177 research outputs found
Electronic Noses and Tongues: Applications for the Food and Pharmaceutical Industries
The electronic nose (e-nose) is designed to crudely mimic the mammalian nose in that most contain sensors that non-selectively interact with odor molecules to produce some sort of signal that is then sent to a computer that uses multivariate statistics to determine patterns in the data. This pattern recognition is used to determine that one sample is similar or different from another based on headspace volatiles. There are different types of e-nose sensors including organic polymers, metal oxides, quartz crystal microbalance and even gas-chromatography (GC) or combined with mass spectroscopy (MS) can be used in a non-selective manner using chemical mass or patterns from a short GC column as an e-nose or โZโ nose. The electronic tongue reacts similarly to non-volatile compounds in a liquid. This review will concentrate on applications of e-nose and e-tongue technology for edible products and pharmaceutical uses
Applications and Advances in Electronic-Nose Technologies
Electronic-nose devices have received considerable attention in the field of sensor technology during the past twenty years, largely due to the discovery of numerous applications derived from research in diverse fields of applied sciences. Recent applications of electronic nose technologies have come through advances in sensor design, material improvements, software innovations and progress in microcircuitry design and systems integration. The invention of many new e-nose sensor types and arrays, based on different detection principles and mechanisms, is closely correlated with the expansion of new applications. Electronic noses have provided a plethora of benefits to a variety of commercial industries, including the agricultural, biomedical, cosmetics, environmental, food, manufacturing, military, pharmaceutical, regulatory, and various scientific research fields. Advances have improved product attributes, uniformity, and consistency as a result of increases in quality control capabilities afforded by electronic-nose monitoring of all phases of industrial manufacturing processes. This paper is a review of the major electronic-nose technologies, developed since this specialized field was born and became prominent in the mid 1980s, and a summarization of some of the more important and useful applications that have been of greatest benefit to man
Odour Detection Methods: Olfactometry and Chemical Sensors
The complexity of the odours issue arises from the sensory nature of smell. From the evolutionary point of view olfaction is one of the oldest senses, allowing for seeking food, recognizing danger or communication: human olfaction is a protective sense as it allows the detection of potential illnesses or infections by taking into account the odour pleasantness/unpleasantness. Odours are mixtures of light and small molecules that, coming in contact with various human sensory systems, also at very low concentrations in the inhaled air, are able to stimulate an anatomical response: the experienced perception is the odour. Odour assessment is a key point in some industrial production processes (i.e., food, beverages, etc.) and it is acquiring steady importance in unusual technological fields (i.e., indoor air quality); this issue mainly concerns the environmental impact of various industrial activities (i.e., tanneries, refineries, slaughterhouses, distilleries, civil and industrial wastewater treatment plants, landfills and composting plants) as sources of olfactory nuisances, the top air pollution complaint. Although the human olfactory system is still regarded as the most important and effective โanalytical instrumentโ for odour evaluation, the demand for more objective analytical methods, along with the discovery of materials with chemo-electronic properties, has boosted the development of sensor-based machine olfaction potentially imitating the biological system. This review examines the state of the art of both human and instrumental sensing currently used for the detection of odours. The olfactometric techniques employing a panel of trained experts are discussed and the strong and weak points of odour assessment through human detection are highlighted. The main features and the working principles of modern electronic noses (E-Noses) are then described, focusing on their better performances for environmental analysis. Odour emission monitoring carried out through both the techniques is finally reviewed in order to show the complementary responses of human and instrumental sensing
An investigation into spike-based neuromorphic approaches for artificial olfactory systems
The implementation of neuromorphic methods has delivered promising results for vision and auditory sensors. These methods focus on mimicking the neuro-biological architecture to generate and process spike-based information with minimal power consumption. With increasing interest in developing low-power and robust chemical sensors, the application of neuromorphic engineering concepts for electronic noses has provided an impetus for research focusing on improving these instruments. While conventional e-noses apply computationally expensive and power-consuming data-processing strategies, neuromorphic olfactory sensors implement the biological olfaction principles found in humans and insects to simplify the handling of multivariate sensory data by generating and processing spike-based information. Over the last decade, research on neuromorphic olfaction has established the capability of these sensors to tackle problems that plague the current e-nose implementations such as drift, response time, portability, power consumption and size. This article brings together the key contributions in neuromorphic olfaction and identifies future research directions to develop near-real-time olfactory sensors that can be implemented for a range of applications such as biosecurity and environmental monitoring. Furthermore, we aim to expose the computational parallels between neuromorphic olfaction and gustation for future research focusing on the correlation of these senses
Advances in Electronic-Nose Technologies Developed for Biomedical Applications
The research and development of new electronic-nose applications in the biomedical field has accelerated at a phenomenal rate over the past 25 years. Many innovative e-nose technologies have provided solutions and applications to a wide variety of complex biomedical and healthcare problems. The purposes of this review are to present a comprehensive analysis of past and recent biomedical research findings and developments of electronic-nose sensor technologies, and to identify current and future potential e-nose applications that will continue to advance the effectiveness and efficiency of biomedical treatments and healthcare services for many years. An abundance of electronic-nose applications has been developed for a variety of healthcare sectors including diagnostics, immunology, pathology, patient recovery, pharmacology, physical therapy, physiology, preventative medicine, remote healthcare, and wound and graft healing. Specific biomedical e-nose applications range from uses in biochemical testing, blood-compatibility evaluations, disease diagnoses, and drug delivery to monitoring of metabolic levels, organ dysfunctions, and patient conditions through telemedicine. This paper summarizes the major electronic-nose technologies developed for healthcare and biomedical applications since the late 1980s when electronic aroma detection technologies were first recognized to be potentially useful in providing effective solutions to problems in the healthcare industry
An Electronic-Nose Sensor Node Based on a Polymer-Coated Surface Acoustic Wave Array for Wireless Sensor Network Applications
This study developed an electronic-nose sensor node based on a polymer-coated surface acoustic wave (SAW) sensor array. The sensor node comprised an SAW sensor array, a frequency readout circuit, and an Octopus II wireless module. The sensor array was fabricated on a large K2 128ยฐ YX LiNbO3 sensing substrate. On the surface of this substrate, an interdigital transducer (IDT) was produced with a Cr/Au film as its metallic structure. A mixed-mode frequency readout application specific integrated circuit (ASIC) was fabricated using a TSMC 0.18 ฮผm process. The ASIC output was connected to a wireless module to transmit sensor data to a base station for data storage and analysis. This sensor node is applicable for wireless sensor network (WSN) applications
Electronic Noses and Tongues in Wine Industry
Producciรณn CientรญficaThe quality of wines is usually evaluated by a sensory panel formed of trained experts or traditional chemical analysis. Over the last few decades, electronic noses (e-noses) and electronic tongues have been developed to determine the quality of foods and beverages. They consist of arrays of sensors with cross-sensitivity, combined with pattern recognition software, which provide a fingerprint of the samples that can be used to discriminate or classify the samples. This holistic approach is inspired by the method used in mammals to recognize food through their senses. They have been widely applied to the analysis of wines, including quality control, aging control, or the detection of fraudulence, among others. In this paper, the current status of research and development in the field of e-noses and tongues applied to the analysis of wines is reviewed. Their potential applications in the wine industry are described. The review ends with a final comment about expected future developments.CM-P agradece a la Universidad de Valladolid por su beca PIF-UVa y CG-H por su contrato pre-doctoral JCYL (BOCYL-D-24112015-9).Ministerio de Economรญa, Industria y Competitividad โ FEDER (Grant AGL2015-67482-R)Junta de Castilla y Leรณn (programa de apoyo a proyectos de investigaciรณn - Ref. VA-032U13
๋๋ ธ๋์คํฌ ๋ฐ ๋๋ ธ๋ฒ ์งํด์ ๋ด์ฅ๋ ํ๊ฐ ์์ฉ์ฒด์ ์ต์ ์ ์์ฐ๊ณผ ๋์์ ํจํด ๋ฐ ์๊ฐํ์ ๋ํ ์์ฉ
ํ์๋
ผ๋ฌธ(๋ฐ์ฌ) -- ์์ธ๋ํ๊ต๋ํ์ : ๊ณต๊ณผ๋ํ ํํ์๋ฌผ๊ณตํ๋ถ, 2022. 8. ๋ฐํํ.G protein-coupled receptors (GPCRs) are the most intensively studied for screening drug targets. Especially, class A GPCR including olfactory receptor (OR) which accounts for about 85 % of GPCR family is more important for codifying and screening target receptors. There are about 400 kinds of ORs in human olfactory system. The interactions between ORs and odorants generate signals which are transferred to brain as combinatorial codes. Humans can discriminate more than 1 trillion olfactory stimuli with a limited number of ORs because of widespread OR-driven modulation such as inhibition and enhancement in peripheral olfactory coding. Since the sense of smell perceives the complex external world as a pattern, many studies have been conducted to mimic the response of ORs. In particular, protein-based nanobiosensor is expected as a platform to mimic the olfaction because it has advantages such as mass production, ease of reuse, and low cost.
However, reconstitution of the structure of GPCRs is challenging because almost all GPCRs produced in E. coli system are expressed as inclusion bodies. For this reason, reconstitution techniques have been developed to recover the functionality of GPCRs, such as the use of detergent micelles, nanovesicles, bicelles and nanodiscs (NDs). Among these materials, NDs have been considered the most effective reconstitution material because of their stability in various environments and their functional lifetimes.
In this thesis, ORs were produced in E. coli system with high productivity and reconstituted to ND or nanovesicle forms. Then the functional reconstituted ORs were applied to monitoring meat freshness/spoilage, disease diagnosis and practical colorimetric sensor.
First, OR was overexpressed by coexpressing effector genes, such as djlA, the membrane-bound DnaK cochaperone, and rraA, inhibitor of the mRNA-degrading activity of E. coli RNase E. The E. coli strains coexpressing DjlA or RraA suppressed protein-induced toxicity and overexpressed the ORs. By controlling the molar ratio of OR, membrane scaffold protein, and phospholipid, ND of appropriate size were made, and high-purity ND could be purified. OR-embedded NDs showed stability to various temperature and storage time.
Second, Human ORs which bind to gastric cancer and halitosis biomarkers were successfully reconstituted to ND form and purified. The NDs had various patterns to artificial saliva samples because NDs had various binding affinities to target molecules. Through principal component analysis of various patterns for artificial saliva samples, it was possible to distinguish between healthy control samples and patient samples.
Third, trace amine-associated receptors (TAARs), TAAR13c and TAAR13d, were successfully overexpressed in E. coli system and reconstituted to ND form. These NDs were utilized for development of ND-based BE-nose for monitoring meat freshness. The ND-based BE-noses was successfully performed towards diverse on-site and the various real samples and could be used to monitor freshness of meat.
Lastly, human OR1A2 (hOR1A2) was reconstituted into detergent micelle and it was used for development of colorimetric sensor detecting geraniol. Polydiacetylene (PDA) was used as secondary transducer for visualization of responses of OR. The structural and functional properties of the hOR1A2 were maintained when it was embedded in PDA/lipid nanovesicles. The hOR1A2 embedded in PDA/lipid nanovesicle caused a color transition from blue to purple when it reacted with geraniol, whereas there was no color transition when it reacted with other molecules.
In this study, various ORs were successfully reconstituted with ND or nanovesicles. The reconstructed OR is expected to be applied to food freshness monitoring, disease diagnosis by pattern analysis, and practical colorimetric sensors.G ๋จ๋ฐฑ์ง ์ฐ๊ฒฐ ์์ฉ์ฒด (GPCR)๋ ์ฝ๋ฌผ ํ์ ์คํฌ๋ฆฌ๋์ ์ํด ๊ฐ์ฅ ์ง์ค์ ์ผ๋ก ์ฐ๊ตฌ๋๋ ๋จ๋ฐฑ์ง์ด๋ค. ํนํ, GPCR ๊ณ์ด์ ์ฝ 85%๋ฅผ ์ฐจ์งํ๋ ํ๊ฐ ์์ฉ์ฒด (OR)๋ฅผ ํฌํจํ๋ ํด๋์ค A GPCR์ ํ์ ์์ฉ์ฒด๋ฅผ ์ฝ๋ํํ๊ณ ์คํฌ๋ฆฌ๋ํ๋ ๋ฐ ๋ ์ค์ํ๋ค. ์ธ๊ฐ์ ํ๊ฐ ์์คํ
์๋ ์ฝ 400 ์ข
๋ฅ์ OR์ด ์๋ค. OR๊ณผ ๋์ ๋ฌผ์ง ์ฌ์ด์ ์ํธ ์์ฉ์ ํจํด์ ์กฐํฉ์ผ๋ก ๋์ ์ ๋ฌ๋๋ ์ ํธ๋ฅผ ์์ฑํ๋ค. ์ธ๊ฐ์ ๋ง์ด ํ๊ฐ ์ฝ๋ฉ์ ์ต์ ๋ฐ ํฅ์๊ณผ ๊ฐ์ ๊ด๋ฒ์ํ OR์ ์ํ ์กฐ์ ๋ก ์ธํด ์ ํ๋ ์์ OR๋ก๋ 1์กฐ๊ฐ ์ด์์ ํ๊ฐ ์ ํธ๋ฅผ ๊ตฌ๋ณํ ์ ์๋ค. ํ๊ฐ์ ๋ณต์กํ ์ธ๋ถ ์ธ๊ณ๋ฅผ ํจํด์ผ๋ก ์ธ์ํ๊ธฐ ๋๋ฌธ์ OR์ ๋ฐ์์ ๋ชจ๋ฐฉํ๊ธฐ ์ํด ๋ง์ ์ฐ๊ตฌ๊ฐ ์ํ๋์๋ค. ํนํ, ๋จ๋ฐฑ์ง ๊ธฐ๋ฐ ๋๋
ธ๋ฐ์ด์ค์ผ์๋ ์์ฐ์ฑ, ์ฌ์ฌ์ฉ ์ฉ์ด์ฑ, ์ ๋น์ฉ ๋ฑ์ ์ฅ์ ์ด ์์ด ํ๊ฐ์ ๋ชจ๋ฐฉํ๋ ํ๋ซํผ์ผ๋ก ๊ธฐ๋๋๋ค.
๊ทธ๋ฌ๋ GPCR ๊ตฌ์กฐ์ ์ฌ๊ตฌ์ฑ์ ๋์ฅ๊ท ์์คํ
์์ ์์ฑ๋๋ ๊ฑฐ์ ๋ชจ๋ GPCR์ด ๋ด์
์ฒด๋ก ๋ฐํ๋๊ธฐ ๋๋ฌธ์ ์ด๋ ค์ด ์ผ์ด๋ค. ์ด๋ฌํ ์ด์ ๋ก ์ธ์ ๋ฏธ์
, ๋๋
ธ๋ฒ ์งํด, ๋ฐ์ด์
๋ฐ ๋๋
ธ๋์คํฌ (ND)์ ๊ฐ์ GPCR์ ๊ธฐ๋ฅ์ ๋ณต๊ตฌํ๊ธฐ ์ํ ์ฌ๊ตฌ์ฑ ๊ธฐ์ ์ด ๊ฐ๋ฐ๋์๋ค. ์ด๋ค ๋ฌผ์ง ์ค ND๋ ๋ค์ํ ํ๊ฒฝ์์์ ์์ ์ฑ๊ณผ ๊ธฐ๋ฅ์ ์๋ช
๋๋ฌธ์ ๊ฐ์ฅ ํจ๊ณผ์ ์ธ ์ฌ๊ตฌ์ฑ ๋ฌผ์ง๋ก ์ฌ๊ฒจ์ ธ ์๋ค.
๋ณธ ๋
ผ๋ฌธ์์๋ ๋์ฅ๊ท ์์คํ
์์ ๋์ ์์ฐ์ฑ์ผ๋ก OR์ ์์ฐํ์ฌ ๋๋
ธ๋์คํฌ ๋๋ ๋๋
ธ๋ฒ ์งํด ํํ๋ก ๊ตฌ์กฐ๋ฅผ ์ฌ๊ตฌ์ฑํ์๋ค. ๊ทธ๋ฐ ๋ค์ ๊ธฐ๋ฅ์ ์ผ๋ก ์ฌ๊ตฌ์ฑ๋ OR์ ์ก๋ฅ ์ ์ ๋/๋ถํจ ๋ชจ๋ํฐ๋ง, ์ง๋ณ ์ง๋จ ๋ฐ ์ค์ฉ์ ์ธ ๋น์ ์ผ์์ ์ ์ฉํ๋ค.
์ฒซ์งธ, OR์ djlA, ๋ง ๊ฒฐํฉ DnaK cochaperone ๋ฐ rraA, E. coli RNase E์ mRNA ๋ถํด ํ์ฑ ์ต์ ์ ์ ๊ฐ์ ์ดํํฐ ์ ์ ์๋ฅผ ๊ณต๋ ๋ฐํํจ์ผ๋ก์จ ๊ณผ๋ฐํ๋์๋ค. DjlA ๋๋ RraA๋ฅผ ๊ณต๋ ๋ฐํํ๋ ๋์ฅ๊ท ๊ท ์ฃผ๋ ๋จ๋ฐฑ์ง ๋ฐํ์ ์ํ ๋
์ฑ์ ์ต์ ํ๊ณ ํ๊ฐ ์์ฉ์ฒด๋ฅผ ๊ณผ๋ฐํํ์ต๋๋ค. ํ๊ฐ ์์ฉ์ฒด, ๋ง ์ง์ง์ฒด ๋จ๋ฐฑ์ง, ์ธ์ง์ง์ ๋ชฐ๋น๋ฅผ ์กฐ์ ํ์ฌ ์ ์ ํ ํฌ๊ธฐ์ ND๋ฅผ ๋ง๋ค๊ณ ๊ณ ์๋ ND๋ฅผ ์ ์ ํ ์ ์์๋ค. ํ๊ฐ ์์ฉ์ฒด๊ฐ ๋ด์ฅ๋ ND๋ ๋ค์ํ ์จ๋ ๋ฐ ๋ณด๊ด ์๊ฐ์ ๋ํด ์์ ์ฑ์ ๋ณด์๋ค.
๋์งธ, ์์ ๋ฐ ๊ตฌ์ทจ ๋ฐ์ด์ค๋ง์ปค์ ๊ฒฐํฉํ๋ ์ธ๊ฐ OR์ ND ํํ๋ก ์ฑ๊ณต์ ์ผ๋ก ์ฌ๊ตฌ์ฑ๋๊ณ ์ ์ ๋์๋ค. ND๋ ํ์ ๋ถ์์ ๋ํ ๋ค์ํ ๊ฒฐํฉ ์นํ์ฑ์ ๊ฐ์ก๊ธฐ ๋๋ฌธ์ ์ธ๊ณต ํ์ก ์ํ์ ๋ํ ๋ค์ํ ํจํด์ ๊ฐ์ก๋ค. ์ธ๊ณต ํ์ก ์ํ์ ๋ํ ๋ค์ํ ํจํด์ ์ฃผ์ฑ๋ถ ๋ถ์์ ํตํด ๊ฑด๊ฐํ ๋์กฐ๊ตฐ ์ํ๊ณผ ํ์ ์ํ์ ๊ตฌ๋ณํ ์ ์์๋ค.
์
์งธ, ๋ฏธ๋ ์๋ฏผ ๊ด๋ จ ์์ฉ์ฒด (TAAR), TAAR13c ๋ฐ TAAR13d๊ฐ ๋์ฅ๊ท ์์คํ
์์ ์ฑ๊ณต์ ์ผ๋ก ๊ณผ๋ฐํ๋์๊ณ ND ํํ๋ก ์ฌ๊ตฌ์ฑ๋์๋ค. ์ด๋ฌํ ND๋ ์ก๋ฅ ์ ์ ๋๋ฅผ ๋ชจ๋ํฐ๋งํ๊ธฐ ์ํ ND ๊ธฐ๋ฐ ์ ์ ์ฝ์ ๊ฐ๋ฐ์ ํ์ฉ๋์๋ค. ND ๊ธฐ๋ฐ ์ ์ ์ฝ๋ ๋ค์ํ ํ์ฅ ๋ฐ ์ค์ ์ํ์ ์ฑ๊ณต์ ์ผ๋ก ์๋๋์์ผ๋ฉฐ ์ก๋ฅ์ ์ ์ ๋๋ฅผ ๋ชจ๋ํฐ๋งํ๋ ๋ฐ ์ฌ์ฉํ ์ ์์๋ค.
๋ง์ง๋ง์ผ๋ก ์ธ๊ฐ OR1A2 (hOR1A2)๋ฅผ ์ธ์ ๋ฏธ์
๋ก ์ฌ๊ตฌ์ฑํ์ฌ ์ ๋ผ๋์ฌ์ ๊ฐ์งํ๋ ๋น์ ์ผ์ ๊ฐ๋ฐ์ ํ์ฉํ์๋ค. ํด๋ฆฌ๋ค์ด์์ธํธ๋ (PDA)์ ํ๊ฐ ์์ฉ์ฒด์ ๋ฐ์์ ์๊ฐํํ๊ธฐ ์ํ 2์ฐจ ๋ณํ๊ธฐ๋ก ์ฌ์ฉ๋์๋ค. hOR1A2์ ๊ตฌ์กฐ์ ๋ฐ ๊ธฐ๋ฅ์ ํน์ฑ์ PDA/์ง์ง ๋๋
ธ๋ฒ ์งํด์ ๋ด์ฅ๋์์ ๋ ์ ์ง๋์๋ค. PDA/์ง์ง ๋๋
ธ๋ฒ ์งํด์ ๋ด์ฅ๋ hOR1A2๊ฐ geraniol๊ณผ ๋ฐ์ํ ๋ ํ๋์์์ ๋ณด๋ผ์์ผ๋ก ์์ ์ ์ด๋ฅผ ์ผ์ผํจ ๋ฐ๋ฉด ๋ค๋ฅธ ๋ถ์์ ๋ฐ์ํ ๋๋ ์์ ์ ์ด๊ฐ ์์์ต๋๋ค.
์ด ์ฐ๊ตฌ์์๋ ๋ค์ํ OR์ด ND ๋๋ ๋๋
ธ๋ฒ ์งํด๋ก ์ฑ๊ณต์ ์ผ๋ก ์ฌ๊ตฌ์ฑ๋์๋ค. ์ฌ๊ตฌ์ฑ๋ OR์ ์ํ ์ ์ ๋ ๋ชจ๋ํฐ๋ง, ํจํด ๋ถ์์ ์ํ ์ง๋ณ ์ง๋จ ๋ฐ ์ค์ฉ์ ์ธ ๋น์ ์ผ์์ ์ ์ฉ๋ ์ ์์ ๊ฒ์ผ๋ก ๊ธฐ๋๊ฐ ๋๋ค.Chapter 1 Research background and objective 15
Chapter 2 Literature review 20
2.1 Olfaction 22
2.1.1 Olfactory system 21
2.1.2 Olfactory receptors 25
2.1.3 Patterns of odorants 29
2.2 Nanobiosensor 32
2.2.1 Nanobiosensor system 32
2.2.2 Components for the nanobiosensor 35
2.2.3 Nanobiosensor detecting smell 37
2.3 Biomarkers in disease and food spoilage 44
2.3.1 Gastric cancer 44
2.3.2 Halitosis 47
2.3.3 Meat spoilage 49
2.4 Expression of GPCR in E. coli system 50
Chapter 3 Experimental procedures 52
3.1 Materials 53
3.2 Gene Cloning . 54
3.3 Expression 54
3.3.1 Expression of olfactory receptors in E. coli. 54
3.3.2 Expression of membrane scaffold protein in E. coli 56
3.3.3 Expression of olfactory receptors in HEK-293T cell 57
3.4 Purification. 57
3.4.1 Purification of olfactory receptors. 57
3.4.2 Purification of membrane scaffold protein 58
3.5 Functional reconstitution of olfactory receptors 59
3.5.1 Nanodisc 59
3.5.2 Detergent micelle. 60
3.5.3 Polydiacetylene/Lipid nanovesicle 61
3.6 Characterization . 61
3.6.1 Nano-glo dual luciferase assay 61
3.6.2 SDS-PAGE analysis 62
3.6.3 Dynamic light scattering 63
3.6.4 Circular dichroism . 63
3.6.5 Tryptophan fluorescence quenching assay 63
3.7 Immobilization of olfactory receptor-embedded nanodisc on graphene 64
Chapter 4 Enhancement of olfactory receptor production in E. coli system and characterization of olfactory receptor-embedded nanodiscs. 66
4.1 Introduction 67
4.2 Expression and purification of olfactory receptor in E. coli system 69
4.3 Purification and size analysis of olfactory receptor-embedded nanodiscs. 73
4.4 Stability of immobilized olfactory receptor-embedded nanodiscs. 77
4.5 Conclusions 82
Chapter 5 Development of nanodisc-based bioelectronic nose using trace amine-associated receptors for monitoring meat freshness/spoilage . 84
5.1 Introduction 85
5.2 Characterization of TAARs 87
5.3 Performance of nanodisc-based bioelectronic nose in the liquid phase. 91
5.4 Gas sensing performance of bioelectronic nose and its application to meat spoilage 97
5.5 Measurements of real samples using TAAR nanodisc-based bioelectronic nose 99
5.6 Conclusions 104
Chapter 6 Pattern analysis for gastric cancer biomarkers using human olfactory receptor-embedded nanodiscs . 105
6.1 Introduction 106
6.2 Affinities of human olfactory receptor-embedded nanodiscs to gastric cancer biomarkers 108
6.3 Patterns for gastric cancer biomarkers in artificial saliva 112
6.4 Principal component analysis for artificial saliva samples 115
6.5 Conclusions 117
Chapter 7 Pattern analysis for halitosis biomarkers in artificial saliva using olfactory receptor-embedded nanodiscs 118
7.1 Introduction 119
7.2 Characterization of olfactory receptor-embedded nanodiscs. 120
7.3 Patterns for halitosis biomarkers in artificial saliva. 122
7.4 Principal component analysis for artificial saliva samples 125
7.5 Conclusions 127
Chapter 8 Visual detection of geraniol using human olfactory receptor embedded in polydiacetylene/lipid nanovesicle 128
8.1 Introduction 129
8.2 Functionality of hOR1A2 embedded in detergent micelle and PDA/lipid nanovesicle. 130
8.3 Structural assay of hOR1A2 embedded in detergent micelle and PDA/lipid nanovesicle. 133
8.4 Size analysis and morphology of hOR1A2 embedded in PDA/lipid nanovesicle. 135
8.5 Photoluminescence intensity of hOR1A2 embedded in PDA/lipid nanovesicle. 137
8.6 Conclusions 141
Chapter 9 Overall discussion and further suggestions. 142
Bibliography . 147
๊ตญ๋ฌธ์ด๋ก 157๋ฐ
Rapid and innovative instrumental approaches for quality and authenticity of olive oils
The quality of virgin olive oils is assessed through the determination of several analytical parameters, whose values must be within the ranges established by the different institutions involved. In addition to official methods, there is a strong need for simple, rapid, and environmentally friendly techniques for the quality control of virgin olive oils and for addressing the challenging task of determining geographical origin and detecting adulterants. Toward this purpose, some of the most interesting applications based on optical spectroscopic techniques, on the measurement of electrical characteristics and on the use of instruments equipped with electronic chemical sensors, including also other promising techniques are herein discussed. These techniques, adequately coupled with an appropriate statistical approach, appear to be promising for assessment of several quality-related parameters. The prediction of sensory attributes and of the oxidative status of virgin olive oils have also been reviewed by adopting these selected techniques, which are also considered to be potentially appropriate solutions for identification of the geographical origin of virgin olive oils and to assess their adulteration with cheaper oils. Overall, the techniques discussed are promising and cutting-edge approaches for the establishment of useful portable instruments for in situ monitoring of the quality of virgin olive oils. Practical applications: The simple, rapid, and environmentally friendly analytical approaches discussed herein represent promising analytical tools for assuring the authenticity and monitoring the quality of virgin olive oils. Such innovative techniques and tools need to be ring-tested and validated. Some innovative reviewed approaches will permit to develop useful portable instruments able to perform in situ appropriate controls also by small laboratories or olive oil mills with limited technical facilities. These equipments will be potentially usable also by trained \u201cnon-professional analytical skilled\u201d people. Some other approaches, rapid but more expensive, will be applicable mainly by quality control labs and will increase the number of samples analyzed per day, thus fostering laboratory proficiency and an effective fighting against olive oil fraud
Analysis of Odorants in Marking Fluid of Siberian Tiger (Panthera tigris altaica) Using Simultaneous Sensory and Chemical Analysis with Headspace Solid-Phase Microextraction and Multidimensional Gas Chromatography-Mass Spectrometry-Olfactometry
Scent-marking is the most effective method of communication in the presence or absence of a signaler. These complex mixtures result in a multifaceted interaction triggered by the sense of smell. The objective was to identify volatile organic compound (VOC) composition and odors emitted by total marking fluid (MF) associated with Siberian tigers (Panthera tigris altaica). Siberian tiger, an endangered species, was chosen because its MF had never been analyzed. Solid phase microextraction (SPME) for headspace volatile collection combined with multidimensional gas chromatography-mass spectrometry-olfactometry for simultaneous chemical and sensory analyses were used. Thirty-two VOCs emitted from MF were identified. 2-acetyl-1-pyrroline, the sole previously identified compound responsible for the โcharacteristicโ odor of P. tigris MF, was identified along with two additional compounds confirmed with standards (urea, furfural) and four tentatively identified compounds (3-methylbutanamine, (R)-3-methylcyclopentanone, propanedioic acid, and 3-hydroxybutanal) as being responsible for the characteristic aroma of Siberian tiger MF. Simultaneous chemical and sensory analyses improved characterization of scent-markings and identified compounds not previously reported in MF of other tiger species. This research will assist animal ecologists, behaviorists, and zookeepers in understanding how scents from specific MF compounds impact tiger and wildlife communication and improve management practices related to animal behavior. Simultaneous chemical and sensory analyses is applicable to unlocking scent-marking information for other species
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