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1.
Food Chem ; 317: 126448, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32114274

RESUMO

The chemometric issues related to the application of non-targeted analysis for the detection of food frauds were analyzed employing discriminant analysis and a one-class classifier. The similarities and differences between the two methods were investigated. The results of classification are characterized by a set of indices called figures of merit. They comprehensively characterized the quality and reliability of classification. The principle is illustrated using an actual example of Oregano herbs adulteration. The informative region 9000-4000 cm-1 of near-Infrared spectroscopy is used as analytical means. The results of the application of each method for Oregano data collection are presented. It is shown that the discriminant method is only partially appropriate for solving the authentication problem. One class classifier is a powerful and devoted for non-targeted analysis. The step by step analysis introduced in the paper can also be successfully utilized in apply for revealing of forgeries of various food products.


Assuntos
Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Fraude , Origanum/química , Análise Discriminante , Análise de Alimentos/estatística & dados numéricos , Contaminação de Alimentos/estatística & dados numéricos , Análise dos Mínimos Quadrados , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Espectroscopia de Luz Próxima ao Infravermelho/métodos
2.
Food Chem ; 315: 126158, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32014672

RESUMO

Rapid, nondestructive, high-throughput testing and screening of volatile ingredients plays an important role in food flavor analysis. Gas chromatography-ion mobility spectrometry (GC-IMS) is a powerful technique for the separation and sensitive detection of volatile organic compounds. It has a fast response, high sensitivity, easy operation, and low cost. In this article, a brief introduction to the working principle of GC-IMS is presented. A summary of recent studies of different food flavor analysis applications is also provided, including food classification and adulteration, the evaluation of food freshness and spoilage, off-flavor detection, monitoring the processing of food products, and evaluation of aroma changes during food storage. Finally, future directions of GC-IMS are proposed.


Assuntos
Cromatografia Gasosa/métodos , Análise de Alimentos/métodos , Espectrometria de Mobilidade Iônica/métodos , Odorantes/análise , Cromatografia Gasosa/estatística & dados numéricos , Aromatizantes/análise , Aditivos Alimentares/análise , Análise de Alimentos/estatística & dados numéricos , Espectrometria de Mobilidade Iônica/estatística & dados numéricos , Controle de Qualidade , Paladar , Compostos Orgânicos Voláteis/análise
3.
Food Chem ; 315: 126247, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32006866

RESUMO

Three non-targeted methods, i.e. 1H NMR, LC-HRMS, and HS-SPME/MS-eNose, combined with chemometrics, were used to classify two table grape cultivars (Italia and Victoria) based on five quality levels (5, 4, 3, 2, 1). Grapes at marketable quality levels (5, 4, 3) were also discriminated from non-marketable quality levels (2 and 1). PCA-LDA and PLS-DA were applied, and results showed that, the MS-eNose provided the best results. Specifically, with the Italia table grapes, mean prediction abilities ranging from 87% to 88% and from 98% to 99% were obtained for discrimination amongst the five quality levels and of marketability/non-marketability, respectively. For the cultivar Victoria, mean predictive abilities higher than 99% were achieved for both classifications. Good models were also obtained for both cultivars using NMR and HRMS data, but only for classification by marketability. Satisfying models were further validated by MCCV. Finally, the compounds that contributed the most to the discriminations were identified.


Assuntos
Análise de Alimentos/métodos , Armazenamento de Alimentos , Espectroscopia de Prótons por Ressonância Magnética/métodos , Vitis/química , Nariz Eletrônico/estatística & dados numéricos , Análise de Alimentos/estatística & dados numéricos , Qualidade dos Alimentos , Análise dos Mínimos Quadrados , Espectrometria de Massas/métodos , Espectrometria de Massas/estatística & dados numéricos , Análise Multivariada , Análise de Componente Principal , Espectroscopia de Prótons por Ressonância Magnética/estatística & dados numéricos , Compostos Orgânicos Voláteis/análise
4.
Food Chem ; 315: 126248, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32018076

RESUMO

Chianti is a precious red wine and enjoys a high reputation for its high quality in the world wine market. Despite this, the production region is small and product needs efficient tools to protect its brands and prevent adulterations. In this sense, ICP-MS combined with chemometrics has demonstrated its usefulness in food authentication. In this study, Chianti/Chianti Classico, authentic wines from vineyard of Toscana region (Italy), together samples from 18 different geographical regions, were analyzed with the objective of differentiate them from other Italian wines. Partial Least Squares-Discriminant Analysis (PLS-DA) identified variables to discriminate wine geographical origin. Rare Earth Elements (REE), major and trace elements all contributed to the discrimination of Chianti samples. General model was not suited to distinguish PDO red wines from samples, with similar chemical fingerprints, collected in some regions. Specific classification models enhanced the capability of discrimination, emphasizing the discriminant role of some elements.


Assuntos
Análise de Alimentos/métodos , Espectrometria de Massas/métodos , Vinho/análise , Análise Discriminante , Análise de Alimentos/estatística & dados numéricos , Itália , Análise dos Mínimos Quadrados , Limite de Detecção , Espectrometria de Massas/estatística & dados numéricos , Metais Terras Raras/análise , Oligoelementos/análise
5.
Food Chem ; 314: 126098, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-31954940

RESUMO

A metabolomics strategy was developed to differentiate strong aroma-type baijiu (SAB) (distilled liquor) from the Sichuan basin (SCB) and Yangtze-Huaihe River Basin (YHRB) through liquid-liquid extraction coupled with GC×GC-TOFMS. PCA effectively separated the samples from these two regions. The PLS-DA training model was excellent, with explained variation and predictive capability values of 0.988 and 0.982, respectively. As a result, the model demonstrated its ability to perfectly differentiate all the unknown SAB samples. Twenty-nine potential markers were located by variable importance in projection values, and twenty-four of them were identified and quantitated. Discrimination ability is closely correlated to the characteristic flavor compounds, such as acid, esters, furans, alcohols, sulfides and pyrazine. Most of the marker compounds were less abundant in the SCB samples than in the YHRB samples. The quantitated markers were further processed using hierarchical cluster analysis for targeted analysis, indicating that the markers had great discrimination power to differentiate the SAB samples.


Assuntos
Bebidas Alcoólicas/análise , Análise de Alimentos/métodos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Metabolômica/métodos , Odorantes/análise , China , Análise por Conglomerados , Análise de Alimentos/estatística & dados numéricos , Cromatografia Gasosa-Espectrometria de Massas/estatística & dados numéricos , Análise dos Mínimos Quadrados , Extração Líquido-Líquido , Análise de Componente Principal , Paladar , Compostos Orgânicos Voláteis/análise
6.
Food Chem ; 302: 125340, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31419775

RESUMO

In this study, 83 wines representating four commercial categories: "Argentinean Malbec", "Brazilian Merlot", "Uruguayan Tannat" and "Chilean Carménère" were analyzed according to their phenolic and volatile compounds. The objective was to identify the chemical compounds that would typify each category. From approximately about 600 peaks obtained by chromatographic techniques, 169 were identified and 53 of them were selected for multivariate statistical analysis. Chilean Carménère was the best discriminated group by the methods applied in our study, followed by Argentinean Malbec. Brazilian Merlot mixed mainly with some Carménère, whileTannat mixed with all wines categories, especially Malbec. In general, Chilean Carménère wines can be characterized by a bluish color, higher amounts of sulphur dioxide, higher content of octanoic acid, isobutanol, ethyl isoamyl succinate and catechin and a smaller amount of quercetin. These data can contribute for further process of authenticity or typification of South American red wines.


Assuntos
Análise de Alimentos/estatística & dados numéricos , Fenóis/análise , Compostos Orgânicos Voláteis/análise , Vinho/análise , Butanóis/análise , Caprilatos/análise , Catequina/análise , Análise de Alimentos/métodos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Cromatografia Gasosa-Espectrometria de Massas/estatística & dados numéricos , Análise Multivariada , Quercetina/análise , América do Sul , Dióxido de Enxofre/análise , Vinho/classificação
7.
Food Chem ; 302: 125370, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31442699

RESUMO

Four Arabica coffees (Brazil, Colombia, Ethiopia, and Guatemala) yield highly variant odours, attesting to the complexities of coffee aroma that command advanced analytical tools. In this study, their volatiles were extracted using solvent-assisted flavour evaporation (SAFE) and headspace solid-phase microextraction (HS-SPME). Due to matrix complexity, some trace odourants were detected in SAFE extracts by aroma extract dilution analysis (AEDA) but remained difficult to quantify by gas chromatography-mass spectrometry (GC-MS). This prompted the application of low energy electron ionisation (EI) coupled with GC-quadrupole time-of-flight (GC-QTOF). Optimal low EI GC-QTOF parameters (EI energy: 15 eV, acquisition rate: 3 Hz) were applied to achieve improved molecular ion signal intensity and reproducibility (relative standard deviation < 10%) across five compounds, which resulted in good linearity (R2 ≥ 0.999) and lowered detection levels (e.g. 0.025 ±â€¯0.005 ng/mL for 4-hydroxy-5-methyl-3(2H)-furanone). Therefore, this method potentially improves the measurement of trace odourants in complex matrices by increasing specificity and sensitivity.


Assuntos
Café/química , Análise de Alimentos/métodos , Odorantes/análise , Compostos Orgânicos Voláteis/análise , Adulto , Brasil , Coffea/química , Colômbia , Etiópia , Feminino , Análise de Alimentos/estatística & dados numéricos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Guatemala , Humanos , Masculino , Pessoa de Meia-Idade , Olfatometria/métodos , Extratos Vegetais/química , Análise de Componente Principal , Reprodutibilidade dos Testes , Microextração em Fase Sólida/métodos , Paladar , Compostos Orgânicos Voláteis/isolamento & purificação
8.
Food Chem ; 302: 125373, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31442706

RESUMO

The aim of this work was to investigate and compare the phenolic profile of 15 wild growing blackthorn (Prunus spinosa L.) genotypes from the slopes of Fruska Gora mountain in north Serbia. Their effect in inhibiting i) α-amylase and α-glucosidase activities and ii) colorectal cancer cell line (HT29) growth was also studied. Blackthorn fruit extracts exhibited high phenolic content being enrich in anthocyanins. Principal component analysis was used to correlate the bioactive response with phenolic composition. It was found that derivatives quercetin and anthocyanin peonidin are the major contributors of the inhibition of carbohydrates hydrolyzing enzymes as well as with the antiproliferative effect of blackthorn. Among all samples, the genotype from Beska locality showed the higher capacity in inhibiting alpha-amylase, alpha-glucosidase and HT29 cell growth. Because of high anthocyanin content and higher bioactive response, these genotypes could be recommended for the further cultivation and investigation.


Assuntos
Polifenóis/análise , Prunus/química , Prunus/genética , Antocianinas/análise , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Antioxidantes/análise , Ácido Clorogênico/análogos & derivados , Ácido Clorogênico/análise , Cromatografia Líquida de Alta Pressão , Análise de Alimentos/estatística & dados numéricos , Frutas/química , Genótipo , Inibidores de Glicosídeo Hidrolases/química , Inibidores de Glicosídeo Hidrolases/farmacologia , Células HT29 , Humanos , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Polifenóis/farmacologia , Análise de Componente Principal , Quercetina/análise , Ácido Quínico/análogos & derivados , Ácido Quínico/análise , Sérvia , alfa-Amilases/antagonistas & inibidores
9.
Food Chem ; 302: 125345, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31445377

RESUMO

This paper compares the results of standard chemical analytical processes and electrochemical impedance spectroscopy (EIS) in the characterization of different beverages, namely ground coffee, soluble coffee, coffee substitutes, barley, cow milk, vegetable drinks, tea, plant infusions and plant mixtures. For the two approaches, the similarities between the experimental data are assessed by means of the Euclidean and Canberra distances. The resulting information is processed by means of the multidimensional scaling (MDS) clustering and visualization algorithm. The results of the chemical analytical processes and EIS reveal identical clusters for the two adopted distances. Furthermore, the robustness of the experimental and computational scheme are assessed by means of the Procrustes technique. The results confirm the effectiveness of combining the EIS and MDS.


Assuntos
Bebidas/análise , Visualização de Dados , Espectroscopia Dielétrica/métodos , Algoritmos , Animais , Técnicas de Química Analítica/métodos , Análise por Conglomerados , Café/química , Espectroscopia Dielétrica/estatística & dados numéricos , Análise de Alimentos/métodos , Análise de Alimentos/estatística & dados numéricos , Leite/química , Processamento de Sinais Assistido por Computador , Chá/química
10.
BMC Public Health ; 19(1): 1365, 2019 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-31651297

RESUMO

BACKGROUND: Lunch is an important part of a healthy diet, which is essential for the development, growth and academic performance of school-aged children. Currently there is an increasing number of Dutch primary schoolchildren who are transitioning from eating lunch at home to school. There is limited knowledge about the current quality of the lunches consumed by primary schoolchildren in the Netherlands and whether there are any differences between lunches consumed at home or at school. To investigate differences in content and quality of lunches consumed by Dutch primary schoolchildren at home and at school. METHODS: Cross-sectional study among 363 Dutch primary schoolchildren aged 4-12 years based on the first two years of the 2012-2016 Dutch National Food Consumption Survey. Demographic characteristics were obtained through a questionnaire. Diet was assessed with two non-consecutive 24-h dietary recalls. Quality of lunches was assessed on their nutritional quality whether they fitted the nutritional guidelines. 'Nonparametric tests were used to examine the content and quality of the lunches between place of consumption and parental educational position. RESULTS: The most consumed lunch products among primary schoolchildren were bread, dairy products and sugar-sweetened beverages. Fruit and vegetable consumption was very low. Consumption of milk and other dairy products was higher among children who eat lunch at home than children who eat lunch at school (p < 0.01). Consumption of sugar-sweetened beverages was higher among children who eat lunch at school than children who eat lunch at home (p < 0.01), and at school a higher proportion of the drinks did not fit within the Dutch dietary recommendations (p < 0.01). CONCLUSIONS: The current content of the lunches consumed by Dutch primary schoolchildren leaves room for improvement, especially regarding fruit and vegetables. The statistically significantly higher consumption of sugar-sweetened beverages and lower consumption of milk and dairy products at school vs. home is worrisome, as currently more children in the Netherlands are transitioning to having lunch at school.


Assuntos
Análise de Alimentos/estatística & dados numéricos , Análise de Alimentos/normas , Almoço , Valor Nutritivo , Instituições Acadêmicas , Animais , Criança , Pré-Escolar , Estudos Transversais , Feminino , Serviços de Alimentação , Frutas , Humanos , Masculino , Leite/estatística & dados numéricos , Países Baixos , Verduras
11.
Food Chem ; 300: 125173, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31319335

RESUMO

The administration of anabolic agents in farm animals to improve meat production has been prohibited in EU, due to the potential risks to human health. Meat quality was investigated to detect the effects of illegal administration of dexamethasone or prednisolone or 17ß-estradiol on Charolais bulls. Three groups of 6 bulls were treated and 12 bulls were the control. Meat quality parameters were measured on live animals, carcasses and on samples of Longissimus thoracis and multivariate statistical data analysis was applied. In Charolais bulls, these parameters were affected by growth promoter administration and the multivariate canonical discriminant analysis was able to distinguish between treated and untreated animals mainly due to three electronic nose's parameters, 24 h carcass temperature and drip loss. Therefore, meat quality control and the multivariate analysis could be useful as a first screening to address targeted controls on farms suspected of illicit use of growth promoters.


Assuntos
Análise de Alimentos/métodos , Substâncias de Crescimento/farmacologia , Carne , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/crescimento & desenvolvimento , Animais , Bovinos , Dexametasona/farmacologia , Análise Discriminante , Nariz Eletrônico , Estradiol/farmacologia , Fazendas , Análise de Alimentos/instrumentação , Análise de Alimentos/estatística & dados numéricos , Qualidade dos Alimentos , Masculino , Carne/análise , Prednisolona/farmacologia
12.
Food Chem ; 298: 125029, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31260974

RESUMO

Thermal processing methods have important effects on food lipids. In this work, ultra-high-performance liquid chromatography-Q-Extractive Orbitrap mass spectrometry and lipidsearch software were applied to analyze effect of three types of thermal processing methods on the lipidomics profile of tilapia fillets. A total 15 classes of compound lipids (Cer, DG, LPC, LPE, LPG, LPI, LPS, PC, PE, PG, PI, PS, SM, So, TG) were analyzed. In addition, free DHA, EPA, and ARA were also identified. Furthermore, statistical analyses of these lipids were performed based on MetaboAnalyst software. The results demonstrated three types of thermal processing methods had different effects on lipidomics profile differences of tilapia fillets. A total of eight lipid species variables (LPS, LPG, LPI, DG, LPC, TG, LPE, and Cer) and 137 individual lipids variables showed significant differences among raw, steamed, boiled, and roasted tilapia fillets. This work could provide useful information for aquatic product processing and lipidomics.


Assuntos
Produtos Pesqueiros/análise , Análise de Alimentos/métodos , Indústria de Processamento de Alimentos/métodos , Lipídeos/química , Tilápia , Animais , Cromatografia Líquida de Alta Pressão/métodos , Análise de Alimentos/estatística & dados numéricos , Lipídeos/análise , Espectrometria de Massas/métodos
13.
Food Chem ; 298: 124966, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31260996

RESUMO

The aim of this study was to evaluate the combination of fatty acid profile and fatty acid δ13C fingerprinting to identify the origins of scallops. Fatty acid contents, as well as fatty acid δ13C values of 300 samples of three scallop species (Patinopecten yessoensis, Chlamys farreri, and Argopecten irradians) from seven sites in China were determined. Principal component analysis was performed on datasets to evaluate their performance of classification. Moreover, 75 samples were tested by discrimination analysis to estimate the accuracy of origin prediction. The results show that the accuracy rate of fatty acid profile and fatty acid δ13C fingerprinting for origin prediction was 92% and 85.3%, respectively. The combination of these two methods improved the identification, with an accuracy rate of 100.0%. These results indicate that the combination of fatty acid profile and fatty acid δ13C fingerprinting can be a precise and promising tool for origin traceability of scallops.


Assuntos
Isótopos de Carbono/análise , Ácidos Graxos/análise , Análise de Alimentos/métodos , Pectinidae/química , Frutos do Mar/análise , Animais , China , Análise Discriminante , Análise de Alimentos/estatística & dados numéricos
14.
Sensors (Basel) ; 19(13)2019 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-31277225

RESUMO

Adulteration is one of the major concerns among all the quality problems of milk powder. Soybean flour and rice flour are harmless adulterations in the milk powder. In this study, mid-infrared spectroscopy was used to detect the milk powder adulterated with rice flour or soybean flour and simultaneously determine the adulterations content. Partial least squares (PLS), support vector machine (SVM) and extreme learning machine (ELM) were used to establish classification and regression models using full spectra and optimal wavenumbers. ELM models using the optimal wavenumbers selected by principal component analysis (PCA) loadings obtained good results with all the sensitivity and specificity over 90%. Regression models using the full spectra and the optimal wavenumbers selected by successive projections algorithm (SPA) obtained good results, with coefficient of determination (R2) of calibration and prediction all over 0.9 and the predictive residual deviation (RPD) over 3. The classification results of ELM models and the determination results of adulterations content indicated that the mid-infrared spectroscopy was an effective technique to detect the rice flour and soybean flour adulteration in the milk powder. This study would help to apply mid-infrared spectroscopy to the detection of adulterations such as rice flour and soybean flour in real-world conditions.


Assuntos
Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Contaminação de Alimentos/estatística & dados numéricos , Leite/química , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Animais , Calibragem , Farinha , Análise de Alimentos/estatística & dados numéricos , Análise dos Mínimos Quadrados , Oryza/química , Pós/análise , Pós/química , Análise de Componente Principal , Soja/química , Espectroscopia de Infravermelho com Transformada de Fourier/estatística & dados numéricos , Máquina de Vetores de Suporte
15.
Food Chem ; 300: 125227, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31351262

RESUMO

Indirect measurements of taste-related compounds are required when a high number of samples has to be analyzed in a short period of time, with a minimum cost. For this purpose, FT-MIR partial least square (PLS) regression models for the prediction of total soluble solids, sugars and organic acids have been developed using three sample sets including breeding lines and commercial varieties of watermelon. Specific models with excellent performance were obtained only for sugars. Nevertheless, a general model supposed a compromise between the best and worse models and offered %RMSEP values of 11.3%, 11.1% and 11.7% for fructose, glucose and sucrose respectively. The model was applied to the selection of high content samples (selection pressure 20% and 30%) obtaining good sensitivity levels and mean percentile of selected samples close to the expected values (100% sensitivity). The robustness of FT-MIR models was assessed with predictions of external assays, obtaining reasonable performances.


Assuntos
Ácido Cítrico/análise , Citrullus/química , Análise de Alimentos/métodos , Malatos/análise , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Açúcares/análise , Análise de Alimentos/estatística & dados numéricos , Análise dos Mínimos Quadrados , Espectroscopia de Infravermelho com Transformada de Fourier/estatística & dados numéricos , Paladar
16.
Food Chem ; 300: 125220, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31352288

RESUMO

Fruits and vegetables play an important role in human nutrition. Study of the contamination sources which result from farming activities is of importance. For this reason, a chitosan-graphene oxide nanocomposite film was prepared and implemented as the extractive phase in thin film microextraction of six organophosphate residues (OPPs) in the samples using high-performance liquid chromatography. The optimized method was validated and the limits of detection (0.7-1.2 µg l-1), limits of quantification (2.3-4.0 µg l-1) and linear dynamic range (2.0-1000.0 µg l-1) were obtained. Principal component analysis revealed clustering of the fruit and vegetable samples based on the selected (OPPs) into two groups of unwashed-unpeeled and peeled-washed. This mapping was further investigated using descriptive method of boxplot. Washing and peeling of the samples, reduced the presence of OPPs to half or one third of interquartile range found in the unpeeled and unwashed samples.


Assuntos
Contaminação de Alimentos/análise , Frutas/química , Organofosfatos/análise , Resíduos de Praguicidas/análise , Verduras/química , Cromatografia Líquida de Alta Pressão/métodos , Análise de Alimentos/instrumentação , Análise de Alimentos/métodos , Análise de Alimentos/estatística & dados numéricos , Grafite/química , Limite de Detecção , Nanoestruturas/química , Óxidos/química , Análise de Componente Principal , Reprodutibilidade dos Testes , Microextração em Fase Sólida/instrumentação , Microextração em Fase Sólida/métodos
17.
Food Chem ; 300: 125243, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31357015

RESUMO

Fatty acids, phenolic compounds, and tocopherols of Coratina, Bosana, Semidana, and Tonda di Cagliari virgin olive oils, were measured over a 45-day harvest period. Phenolic composition was the primary factor distinguishing Bosana, Tonda di Cagliari, and Semidana, whereas fatty acids differentiated Coratina and the other cultivars. Harvest period principally influenced oleacein, oleocanthal, oleuropein and ligstroside aglycones, and flavonoids. High phenolic content was observed for Coratina (1039-688 mg/kg) and Bosana (788-592 mg/kg). A drastic decrease in phenolic content was observed in Semidana (529-134 mg/kg) and Tonda di Cagliari (507-142 mg/kg) during the harvest period. These two cultivars also had low MUFA/PUFA (6.0-4.0 and 4.9-3.2 respectively), suggesting that these varieties should be harvested earlier in the season. These results provide information to producers for improved management of the harvesting process, which is strongly affected by varietal factors.


Assuntos
Análise de Alimentos/métodos , Azeite de Oliva/análise , Azeite de Oliva/química , Agricultura , Aldeídos/análise , Ácidos Graxos/análise , Flavonoides/análise , Análise de Alimentos/estatística & dados numéricos , Glucosídeos/análise , Iridoides/análise , Itália , Olea/química , Fenóis/análise , Piranos/análise , Especificidade da Espécie , Tocoferóis/análise
18.
Food Chem ; 300: 125251, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31357018

RESUMO

Targeted ultra-performance liquid chromatography with triple quadrupole mass spectrometric (UPLC-QqQ-MS/MS) profiling of phenolic compounds was utilised for varietal differentiation of 173 wines made from four red and six white grape varieties. Among 58 identified phenols many were found relevant as exclusive or partial discriminators between wines. Successful differentiation models were built by linear discriminant analysis with the percentage of correct classification higher than 95% in all cases, with peonidin 3-(6″-acetyl)-glucoside and taxifolin as the most potent differentiators between red, and cis-piceid between white monovarietal wines. Diverse typical colour attributes among the monovarietal wines were tentatively ascribed to the variations in the composition of monomeric anthocyanins. Plavac mali red wine exhibited the most specific composition, and its most typical samples were distinguished by the abundance in trans-fertaric acid, isorhapontin, phlorizin, quercetin 3-rhamnoside, and myricitrin. Despite positive correlations with particular astringent flavonols, the typical astringency of Plavac mali wine remained unresolved.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Análise de Alimentos/métodos , Fenóis/análise , Espectrometria de Massas em Tandem/métodos , Vinho/análise , Adulto , Cor , Análise Discriminante , Feminino , Flavonóis/análise , Análise de Alimentos/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Paladar , Vitis/química
19.
Food Chem ; 299: 125107, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31302428

RESUMO

Traceability and authenticity is crucial to the food safety of scallop. The present study investigated the possibility of using stable isotope analysis to identify the origins and species of scallops (Patinopecten yessoensis, Chlamys farreri, and Argopecten irradians) in the coastal areas of China. The δ13C and δ15N values of a total of 575 samples from seven sites around China were determined and additional 150 samples were tested by fisher linear discrimination analysis (LDA) to estimate the accuracy of origin identification and species prediction. The results show that the stable C and N isotope composition differed significantly depending on the origin, season and species of scallops. Meanwhile, the LDA shows that 92% of the samples were correctly classified for origin prediction, and an accuracy of 98.3% was obtained for species prediction. This study reveals that stable isotope ratio is an effective technique to trace the geographical origin and identify the species of scallops.


Assuntos
Isótopos de Carbono/análise , Análise de Alimentos/métodos , Isótopos de Nitrogênio/análise , Pectinidae/química , Frutos do Mar/análise , Animais , China , Análise Discriminante , Análise de Alimentos/estatística & dados numéricos , Especificidade da Espécie
20.
Food Chem ; 293: 348-357, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31151622

RESUMO

Camellia oil is a high quality oil mainly produced in southern China. It is common that unscrupulous merchants attempt to make huge profits by adulterating camellia oil with other cheaper or lower-quality vegetable oils. Therefore, this paper proposed excitation-emission matrix fluorescence spectroscopy combined with chemometric methods for the rapid identification and quantification of camellia oil adulteration with other cheaper vegetable oils. A five-component parallel factor analysis (PARAFAC) model roughly completed spectral characterization of oil samples, and obtained chemically meaningful information. Four advanced chemometrics methods were used for the classification of camellia oil and other vegetable oils (model 1) and the classification of camellia oil and adulterated camellia oil (models 2 and 3), respectively. Two-directional two-dimensional linear discriminant analysis ((2D)2LDA) was used for chemical data for the first time and showed huge potential. Furthermore, the developed N-PLS regression model used for the prediction of adulteration level in camellia oil showed satisfactory accuracy.


Assuntos
Camellia/química , Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Óleos Vegetais/química , Espectrometria de Fluorescência/métodos , China , Análise Discriminante , Análise de Alimentos/estatística & dados numéricos , Análise dos Mínimos Quadrados , Reprodutibilidade dos Testes , Espectrometria de Fluorescência/estatística & dados numéricos
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