Relationship between the chemical components of taro rhizome mucilage and its emulsifying property

AbstractThe objective of this study was to determine the chemical composition of taro mucilage (TM) and explain its emulsification properties using different commercial emulsifiers and gums as benchmarks. The following analyses were performed: moisture, ether extract, protein, fiber, ash, sugar fraction, starch content, infrared spectroscopy and determination of monosaccharides and amino acids using HPLC. The analyses showed that TM has a high carbohydrate content and small protein fraction, similar to commercial gums. Commercial emulsifiers have a high content of lipids compared to TM. Therefore, it can be concluded that the emulsifying power of the studied mucilage is primarily caused by the protein content along with weakly polar amino acids, which occur in gums. The methyl group (CH3), which was observed in the infrared spectrum, and the lipid content may also contribute to the emulsifying activity by providing a hydrophobic moiety

Physical and chemical analysis in crude taro mucilage obtained by simple extraction technique

Crude taro mucilage (CM) is considered a product that contains the presence of starch, in addition to other carbohydrates. The use of this mucilage is interesting in the bakery industry, mainly as an emulsifier. The objective of this study was to understand the chemical and physical characteristics of CM to justify its emulsifying action and find other potential applications in the food industry. In the first stage of the work, the raw material (taro rhizome) used for the extraction of mucilage was chemically characterized (moisture, ether extract, crude protein, crude fiber, ashes and glicidic fraction). CM was extracted through a simple method and without the use of chemical reagents, using rhizome crushed, filtration on a polyester mesh and lyophilized. Proximate composition, starch, minerals, monosaccharides, amino acids, infrared spectrum, X-ray diffractometry and thermal property analyses were conducted in the mucilage. CM has thermal stability up to approximately 200 °C and has semi-crystalline structure. Mucilage studied contains arabinogalactan polysaccharide, which can be linked to the protein fraction, according to infrared analysis, forming the arabinogalactan-protein macromolecule, responsible for the emulsifying property. The starch found is considered the main responsible for its thickening action. Moreover, CM can be considered mineral-enriching flour in food products due to the increase of ashes by the mucilage extraction process and the high content of iron micromineral

Perfil sensorial de cultivares de café processados por via seca e via úmida após armazenamento

The different types of post-harvest processing employed in coffee fruits may yield different beverages, whose sensory profile depends on environmental factors and management in the production process. All the processes involved in coffee production, from soil and climatic characteristics of the growing area to the adopted storage system, interfere in the coffee beverage quality. The objective of this research was to describe the sensory profile of different coffee varieties processed by dry (natural) and wet (demucilated), after one year of storage. Were evaluated sensorially four coffee cultivars (Red Catuaí IAC 144, Iapar 59, Yellow Bourbon e Paraíso MG H 419-1), of Coffea arabica L. of the 2012/2013 season with the completion of two post-harvest processing (natural and demucilated cherry) after one year of storage. Sensory analysis was performed by two accredited tasters and enabled through the protocol of the Specialty Coffee Association of America - SCAA. Cultivars behave differently in quality according to the adopted process. Coffees of the natural processing stood out in most sensory attributes evaluated in relation to demucilated coffees after one year of storage. The Red Catuaí IAC 144 and Iapar 59 showed better quality when subjected to natural processing. Already in demucilated coffees, highest scores were awarded the Yellow Bourbon cultivars and Paraíso.Os diferentes tipos de processamentos pós-colheita empregados nos frutos de café podem originar diferentes bebidas, cujo perfil sensorial depende de fatores ambientais e do manejo no processo de produção. Todos os processos envolvidos na produção de café, desde as características edafoclimáticas da área de cultivo até o sistema de armazenamento adotado, interferem na qualidade de bebida do café. Objetivou-se neste trabalho descrever o perfil sensorial de diferentes cultivares de café processados por via seca (natural) e via úmida (desmucilado), após um ano de armazenamento. Foram avaliados sensorialmente quatro cultivares de café (Catuaí Vermelho IAC 144, Iapar 59, Bourbon Amarelo e Paraíso MG H 419-1), da espécie Coffea arabica L. da safra de 2012/2013, com a realização de dois processamentos pós-colheita (natural e cereja desmucilado) após um ano de armazenamento. A análise sensorial foi realizada por dois provadores credenciados e habilitados por meio do protocolo da Specialty Coffee Association of America – SCAA. As cultivares se comportam de maneira diferenciada na qualidade em função do processamento adotado. Os cafés do processamento natural se destacaram na maioria dos atributos sensoriais avaliados em relação aos cafés desmucilados após um ano de armazenamento. As cultivares Catuaí Vermelho IAC 144 e Iapar 59 apresentaram melhor qualidade quando submetidas ao processamento natural. Já nos cafés desmucilados, maiores notas foram atribuídas às cultivares Bourbon Amarelo e Paraíso

PROFILE OF ORGANIC ACIDS AND BIOACTIVE COMPOUNDS IN THE SENSORY QUALITY DISCRIMINATION OF ARABICA COFFEE

This study was conducted to investigate the potential of organic acids and bioactive compounds present in rawbeans to differentiate the sensory quality of coffee from different genotypes and processing methods. During the 2010, 2011 and 2012 crop seasons, beverage quality was analyzed, as well as the profile of organic acids and bioactive compounds caffeine, trigonelline and chlorogenic acids (3,4 and 5-CQA) in raw coffee beans from genotypes Bourbon Amarelo and Acaiá. The samples were collected in commercial fields with altitudes ranging from 932 to 1391 m, in the municipality of Carmo de Minas, MG, Brazil. Two processing methods were adopted: dry process (natural) and wet process (mechanically pulped and demucilaged coffee). All harvest and post-harvest procedures were carried out according to the main technologies for the production of specialty coffees. The sensory analysis was performed using the methodology proposed by the Specialty Coffee Association of America (SCAA). Chemical analyses were performed by High performance liquid chromatography. Data were investigated using Principal Component Analysis (PCA). The variations in the contents of organic acids and bioactive compounds were due to the coffee processing method. For genotypes Bourbon Amarelo and Acaiá, the differences in the organic acid profile, associated with caffeine, trigonelline and chlorogenic acids (3,4 and 5-CQA), were essential to differentiate the quality of mechanically pulped and demucilaged coffee. No significant differences were observed in the sensory quality of natural coffee due to the analysis of organic acids and bioactive compounds.This study was conducted to investigate the potential of organic acids and bioactive compounds present in rawbeans to differentiate the sensory quality of coffee from different genotypes and processing methods. During the 2010, 2011 and 2012 crop seasons, beverage quality was analyzed, as well as the profile of organic acids and bioactive compounds caffeine, trigonelline and chlorogenic acids (3,4 and 5-CQA) in raw coffee beans from genotypes Bourbon Amarelo and Acaiá. The samples were collected in commercial fields with altitudes ranging from 932 to 1391 m, in the municipality of Carmo de Minas, MG, Brazil. Two processing methods were adopted: dry process (natural) and wet process (mechanically pulped and demucilaged coffee). All harvest and post-harvest procedures were carried out according to the main technologies for the production of specialty coffees. The sensory analysis was performed using the methodology proposed by the Specialty Coffee Association of America (SCAA). Chemical analyses were performed by High performance liquid chromatography. Data were investigated using Principal Component Analysis (PCA). The variations in the contents of organic acids and bioactive compounds were due to the coffee processing method. For genotypes Bourbon Amarelo and Acaiá, the differences in the organic acid profile, associated with caffeine, trigonelline and chlorogenic acids (3,4 and 5-CQA), were essential to differentiate the quality of mechanically pulped and demucilaged coffee. No significant differences were observed in the sensory quality of natural coffee due to the analysis of organic acids and bioactive compounds

Mid-infrared spectroscopy and sensory analysis applied to detection of adulteration in roasted coffee by addition of coffee husks

Mid-infrared spectroscopy and chemometrics were used to identify adulteration in roasted and ground coffee by addition of coffee husks. Consumers' sensory perception of the adulteration was evaluated by a triangular test of the coffee beverages. Samples containing above 0.5% of coffee husks from pure coffees were discriminated by principal component analysis of the infrared spectra. A partial least-squares regression estimated the husk content in samples and presented a root-mean-square error for prediction of 2.0%. The triangular test indicated that were than 10% of coffee husks are required to cause alterations in consumer perception about adulterated beverages.

Use of the pyrolysis coupled with gas chromatography and mass spectrometry in the determination of the syringyl/guaiacyl ratio in Eucalyptus spp. clones lignins

A relação siringil/guaiacil (S/G) foi determinada em madeiras de seis diferentes clones de Eucalyptus cultivados em quatro regiões do estado brasileiro de Minas Gerais. As determinações foram realizadas por pirólise acoplada à cromatografia gasosa e à espectrometria de massas (Pi- CG/EM) e os resultados obtidos foram comparados à valores de referência obtidos pelo método de oxidação alcalina com nitrobenzeno. Os cálculos da relação S/G foram realizados considerando todos os compostos derivados de lignina identificados nos pirogramas e através de dois grupos de marcadores. O primeiro grupo considerou os compostos guaiacol, 4-metilguaiacol, 4-vinilguaiacol, trans-isoeugenol, siringol, 4-metilsiringol, 4-vinilsiringol e trans-4- propenilsiringol como marcadores. O segundo grupo considerou como marcadores, os compostos guaiacol, 4-metilguaiacol, 4- vinilguaiacol, vanilina, 4-etilsiringol, 4-vinilsiringol, homovanilina, siringaldeído, siringilcetona e trans-4- propenilsiringol. Pelo do teste t, verificou-se que os valores obtidos por Pi-CG/EM empregando marcadores não se diferenciaram significativamente dos valores de referência, ao contrário das determinações em que foram considerados todos os compostos derivados de lignina. O segundo grupo de marcadores mostrou-se mais indicado por apresentar picos mais definidos nos pirogramas. A Análise das Componentes Principais mostrou que os compostos trans-4-propenilsiringol, 4-vinilsiringol e siringol foram responsáveis por promover distinções entre as amostras e que os valores de relação S/G se apresentaram com pouca variação entre os vários clones cultivados nas diferentes regiões.The syringyl/guaiacyl ratio (S/G) was determined in wood of six different Eucalyptus clones cultivated in four regions of Minas Gerais Brazilian state. The determinations were accomplished by pyrolysis coupled with gaseous chromatography and mass spectrometry (Py-GC/MS) and the obtained results were compared to reference values obtained by alkaline nitrobenzene oxidation method. The S/G ratio calculations were accomplished considering all the lignin compounds derived identified in the pyrograms and through two markers groups. The first group considered the compounds guaiacol, 4-methylguaiacol, 4-vinylguaiacol, trans-isoeugenol, syringol, 4-methylsyringol, 4-vinylsyringol and trans-4-propenylsyringol as markers. The second group considered as markers, the compounds guaiacol, 4- methylguaiacol, 4-vinhylguaiacol, vanilin, 4-ethylsyringol, 4- vinylsyringol, homovanilin, syringaldehyde, syringylcetone and trans-4-propenylsyringol. Through the t test, it was verified that the values obtained through the markers compounds didn't differ significantly from the reference values, unlike the determinations witch all were considered the lignin compounds derived. The second markers group was shown to be more suitable for presenting more defined picks in the pyrograms. The Principal Component Analysis showed that the compounds trans-4-propenylsyringol, the 4-vinylsyringol and the syringol were responsible for promoting distinctions among the samples and that the S/G ratio values came with little variation among the several clones cultivated in the different regions

SensoMaker: a tool for sensorial characterization of food products SensoMaker: uma ferramenta para caracterização sensorial de produtos alimentícios

SensoMaker is a free software for data analysis from sensory studies, which has modules with user-friendly interface. Data acquisition can be performed using different methods, such as category scale, linear scale, temporal dominance of sensations (TDS), and time-intensity (TI). Results can be analyzed by a variety of methods, such as conventional internal and external preference mapping, three-way internal and external preference mapping, principal component analysis, hierarchical cluster analysis, TDS and TI curves, in addition to Tukey and Dunnett tests. High quality graphics are easily obtained and exported to several formats. The software is useful during the development or improvement of products, when it is important to carefully note consumer preferences and to relate it to descriptive characteristics in order to ensure good product acceptance.SensoMaker é um software livre para análise de dados de estudos sensoriais que tem módulos com uma interface gráfica amigável. A aquisição de dados pode ser realizada por meio de diferentes métodos, tais como escala de categoria, escala linear, dominância temporal de sensações (TDS) e tempo-intensidade (TI). Os resultados podem ser analisados por uma variedade de métodos, tais como mapas de preferência interno e externo (convencional e de três vias), análise de componentes principais, análise de agrupamento hierárquico, curvas de TDS e TI, além de testes de Tukey e Dunnett. Gráficos de alta qualidade são facilmente obtidos e exportados para vários formatos. O software é útil durante o desenvolvimento ou a melhoria de produtos, quando é importante observar cuidadosamente as preferências dos consumidores e relacioná-la com características descritivas, a fim de garantir sua boa aceitação

The use of statistical software in food science and technology: advantages, limitations and misuses

Strict requirements of scientific journals allied to the need to prove the experimental data are (in)significant from the statistical standpoint have led to a steep increase in the use and development of statistical software. In this aspect, it is observed that the increasing number of software tools and packages and their wide usage has created a generation of ‘click and go’ users, who are eagerly destined to obtain the p-values and multivariate graphs (projection of samples and variables on the factor plane), but have no idea on how the statistical parameters are calculated and the theoretical and practical reasons he/she performed such tests. However, in this paper, some published examples are listed and discussed in detail to provide a holistic insight (positive points and limitations) about the uses and misuses of some statistical methods using different available statistical software. Additionally, a brief description of several commercial and free statistical software is made highlighting their advantages and limitations75270280CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPSem informaçãoSem informaçãoSem informaçã

Determinação de constituintes químicos em madeira de eucalipto por Pi-CG/EM e calibração multivariada: comparação entre redes neurais artificiais e máquinas de vetor suporte

Multivariate models were developed using Artificial Neural Network (ANN) and Least Square - Support Vector Machines (LS-SVM) for estimating lignin siringyl/guaiacyl ratio and the contents of cellulose, hemicelluloses and lignin in eucalyptus wood by pyrolysis associated to gaseous chromatography and mass spectrometry (Py-GC/MS). The results obtained by two calibration methods were in agreement with those of reference methods. However a comparison indicated that the LS-SVM model presented better predictive capacity for the cellulose and lignin contents, while the ANN model presented was more adequate for estimating the hemicelluloses content and lignin siringyl/guaiacyl ratio