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1.
Nutr Res Pract ; 18(3): 372-386, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38854475

RESUMO

BACKGROUND/OBJECTIVES: The growing aging population has led to an increased utilization of senior daycare centers. This study was conducted to design a program to enhance the health of older adults in senior daycare centers in Chuncheon City, South Korea. SUBJECTS/METHODS: The study explored the health conditions and dietary patterns of older adults in senior daycare centers. Participants included staff and older adults from senior daycare centers in Chuncheon City. A mixed methods research design was used to obtain both qualitative and quantitative data. Qualitative insights were obtained through in-depth interviews with 26 staff members and older adults, coupled with observations made at 10 senior daycare centers. The quantitative component comprised structured questionnaires and physical measurements of 204 older adults at these centers. RESULTS: Many of the older adults relied on the meals provided by the center due to their limited cooking abilities. Dental health issues and dysphagia were common. Interviews highlighted the budgetary constraints of the centers in providing wholesome meals and the need for government support to alleviate meal expenses and enhance quality. A structured survey of older adults showed that the average age was 83.3 yrs, with an average of 2 chronic conditions per participant. Frailty analysis of the participants revealed that 56.2% were prefrail and 32.0% were frail. Almost half of the participants (47.0%) used dentures. Based on these findings, a preventive intervention program was proposed, addressing the specific needs and challenges of older adults while promoting overall well-being and preventing frailty. CONCLUSION: Tailored health promotion strategies are crucial in senior daycare centers. Recommended interventions include staff nutrition education, improved dietary plans, and cost-effective strength training programs. These interventions aim to reduce frailty and enhance the quality of life of older adults in the community via interventions in daycare centers.

2.
Meat Sci ; 206: 109325, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37690433

RESUMO

With growing consumer interest in meat quality, the need for accurate quality assessment becomes increasingly important. One crucial factor of Korean beef quality is the longissimus muscle area, which is closely associated with both quality and yield grade. Currently, the measurement is visually assessed, introducing subjectivity and placing a substantial burden on inspectors in terms of labor. To address these challenges, we have developed a compact image acquisition system designed to acquire accurate grading assessment images of beef carcasses. Several preprocessing steps after image acquisition were conducted, including radial distortion correction and color calibration. We have employed conventional image-processing techniques and four deep-learning models to segment the longissimus muscle area using the calibrated images. Among the segmentation models, DeepLab model based on ResNet50 achieved the highest accuracy. It demonstrated a Global Accuracy, Weighted IoU, and Mean BF Score of approximately 99.26%, 98.54%, and 95.70%, respectively. The results of our study are expected to contribute to the development of objective criteria for loin area assessment. By enabling precise and consistent determination of beef carcass quality, our research has the potential to reduce labor requirements for inspectors and provide a standardized approach to assessing loin area.

3.
Sensors (Basel) ; 23(4)2023 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-36850558

RESUMO

A Tungsten-Halogen (TH) lamp is the most popular light source in NIR spectroscopy and hyperspectral imaging, which requires a warm-up to reach very high temperatures of up to 250 °C and take a long time for radiation stabilization. Consequently, it has a large enough volume to enable heat dissipation to prevent the thermal runaway of the electric circuit and turn out its power efficiency very low. These are major barriers for miniaturizing spectral systems and hyperspectral imaging devices. However, TH lamps can be replaced by pc-NIR LEDs in order to avoid high temperature and large volume. We compared the spectral emission of the available commercial pc-NIR LEDs under the same condition. As a replacement for the TH lamp, the VIS + NIR LED module was developed to combine a warm-white LED and pc-NIR LEDs. In order to feature out the availability of the VIS + NIR LED module against the TH lamp, they were used as the light source for evaluating the Soluble Solid Content (SSC) of an apple through VIS-NIR spectroscopy. The results show a remarkable feasibility in the performance of the partial least square (PLS) model using the VIS + NIR LED module; during PLS calibration, the correlation coefficient (R) values are 0.664 and 0.701, and the Mean Square Error (MSE) values are 0.681 and 0.602 for the TH lamp and VIS + NIR LED module, respectively. In VIS-NIR spectroscopy, this study indicates that the TH lamp could be replaceable with a warm-white LED and pc-NIR LEDs.

4.
Sensors (Basel) ; 21(6)2021 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-33809942

RESUMO

Biofilms formed on the surface of agro-food processing facilities can cause food poisoning by providing an environment in which bacteria can be cultured. Therefore, hygiene management through initial detection is important. This study aimed to assess the feasibility of detecting Escherichia coli (E. coli) and Salmonella typhimurium (S. typhimurium) on the surface of food processing facilities by using fluorescence hyperspectral imaging. E. coli and S. typhimurium were cultured on high-density polyethylene and stainless steel coupons, which are the main materials used in food processing facilities. We obtained fluorescence hyperspectral images for the range of 420-730 nm by emitting UV light from a 365 nm UV light source. The images were used to perform discriminant analyses (linear discriminant analysis, k-nearest neighbor analysis, and partial-least squares discriminant analysis) to identify and classify coupons on which bacteria could be cultured. The discriminant performances of specificity and sensitivity for E. coli (1-4 log CFU·cm-2) and S. typhimurium (1-6 log CFU·cm-2) were over 90% for most machine learning models used, and the highest performances were generally obtained from the k-nearest neighbor (k-NN) model. The application of the learning model to the hyperspectral image confirmed that the biofilm detection was well performed. This result indicates the possibility of rapidly inspecting biofilms using fluorescence hyperspectral images.


Assuntos
Escherichia coli O157 , Bactérias , Biofilmes , Contagem de Colônia Microbiana , Análise Discriminante , Microbiologia de Alimentos , Imageamento Hiperespectral , Aço Inoxidável
5.
Sensors (Basel) ; 21(9)2021 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-33919118

RESUMO

Contamination is a critical issue that affects food consumption adversely. Therefore, efficient detection and classification of food contaminants are essential to ensure food safety. This study applied a visible and near-infrared (VNIR) hyperspectral imaging technique to detect and classify organic residues on the metallic surfaces of food processing machinery. The experimental analysis was performed by diluting both potato and spinach juices to six different concentration levels using distilled water. The 3D hypercube data were acquired in the range of 400-1000 nm using a line-scan VNIR hyperspectral imaging system. Each diluted residue in the spectral domain was detected and classified using six classification methods, including a 1D convolutional neural network (CNN-1D) and five pre-processing methods. Among them, CNN-1D exhibited the highest classification accuracy, with a 0.99 and 0.98 calibration result and a 0.94 validation result for both spinach and potato residues. Therefore, in comparison with the validation accuracy of the support vector machine classifier (0.9 and 0.92 for spinach and potato, respectively), the CNN-1D technique demonstrated improved performance. Hence, the VNIR hyperspectral imaging technique with deep learning can potentially afford rapid and non-destructive detection and classification of organic residues in food facilities.


Assuntos
Aprendizado Profundo , Imageamento Hiperespectral , Redes Neurais de Computação , Projetos Piloto , Verduras
6.
Sensors (Basel) ; 20(14)2020 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-32708061

RESUMO

Meat consumption has shifted from a quantitative to a qualitative growth stage due to improved living standards and economic development. Recently, consumers have paid attention to quality and safety in their decision to purchase meat. However, foreign substances which are not normal food ingredients are unintentionally incorporated into meat. These should be eliminated as a hazard to quality or safety. It is important to find a fast, non-destructive, and accurate detection technique of foreign substance in the meat processing industry. Hyperspectral imaging technology has been regarded as a novel technology capable of providing large-scale imaging and continuous observation information on agricultural products and food. In this study, we considered the feasibility of the short-wave near infrared (SWIR) hyperspectral reflectance imaging technique to detect bone fragments embedded in chicken meat. De-boned chicken breast samples with thicknesses of 3, 6, and 9-mm and 5 bone fragments with lengths of about 20-30-mm are used for this experiment. The reflectance spectra (in the wavelength range from 987 to 1701-nm) of the 5 bone fragments embedded under the chicken breast fillet are collected. Our results suggested that these hyperspectral imaging technique is able to detect bone fragments in chicken breast, particularly with the use of a subtraction image (corresponding to image at 1153.8-nm and 1480.2-nm). Thus, the SWIR hyperspectral reflectance imaging technique can be potentially used to detect foreign substance embedded in meat.


Assuntos
Imageamento Hiperespectral , Carne/análise , Espectroscopia de Luz Próxima ao Infravermelho
7.
J Food Drug Anal ; 26(2): 769-777, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29567248

RESUMO

For the authentication of white rice from different geographical origins, the selection of outstanding discrimination markers is essential. In this study, 80 commercial white rice samples were collected from local markets of Korea and China and discriminated by mass spectrometry-based untargeted metabolomics approaches. Additionally, the potential markers that belong to sugars & sugar alcohols, fatty acids, and phospholipids were examined using several multivariate analyses to measure their discrimination efficiencies. Unsupervised analyses, including principal component analysis and k-means clustering demonstrated the potential of the geographical classification of white rice between Korea and China by fatty acids and phospholipids. In addition, the accuracy, goodness-of-fit (R2), goodness-of-prediction (Q2), and permutation test p-value derived from phospholipid-based partial least squares-discriminant analysis were 1.000, 0.902, 0.870, and 0.001, respectively. Random Forests further consolidated the discrimination ability of phospholipids. Furthermore, an independent validation set containing 20 white rice samples also confirmed that phospholipids were the excellent discrimination markers for white rice between two countries. In conclusion, the proposed approach successfully highlighted phospholipids as the better discrimination markers than sugars & sugar alcohols and fatty acids in differentiating white rice between Korea and China.


Assuntos
Espectrometria de Massas/métodos , Metabolômica/métodos , Oryza/química , Biomarcadores/análise , China , Análise Discriminante , Geografia , Análise Multivariada , Oryza/classificação , Oryza/metabolismo , Análise de Componente Principal
8.
J Food Drug Anal ; 26(1): 260-267, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29389563

RESUMO

The authenticity determination of white rice is crucial to prevent deceptive origin labeling and dishonest trading. However, a non-destructive and comprehensive method for rapidly discriminating the geographical origins of white rice between countries is still lacking. In the current study, we developed a volatile organic compound based geographical discrimination method using headspace solid-phase microextraction coupled to gas chromatography-mass spectrometry (HS-SPME/GC-MS) to discriminate rice samples from Korea and China. A partial least squares discriminant analysis (PLS-DA) model exhibited a good classification of white rice between Korea and China (accuracy = 0.958, goodness of fit = 0.937, goodness of prediction = 0.831, and permutation test p-value = 0.043). Combining the PLS-DA based feature selection with the differentially expressed features from the unpaired t-test and significance analysis of microarrays, 12 discriminatory biomarkers were found. Among them, hexanal and 1-hexanol have been previously known to be associated with the cultivation environment and storage conditions. Other hydrocarbon biomarkers are novel, and their impact on rice production and storage remains to be elucidated. In conclusion, our findings highlight the ability to rapidly discriminate white rice from Korea and China. The developed method maybe useful for the authenticity and quality control of white rice.


Assuntos
Cromatografia Gasosa-Espectrometria de Massas , Oryza/química , Microextração em Fase Sólida , Compostos Orgânicos Voláteis/química , Compostos Orgânicos Voláteis/isolamento & purificação , Biomarcadores , China , Metaboloma , Metabolômica/métodos , República da Coreia
9.
Sensors (Basel) ; 18(1)2018 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-29301319

RESUMO

Fusarium is a common fungal disease in grains that reduces the yield of barley and wheat. In this study, a near infrared reflectance spectroscopic technique was used with a statistical prediction model to rapidly and non-destructively discriminate grain samples contaminated with Fusarium. Reflectance spectra were acquired from hulled barley, naked barley, and wheat samples contaminated with Fusarium using near infrared reflectance (NIR) spectroscopy with a wavelength range of 1175-2170 nm. After measurement, the samples were cultured in a medium to discriminate contaminated samples. A partial least square discrimination analysis (PLS-DA) prediction model was developed using the acquired reflectance spectra and the culture results. The correct classification rate (CCR) of Fusarium for the hulled barley, naked barley, and wheat samples developed using raw spectra was 98% or higher. The accuracy of discrimination prediction improved when second and third-order derivative pretreatments were applied. The grains contaminated with Fusarium could be rapidly discriminated using spectroscopy technology and a PLS-DA discrimination model, and the potential of the non-destructive discrimination method could be verified.


Assuntos
Espectroscopia de Luz Próxima ao Infravermelho , Fusarium , Hordeum , Análise dos Mínimos Quadrados , Triticum
10.
J AOAC Int ; 101(2): 498-506, 2018 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-28762322

RESUMO

In this study, we examined the effects of different extraction methods for the GC-MS- and LC-MS-based metabolite profiling of white rice (Oryza sativa L.). In addition, the metabolite divergence of white rice cultivated in either Korea or China was also evaluated. The discrimination analysis of each extraction method for white rice from Korea and China and the corresponding discriminatory markers were estimated by unpaired t-test, principal component analysis, k-means cluster analysis, partial least-squares discriminant analysis (PLS-DA), and random forest (RF). According to the prediction parameters obtained from PLS-DA and RF classifiers as well as features that could be identified, the extraction method using 75% isopropanol heated at 100°C coupled with LC-MS analysis was confirmed to be superior to the other extraction methods. Noticeably, lysophospholipid concentrations were significantly different in white rice between Korea and China, and they are novel markers for geographical discrimination. In conclusion, our study suggests an optimized extraction and analysis method as well as novel markers for the geographical discrimination of white rice.


Assuntos
Cromatografia Líquida/métodos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Oryza/classificação , Oryza/metabolismo , Extratos Vegetais/análise , China , Análise por Conglomerados , Análise Discriminante , Ácidos Graxos/análise , Geografia , Coreia (Geográfico) , Análise dos Mínimos Quadrados , Lisofosfolipídeos/análise , Análise de Componente Principal , Açúcares/análise
11.
Sensors (Basel) ; 17(10)2017 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-28974012

RESUMO

The purpose of this study is to use near-infrared reflectance (NIR) spectroscopy equipment to nondestructively and rapidly discriminate Fusarium-infected hulled barley. Both normal hulled barley and Fusarium-infected hulled barley were scanned by using a NIR spectrometer with a wavelength range of 1175 to 2170 nm. Multiple mathematical pretreatments were applied to the reflectance spectra obtained for Fusarium discrimination and the multivariate analysis method of partial least squares discriminant analysis (PLS-DA) was used for discriminant prediction. The PLS-DA prediction model developed by applying the second-order derivative pretreatment to the reflectance spectra obtained from the side of hulled barley without crease achieved 100% accuracy in discriminating the normal hulled barley and the Fusarium-infected hulled barley. These results demonstrated the feasibility of rapid discrimination of the Fusarium-infected hulled barley by combining multivariate analysis with the NIR spectroscopic technique, which is utilized as a nondestructive detection method.


Assuntos
Hordeum , Análise Discriminante , Fusarium , Análise dos Mínimos Quadrados , Espectroscopia de Luz Próxima ao Infravermelho
12.
J Chromatogr B Analyt Technol Biomed Life Sci ; 1061-1062: 185-192, 2017 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-28743095

RESUMO

The expansion of the global rice marketplace ultimately raises concerns about authenticity control. Several analytical methods for differentiating the geographical origin of rice have been developed, yet a high-throughput method is still in demand. In this study, we developed a rapid approach using direct infusion-mass spectrometry (DI-MS) to distinguish rice products from different countries. Specifically, the elimination of the matrix effect by a polytetrafluoroethylene (PTFE) filter, a mixed-mode cation exchange (MCX) solid-phase extraction (SPE) with 20% methanol, and an MCX SPE with 100% methanol were measured. Afterward, partial least squares discriminant analysis and random forests were applied to seek the optimal discrimination method. The results revealed that the combination of MCX SPE with 100% methanol and DI-MS in positive ion mode (accuracy=1.000, R2=0.916, Q2=0.720, B/W-based p-value=0.015) or the combination of MCX SPE with 20% methanol and targeted DI-MS/MS in positive ion mode (accuracy=1.000, R2=0.931, Q2=0.849, B/W-based p-value=0.002) showed the excellent discriminatory ability. Furthermore, differentially expressed metabolites including sodiated lysophosphatidylcholine, lysophosphatidylcholine, lysophosphatidylethanolamines and lysophosphatidylglycerol classes were found. In conclusion, our study provides a rapid and reliable platform for geographical discrimination of white rice and will contribute to the authenticity control of rice products.


Assuntos
Cromatografia por Troca Iônica/métodos , Oryza/química , Extração em Fase Sólida/métodos , Espectrometria de Massas em Tandem/métodos , Reprodutibilidade dos Testes
13.
J Sci Food Agric ; 97(12): 3985-3993, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28188636

RESUMO

BACKGROUND: Non-destructive methods based on fluorescence hyperspectral imaging (HSI) techniques were developed to detect worms on fresh-cut lettuce. The optimal wavebands for detecting the worms were investigated using the one-way ANOVA and correlation analyses. RESULTS: The worm detection imaging algorithms, RSI-I(492-626)/492 , provided a prediction accuracy of 99.0%. The fluorescence HSI techniques indicated that the spectral images with a pixel size of 1 × 1 mm had the best classification accuracy for worms. CONCLUSION: The overall results demonstrate that fluorescence HSI techniques have the potential to detect worms on fresh-cut lettuce. In the future, we will focus on developing a multi-spectral imaging system to detect foreign substances such as worms, slugs and earthworms on fresh-cut lettuce. © 2017 Society of Chemical Industry.


Assuntos
Helmintos/química , Lactuca/química , Lactuca/parasitologia , Análise Espectral/métodos , Algoritmos , Animais , Fluorescência , Controle de Qualidade , Análise Espectral/instrumentação
14.
Talanta ; 151: 183-191, 2016 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-26946026

RESUMO

Illegal use of nitrogen-rich melamine (C3H6N6) to boost perceived protein content of food products such as milk, infant formula, frozen yogurt, pet food, biscuits, and coffee drinks has caused serious food safety problems. Conventional methods to detect melamine in foods, such as Enzyme-linked immunosorbent assay (ELISA), High-performance liquid chromatography (HPLC), and Gas chromatography-mass spectrometry (GC-MS), are sensitive but they are time-consuming, expensive, and labor-intensive. In this research, near-infrared (NIR) hyperspectral imaging technique combined with regression coefficient of partial least squares regression (PLSR) model was used to detect melamine particles in milk powders easily and quickly. NIR hyperspectral reflectance imaging data in the spectral range of 990-1700nm were acquired from melamine-milk powder mixture samples prepared at various concentrations ranging from 0.02% to 1%. PLSR models were developed to correlate the spectral data (independent variables) with melamine concentration (dependent variables) in melamine-milk powder mixture samples. PLSR models applying various pretreatment methods were used to reconstruct the two-dimensional PLS images. PLS images were converted to the binary images to detect the suspected melamine pixels in milk powder. As the melamine concentration was increased, the numbers of suspected melamine pixels of binary images were also increased. These results suggested that NIR hyperspectral imaging technique and the PLSR model can be regarded as an effective tool to detect melamine particles in milk powders.


Assuntos
Análise dos Mínimos Quadrados , Leite/química , Pós/química , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Triazinas/análise , Algoritmos , Animais , Análise de Alimentos/métodos , Reprodutibilidade dos Testes , Espectroscopia de Luz Próxima ao Infravermelho/instrumentação
15.
Sensors (Basel) ; 15(11): 29511-34, 2015 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-26610510

RESUMO

Rapid visible/near-infrared (VNIR) hyperspectral imaging methods, employing both a single waveband algorithm and multi-spectral algorithms, were developed in order to discrimination between sound and discolored lettuce. Reflectance spectra for sound and discolored lettuce surfaces were extracted from hyperspectral reflectance images obtained in the 400-1000 nm wavelength range. The optimal wavebands for discriminating between discolored and sound lettuce surfaces were determined using one-way analysis of variance. Multi-spectral imaging algorithms developed using ratio and subtraction functions resulted in enhanced classification accuracy of above 99.9% for discolored and sound areas on both adaxial and abaxial lettuce surfaces. Ratio imaging (RI) and subtraction imaging (SI) algorithms at wavelengths of 552/701 nm and 557-701 nm, respectively, exhibited better classification performances compared to results obtained for all possible two-waveband combinations. These results suggest that hyperspectral reflectance imaging techniques can potentially be used to discriminate between discolored and sound fresh-cut lettuce.


Assuntos
Processamento de Imagem Assistida por Computador/métodos , Lactuca/química , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Agricultura , Algoritmos , Análise de Variância , Análise de Alimentos
16.
Sensors (Basel) ; 15(11): 27420-35, 2015 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-26528973

RESUMO

This research aims to design and fabricate a system to measure the capsaicinoid content of red pepper powder in a non-destructive and rapid method using visible and near infrared spectroscopy (VNIR). The developed system scans a well-leveled powder surface continuously to minimize the influence of the placenta distribution, thus acquiring stable and representative reflectance spectra. The system incorporates flat belts driven by a sample input hopper and stepping motor, a powder surface leveler, charge-coupled device (CCD) image sensor-embedded VNIR spectrometer, fiber optic probe, and tungsten halogen lamp, and an automated reference measuring unit with a reference panel to measure the standard spectrum. The operation program includes device interface, standard reflectivity measurement, and a graphical user interface to measure the capsaicinoid content. A partial least square regression (PLSR) model was developed to predict the capsaicinoid content; 44 red pepper powder samples whose measured capsaicinoid content ranged 13.45-159.48 mg/100 g by per high-performance liquid chromatography (HPLC) and 1242 VNIR absorbance spectra acquired by the pungency measurement system were used. The determination coefficient of validation (RV2) and standard error of prediction (SEP) for the model with the first-order derivative pretreatment method for Korean red pepper powder were 0.8484 and ±13.6388 mg/100 g, respectively.


Assuntos
Capsaicina/análise , Capsicum/química , Extratos Vegetais/química , Análise dos Mínimos Quadrados , Processamento de Sinais Assistido por Computador , Espectroscopia de Luz Próxima ao Infravermelho
17.
Sensors (Basel) ; 15(4): 8884-97, 2015 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-25884791

RESUMO

Whole-cell Systemic Evolution of Ligands by Exponential enrichment (SELEX) is the process by which aptamers specific to target cells are developed. Aptamers selected by whole-cell SELEX have high affinity and specificity for bacterial surface molecules and live bacterial targets. To identify DNA aptamers specific to Staphylococcus aureus, we applied our rapid whole-cell SELEX method to a single-stranded ssDNA library. To improve the specificity and selectivity of the aptamers, we designed, selected, and developed two categories of aptamers that were selected by two kinds of whole-cell SELEX, by mixing and combining FACS analysis and a counter-SELEX process. Using this approach, we have developed a biosensor system that employs a high affinity aptamer for detection of target bacteria. FAM-labeled aptamer sequences with high binding to S. aureus, as determined by fluorescence spectroscopic analysis, were identified, and aptamer A14, selected by the basic whole-cell SELEX using a once-off FACS analysis, and which had a high binding affinity and specificity, was chosen. The binding assay was evaluated using FACS analysis. Our study demonstrated the development of a set of whole-cell SELEX derived aptamers specific to S. aureus; this approach can be used in the identification of other bacteria.


Assuntos
Aptâmeros de Nucleotídeos/genética , Técnicas Biossensoriais/métodos , Técnica de Seleção de Aptâmeros/métodos , Staphylococcus aureus/genética
18.
Biosens Bioelectron ; 67: 243-7, 2015 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-25172028

RESUMO

Rapid detection of pathogenic Salmonella in food products is extremely important for protecting the public from salmonellosis. The objective of the present study was to explore the feasibility of using a microfluidic nano-biosensor to rapidly detect pathogenic Salmonella. Quantum dot nanoparticles were used to detect Salmonella cells. For selective detection of Salmonella, anti-Salmonella polyclonal antibodies were covalently immobilized onto the quantum dot surface. To separate and concentrate the cells from the sample, superparamagnetic particles and a microfluidic chip were used. A portable fluorometer was developed to measure the fluorescence signal from the quantum dot nanoparticles attached to Salmonella in the samples. The sensitivity for detection of pathogenic Salmonella was evaluated using serially diluted Salmonella Typhimurium in borate buffer and chicken extract. The fluorescence response of the nano-biosensor increased with increasing cell concentration. The detection limit of the sensor was 10(3) CFU/mL Salmonella in both borate buffer and food extract.


Assuntos
Técnicas Biossensoriais/instrumentação , Análise de Alimentos/instrumentação , Contaminação de Alimentos/análise , Microbiologia de Alimentos/instrumentação , Dispositivos Lab-On-A-Chip/instrumentação , Salmonella/isolamento & purificação , Carga Bacteriana/instrumentação , Desenho de Equipamento , Análise de Falha de Equipamento , Separação Imunomagnética/instrumentação , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Espectrometria de Fluorescência/instrumentação
19.
Sensors (Basel) ; 14(11): 20262-73, 2014 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-25350510

RESUMO

Recent studies have suggested the need for imaging devices capable of multispectral imaging beyond the visible region, to allow for quality and safety evaluations of agricultural commodities. Conventional multispectral imaging devices lack flexibility in spectral waveband selectivity for such applications. In this paper, a recently developed portable 3CCD camera with significant improvements over existing imaging devices is presented. A beam-splitter prism assembly for 3CCD was designed to accommodate three interference filters that can be easily changed for application-specific multispectral waveband selection in the 400 to 1000 nm region. We also designed and integrated electronic components on printed circuit boards with firmware programming, enabling parallel processing, synchronization, and independent control of the three CCD sensors, to ensure the transfer of data without significant delay or data loss due to buffering. The system can stream 30 frames (3-waveband images in each frame) per second. The potential utility of the 3CCD camera system was demonstrated in the laboratory for detecting defect spots on apples.


Assuntos
Técnicas Biossensoriais/instrumentação , Frutas/anatomia & histologia , Interpretação de Imagem Assistida por Computador/instrumentação , Malus/anatomia & histologia , Refratometria/instrumentação , Processamento de Sinais Assistido por Computador/instrumentação , Análise Espectral/instrumentação , Desenho Assistido por Computador , Desenho de Equipamento , Análise de Falha de Equipamento , Lentes , Miniaturização , Semicondutores
20.
Sensors (Basel) ; 14(4): 7489-504, 2014 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-24763251

RESUMO

In this study, we developed a viability evaluation method for pepper (Capsicum annuum L.) seeds based on hyperspectral reflectance imaging. The reflectance spectra of pepper seeds in the 400-700 nm range are collected from hyperspectral reflectance images obtained using blue, green, and red LED illumination. A partial least squares-discriminant analysis (PLS-DA) model is developed to classify viable and non-viable seeds. Four spectral ranges generated with four types of LEDs (blue, green, red, and RGB), which were pretreated using various methods, are investigated to develop the classification models. The optimal PLS-DA model based on the standard normal variate for RGB LED illumination (400-700 nm) yields discrimination accuracies of 96.7% and 99.4% for viable seeds and nonviable seeds, respectively. The use of images based on the PLS-DA model with the first-order derivative of a 31.5-nm gap for red LED illumination (600-700 nm) yields 100% discrimination accuracy for both viable and nonviable seeds. The results indicate that a hyperspectral imaging technique based on LED light can be potentially applied to high-quality pepper seed sorting.


Assuntos
Capsicum/metabolismo , Imageamento Tridimensional , Fenômenos Ópticos , Sementes/metabolismo , Capsicum/crescimento & desenvolvimento , Análise Discriminante , Germinação , Análise dos Mínimos Quadrados , Análise de Regressão
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