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1.
J Water Health ; 18(4): 574-578, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32833683

RESUMO

Giardia and Cryptosporidium are recognized as leading causes of waterborne and foodborne diarrhoeal disease with worldwide distribution. The study aimed to determine the protozoan contamination of various foods of plant origin. A total of 72 samples from 27 different varieties of fresh vegetables and fruits were collected from supermarkets and open markets in North-Western Greece and were examined using conventional diagnostic methods. Two out of 72 (2.8%) samples were found positive for Cryptosporidium oocysts, while no sample was found to be positive for Giardia cysts. The results show the presence of protozoan contamination in foods of plant origin, which may constitute a potential health hazard.


Assuntos
Cryptosporidium , Contaminação de Alimentos/análise , Giardia , Animais , Criptosporidiose , Análise de Alimentos , Giardíase , Grécia , Oocistos
2.
Ecotoxicol Environ Saf ; 204: 111107, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32823057

RESUMO

Heavy metal pollution in marine environment poses a severe threat to the safety of marine products and is thus causing increasingly concerns in terms of their toxicity and potential health risks pose to human. Due to the complex matrix of marine products, a fast screening method for heavy metals at trace level with low price, reusability, high accuracy and long lifetime is of urgency and necessity for consumers and processing factories. This work described a simplified screening system through the preparation, characterization and particular application of Au nano particle sensor (AuNPS) in the complex marine matrix, the main aim is to significantly increase the stability, sensitivity and lifetime of detection system dedicated to Cu and Hg trace analysis in marine products. It is worth mentioning that, the proposed screening system was characterized through electrochemical experiments and theoretical calculations, which could be a new evidence for selecting the detection system in commercially complex samples. Importantly, the discipline of deposition and oxidative stripping process on AuNPS was explained based on the mechanism of Metal Ion Deficient Layer (MIDL), and illustrated with SEM changes during stripping process, as well as the dissolving-out rate of metals on AuNPS material. Moreover, to further improve the reusability and stability of AuNPS sensor, the complex marine matrix was purified by pre-plating interferences on indium tin oxide glass electrode. The screening system exhibited a liner response in the range of 0.02-0.10 µg mL-1 for Hg, 0.01-0.10 µg mL-1 and 0.001-0.01 µg mL-1 for Cu with the detection limits of 0.138 mg kg-1 and 1.51 mg kg-1 in marine matrix, respectively. The sensitivity and lifetime was at least two times better as compared to similar works even after 20-times use. Finally, this proposed analysis system combined with purification procedure was successfully applied for the edible and medicinal marine products analysis, meanwhile, the accuracy and stability were confirmed with standard analytical methods.


Assuntos
Análise de Alimentos/métodos , Nanopartículas Metálicas/química , Metais Pesados/análise , Eletrodos , Contaminação de Alimentos , Ouro/química , Humanos , Mercúrio/análise , Compostos de Estanho , Oligoelementos
3.
J Oleo Sci ; 69(9): 973-984, 2020 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-32788511

RESUMO

China has taken olive cultivation as a significant part of its agricultural development. Longnan city of Gansu province was marked into the world olive distribution map by International Olive Oil Council in 1998. However, so far, little research has been done on the growth and development stages of Chinese olives. The objective of this study was to investigate the dynamics changes of several quality characteristics of olive oil at different sampling times. Olive fruit of 'Chenggu-32' grown in Longnan were harvested at twenty-four time periods and used for determination of phenotypic traits and oil quality characteristics: total polyphenols and flavonoids contents, as well as fatty acid composition by using Gas Chromatography-Mass Spectrometer (GC-MS) and analysed by using Principal Components Analysis (PCA). Towards maturation, fruit moisture content decreased while oil content increased. Levels of both total flavonoids and total polyphenols contents slightly decreased first then increased. The ratio of unsaturated to saturated fatty acids was close to three. The ratio of monounsaturated fatty acids (MUFA)/ polyunsaturated fatty acids (PUFA) was from 2.28 to 4.05. The oleic acid (C18:1)/linoleic acid (C18:2) ratio was varied between 5.23 and 10.67 according to different sampling dates. The olive oil had lower oleic acid (C18:1) levels, higher linoleic acid (C18:2), linolenic acid (C18:3), and palmitic acid (C16:0) levels compared to Codex values (2017) in some periods, which is the characteristics fatty acid composition of 'Chenggu-32' variety in Longnan, China.


Assuntos
Olea/química , Olea/genética , Azeite de Oliva/análise , Fenótipo , China , Ácidos Graxos Monoinsaturados/análise , Ácidos Graxos Insaturados/análise , Flavonoides/análise , Análise de Alimentos , Qualidade dos Alimentos , Cromatografia Gasosa-Espectrometria de Massas , Ácido Linoleico/análise , Olea/classificação , Ácido Oleico/análise , Ácido Palmítico/análise , Polifenóis/análise
4.
J Oleo Sci ; 69(9): 1031-1041, 2020 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-32788512

RESUMO

To accelerate the fermentation rate and reduce the adverse effects of undesirable microorganism contamination on rice noodle quality, the pure inoculum fermentation method was used to produce fermented rice noodles. The results indicated that the pure inoculum fermented rice slurry required 10 h to reach a stable pH value. While, the pH value of the natural, pure and natural inoculum fermented rice slurries required 54, 18 and 20 h to stabilize, respectively. Free amino acids and lactic acid concentrations of the pure inoculum fermented rice slurry were higher than those of the natural and natural inoculum fermented rice slurries. The pure inoculum fermentation modified the proximate composition and lowered the pasting viscosities of the rice flour. The texture, cooking and eating qualities of the pure inoculum fermented rice noodles were similar to those of the natural fermented ones. In addition, the pure inoculum fermented rice noodles had higher relative contents of aldehydes than other fermented rice noodles and thus had a better flavor. Therefore, pure inoculum fermentation accelerated the fermentation rate and improved the rice noodle flavor while maintaining the texture, cooking and eating qualities of the rice noodles.


Assuntos
Fermentação , Manipulação de Alimentos/métodos , Qualidade dos Alimentos , Lactobacillus plantarum/metabolismo , Oryza/química , Oryza/microbiologia , Aldeídos/análise , Análise de Alimentos , Concentração de Íons de Hidrogênio , Paladar , Fatores de Tempo
5.
J Chromatogr A ; 1626: 461383, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32797856

RESUMO

The potential of Micellar Electrokinetic Chromatography to achieve enantiomeric separations is reviewed in this article. The separation principles and the most frequently employed separation strategies to achieve chiral separations by Micellar Electrokinetic Chromatography are described. The use of chiral micellar systems alone or combined with other micellar systems or chiral selectors, as well as of mixtures of achiral micellar systems with chiral selectors is discussed together with the effect of different additives present in the separation medium. Indirect methods based on the derivatization of analytes with chiral derivatizing reagents and the use of achiral micelles are also considered. Preconcentration techniques employed to improve sensitivity and the main approaches developed to facilitate the coupling with Mass Spectrometry are included. The most recent and relevant methodologies developed by chiral Micellar Electrokinetic Chromatography and their applications in different fields are presented.


Assuntos
Cromatografia Capilar Eletrocinética Micelar/métodos , Aminoácidos/química , Ciclodextrinas/química , Análise de Alimentos , Espectrometria de Massas , Oryza/química , Oryza/metabolismo , Estereoisomerismo , Vinho/análise
6.
J Environ Sci Health B ; 55(9): 827-834, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32602778

RESUMO

The present study was carried out with the objectives to determine the occurrence of aflatoxin M1 (AFM1) in raw milk and identification of associated risk factors from three different types of animal farming systems. A total of 189 pooled raw milk samples were tested for AFM1 with enzyme linked immunosorbant assay (ELISA) as screening and high performance liquid chromatography with fluorescence detection (HPLC-FLD) as confirmatory techniques. AFM1 was found positive in 58% pooled milk samples with the mean level of 0.917 µg/L, while 50.8% and 36.5% samples were found above the legal limits set by European Commission (EC) and Food safety and standard authority of India (FSSAI), respectively for AFM1 in milk. Among all investigated risk factors, feeding of readymade concentrate feed and leftover household cereals, longer feed storage duration and feed storage quality were found significantly associated with presence of AFM1 in farm milk. High prevalence as well as levels of AFM1 in farm milk poses a health risk to the consumers especially children. Therefore, efforts are urgently required to create awareness among dairy farmers about aflatoxins contamination of feed and milk, to improve farm management practices and to control AFM1 level in milk below the legal limits.


Assuntos
Aflatoxina M1/análise , Contaminação de Alimentos/análise , Leite/química , Animais , Criança , Cromatografia Líquida de Alta Pressão , Indústria de Laticínios , Ensaio de Imunoadsorção Enzimática , Fazendas , Análise de Alimentos , Humanos , Índia , Medição de Risco , Fatores de Risco
7.
Food Chem ; 332: 127395, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32615385

RESUMO

This paper describes a simple, efficient and rapid analytical method for extraction and determination of nitrite in meat and chicken products by vortex-assisted supramolecular solvent-based liquid phase microextraction (VA-SUPRAS-LPME) prior to spectrophotometric detection. The SUPRAS was rapidly formed by the addition of a colloidal decanoic acid suspension to tetrahydrofuran (THF). The validation studies were carried out in terms of linearity, limit of detection (LOD), limit of quantitation (LOQ), matrix effects, robustness, uncertainty measurement, precision, accuracy, and certified reference material (CRM) analysis using optimized experimental conditions. The LOD, LOQ, linearity and matrix effect were 0.035 ng mL-1, 0.1 ng mL-1, 0.1-300 ng mL-1, and 9.6% respectively, with high preconcentration factor (200). The method was successfully applied for the determination of nitrite in processed products. Moreover, the results obtained by the proposed method were compared to the standard Griess method, and showed no significant differences in term of Student's t-test.


Assuntos
Galinhas , Análise de Alimentos/métodos , Microextração em Fase Líquida/métodos , Carne/análise , Nitritos/análise , Nitritos/isolamento & purificação , Solventes/química , Animais , Contaminação de Alimentos/análise , Manipulação de Alimentos , Química Verde , Humanos , Limite de Detecção , Espectrofotometria Ultravioleta
8.
Food Chem ; 332: 127392, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32623126

RESUMO

The present work describes a novel and rapid approach for evaluating total phenolic compounds (TPCs) in tea and fruits using colorimetric spots and the digital image-based (DIB) method. Colorimetric spots were formed by reacting diazotized aminobenzenes namely sulfanilic acid, sulfanilamide, or aniline with TPCs in the extract to form an azo dye. The limit of detection (LOD) was 6.5, 5.5, or 5.1 mg GAE (gallic acid equivalent) L-1 and the analytical range was 25-500, 20-500, or 18-200 mg GAE L-1, respectively. Correlation with the Folin-Ciocalteu assay was significant (Pearson coefficient, R = 0.970-0.991) while the antioxidant activity assay was moderate to high (R = 0.737-0.977). The method developed was successfully applied to the analysis of tea and fruits and showed RSD (n = 3) not exceeding 9.6, 8.5, and 9.7%, respectively. Ecologically, the DIB method developed could determine the variation of TPCs within cultivars and was found to be strongly dependent on the growing environment.


Assuntos
Benzeno/química , Colorimetria/métodos , Análise de Alimentos/métodos , Frutas/química , Fenóis/análise , Chá/química , Antioxidantes/análise , Limite de Detecção
9.
Food Chem ; 332: 127397, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32645675

RESUMO

Polyphosphates are permitted as food additives (Regulation EC No 1129/2011) but their undeclared utilisation is considered fraudulent. They improve water holding capacity of the seafood, preventing biochemical/physical changes during commercialization. The key objective of this study was the detection of polyphosphate in various seafood categories, by means of high-performance ion-exchange chromatography with suppressed conductometry (HPIEC-SCD) coupled to Q-Exactive Orbitrap high resolution mass spectrometry (HRMS-Orbitrap). Ten frozen cuttlefish samples did not reveal any treatment, while in ten frigate tunas, high concentration of orthophospate was found. Unambiguous hexametaphosphate presence was demonstrated in four prawn samples, while triphosphate was quantified (11.2 ± 4 ug/g) in another four prawn samples that contained orthophosphate (10225 ± 1102 ug/g), as well. Other samples sporadically encompassed polyphosphates profiles that varied according species and processing type. This analytical approach provided sustenance in better understanding regarding utilization of polyphosphates through HRMS fingerprinting of anionic species that would be specific in food safety control.


Assuntos
Aditivos Alimentares/análise , Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Inocuidade dos Alimentos , Polifosfatos/análise , Alimentos Marinhos/análise , Animais , Cromatografia Líquida de Alta Pressão , Cromatografia por Troca Iônica , Decapodiformes , Limite de Detecção , Espectrometria de Massas
10.
J Chromatogr A ; 1625: 461275, 2020 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-32709327

RESUMO

Efficient extraction of polar sulfonamides antibiotics from aqueous samples and food is very challenging, because they are hydrophilic, their concentration is very low, and the matrix is complex. Covalent organic frameworks (COFs), a novel porous organic material, have attracted great attention. In this work, the spherical triphenylbenzene-dimethoxyterephthaldehyde-COFs (TPB-DMTP-COFs) were synthesized by a simple room temperature method, and due to their attractive properties, such as high outstanding acid-base stability, large specific surface area, low skeletal density, inherent porosity and high crystallinity, so TPB-DMTP-COFs as ideal solid phase extraction adsorbents showed excellent adsorption performance for trace polar sulfonamides in food and water. TPB-DMTP-COFs were characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, powder X-ray diffraction, and so on. The important parameters were optimized to improve the extraction efficiency of TPB-DMTP-COFs toward sulfonamides. Analysis of sulfonamides was performed by liquid chromatography-tandem mass spectrometry. The developed method based on TPB-DMTP-COFs material achieved low limits of detection (0.5-1.0 ng L-1), wide linearity (5-1000 ng L-1), and good repeatability (2.5%-8.7%). The possible extraction mechanism was also discussed. Finally, the method was successfully applied to the enrichment and detection of sulfonamides in environmental water samples and food samples. The present study indicated that TPB-DMTP-COFs had splendid prospects in highly sensitive analysis of other pollutants in complex matrix.


Assuntos
Análise de Alimentos , Estruturas Metalorgânicas/química , Extração em Fase Sólida/métodos , Sulfonamidas/análise , Espectrometria de Massas em Tandem/métodos , Poluentes Químicos da Água/análise , Adsorção , Animais , Cromatografia Líquida , Contaminação de Alimentos/análise , Leite/química , Carne de Porco/análise , Porosidade , Sulfonamidas/química , Água/química
11.
Food Chem ; 332: 127339, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32659697

RESUMO

Non-targeted NMR-based approach has received great attention as a rapid method for food product authenticity assessment. The availability of a database containing many comparable NMR spectra produced by different spectrometers is crucial to develop functional classifiers able to discriminate rapidly the commodity class of a given food product. Nevertheless, variability in spectrometer features may hamper the production of comparable spectra due to inherent variations in signal resolution. In this paper, we report on the development of a class-discrimination model for grape juice authentication by application of non-targeted NMR spectroscopy. Different approaches for the pre-treatment of data will be described along with details about the model validation. The developed model performed excellently (95.4-100% correct predictions) even when it was tested against 650 spectra produced by 65 spectrometers with different configurations (magnetic field strength, manufacturer, age). This study may boost the use of non-targeted NMR methods for food control.


Assuntos
Análise de Alimentos/métodos , Qualidade dos Alimentos , Campos Magnéticos , Espectroscopia de Ressonância Magnética/métodos , Bases de Dados Factuais , Sucos de Frutas e Vegetais/análise , Vitis/química
12.
J Chromatogr A ; 1625: 461305, 2020 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-32709348

RESUMO

A novel kind of magnetic porous carbon nano-fibers (Fe3O4@P-CNFs) materials was successfully prepared and used as an adsorbent. Based on the above-mentioned adsorbent, a simple and effective magnetic disperse solid-phase extraction (MSPE) method was developed and first utilized to the enrichment and purification of five Sudan dyes (including Sudan I, Sudan II, Sudan III, Sudan IV, and Sudan Red 7B) in foodstuffs for the first time. High-performance liquid chromatography was used to determine the content of the Sudan dyes. The parameters affecting the extraction performance were studied and optimized, including the amount of the adsorbent and inorganic salt, type and the volume of the eluent, pH of the sample solution and extraction time. Under the optimized experimental conditions, the results show that the proposed method has a good linear relationship (r≥ 0.9993). The limits of detection range from 0.88 µg L-1 to 1.27 µg L-1. The recoveries range from 86.6% to 99.7% with the relative standard deviations ranging from 0.6% to 7.9% in the methodology validation. The above-mentioned results indicate that the proposed method is a sensitive and reliable procedure with good reproducibility for the detection of Sudan dyes residues in foodstuffs.


Assuntos
Compostos Azo/análise , Fibra de Carbono/química , Corantes/análise , Análise de Alimentos , Fenômenos Magnéticos , Nanofibras/química , Adsorção , Compostos Azo/química , Corantes/química , Concentração de Íons de Hidrogênio , Limite de Detecção , Nanofibras/ultraestrutura , Porosidade , Análise de Regressão , Reprodutibilidade dos Testes , Sais/química , Fatores de Tempo
14.
J Environ Manage ; 270: 110866, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32721312

RESUMO

Industrial symbiosis (IS) is one of the alternative ways of using natural resources in industrial processes. Eco-industrial parks (EIPs), as commonly known areas of IS practices, increase resource efficacy and reduce environmental effects by implementing waste/by product exchanges among tenant plants. Although there is an increasing but limited number of EIPs around the world, their circularity is not ensured due to high dynamic market and business conditions. This paper aims at offering an innovative design approach for EIPs taking into account the potential waste exchanges between the plants potentially to be co-located within EIPs with the goal of eliminating adverse impacts of market and business dynamicity. To this end, first an analysis of an existing IS database is conducted and the sectors potentially to be co-located are identified. Second, inspired by natural eco-systems, the food web (FW) metrics are defined to measure the potential EIPs' circularity. Third, a non-linear optimization method, namely branch and bound algorithm, is adopted to decide which plants should be included in the EIP designs to maximize the cyclicity of the networks. Lastly, a location analysis is conducted in order to co-locate the plants and to minimize the operational costs of implementing and running the EIPs. The use of this integrated approach is illustrated in a scenario analysis for four theoretical EIPs, two taking the construction industry as an anchor industry and two considering the random inclusion of various industries that can exchange wastes with the constructions industry. These EIPs' FW metric values are compared with the biological FW averages of natural ecosystems. The results support the method's ability to design sustainable and circular EIPs and point out practical implications for practitioners and policy-makers. The study is a seminal one integrating three methodologies for the first time to design IS networks in the form of EIPs.


Assuntos
Ecossistema , Cadeia Alimentar , Conservação dos Recursos Naturais , Análise de Alimentos , Indústrias
15.
PLoS One ; 15(7): e0234899, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32645020

RESUMO

The increasing prevalence of individuals with multiple food allergies and the need to distinguish between foods containing homologous, cross-reactive proteins have made the use of single-analyte antibody-based methods (e.g., ELISAs) sometimes insufficient. These issues have resulted in the need to conduct multiple analyses and sometimes employ orthogonal methods like mass spectrometry or DNA-based methods for confirmatory purposes. The xMAP Food Allergen Detection Assay (xMAP FADA) was developed to solve this problem while also providing increased throughput and a modular design suitable for adapting to changes in analytical needs. The use of built-in redundancy provides the xMAP FADA with built-in confirmatory analytical capability by including complementary antibody bead sets and secondary analytical end points (e.g., ratio analysis and multi-antibody profiling). A measure of a method's utility is its performance when employed by analysts of varying expertise in multiple laboratory environments. To gauge this aspect, a multi-laboratory validation (MLV) was conducted with 11 participants of different levels of proficiency. The MLV entailed the analysis of incurred food samples in four problematic food matrices, meat sausage, orange juice, baked muffins, and dark chocolate. Except for a couple of instances, involving two confirmatory components in the analysis of baked muffins, the allergenic foods were detected by all participants at concentrations in the analytical samples comparable to ≤ 10 µg/g in the original food sample. In addition, despite high levels of inter-lab variance in the absolute intensities of the responses, the intra-laboratory reproducibility was sufficient to support analyses based on the calibration standards and direct comparison controls (DCCs) analyzed alongside the samples. In contrast, ratio analyses displayed inter-laboratory %CV (RSDR) values < 20%; presumably because the ratios are based on inherent properties of the antigenic elements. The excellent performance of the xMAP FADA when performed by analysts of varying proficiency indicates a reliability sufficient to meet analytical needs.


Assuntos
Ensaio de Imunoadsorção Enzimática/métodos , Hipersensibilidade Alimentar/diagnóstico , Hipersensibilidade Alimentar/imunologia , Alérgenos/imunologia , Anticorpos/imunologia , Bioensaio , Reações Cruzadas , Análise de Alimentos/métodos , Humanos , Laboratórios , Espectrometria de Massas , Reprodutibilidade dos Testes
16.
Food Chem ; 333: 127379, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32653678

RESUMO

The safety and regulatory status of fermented products derived from gluten-containing grains for patients with celiac disease remains controversial. Bottom-up mass spectrometry (MS) has complemented immunoassays for the compositional and immunogenic analyses of wheat beers. However, uncharacterized proteolysis during brewing followed by the secondary digestion for MS has made the analysis and data interpretation complicated. In this study, the composition and immunogenic potential of seven commercially available wheat beers were evaluated using bottom-up MS with the aid of fractionation and a multi-step peptide search strategy to identify peptides generated by various types of proteolysis. Gluten-derived peptides accounted for approximately 50% and 20% of the total number of wheat-derived and barley-derived peptides, respectively, in the investigated beers. Although relatively large polypeptides cannot be thoroughly characterized using traditional bottom-up proteomics, up to 50% of peptides identified contained celiac-immunogenic motifs, and consumption of wheat beers would pose risks for celiac patients.


Assuntos
Cerveja/análise , Análise de Alimentos/métodos , Espectrometria de Massas , Triticum/química , Triticum/imunologia , Fermentação , Glutens/química , Humanos , Peptídeos/análise , Peptídeos/imunologia
17.
Food Chem ; 333: 127421, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32653681

RESUMO

An extraction procedure was developed for the determination of aflatoxin M1 in milk and dairy products. A sorbent based on UVM-7 mesoporous silica was used as solid phase for the sample clean-up, and the analyte determination was carried out by HPLC coupled to a fluorescence detector. The material architecture was characterized by transmission electronic microscopy, X-ray diffraction, 29Si NMR and nitrogen adsorption-desorption. After the optimization of extraction parameters, the influence of the matrix has been evaluated, obtaining recoveries in the range 78-105% for whole and skimmed milk and yogurt matrix. The reusability of the material was also proved. The sensitivity of the method was also evaluated, and a LOQ (0.015 µg kg-1) below the European legislation limit was obtained. The procedure was successfully applied for the determination of aflatoxin M1 in real samples. The results were compared with those obtained with a reference method, being the results statistically comparable.


Assuntos
Aflatoxina M1/análise , Custos e Análise de Custo , Análise de Alimentos/métodos , Leite/química , Nanoestruturas/química , Dióxido de Silício/química , Iogurte/análise , Adsorção , Aflatoxina M1/química , Animais , Fluorescência , Análise de Alimentos/economia , Contaminação de Alimentos/análise , Limite de Detecção , Porosidade
18.
Food Chem ; 331: 127348, 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-32619908

RESUMO

Information concerning food composition, including information on its glucose content, is essential for modern food industry due to greater consumer awareness and expectations. In this work, the gene encoding d-glucose dehydrogenase (GDH) from Bacillus Natto was expressed in Escherichia coli BL21(DE3) firstly. Ni-IDA column was used for the purification of GDH. Then, the purified GDH was used to construct a color system with stable and effective measurement of concentration of d-glucose. The smart phone photographing and the software Microsoft Photoshop have been used in the system for determination of the color. The enzymatic analysis system can detect the concentration of d-glucose from 5 mM to 40 mM, and other various sugars has no interference to the system. The system was used to quantitatively detect the concentration of d-glucose in honey. The system can be used for convenient and rapid detection of d-glucose in food, especially for large numbers of samples.


Assuntos
Análise de Alimentos/métodos , Glucose/análise , Mel/análise , Smartphone , Bacillus/genética , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Cor , Escherichia coli/genética , Análise de Alimentos/instrumentação , Glucose 1-Desidrogenase/genética , Glucose 1-Desidrogenase/metabolismo , Concentração de Íons de Hidrogênio , Limite de Detecção , Software
19.
Food Chem ; 331: 127361, 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-32650229

RESUMO

A low cost hand-held spectral analytical system was developed for in situ screening of phenolics and flavonoids in puff dried Ziziphus jujuba (Z. Jujuba) samples. Standards of gallic acid, caffeic acid, l-epicatechin, phloridzin and cianidanol were used to quantify the individual phenolics and flavonoids using high performance liquid chromatography-diode array detector (HPLC-DAD). The synergy interval partial least square with ant colony optimization (Si-ACO-PLS) was attempted to optimize and capture informative variables for the prediction of target compounds. The model performance was evaluated using correlation coefficients of prediction (Rp); root mean square error of prediction (RMSEP) and residual predictive deviation (RPD). The Si-ACO-PLS yielded optimal performance, 0.8540 ≤ Rc ≤ 0.9250, 0.8360 ≤ Rp ≤ 0.9056, 0.84 ≤ RMSEP ≤ 16.30 and 2.03 ≤ RPD ≤ 2.26. The hand-held spectral analytical system coupled with Si-ACO-PLS proved to the reliable, rapid and cost-effective method to quantify the phenolics and flavonoids in Z. Jujuba.


Assuntos
Flavonoides/análise , Análise de Alimentos/instrumentação , Análise de Alimentos/métodos , Fenóis/análise , Ziziphus/química , Algoritmos , Cromatografia Líquida de Alta Pressão , Dessecação/métodos , Análise de Alimentos/estatística & dados numéricos , Análise dos Mínimos Quadrados , Análise Espectral/instrumentação , Análise Espectral/métodos
20.
Food Chem ; 333: 127439, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32653686

RESUMO

Anthocyanin is derived from a flavylium cation structure, and it promotes health in humans and functions in plants as protection against environmental stress. The rapid analysis of anthocyanin structure and content is a critical challenge for improving fruit quality. In this study, the tomato cultivar Indigo Rose, which is a popular purple cultivated tomato used for breeding, was taken as an example for anthocyanin analysis. A rapid analysis method was developed to minimize anthocyanin loss from the fresh fruit. Four new anthocyanins were discovered in the tomato, and the structures of a total of 12 anthocyanins were determined. Among these, petunidin-3-(trans-p-coumaroyl)-rutinoside-5-glucoside and malvidin-3-(trans-p-coumaroyl)-rutinoside-5-glucoside were the main anthocyanins in Indigo Rose. The structural modifications of these anthocyanins were mainly glycosylation and acylation, and there were also hydroxylation and methylation. Our findings provide new insight into the biosynthesis pathway in tomato fruit.


Assuntos
Antocianinas/análise , Antocianinas/química , Lycopersicon esculentum/química , Espectrometria de Massas/métodos , Acilação , Antocianinas/metabolismo , Cromatografia Líquida de Alta Pressão , Análise de Alimentos/métodos , Congelamento , Frutas/química , Glicosilação , Estrutura Molecular
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