Дисертації: "Detection of food adulteration"

1

Gu, Youyang. "Food adulteration detection using neural networks." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/106015.

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Thesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2016.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 99-100).
In food safety and regulation, there is a need for an automated system to be able to make predictions on which adulterants (unauthorized substances in food) are likely to appear in which food products. For example, we would like to know that it is plausible for Sudan I, an illegal red dye, to adulter "strawberry ice cream", but not "bread". In this work, we show a novel application of deep neural networks in solving this task. We leverage data sources of commercial food products, hierarchical properties of substances, and documented cases of adulterations to characterize ingredients and adulterants. Taking inspiration from natural language processing, we show the use of recurrent neural networks to generate vector representations of ingredients from Wikipedia text and make predictions. Finally, we use these representations to develop a sequential method that has the capability to improve prediction accuracy as new observations are introduced. The results outline a promising direction in the use of machine learning techniques to aid in the detection of adulterants in food.
by Youyang Gu.
M. Eng.

2

September, Danwille Jacqwin Franco. "Detection and quantification of spice adulteration by near infrared hyperspectral imaging." Thesis, Stellenbosch : University of Stellenbosch, 2011. http://hdl.handle.net/10019.1/6624.

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Thesis (MSc Food Sc)--University of Stellenbosch, 2011.
ENGLISH ABSTRACT: Near infrared hyperspectral imaging (NIR HSI) in conjunction with multivariate image analysis was evaluated for the detection of millet and buckwheat flour in ground black pepper. Additionally, midinfrared (MIR) spectroscopy was used for the quantification of millet and buckwheat flour in ground black pepper. These techniques were applied as they allow non-destructive, invasive and rapid analysis. Black pepper and adulterant (either millet or buckwheat flour) mixtures were made in 5% (w/w) increments spanning the range 0-100% (w/w). The mixtures were transferred to eppendorf tube holders and imaged with a sisuChema short wave infrared (SWIR) pushbroom imaging system across the spectral range of 1000–2498 nm. Principal component analysis (PCA) was applied to pseudo-absorbance images for the removal of unwanted data (e.g. background, shading effects and bad pixels). PCA was subsequently applied to the ‘cleaned’ data. An adulterant concentration related gradient was observed in principal component one (PC1) and a difference between black pepper adulterated with buckwheat and millet was noted in PC4. Four absorption peaks (1461, 2241, 2303 and 2347 nm) were identified in the loading line plot of PC1 that are associated with protein and oil. The loading line plot of PC4 revealed absorption peaks at 1955, 1999, 2136 and 2303 nm, that are related to protein and oil. Partial least squares discriminant analysis (PLS-DA) was applied to NIR HSI images for discrimination between black pepper adulterated with varying amounts of adulterant (millet or buckwheat). The model created with millet adulterated black pepper samples had a classification accuracy of 77%; a classification accuracy of 70% was obtained for the buckwheat adulterated black pepper samples. An average spectrum was calculated for each sample in the NIR HSI images and the resultant spectra were used for the quantification of adulterant (millet or buckwheat) in ground black pepper. All samples were also analysed using an attenuated total reflectance (ATR) Fourier transform (FT) – infrared (IR) instrument and MIR spectra were collected between 576 and 3999 cm-1. PLS regression was employed. NIR based predictions (r2 = 0.99, RMSEP = 3.02% (w/w), PLS factor = 4) were more accurate than MIR based predictions (r2 = 0.56, RMSEP = 19.94% (w/w), PLS factors = 7). Preprocessed NIR spectra revealed adulterant specific absorption bands (1743, 2112 and 2167 nm) whereas preprocessed MIR spectra revealed a buckwheat specific signal at 1574 cm-1. NIR HSI has great promise for both the qualitative and quantitative analysis of powdered food products. Our study signals the beginning of incorporating hyperspectral imaging in the analysis of powdered food substances and results can be improved with advances in instrumental development and better sample preparation.
AFRIKAANSE OPSOMMING: Die gebruik van naby infrarooi hiperspektrale beelding (NIR HB) tesame met veelvoudige beeldanalise is ondersoek vir die opsporing van stysel-verwante produkte (giers en bokwiet) in gemaalde swart pepper. Middel-infrarooi (MIR) spektroskopie is addisioneel gebruik vir die kwantifisering van hierdie stysel-verwante produkte in swart pepper. Albei hierdie tegnieke is toegepas aangesien dit deurdringend van aard is en dit bied nie-destruktiewe sowel as spoedige analise. Swart pepper en vervalsingsmiddel (giers of bokwiet) mengsels is uitgevoer in 5% (m/m) inkremente tussen 0 en 100% (m/m). Eppendorfbuishouers is met die mengsels gevul en hiperspektrale beelde is verkry deur die gebruik van ‘n sisuChema SWIR (kortgolf infrarooi) kamera met ‘n spektrale reikwydte van 1000–2498 nm. Hoofkomponent-analise (HK) is toegepas op pseudo-absorbansie beelde vir die verwydering van ongewenste data (bv. agtergrond, skadu en dooie piksels). Hoofkomponent-analise is vervolgens toegepas op die ‘skoon’ data. Hoofkomponent (HK) een (HK1) het die aanwesigheid van ‘n vervalsingsmiddel konsentrasie verwante gradient getoon terwyl HK4 ‘n verskil getoon het tussen swart pepper vervals met giers en bokwiet. Vier absorpsiepieke (1461, 2241, 2303 en 2347 nm) was geïdentifiseer binne die HK lading stip van HK1 wat met proteïen en olie geassosieer kon word. Die HK lading stip van HK4 het absorpsipieke by 1955, 1999, 2136 en 2303 nm aangedui wat verband hou met proteïen en olie. Parsiële kleinste waarde diskriminant-analise (PKW-DA) is toegepas op die hiperspektrale beelde vir die moontlike onderskeiding tussen swart pepper vervals met verskeie hoeveelhede vervalsingsmiddel (giers of bokwiet). ‘n Klassifikasie koers van 77% is verkry vir die model ontwikkel met giers vervalsde swart pepper terwyl die model ontwikkel met bokwiet vervalsde swarte pepper ‘n klassifikasie koers van 70% bereik het. ‘n Gemiddelde spektrum is bereken vir elke monster in die hiperspektrale beelde en die resulterende spektra is gebruik vir die kwantifisering van vervalsingsmiddels (giers of bokwiet) in gemaalde swart pepper. ‘n ATR FT-IR instrument met spektrale reikwydte van 576-3999 cm-1 is additioneel gebruik vir die analise van alle monsters. Parsiële kleinste waarde regressie is gebruik vir kwantifikasie doeleindes. NIR gebasseerde voorspellings (r2 = 0.99, RMSEP = 3.02% (m/m), PLS faktore = 4) was meer akkuraat as die MIR gebasseerde voorspellings (r2 = 0.56, RMSEP = 19.94% (m/m), PLS faktore = 7). Vooraf behandelde NIR spektra het vervalsingsmiddel verwante absorpsiepieke (1743, 2112 en 2167 nm) aangetoon terwyl vooraf behandelde MIR spektra ‘n bokwiet verwante absorpsiepiek by 1574 cm-1 aangedui het. NIR HB toon goeie potensiaal vir beide kwalitatiewe en kwantitatiewe analise van gepoeierde voedsel produkte. Ons studie kan gesien word as die begin van die inkorporasie van hiperspektrale beelding in die analise van gepoeierde voedsel material en verbeterde resulte kan verkry word deur die vordering in instrumentasie ontwikkeling en verbeterde monstervoorbereiding.

3

Mendenhall, Ivan Von. "Rapid Determination of Milk Components and Detection of Adulteration Using Fourier Transform Infrared Technology." DigitalCommons@USU, 1991. https://digitalcommons.usu.edu/etd/5367.

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Absorption bands responding to changes in fat, protein, and lactose concentrations in milk were determined. The effects of milk fat variation and lipolysis on the infrared spectrum were studied. Absorbances from 1283 to 1100 cm-1 correlated with fat, protein, and lactose concentration and showed a low response to milk fat variation and lipolysis. A Fourier transform infrared spectrometer equipped with an attenuated total internal reflectance cell was calibrated using these absorption band s, partial least squares statistics, and milk samples from herds in Minnesota. When the fat, protein, and lactose concentrations in these samples were predicted, the standard deviations of difference (reference - infrared) were .22, .06, and .02% . When the fat, protein, and lactose concentrations in a separate set of samples from herds in California were predicted, the standard deviations of difference were 1.23, .10, and .07%. Substitution of a 15 μm pathlength transmission cell for the attenuated total internal reflectance cell changed the standard deviations of difference to .07, .11, and .06% in the calibration (Minnesota) samples and .09, .10, and .16% in the validation (California) samples. Infrared spectroscopy was used to measure whey powder in an adulterated sample of nonfat dry milk. Mixtures of nonfat dry milk containing whey powder at various concentrations were analyzed using absorption bands between 1400 and 1200 cm-1 in the infrared spectrum. There was a strong correlation (r > .99) between predicted and measured concentrations of whey powder in adulterated samples. Accuracy was not affected by processing conditions , source of nonfat dry milk, and origin of whey powder. A rapid method for detecting soybean oil in process cheese was developed. The infrared spectrum of each sample was collected using an accessory designed for analysis of solid samples. A linear relationship fit (= .98) when the ratio of absorbance at 2957 and 2852 cm-1 was plotted versus percent adulteration.

4

Menevseoglu, Ahmed. "METABOLOMICS APPROACH FOR AUTHENTICATION OF PISCO AND DETECTION OF CONTAMINANTS." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1574841283680933.

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5

Woodbury, Simon Edward. "Application of gas chromatography combustion-isotope ratio mass spectrometry to the detection of adulteration of vegetable oils." Thesis, University of Bristol, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.246268.

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6

Kelly, Simon Douglas. "The development of continuous-flow isotope ratio mass spectrometry methods and their application to the detection of food adulteration." Thesis, University of East Anglia, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.251500.

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7

Prachárová, Adriana. "Stanovení autenticity potravinářských výrobků s ovocnou složkou." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2021. http://www.nusl.cz/ntk/nusl-449765.

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The aim of this thesis was to determine the authenticity of fruit food for infants using molecular and instrumental methods. In the experimental part, plant DNA isolations from fruit leaves (peaches, apricots, plums and apples) and bananas were performed. Further, DNA was isolated also from five commercial products, and from model mixtures that were prepared in terms of content identical to the commercial mixtures. The isolated DNA was characterized and verified by qPCR with plant DNA-specific ITS2 primers. Three triple primer pairs were selected, and their specificity was evaluated when performing multiplex PCR. This method makes it possible to detect more types of fruit in one reaction, reducing the economic and time requirements for detection. As none of the selected primer pairs were sufficiently specific for the apricot, the evidence from the plum and peach was further realized using duplex PCR. High resolution melting curve analysis was used for better DNA type recognition. Subsequently, agarose gel electrophoresis was performed to analyse the fragment lengths. Furthermore, experiments have been made to identify some specific phenolic substances in commercial and model fruit mixtures by HPLC. Since phenolic substances are degradable under unsuitable storage conditions, the presence of individual compounds was not detected by this method.

8

Plášková, Anna. "Stanovení autenticity potravin rostlinného původu pomocí molekulárních metod." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2020. http://www.nusl.cz/ntk/nusl-433058.

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The aim of presented diploma thesis was to determination of authenticity of fruit baby foods for early infant feeding using molecular methods. In the experimental part, isolation kit was used for isolation of plant DNA from fruits (strawberry, apricot, raspberry, apple) and from six commercial fruit products for children. Isolated DNA was characterized and verified using PCR methods with primers specific for plant rDNA (ITS2). Specific primer pairs were designed to amplify DNA for the detection of one fruit species. Primer specificity was assessed with four fruit species. A mixture of fruit puree from the two fruits was used to determine the sensitivity of the multiplex PCR assay. Six commercial fruit products were evaluated to verify the applicability of the multiplex PCR assay. The methodology of molecular detection of fruit DNA by qPCR and multiplex qPCR (duplex) includes approaches, which enable to detect two fruits (strawberry-raspberry, apricot-apple) in one reaction and thus reduces time and money requirements.

9

Narayanan, Deepak. "Building and processing a dataset containing articles related to food adulteration." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/100641.

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Thesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2015.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (page 69).
In this thesis, I explored the problem of building a dataset containing news articles related to adulteration, and curating this dataset in an automated fashion. In particular, we looked at food-adulterant co-existence detection, query reforumulation, and entity extraction and text deduplication. All proposed algorithms were implemented in Python, and performance was evaluated on multiple datasets. Methods described in this thesis can be generalized to other applications as well.
by Deepak Narayanan.
M. Eng.

10

Pillsbury, Laura Anne. "Food cultures, total diet studies and risk management implications for global food policy and public health /." Connect to this title, 2008. http://scholarworks.umass.edu/theses/157/.

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11

Kulas, Megan. "Policy responses to reduce the opportunity for horsemeat adulteration fraud: the case of the European Union." Thesis, Kansas State University, 2014. http://hdl.handle.net/2097/18243.

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Master of Science
Department of Diagnostic Medicine/Pathobiology
Justin Kastner
Food production is changing in response to an expanding global population. The ability to distribute and process ingredients amongst many individuals and countries has brought economic benefits while also creating new problems. By increasing the complexity of the supply chain, the food industry has birthed new dynamics, thus creating new opportunities for contamination, fraud, and other threats. One threat dynamic is the varying levels of food safety and quality control at different nodes along a supply chain. Contaminations pinpoint weaknesses of a supply chain, and such weaknesses could be exploited for harm. One way foods are intentionally contaminated is through food fraud. Food fraud involves substitution, mislabeling, dilution, and other means of criminal deception. Routine testing by an independent science-based group led to the discovery of one the largest scales of substitution and mislabeling in history—the 2013 adulteration of beef products with horsemeat. Commonly referred to as the horsemeat scandal of 2013, this important event in the history of the global food system affected several regions, hundreds of products, and thousands of retailers and consumers. To date, this scandal was one of the largest incidents of food fraud. Mostly based in the European Union, the horsemeat scandal prompted the European Commission to take regulatory action. The European Union’s policy response included the creation of a five-point plan that addresses the different facets associated with the scandal. The five-point plan sought to strengthen food fraud prevention; testing programs; horse passports; official control, implementation, penalties; and origin labelling. The five-point plan is intended to decrease the fraud opportunity for the adulteration of beef with horsemeat. According to the crime triangle, a concept frequently cited in the field of criminology, fraud opportunity has three main elements: the victims, the fraudsters, and the guardian and hurdle gaps. When any of these elements change, the opportunity for a fraudster to commit a crime also changes. The research question of this thesis explores the policy responses of the European Commission. The Commission’s five-point plan targets the three elements of fraud opportunity; therefore, future fraud opportunity for the adulteration of beef products with horsemeat will theoretically decrease.

12

Surendera, Babu Aruna. "Food safety communication in Nevada needs assessment /." abstract and full text PDF (free order & download UNR users only), 2006. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1433410.

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13

Hurley, Ian Patrick Colles. "Detection of the adulteration of dairy products using immunological and DNA-based techniques." Thesis, University of Liverpool, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.439615.

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14

Di, Anibal Carolina Vanesa. "Determination of banned sudan dyes in culinary spices through spectroscopic techniques and multivariate analysis." Doctoral thesis, Universitat Rovira i Virgili, 2011. http://hdl.handle.net/10803/52794.

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La presente tesis esta focalizada en el desarrollo de métodos analíticos para determinar la adulteración de especias culinarias con colorantes Sudan I, II, III y IV. Estos colorantes están prohibidos como aditivos para uso alimentario por la legislación europea ya que son carcinógenos. Las metodologías analíticas desarrolladas están basadas en el uso de técnicas espectroscópicas como UV-visible, Resonancia Magnética de protón y Raman junto con tratamiento multivariante de los datos obtenidos. En relación al análisis multivariante, como principal objetivo se planteó el establecimiento de modelos de clasificación y posteriormente se utilizaron diversas herramientas quimiométricas con el objetivo de mejorar los resultados de clasificación: análisis exploratorio de datos, métodos de selección de variables y procesamiento de espectros, estrategias de fusión de datos y métodos de transferencia (estandarización).
This thesis is focused at developing multivariate analytical screening methodologies for determining the adulteration of culinary spices with Sudan I, II, III and IV dyes. Such dyes are prohibited to be used as additive in foods according to the European legislation because they are Class 3 carcinogens. The proposed methodologies are based on the use of spectroscopic techniques such as UV-Visible, 1H-NMR and Raman along with multivariate data treatment. The applied chemometric tools include the establishment and application of supervised classification techniques combined with exploratory data analysis, data processing and variable selection techniques to extract the maximum possible information from the spectral data. Otherwise some strategies to improve the classification have been evaluated such as data fusion strategies and multivariate transfer (standardization) methods.

15

Nicolaou-Markide, Nicoletta. "The use of analytical techniques for the rapid detection of microbial spoilage and adulteration in milk." Thesis, University of Manchester, 2011. https://www.research.manchester.ac.uk/portal/en/theses/the-use-of-analytical-techniques-for-the-rapid-detection-of-microbial-spoilage-and-adulteration-in-milk(014652ea-b404-4bd5-bd8b-5b91bcb06cff).html.

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Milk is an important nutritious component of our diet consumed by most humans on a daily basis. Microbiological spoilage affects its safe use and consumption, its organoleptic properties and is a major part of its quality control process. European Union legislation and the Hazard Analysis and the Critical Control Point (HACCP) system in the dairy industry are therefore in place to maintain both the safety and the quality of milk production in the dairy industry. A main limitation of currently used methods of milk spoilage detection in the dairy industry is the time-consuming and sometimes laborious turnover of results. Attenuated total reflectance (ATR) and high throughput (HT) Fourier transform infrared (FTIR) spectroscopy metabolic fingerprinting techniques were investigated for their speed and accuracy in the enumeration of viable bacteria in fresh pasteurized cows' milk. Data analysis was performed using principal component-discriminant function analysis (PC-DFA) and partial least squares (PLS) multivariate statistical techniques. Accurate viable microbial loads were rapidly obtained after minimal sample preparation, especially when FTIR was combined with PLS, making it a promising technique for routine use by the dairy industry. FTIR and Raman spectroscopies in combination with multivariate techniques were also explored as rapid detection and enumeration techniques of S. aureus, a common milk pathogen, and Lactococcus lactis subsp cremoris, a common lactic acid bacterium (LAB) and potential antagonist of S. aureus, in ultra-heat treatment milk. In addition, the potential growth interaction between the two organisms was investigated. FTIR spectroscopy in combination with PLS and kernel PLS (KPLS) appeared to have the greatest potential with good discrimination and enumeration attributes for the two bacterial species even when in co-culture without previous separation. Furthermore, it was shown that the metabolic effect of L. cremoris predominates when in co-culture with S. aureus in milk but with minimal converse growth interaction between the two microorganisms and therefore potential implications in the manufacture of dairy products using LAB. The widespread and high consumption of milk make it a target for potential financial gain through adulteration with cheaper products reducing quality, breaking labeling and patent laws and potentially leading to dire health consequences. The time consuming and laborious nature of currently used analytical techniques in milk authentication enabled the study of FTIR spectroscopy and matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-ToF-MS) as rapid analytical techniques in quantification of milk adulteration, using binary and tertiary fresh whole cows', goats' and sheep's milk mixture samples. Chemometric data analysis was performed using PLS and KPLS multivariate analyses. Overall, results indicated that both techniques have excellent enumeration and detection attributes for use in milk adulteration with good prospects for potential use in the dairy industry.

16

Yasir, Muhamad Samudi Bin. "Detection of irradiated potatoes." Thesis, University of Salford, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.315359.

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17

Siu, Wing-ho Joseph. "The privatization of food and environmental hygiene services in Hong Kong : an evaluation and future prospects /." Hong Kong : University of Hong Kong, 2001. http://sunzi.lib.hku.hk:8888/cgi-bin/hkuto%5Ftoc%5Fpdf?B23294930.

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18

Zhang, Yingchuan. "Product quality modeling and control based on vision inspection with an application to baking processes." Diss., Available online, Georgia Institute of Technology, 2005, 2005. http://etd.gatech.edu/theses/available/etd-04082005-150621/.

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Thesis (Ph. D.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2005.
Dr. Jennifer E. Michaels, Committee Chair ; Dr. Bonnie Heck Ferri, Committee Member ; Dr. George J. Vachtsevanos, Committee Member ; Dr. Magnus Egerstedt, Committee Member ; Dr. Farrokh, Ayazi, Committee Member ; Dr. Sheldon M. Jeter, Committee Member. Vita. Includes bibliographical references.

19

Webb-Yeates, Morgan. "Food Defense Among Meat Processing and Food Service Establishments in Kentucky." TopSCHOLAR®, 2013. http://digitalcommons.wku.edu/theses/1249.

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Agroterrorism is the deliberate introduction of a plant or animal disease with thegoal of causing fear, economic instability, illness, or death. After the 2002 terroristattacks on the World Trade Center, the security of the food supply is of increasingconcern to the United States. A major incidence of agroterrorism or food tampering would have far reaching impacts on the economy and public health. The first objective of this project was to determine knowledge and concern of agroterrorism in meat processing facilities in Kentucky, and to determine knowledge and concern of food tampering and food defense in food service establishments in Warren County, Kentucky. The second objective was to determine security strategies that were being implemented by these facilities. Two separate surveys, one for meat processors and the other for food service establishments, were designed to meet these objectives. An observational study was conducted for meat processing facilities. It was found that these facilities were generally unconcerned with agroterrorism, although a reasonable amount of security implementations were in place at these facilities. A statistical comparison between restaurants and non-restaurant food service establishments, such as schools, hospitals, and hotels, was performed. Both types of food service establishments expressed little concern about a food tampering event. Non- restaurant food service establishments were slightly more concerned than restaurants about both food tampering and food defense.

20

Hill, Helena Anne. "Non cultural detection of Campylobacter." Thesis, Queen's University Belfast, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.247366.

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21

Ireland, P. A. "Analysis of food saponins." Thesis, University of Reading, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.380851.

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22

Oplatowska, Michalina. "Detection of illegal food dyes using immunochemical techniques." Thesis, Queen's University Belfast, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.534597.

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23

Alberts, P. "Development of a novel LC-MS/MS method for the detection of adulteration of South African sauvignon blanc wines with 3-alkyl-2-methoxypyrazines." Thesis, Link to the Internet, 2008. http://hdl.handle.net/10019/805.

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24

Garcia-Amoedo, Luis Henrique. "Geléia real: análises físico-químicas e químicas úteis para a caracterização e detecção da autenticidade ou adulteração do produto." Universidade de São Paulo, 1999. http://www.teses.usp.br/teses/disponiveis/9/9131/tde-08062017-124034/.

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A geléia real é um dos principais produtos da colméia que serve como alimento para as larvas em desenvolvimento, assim como para a abelha rainha por toda a sua vida. Tem sido utilizada pelas pessoas como um complemento alimentar devido às suas propriedades revitalizantes. O principal objetivo deste trabalho foi estabelecer as análises físico-químicas e químicas que poderão ser usadas para a caracterização da geléia real e detecção de sua autenticidade ou adulteração, enfatizando-se a determinação do ácido 10-hidroxi-trans-2-decenóico (10-HDA). A proposta do trabalho está justificada pela falta de legislação com relação a padrões de identidade e qualidade da geléia real e derivados. Foram determinados emalostras puras e adulteradas (com clara de ovo, água potável, iogurte natural, pasta de amido e uma mistura de leite condensado com própolis) os teores de umidade, cinzas, Iípides, proteínas, carboidratos, 10-HDA, pH, acidez titulável, reação com lugol e teste de solubilidade em meio alcalino. Como análises complementares foram determinados os teores das vitaminas B6 , A, pró-vitamina A (β-caroteno) e vitamina E nas amostras puras. Considerando-se os resultados obtidos preconizou-se as determinações de umidade, cinzas, lípides, proteínas, carboidratos, 10-HDA e teste de solubilidade em meio alcalino como os principais itens a serem observados.
Royal jelly is one of the most important products from beehive, which is used by growing up larves like food, and also for the queen bee for her entire life. It has being used by people as a complement because of the revitalizing properties. The main objective of this work was to establish the physicalchemical and chemical analysis, which could be used for characterization of the adulteration of royal jelly, mainly the 10-hidroxy-trans-2-decenoic acid (10-HDA). The purpose of this study is justified by the lack of legislation concerning the quality and identity standards of royal jelly and derivatives. There were determined in pure and adulterated samples (with condensed milk, water, yogurt, starch, egg white) the analysis of moisture, ash, lipids, proteins, carbohydrates, 10-HDA, pH, titrate acidity, iodine reaction, solubilíty test in alkaline solution. For complementary tests It was determined the values of vitamin B6 , A, provitamin A, and E in pure samples. Considering the obtained results it was suggested the use of moisture content, ash, lipids, proteins, carbohydrates, 10-HDA and solubility in alkaline solution, as the main items to be observed.

25

Brooks, Joy Lynne. "Sensor systems for the rapid detection of microorganisms in food." Thesis, University of Reading, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.306341.

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Kemp, Francisca. "Detection of Enterobacter sakazakii in South African food products." Thesis, Link to the online version, 2005. http://hdl.handle.net/10019/1064.

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27

Hirneisen, Kirsten. "Enteric virus detection and inactivation in model food systems." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 108 p, 2008. http://proquest.umi.com/pqdweb?did=1654490301&sid=2&Fmt=2&clientId=8331&RQT=309&VName=PQD.

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28

Bjornsdottir, Kristin. "Detection and Control of Histamine-Producing Bacteria in Fish." NCSU, 2009. http://www.lib.ncsu.edu/theses/available/etd-03242009-101524/.

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Histamine (or scombroid) fish poisoning the most frequently reported illness associated with consumption of fish despite efforts of its control. The lack of adequate control measures and unreliable detection method for histamine-producing bacteria (HPB) can in part be responsible for the high incidence of the disease. The aim of the studies was to address these concerns. Available detection methods were compared and related to histamine-production. Next, a DNA probe based on the histidine decarboxylase (hdc) gene was developed and applied to colony lift hybridization for enumeration of HPB from fish. Finally, the used of phosphate as a control of HPB was examined. The results demonstrated that the potentiometric, and PCR detection methods accurately detected high-HPB but did not detect the low histamine producing isolates. Although, the culture-based Nivens method, detected low histamine-producing bacteria, it resulted in 38% false positive responses. A hdc-probe mix from four HPB detected all 73 high-histamine producing bacteria in DNA dot-blot hybridization. However, six low and seventy-three non-HPB were not detected. Application of the hdc-probe mix in colony-lift hybridization resulted in more accurate quantification of HPB compared to the commonly used Nivenâs method. Phosphate treatment of mahi-mahi samples significantly reduced histamine-production by increasing the surface pH of the fish muscle. The ability not only to detect but enumerate histamine-producing bacteria in fish is important for evaluating the potential risks and to develop adequate control strategies prior to formation of toxic levels of histamine.

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Leuer, Debora Kim. "A comparison study of food facility inspection scores and consumer complaints." CSUSB ScholarWorks, 1999. https://scholarworks.lib.csusb.edu/etd-project/1711.

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30

McFarlane, Nigel James Bruce. "Foreign body detection in food materials using Compton scattered X-rays." Thesis, University College London (University of London), 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.271701.

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31

Damario, Natália 1988. "Estudo de adulteração de queijos = espectrometria de massas por uma abordagem inovadora." [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/312429.

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Orientador: Rodrigo Ramos Catharino
Texto em português e inglês
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas
Made available in DSpace on 2018-08-25T16:32:16Z (GMT). No. of bitstreams: 1 Damario_Natalia_M.pdf: 490227 bytes, checksum: 825e09295040a1c513eea757bb6936f0 (MD5) Previous issue date: 2014
Resumo: O alto consumo global de queijos e a flutuação de disponibilidade e preço destes produtos lácteos os tornam alvos de fraudes. Uma das mais comuns é a adulteração de leites de alto valor agregado, como os de cabra e ovelha, com o então menos valioso leite de vaca, posteriormente vendido como matéria-prima para a indústria de queijo. Esta prática cria a necessidade de técnicas sensíveis para avaliar a autenticidade de queijos, incentivando o desenvolvimento e melhoria de métodos analíticos. Neste caminho, nós trazemos esta abordagem empregando a Direct Imprinting in Glass Surface Mass Spectrometry (DIGS-MS) para análise qualitativa de queijo em um instrumento MALDI. Esse método inclui uma preparação de amostra simples e eficaz além de rápida aquisição e interpretação de dados. A abordagem comprovou identificar prontamente lipídios de massas grandes em diferentes tipos de queijo, que podem ser associados a marcadores de qualidade. Também representa um potencial para controlar não só o produto final, mas também etapas produtivas, através da integração de dados estatísticos e analíticos, resultando em uma combinação poderosa para a discriminação de amostras com base no perfil lipídico. A ausência do efeito de matriz em toda cadeia analítica garante maior limpeza de sinal de espectros de massa e simplifica o processo
Abstract: High global consumption of cheeses and their availability and price fluctuations make these foodstuffs targets for frauds. One of the most common is the adulteration of highly priced milk (goat and sheep) with less valuable cow milk, which is sold as raw material for cheese industry. This creates the need for sensitive techniques to assess cheese authenticity by encouraging the development and improvement of analytical methods. In this path, we bring this approach employing Direct Imprinting in Glass Surface Mass Spectrometry (DIGS-MS) for qualitative cheese analysis in a MALDI instrument. This method includes simple and effective sample preparation and fast data acquisition and interpretation. It has proven to readily identify higher mass lipids in different types of cheese, which can be associated as quality markers. This can also represent potential to control not only the final product, but also productive stages, by integrating analytical and statistical data, resulting in a powerful combination for sample discrimination based on lipid profiles. The absence of matrix effect in the whole analytical chain ensures greater signal cleanliness of mass spectra and simplifies the process
Mestrado
Ciencias Biomedicas
Mestra em Ciências Médicas

32

Landgraf, Maria. "Detection of food relevant filamentous fungi by real time PCR." [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=98023946X.

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33

Henshilwood, Kathleen. "The detection of food-borne viruses in bivalve molluscan shellfish." Thesis, University of Surrey, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.367689.

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34

Almaghrabi, Merfat Abdulrahman. "Detection and determination of aflatoxin in food and human serum." Thesis, University of Leeds, 2016. http://etheses.whiterose.ac.uk/15345/.

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35

Bird, Julie Ann. "Detection of sub-lethally injured salmonellae in foods." Thesis, University of Portsmouth, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.277229.

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36

Dubbels, Anne M. "Cloning and expression of antibody fragments for detection of Listeria monocytogenes in food." Thesis, University of Aberdeen, 1996. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU078320.

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Single chain Fv (scFv) and Fv antibody fragments derived from a monoclonal antibody recognising flagellae of Listeria species were cloned, expressed and purified from Escherichia coli. ScFv and Fv were purified by affinity chromatography on anti-flagellar and anti-hydrophil 2 affinity columns respectively. These fragments successfully compete with the parent monoclonal antibody for antigen binding but do not complete with a second monoclonal antibody which recognises a different epitope on the flagellae. The amount of antibody fragments expressed has been estimated as 0.1 mg 1-1 for scFc and 0.22 mg 1-1 for Fv. The relative affinities of the scFv, Fv and parental monoclonal antibody for binding to antigen were compared. Characterisation of ScFv by antigen binding profile showed it to have a sensitivity of the same order of magnitude as the parent monoclonal. Fv had a sensitivity one order of magnitude below that of the parent monoclonal and the scFv. ScFv was purified as a dimer and analysed by HPLC size exclusion chromatography. The variable heavy region (VH) sequence has been determined for a second anti-flagellar monoclonal antibody and this has been cloned into an E. coli expression vector. An IgM monoclonal antibody with broad range specificity to bacteria has been generated and the VH sequence determined.

37

Pakpour, Sepideh. "Detection of antibiotic resistance in swine production." Thesis, McGill University, 2011. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=97152.

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Since antibiotics have been added to animal feed for decades, foodanimals and their wastes constitute a reservoir of antibiotic-resistant bacteria. Atthe Swine Complex of McGill University, the addition of antibiotics to swine feedfor subtherapeutic applications has been discontinued since January 2007. Theobjective of this work was to assess the prevalence and short-term evolution ofantibiotic resistance among bacterial populations in swine production 2.5 yearsafter this discontinuation. Feces from ten healthy pigs (6 males and 4 females)born at the Swine Complex of McGill from the same sow and administered feedwithout antibiotics were sampled during suckling, weanling, growing andfinishing. The percentage of chlortetracycline-resistant anaerobic bacterialpopulations (TetR) was higher than that of tylosin-resistant anaerobic bacterialpopulations (TylR) at weanling, growing and finishing, with generally largerdifferences in males than in females. At the finishing stage, i.e. prior to thetransportation of animals to the slaughterhouse, resistant populations variedbetween 3.1x10^6 and 2.5x10^9 CFU g^-1. In all pigs, tet(L), tet(O) and erm(B) weredetected by PCR at suckling and weanling, whereas only tet(O) was detected atgrowing and finishing. Quantification of tet(O) by real-time PCR showed that atsuckling, the abundance of this gene was 18 times higher in females than inmales, was similar between the two genders at weanling and growing, andreached 5.1x10^5 and 5.6x10^5 copies of tet(O)/g of total DNA in the feces ofmales and females, respectively, at finishing. In this study, the high abundanceand proportion of antibiotic-resistant populations, as well as the occurrence ofresistance genes within these populations despite the discontinuation of antibioticaddition to feeds imply either that more time would be required for antibioticresistance to decrease to lower levels, and/or that factors such as the presence ofmetals in feed impose a selective pressure that maintains antibiotic resistancegenes among these bacterial populations.
Puisque des antibiotiques sont ajoutés aux moulées des animaux de fermedepuis des décennies, ces animaux et leurs déjections constituent un réservoir debactéries résistantes aux antibiotiques. Au Complexe porcin de l'UniversitéMcGill, l'ajout d'antibiotiques dans les aliments pour porcs pour les applicationssous-thérapeutiques a été interrompu en janvier 2007. L'objectif de ce travail étaitd'évaluer la prévalence et l'évolution à court terme de la résistance auxantibiotiques chez les populations bactériennes en production porcine 2,5 ansaprès cette interruption. Les matières fécales de dix porcs sains (6 mâles et 4femelles) nés au Complexe porcin de McGill de la même truie et nourris avec desmoulées sans antibiotiques ont été échantillonnées durant les phases d'allaitement,sevrage, croissance et finition. Le pourcentage de bactéries anaérobies résistantesà la chlortétracycline (TetR) était généralement plus élevé que le pourcentage debactéries anaérobies résistantes à la tylosine (TylR) lors des phases de sevrage,croissance et finition, avec des différences plus grandes chez les mâles que chezles femelles. Au stade de la finition, c'est à dire avant le transport des animauxvers l'abattoir, les populations résistantes variaient entre 3.1x10^6 et 2.5x10^9 UFCg^-1. Chez tous les porcs, les gènes tet(L), tet(O) et erm(B) ont été détectés parPCR lors des phases d'allaitement et de sevrage, alors que seulement tet(O) a étédétecté en croissance et finition. La quantification de tet(O) par PCR en tempsréel a montré que, à l'allaitement, l'abondance de ce gène était de 18 fois plusélevé chez les femelles que chez les mâles, était similaire entre les deux sexes ensevrage et en croissance, et a atteint 5.1x10^5 et 5.6x10^5 copies de tet(O)/gd'ADN total dans les excréments des males et des femelles, respectivement, à laphase de finition. La forte abondance et la proportion élevée de populationsrésistantes aux antibiotiques, ainsi que la présence de gènes de résistance au seinde ces populations malgré l'interruption de l'ajout d'antibiotiques aux mouléesimpliquent soit que plus de temps serait nécessaire pour que la résistance auxantibiotiques décroisse à des niveaux inférieurs, et/ou que des facteurs tel laXII présence de métaux dans les moulées impose une pression sélective qui maintientles gènes de résistance aux antibiotiques parmi ces populations bactériennes.

38

Wilson, Ian Gerald. "Detection of Staphylococcus aureus by DNA hybridization." Thesis, Queen's University Belfast, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.335445.

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39

Ding, Yuhua. "An integrated approach to real-time multisensory inspection with an application to food processing." Diss., Available online, Georgia Institute of Technology, 2003:, 2003. http://etd.gatech.edu/theses/available/etd-11242003-180728/unrestricted/dingyuhu200312.pdf.

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Thesis (Ph. D.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2004.
Vachtsevanos, George J., Committee Chair; Dorrity, J. Lewis, Committee Member; Egerstedt, Magnus, Committee Member; Heck-Ferri, Bonnie S., Committee Co-Chair; Williams, Douglas B., Committee Member; Yezzi, Anthony J., Committee Member. Includes bibliography.

40

Lewis, Andrew (Andrew Michael). "Using Stochastic Optimization and Real-Options Models to Value Private Sector Incentives to Invest in Food Protection Measures." Thesis, North Dakota State University, 2006. https://hdl.handle.net/10365/29905.

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Agro-terrorism has become a major concern since the September 11, 2001, terrorist attacks due to characteristics that create unique problems for managing the threat of an agro-terrorist attack. The costs of trucking delays alone were in the tens of millions of dollars. Over the last few years, the government has spent billions of dollars on biological surveillance and record keeping in preventing potential attacks. Several public and private initiatives are currently in use. Examples include 1) the bio-terrorism regulation of 2004 on maintenance of records; 2) establishment of food protection centers for research and teaching excellence; and 3) investments in emerging technology, such as radio frequency monitoring (RFEM) technology, with the potential to track shipments and provide real-time data that can be used to prevent agro-terrorism risks along food supply chains. This thesis addresses the costs and risk premiums associated with alternative tracking strategies, where and when along the milk supply chain these strategies will reduce the most risks, and what policy implications are associated with the most costeffective tracking strategy. To accomplish these objectives, stochastic optimization is used to determine the costs and risk premiums of alternative tracking strategies. Next, the realoptions method along with a portfolio of options, also referred to as the "tomato garden" framework, is used to determine where and when alternative intervention strategies should be implemented to reduce the most risks. Finally, policy implications are derived on the cost-risk tradeoffs, probability of attacks, and containment efforts if there is an attack by using game theory to determine the incentives needed to motivate participants in the milk supply chain to invest in security measures.

41

Lewis, Andrew Michael. "Using Stochastic Optimization and Real-Options Models to Value Private Sector Incentives to Invest in Food Protection Measures." Thesis, North Dakota State University, 2006. https://hdl.handle.net/10365/29905.

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Agro-terrorism has become a major concern since the September 11, 2001, terrorist attacks due to characteristics that create unique problems for managing the threat of an agro-terrorist attack. The costs of trucking delays alone were in the tens of millions of dollars. Over the last few years, the government has spent billions of dollars on biological surveillance and record keeping in preventing potential attacks. Several public and private initiatives are currently in use. Examples include 1) the bio-terrorism regulation of 2004 on maintenance of records; 2) establishment of food protection centers for research and teaching excellence; and 3) investments in emerging technology, such as radio frequency monitoring (RFEM) technology, with the potential to track shipments and provide real-time data that can be used to prevent agro-terrorism risks along food supply chains. This thesis addresses the costs and risk premiums associated with alternative tracking strategies, where and when along the milk supply chain these strategies will reduce the most risks, and what policy implications are associated with the most costeffective tracking strategy. To accomplish these objectives, stochastic optimization is used to determine the costs and risk premiums of alternative tracking strategies. Next, the realoptions method along with a portfolio of options, also referred to as the "tomato garden" framework, is used to determine where and when alternative intervention strategies should be implemented to reduce the most risks. Finally, policy implications are derived on the cost-risk tradeoffs, probability of attacks, and containment efforts if there is an attack by using game theory to determine the incentives needed to motivate participants in the milk supply chain to invest in security measures.

42

Rowe, Tessa F. "Use of non-radioactive DNA probes for the detection of bacteria in irradiated foodstuffs." Thesis, University of Nottingham, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.318311.

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43

Rip, Diane. "Sample preparation methods and molecular based detection for the rapid isolation and identification of Listeria monocytogenes in food samples." Thesis, University of the Western Cape, 2006. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_1346_1255007553.

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Listeria monocytogenes is a Gram-positive bacterium responsible for listeriosis, a food-borne disease, which may result in severe illness and possible death. The importance of L. monocytogenes as a food-borne pathogen has been recognized since the 1980's when a correlation between the cunsumption of contaminated foodstuffs and human listeriosis outbreaks was observed. Listeriosis occurs with the ingestion of contaminated foods. The aim of this study involved developing DNA based methods to aid the food industry for the fast detection of L. monocytogenes in food products. Therefore assays were developed in such a way that they will have potential applications in the food idustry.

44

Cassoli, Laerte Dagher. "Validação da metodologia de infravermelho com transformada de Fourier para identificação de adulteração em leite cru." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/11/11139/tde-20102010-165655/.

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Objetivou-se avaliar a utilização da metodologia de infravermelho com transformada de Fourier (IVTF) na identificação de adulteração em leite cru. O objetivo no primeiro estudo foio de desenvolver calibração para identificação de adulteração através da comparação do espectro de leite adulterado com um espectro de referência para leite cru. Para construção do espectro referência foram coletadas 800 amostras de diferentes fazendas localizadas na região de estudo no período de agosto de 2009 a março de 2010. Através da análise de componentes principais, foram desenvolvidas oito calibrações com diferentes números de fatores (componentes principais). Para validação das diferentes calibrações, foram coletadas outras 100 amostras da mesma região de estudo. As amostras foram adulteradas com três diferentes adulterantes geralmente utilizados na adulteração do leite cru sendo eles: bicarbonato de sódio (BS), citrato de sódio (CS) e soro de queijo (SO). Para cada adulterante foram utilizadas três diferentes concentrações (BS: 0,05, 0,10 e 0,25 %; CS: 0,025, 0,050 e 0,075% e SO: 5, 10 e 20%). Para avaliação do desempenho das calibrações foram calculadas a especificidade e a sensibilidade para cada adulterante e respectivas concentrações. A especificidade foi de 92,9% na calibração com 12 fatores. Já a sensibilidade variou em função do adulterante, concentração e número de fatores. Todas as amostras adulteradas com bicarbonato foram identificadas corretamente com modelos de 10 fatores e na concentração mais baixa (0,05%). Já para o citrato, somente amostras com concentração de 0,075% foram identificadas em 93,9% dos casos para o modelo de 18 fatores. Amostras adulteradas com soro, mesmo na concentração mais alta (20%) puderam ser identificadas em menos de 47,1% dos casos, talvez pelo tratamento espectral realizado pelo software ASM em que parte do espectro não é considerado na construção das calibrações. A comparação espectral mostrou-se uma técnica interessante para identificação de leite adulterado e que também poderia antecipar a descoberta de novos adulterantes. Já no segundo estudo o objetivo foi desenvolver calibrações para determinação da concentração dos adulterantes bicarbonato de sódio, citrato de sódio e soro de queijo. Para desenvolvimento das calibrações foram utilizadas as amostras adulteradas do primeiro estudo e, para validação, foram coletadas outras 60 amostras que foram novamente adulteradas. O desempenho de cada calibração foi avaliado através da acurácia (Se), limite de detecção (LD) e coeficiente de determinação (R2). Todas as calibrações apresentaram R2 superior a 0,91 com LD de 0,015%, 0,017% e 3,9% para BS, CS e SO, respectivamente. Já a acurácia foi de 0,005%, 0,009 % e 2,26% para BS, CS e SO, respectivamente. Através dos resultados obtidos neste estudo, conclui-se que a metodologia de IVTF pode ser utilizada para determinação da concentração de bicarbonato de sódio, citrato de sódio e soro de queijo em leite cru. Associada à equipamentos automatizados, é uma opção viável no monitoramento destes adulterantes, tendo o baixo custo operacional e alto desempenho analítico como características adicionais.
The objective of this research was to evaluate the use of the methodology of Fourier Transform Infrared (FTIR) in identifying adulteration in raw milk. The objective of the first study was to develop scales to identify contamination by comparing the spectrum of adulterated milk with a reference spectrum for raw milk. To build the reference spectrum, 800 samples were collected from different farms located in the study area from August 2009 to March 2010. Through the analysis of principal components, eight scales with different numbers of factors (principal components) were developed. To validate the different calibrations, other 100 samples were collected from the same region of study. The samples were adulterated with three different adulterants commonly used in the adulteration of raw milk: sodium bicarbonate (SB), sodium citrate (SC) and whey (W). Each adulterant was used at three different concentrations (SB: 0.05, 0.10 and 0.25%; SC: 0.025, 0.050 and 0.075% and W: 5, 10 and 20%). To evaluate the performance of the calibrations, the specificity and sensitivity for each adulterant and its concentration were calculated. The specificity was 92.9% in the calibration with 12 factors. Sensitivity varied according to the adulterant, concentration and number of factors. All samples adulterated with bicarbonate were accurately identified in the 10-factor model and at the lowest concentration (0.05%). As for citrate, only samples at a concentration of 0.075% were identified in 93.9% of cases for the 18-factor model. Samples adulterated with whey, even at the highest concentration (20%) were identified in less than 47.1% of cases, which maybe attributed to the fact that part of the spectrum is not consideredin the spectral processing performed by ASM software. The spectral comparison proved to be an interesting technique for the identification of adulterated milk and that could also be used to discover new adulterants. In the second study, the aim was to develop calibrations for determining the concentration of sodium bicarbonate, sodium citrate and whey used as raw milk adulterants. To develop the calibrations, adulterated samples of the first study were used and, for validation, other 60 samples were collected and adulterated. The performance of each calibration was evaluated regarding accuracy (Se), detection limit (DL) and determination coefficient (R2). All calibrations presented R2 higher than 0.91 with DL of 0.015%, 0.017% and 3.9% for SB, SC and W, respectively. Accuracy was 0.005%, 0.009% and 2.26% for SB, SC and W, respectively. Results show that the FTIR methodology can be used for determining the concentration of sodium bicarbonate, sodium citrate and whey in raw milk. Associated with automated equipment, it is a feasible option for monitoring these adulterants, presenting low operational costs and high analytical performance as additional features.

45

Chang, Su-Sen. "Guaiacol producing Alicyclobacillus spp. differentiation, detection, and control /." Pullman, Wash. : Washington State University, 2008. http://www.dissertations.wsu.edu/Dissertations/Fall2008/S_Chang_090208.pdf.

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46

Duffy, Geraldine. "The development of rapid methods for the isolation and detection of Listeria monocytogenes from meat." Thesis, University of Ulster, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.339253.

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47

Baxter, George Andrew. "Application of optical immunobiosensor to the detection of veterinary drug residues." Thesis, Queen's University Belfast, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.301752.

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48

Afshari, Kashanian Elisa. "Detection of celery (Apium graveolens) in food with Real-Time PCR." Thesis, Uppsala University, Department of Medical Biochemistry and Microbiology, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-7130.

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Directive EC 2003/89/EC of the European Parliament and of the Council states that certain

ingredients and products derived there of known to cause allergen reactions must always be

declared. Furthermore labelling is mandatory irrespective of the amount included. The National

Food Administration therefore needs methods for monitoring the presence of allergens in food.

Methods already exist for most of the allergens on the EU-list, but an operational method for

celery (Apium graveolens) is missing.

A specific DNA-method was developed, based on TaqMan Real-Time PCR with the celery

mannitol dehydrogenase gene as target sequence. The analysis was started with homogenisation

of the sample followed by extraction of DNA. The Real-Time PCR method was shown to be

specific for celery, producing a 113 bp fragment with two celery varieties and negative results

with other closely selected species commonly present together with celery in food products (12

samples). The detection limit was 2-20 pg DNA, which corresponds to 1-7 haploid genome

copies. When evaluated with model samples of celery in meat, a detection limit of less than

0,01 % was determined. When used to analyse food products from the market, six out of seven

products declared to contain celery were correctly identified as positive.

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Orebrand, Ulrika. "detection and quantification of almond (Prunus dulcis) in food with ELISA." Thesis, Uppsala University, Department of Medical Biochemistry and Microbiology, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-7031.

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Reliable methods to analyze food for the presence of almond are important – not only for those allergic to almond, but also for monitoring the compliance with labelling regulations (EG directive 2003/89). Until now the Swedish National Food Administration has used methods like rocket immunoelectrophoresis and real-time PCR to detect almond in food. These methods are, however, not sensitive enough for protecting the most sensitive individuals. Therefore, the performance of a commercial ELISA kit was tested with regard to specificity/cross reactivity and limit of detection for almond both in solution and in different matrixes.

The limit of quantitation was at least 3,1 ppm (mg/kg) in solution and similar concentrations were measured in bisquits and chocolate. The ELISA method was about 100-fold more sensitive than rocket immunoelectrophoresis and PCR.

The specificity of the test kit was evaluated against a number of different nuts and seeds. No important cross reactivity was found. The antibodies against almond used in the kit can not differentiate between almond and apricot kernel. For such purposes the PCR method could be used.

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Bueno, Hernandez Diana. "Optical and electrochemical sensing methods for the detection of food contaminants." Thesis, Perpignan, 2016. http://www.theses.fr/2016PERP0044/document.

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Un appareil de mesure de la fluorescence, à faible coût et portable a été développé pour quantifier les concentrations d’Ochratoxine A (OTA) dans des échantillons réels. Le système est basé sur l’excitation par une UV-LED à 365 nm et un photo détecteur contrôlé par une interface dans LabVIEW. Aussi, une image capteur, CMOS, contrôlée par une interface conçue dans MATLAB. L’OTA est une molécule naturellement fluorescente. Après excitation par une UV-, l’image de la fluorescence émise est captée par une caméra et traitée en vue de la mesure de la concentration de l’OTA. Le système d’analyse a été basé sur les 3 composants rouge, vert et bleu (RGB, selon l'acronyme anglais). La gamme est linéaire entre de 2-40 µg/L. L’extraction de l’OTA est réalisée par des colonnes d'immuno affinité (IAC, selon l'acronymeanglais) et les colonnes à empreinte moléculaire (MIP, selon l'acronyme anglais) pour les échantillons de cacao, de la bière et du vin. Les résultats obtenus ont été validés par la méthode chromatographique (HPLC). L'appareil conçu est facile à utiliser, économique et portable. En outre, l'utilisation des nouvelles technologies a été inclus tels que l'emploi du smartphone pour détecter l'OTA et la création d'un APP. Des données d'image de fluorescence provenant de la caméra du smartphone et sont analysées par un ordinateur personnel et présentés dans les composantes RGB, où l'image est envoyée à l'ordinateur par WIFI et le téléphone intelligent est utilisé comme source d'énergie trop. Enfin, une APP pour le système Android a été créé pour capturer l'image et fournit les valeurs RGB. Enfin l'utilisation du traitement de l'image a été utilisée pour quantifier l'OTA dans les échantillons réels sans colonnes IAC ou MIP, employée pour extraire la mycotoxine. L’analyse a été réalisée par des techniques colorimétriques et d’analyse de la couleur
A portable and low cost fluorescence set-up to quantify the concentrations of Ochratoxin A(OTA) in real samples was developed. The detection through the device consist of anultraviolet light at 365 nm and an photo detector or a CMOS sensor controlled by anexecutable interface designed in LabVIEW or MATLAB. It has been reported that OTA is naturally fluorescent, so it allows the user to get a UV LED to excite the sample, get a value involtage when a photodetector is employed or a photograph of the OTA under excitationconditions, and process that image in order to predict the concentrations of the sample. Tocapture and process the image, in an automatically manner, the system was completely basedon the Red, Green and Blue (RGB) components. The linearity for OTA obtained in the rangeof concentrations corresponds to 2-40 µg/L. Immunoaffinity columns (IAC) and molecularimprinted polymer columns (MIP) were used with cocoa, beer and wine samples. Theobtained results were cross-validated using chromatographic method such as HPLC and theFluoroskan equipment. The developed setup is easy to use, economical and portable. Besides,the use of new tendencies was included such as employ the smartphone to detect OTA and thecreation of an APP. Fluorescence image data from the smartphone camera are analyzed by apersonal computer and presented in RGB components, where the image is sent to thecomputer by WIFI and the smartphone is used as a power source too. Finally, an APP forandroid system was created to capture the image and provides the RGB values. At the end, theuse of image processing to quantify the OTA in real samples without incorporated IAC or MIPcolumns to extract the mycotoxin from a complex solution, employing colorimetric techniquesand color analysis

Дисертації з теми "Detection of food adulteration"

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