Purpose: The aimed witch of this study was to verify the quality of the fuel sold by gas stations in the Amazonian towns of Bragança and Tracuateua (Brazil). Method: It were applied ...physicochemical analyses to verify the anhydrous ethyl alcohol content of samples of gasoline, as well as the specific mass of samples of diesel and gasoline. Result and conclusion: Just over a quarter (26.47%) of the samples of gasoline collected in Bragança contained more ethanol than permitted by Brazilian law and were thus classified as in non-conformity. Three (75%) of the four gasoline samples from Tracuateua were non-conformity. In addition, 11.76% of the gasoline samples collected in Bragança were less dense at 20 °C than specified by the Brazilian legislation, and were thus considered as in non-conformity. Based on this same criterion, half (50%) of the gasoline samples collected in Tracuateua were also non-conformity. Diesel was the only fuel that presented no alteration in specific mass in either town. Research implications: There is a lack of academic studies related to this serious problem in the surveyed sites. This pioneering study is of great importance because it will alert local authorities about the problem of marketing fuels that do not meet the current specifications of the Brazilian legislation and whose emission of gases causes atmospheric pollution besides being harmful to life and to the environment. Originality/value: This study indicated that both types of gasoline (regular and premium) may be subject to adulteration in both Amazonian towns (Pará, Brazil).
Objetivo: O objetivo deste estudo foi verificar a qualidade dos combustíveis comercializados pelos postos de abastecimento das cidades amazônicas de Bragança e Tracuateua (Brasil). Método: Foram aplicadas análises físico-químicas para verificar o teor de álcool etílico anidro de amostras de gasolina, bem como a massa específica de amostras de óleo diesel e gasolina. Resultados e conclusão: Pouco mais de um quarto (26,47%) das amostras de gasolina coletadas em Bragança continham mais etanol do que o permitido pela legislação brasileira e, portanto, foram classificadas como não conformes. Três (75%) das quatro amostras de gasolina de Tracuateua não estavam conformes. Além disso, 11,76% das amostras de gasolina coletadas em Bragança eram menos densas a 20 °C do que o especificado pela legislação brasileira, sendo assim consideradas não conformes. Com base neste mesmo critério, metade (50%) das amostras de gasolina coletadas em Tracuateua também apresentavam inconformidade. O diesel foi o único combustível que não apresentou alteração na massa específica em nenhum dos municípios. Implicações da pesquisa: Existe uma carência de estudos acadêmicos nos locais pesquisados em relação a este sério problema. Este estudo pioneiro é de grande importância porque alertará as autoridades locais sobre o problema da comercialização de combustíveis que não atendem às especificações vigentes da legislação brasileira e cuja emissão de gases causa poluição atmosférica além de ser prejudicial à vida e ao meio ambiente. Originalidade/valor: Este estudo indicou que ambos os tipos de gasolina (comum e premium) podem estar sujeitos a adulteração em ambas as cidades amazônicas (Pará, Brasil). Palavras-chave: análises físico-químicas, qualidade do combustível, álcool etílico anidro, não conformidade, adulteração.
In the present work, degradation analysis associated with the thermal stress in a 320 kV Cross-linked Polyethylene (XLPE) insulated cable insulation has been carried out. Accelerated thermal ageing ...at 140 °C for 30 days is done for XLPE insulation to understand the material degradation. Physicochemical analyses such as Fourier Transform Infrared (FTIR) Spectroscopy, Differential Scanning Calorimetry (DSC), X-Ray Diffraction (XRD) analyses have been performed to understand the material degradation due to thermal stress. These material investigations show interesting features regarding changes in characteristic peaks and formation of carbonyl group, micro-structural changes and decreased degree of crystallinity with thermal ageing as evident by FTIR, XRD and DSC respectively. Measurement of Polarization and Depolarization Current (PDC) have been carried out in the thermally aged insulation samples. It is observed that with thermal ageing the polarization and depolarization current magnitude seem to increase. A novel technique employing Relaxation Frequency Distribution (RFD) has been used to get a deeper insight into the thermal degradation of the material by understanding the relaxation mechanism of the dipoles with the thermal ageing. RFD spectrum shows a dominant slow polarization as the material undergoes thermal ageing. Higher dielectric loss with thermal ageing of the samples has been observed from the RFD spectrum.This higher dielectric loss is also validated using Dielectric Dissipation Factor (tanδ) measurement. Moreover, a correlation between RFD spectrum and physicochemical analyses has been established.
Sometimes, analytical chemicals forget that the measurement process begins with the selection of the sample; thus, it must be understood that the measurement uncertainty is constituted by the ...association of the uncertainty arising from the sampling and the uncertainty arising from the traditional analytical process, that which is carried out in the laboratory. The analytical process is well-controlled, so its uncertainty is well defined; however, the uncertainty arising from sampling, for not having this controlled environment, is often not evident, so that there is still no culture to consider it for the calculation of measurement uncertainty. This study discusses the importance of the sampling uncertainty concerning the analytical uncertainty and details the current approaches available in the literature, such as the classical analysis of variance, the robust analysis of variance, and the range statistics. Moreover, this work highlights the recent manuscripts that are using these mentioned approaches, correlating them to the matrices, chemical and physical-chemical analytes, and analytical techniques. Finally, some case studies using the uncertainty information in compliance assessment show that the measurement uncertainty arising from sampling in chemical and physicochemical analyses cannot always be neglected.
Some of the key components that contribute to the acceptance of high-quality fresh mangoes by consumers are its flavour, odour, texture and chemical constituents that depend mainly on level of ...maturity. In the European market, the demand for tree-ripened fruit has increased in recent decades. Nevertheless, the qualitative response and the marketable characteristics of tree-ripened mango fruit grown in the Mediterranean area are not yet studied. Tree-ripened fruits of cv Keitt, Glenn, Osteen, Maya, Kensington Pride and Tommy Atkins were submitted to analytical (fruit weight, transversal diameter, longitudinal diameter, flesh firmness, total soluble solid content, titratable acidity, seed weight, peel weight, percentage of flesh and fibre, ash content, fat content, carbohydrate content, riboflavin, niacin, thiamin, K, Na, Ca, Mg, Fe, Cu, Mn and Zn contents, ascorbic acid and vitamin A) and sensory evaluations. Significant differences were observed for sensory and physicochemical characteristics in a cultivar-dependent manner. The mango Keitt, in addition to its interesting physicochemical traits, content of protein and vitamin, has a higher sensory appeal. Glenn fruit showed more suitable weight, flesh firmness, soluble solids, vitamin content, total antioxidant activity and total polyphenolics content; Maya had the lowest titratable acidity and the highest soluble solid content, whereas Tommy Atkins revealed preferable ground colour, total antioxidant activity, and vitamin B2 and vitamin C contents. Tree-ripened fruits grown in the Mediterranean climate show interesting peculiarities in regard to fresh market requirements. The analytical-sensory approach established a qualitative characterization of the six observed cultivars.
Summary
Cannabis sativa L. seeds (hemp) have a high level of omega 3 and 6 fatty acids; therefore, it has the potential to nutrition properties of the food product. In the present study, camel yogurt ...enriched with hemp seeds was prepared at four concentrations (0%, 1%, 3%, 5%). Several tests such as pH level, titratable acidity, syneresis, water holding capacity (WHC), viscosity, phenolic component, DPPH inhibition and sensory evaluation were determined during 0, 7, 14 and 21 days at 4 °C. At the end of storage, fatty acid profile and scanning electron microscopy (SEM) were performed on control and optimal treatments. The results illustrated that lowest pH (3.79) corresponded to treatment supplemented with 5% hemp seeds. On the 21st day, the lowest syneresis (7.04%) and also the highest viscosity (157.50 mPa.s) and WHC (17.02%) were attributed to camel yogurt containing 3% hemp seeds. The phenolic components (14.14 mg gallic acid 100 g−1) and antioxidant features (20.21%) were elevated by adding hemp seed (to 5%), but increasing shelf life had an adverse effect on these factors (P < 0.05). The sensory assessment of treatments with 3% of hemp seeds had the most desirability degree on the 14th day. The saturated and unsaturated fatty acids significantly decreased and increased with 3% hemp seeds (optimal) compared with control, respectively. The SEM also exhibited better structural microscopy in optimal treatment compared to yogurt with no additives. Hence, hemp seed was considered as an appropriate dietary supplement for camel yogurt.
Camel yogurt.
In this study, fourty monofloral honeys belonging to four sources (Chaste, thyme, citrus and heather) were obtained from South West Anatolia (Mugla, Aydin, Denizli and Antalya provinces). Firstly, ...pollen species of honeys were identified and categorized according to pollen concentrations. Then, physicochemical analyses of honey samples were carried out in terms of moisture, pH, free acidity, conductivity, diastase, proline and sugar profile. Physicochemical results of moisture values 15.04-19.52 %, density values 1.32-1.43 (g/cm3), viscosity values 5.81-11.49 25 0C/Pa.s, ash content 1.32-1.43 %, pH values 3.74-4.78, free acidity values 8.96-33.92 meq/kg, conductivity values 0.15-1.41 mS/cm, diastase numbers 3.44-17.26 g/100g, proline contents 204.06-1588.93 mg/kg and sugar contents (glucose+fructose) 62.02-74.90 %. It was shown that the results obtained when compared to TFC (Turkish Food Codex) and CODEX Alimentarius Commission Honey Standards were in line with the standards.
In this study, fourty monofloral honeys belonging to four sources (Chaste, thyme, citrus and heather) were obtained from South West Anatolia (Mugla, Aydin, Denizli and Antalya provinces). Firstly, pollen species of honeys were identified and categorized according to pollen concentrations. Then, physicochemical analyses of honey samples were carried out in terms of moisture, pH, free acidity, conductivity, diastase, proline and sugar profile. Physicochemical results of moisture values 15.04-19.52 %, density values 1.32-1.43 (g/cm3), viscosity values 5.81-11.49 25 0C/Pa.s, ash content 1.32-1.43 %, pH values 3.74-4.78, free acidity values 8.96-33.92 meq/kg, conductivity values 0.15-1.41 mS/cm, diastase numbers 3.44-17.26 g/100g, proline contents 204.06-1588.93 mg/kg and sugar contents (glucose+fructose) 62.02-74.90 %. It was shown that the results obtained when compared to TFC (Turkish Food Codex) and CODEX Alimentarius Commission Honey Standards were in line with the standards.
The aim of this study was to develop models based on Linear Discriminant Analysis (LDA), Classification and Regression Trees (C&RT), and Artificial Neural Network (ANN) for the prediction of the ...botanical origin of honeys using their physicochemical parameters as well as their antioxidative and thermal properties. Also Principal Component Analysis (PCA) and Cluster Analysis (CA) were performed as initial steps of data mining. The datasets consisted of 72 honey samples (false acacia, rape, buckwheat, honeydew, linden, nectar-honeydew and multifloral) obtained from different regions of Poland and collected between April 2014 and November 2016. Ash content, pH, free acidity, colorimetric coordinates in the CIELAB space (L*, a*, b*, h*, C*), total phenolics content, antioxidant activity, and glass transition temperatures (Tg) of the honey samples were determined. The first four principal components accounted for about 85% of the total variance. PC1 was highly correlated with colour intensity, the hue angle (h*), and total phenolics content, whereas PC2 was dominated by chroma (C*) value and glass transition temperatures (Tg). The CA dendrogram displays two clusters: one with light coloured honey samples and second with dark coloured honey samples. On the basis of the LDA analysis, the colour parameters possessed the highest discrimination power according to the botanical origin of honey samples. The models based on ANN and C&RT algorithms were characterized by 100% accuracy. Study results demonstrate that the chemometric approach enables high-accuracy classification of honeys according to their botanical origin.
Milk and water kefir have been attractive to consumers as health-promoter fermented beverages. Although both are called “kefir”, they differ in physicochemical and microbial properties. In this ...study, we aimed to compare milk and water kefir in terms of biomass increase, physicochemical properties, sensory qualities, and microbial loads incubated at different incubation temperatures (20 °C, 25 °C, and 30 °C) to mimic approximate room temperatures in various seasons. Additionally, the microbial diversity of the grains was compared through metagenomic analysis. The results showed that the biomass increase, physicochemical properties, and sensory analysis of milk kefir grains depended on the fermentation temperature (p < 0.05); while in general, water kefir was not affected by the fermentation temperature. The highest total dry matter, protein, and fat content, and the least acidity were recorded at 20 °C in milk kefir drinks (p < 0.05). Around 8 and 6 log CFU/ml microorganism loads (Lactobacillus spp., Lactococcus spp., yeasts, total aerobe, and anaerobe bacteria) were recorded for milk and water kefir drinks, respectively, regardless of the temperature. Bifidobacterium load was recorded as the lowest for both kefir drinks. The dominant species of bacteria and yeasts were determined as Lactobacillus parakefiri (21.28%) and Geotricum silvicola (65.10%) in milk kefir grain, and Lactobacillus nagelii (95.69%) and Dekkera bruxellensis (95.24%) in water kefir grain, respectively. The study showed that milk and water kefir differ in terms of physicochemical, sensory, and microbial aspects. Despite its low protein content, water kefir would be a probiotic substitute for milk kefir due to its probiotic features for vegans or people with lactose intolerance.
•Biomass increase and physicochemical properties of milk kefir were affected by fermentation temperature.•The ideal fermentation temperature for milk kefir fermentation can be recommended as 20 °C.•In milk kefir, Lb. parakefiri and G. silvicola were predominant for bacteria and yeast, respectively.•In water kefir, Lb. nagelii and D. bruxellensis were predominant for bacteria and yeast, respectively.•To the authors' knowledge, this is the first time Geotrichum silvicola was reported in milk kefir.
The sources and quality of Iranian honey Khansaritoreh, Elmira; Salmaki, Yasaman; Akbari Azirani, Tayebeh ...
Heliyon,
04/2021, Letnik:
7, Številka:
4
Journal Article
Recenzirano
Odprti dostop
Iran is one of the largest honey-producing countries worldwide and is considered as an important source of honey for international markets. However, since Iran is not registered for honey export to ...Europe, the quality of Iranian honey remains unknown to European traders. As the first step in filling this gap, we analyzed 225 honey samples using palynology, sensory, nuclear magnetic resonance (NMR) and conventional physicochemical analyses as outlined by the European Union coordinated control plan. The results show that while various types of genuine unifloral honey can be harvested in Iran, 85% of collected samples were adulterated. Performing principal component analysis on physicochemical parameters reveals that feeding tablet sugar and syrup of C4 origin to bees during the foraging season is a common mode of fraud. Replacement of natural nectar with sugar syrup together with presence of intensive aftertaste from Taraxacum and Eryngium affect the taste of unifloral honeys produced in Iran.
Honey, adulteration, NMR, melissopalynology, sensory, physicochemical analyses
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