
The present invention comprises of a visual indicator strip used to detect and
qualitatively measure body
odour. The strip includes a section where visual indicating reagents are
affixed and another section
comprising of a colour intensity scale. The reagents undergo a colorimetric
reaction upon contact with the
body odour compounds from the skin. In one embodiment of the invention, two
reagents, sodium nitrite
and acriflavine, are used to detect carboxylic acids in body odour. The change
of colour on the strip and
its intensity can be qualitatively assessed using the colour intensity scale.
Brief Description of the Drawings
FIG. 1 is the housing of the strip in its entirety.
FIG. 2 is the detailed anatomy of the strip according to one embodiment of the
invention, comprising of
various sections.
FIG. 3 is the folded configuration of the strip, when the two major sections
are brought into contact.
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Detailed Description of the Art
The housing of the present invention is shown in Figure 1. The housing
comprises of material that will
protect, preserve, and cover the strip. The housing is preferably made of
light paper material that covers
the strip in order to preserve the reagents on the strip. Its purpose is to
prevent the reagents from drying
out and/or getting contaminated from the exterior environment. In a preferred
embodiment of the
invention, the housing contains closed sealed edges 1 and an openable sealed
edge 2. The user can
remove the housing by peeling it from the openable end 2.
Figure 2 shows the strip removed from its housing or packaging material. It
consists of 3 sections. The two
equal sections 3 and 4 contain two reagents involved in the colorimetric
reaction. Section 3 is the region
of the strip furthest away from the colour intensity scale 7. Section 4 is the
region of the strip closest to
the colour intensity scale 7. Sections 3 and 4 are separated by a perforated
line 6. The perforation allows
the strip to be folded so that the reagents can be brought into contact with
one another, leading to the
initiation of the reaction. In a preferred embodiment of the invention,
section 5 of the strip comprises of a
scale containing a range of colours 7 that correlate to the intensities of the
body odour. Additionally,
section 5 is an area where the user can hold the strip and apply it to the
body region.
In a preferred application of the invention, the user first removes the
housing of the strip. The strip is held
by the end containing section 5 and applied onto the body area (ie. the
axilla). Only section 3, the section
farthest from the intensity scale 7, should preferably be applied onto the
body area. This ensures minimal
loss of the reagents and that only one reagent is in contact with the skin.
Although it is possible to apply
the whole strip onto the body area, the reaction progression will be less
effective. Once the reagents have
been exposed to the odour-containing body area, the user folds the strip at
the perforated line 6. The two
reagents come into contact with one another and the reaction is allowed to
proceed for a preferred time
interval of 15 seconds. Figure 3 shows the folded strip conformation. Further
after, the user unfolds the
strip and observes a qualitative change in the colour of the strip. The colour
of the strip can be matched
to the closest of the colours on the intensity scale 7.
In a preferred and advantageous embodiment of the invention, the colorimetric
reaction that is employed
uses two reagents, namely sodium nitrite and acriflavine. Aqueous sodium
nitrite, with a preferred
concentration of 0.1 %w/w is added to section 3 of the strip and aqueous
acriflavine, with a preferred
concentration of 0.1 %w/w is added to section 4. As described in the
background, the reaction takes place
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when carboxylic acids from the body odour and sodium nitrite are exposed to
acriflavine solution. The
acriflavine solution is initially yellow-orange but changes to a violet colour
when the reaction proceeds.
The reaction will proceed when the strip is folded at the perforated line 6.
The change of colour and the
intensity of the change of colour can be compared to the standard intensity
scale 7 and a qualitative
assessment of the intensity of the body odour can be determined.
In further extensions to the present invention, carboxylic acid responding
calorimetric reactions other
than sodium nitrite and acriflavine can also be used. A single reagent can
also be used throughout the
strip. This includes any pH visual indicating agent that responds to
carboxylic acids, such as but not limited
to phenol red, cresol red, 3-nitrophenol, Brilliant Yellow, Bromothymol Blue,
and Chlorophenol Red.
In a preferred embodiment of the invention, the length of the strip is 7 cm
and the width of the strip is 3
cm. In a preferred construction of the strip, these dimensions are presented
as such in order to maintain
the ease of use. The thickness of the strip should be great enough so that the
strip stays rigid and firm for
easy handling. In a preferred embodiment of the invention, the thickness is
0.25 mm, similar to that of
regular US card stock. This would allow enough comfort for the user to apply
the strip on an area
containing body odour.
In the embodiment of the invention, it is preferred that the strip be
comprised of an adsorbent material.
This material will ensure that the reagents are not evaporated or removed from
the surface. The
preferred adsorbent material may consist of silica, alumina, alumina
hydroxide, aluminum oxide,
cellulose, cellulose acetate, polyamide 6 (Nylon 6), derivatives or
combinations thereof. The adsorbent
material will allow a range of aqueous reagents to be applied on its surface.
As well, this material will also
be ideal to have fine powdered reagents dispersed on its surface because of
its polymer matrix
characteristics.
While the invention has been presented in full detail with respect to the
specific embodiments, it shall
become apparent to those skilled in the art that various modifications can be
made to the invention
without departing from the scope and essence of the present invention.
