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1.
Gels ; 10(3)2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38534612

RESUMO

Five varieties of vegetable oil underwent oleogelation with two types of wax as follows: beeswax (BW) and rice bran wax (RW). The oleogels were analyzed for their physicochemical, thermal, and textural characteristics. The oleogels were used in the bun dough recipe at a percentage level of 5%, and the textural and rheological properties of the oleogel doughs were analyzed using dynamic and empirical rheology devices such as the Haake rheometer, the Rheofermentometer, and Mixolab. The thermal properties of beeswax oleogels showed a melting peak at a lower temperature for all the oils used compared with that of the oleogels containing rice bran wax. Texturally, for both waxes, as the percentage of wax increased, the firmness of the oleogels increased proportionally, which indicates better technological characteristics for the food industry. The effect of the addition of oleogels on the viscoelastic properties of the dough was measured as a function of temperature. All dough samples showed higher values for G' (storage modulus) than those of G″ (loss modulus) in the temperature range of 20-90 °C, suggesting a solid, elastic-like behavior of all dough samples with the addition of oleogels. The influence of the beeswax and rice bran oleogels based on different types of vegetable oils on the thermo-mechanical properties of wheat flour dough indicated that the addition of oleogels in dough recipes generally led to higher dough stability and lower values for the dough development time and those related to the dough's starch characteristics. Therefore, the addition of oleogels in dough recipes inhibits the starch gelatinization process and increases the shelf life of bakery products.

2.
Curr Res Food Sci ; 7: 100642, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38115897

RESUMO

Honey adulteration is a major issue for European Union and its members because of an unfair practice of different producers and beekeepers, many adulterations involve the addition of sweet, concentrated syrups which may appear like honey. In our study we analysed the influence of adulteration of tilia honey with different syrups (such as corn, rice, inverted sugar, agave, maple syrups) in different percentages (5%, 10%, and 20% respectively) on physicochemical parameters (moisture content, L*, hab,cab, pH, free acidity, electrical conductivity (EC), 5-hydroxymetilfurfural (HMF), fructose, glucose, sucrose, turanose, trehalose, melesitose and raffinose) and impedimetric properties using electrochemical impedance spectroscopy. The impedimetric sensing was made using an electrochemical cell composed of two gold electrodes, and the frequency ranged between 0.1 kHz and 100 kHz. The impedimetric parameters (Z', Z″ and phase) and Randal circuit parameters can distinguish the authentic honeys from the adulterated ones (based on the adulteration agent and adulteration percentage, respectively). The partial least squares - discriminant analysis (PLS-DA) and support vector machines (SVM) were used in a binary mode to separate the authentic honeys from the adulterated ones, and the SVM proved to separate much better than PLS-DA.

3.
Gels ; 9(3)2023 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-36975665

RESUMO

The aim of the study was to characterize the gelling effect of beeswax (BW) using different types of cold pressed oil. The organogels were produced by hot mixing sunflower oil, olive oil, walnut oil, grape seed oil and hemp seed oil with 3%, 7% and 11% beeswax. Characterization of the oleogels was done using Fourier transform infrared spectroscopy (FTIR), the chemical and physical properties of the oleogels were determined, the oil binding capacity was estimated and the SEM morphology was studied. The color differences were highlighted by the CIE Lab color scale for evaluating the psychometric index of brightness (L*), components a and b. Beeswax showed excellent gelling capacity at 3% (w/w) of 99.73% for grape seed oil and a minimum capacity of 64.34%for hemp seed oil. The value of the peroxide index is strongly correlated with the oleogelator concentration. Scanning electron microscopy described the morphology of the oleogels in the form of overlapping structures of platelets similar in structure, but dependent on the percentage of oleogelator added. The use in the food industry of oleogels from cold-pressed vegetable oils with white beeswax is conditioned by the ability to imitate the properties of conventional fats.

4.
Spectrochim Acta A Mol Biomol Spectrosc ; 293: 122459, 2023 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-36812751

RESUMO

The aim of this study was to evaluate the usefulness of emission-excitation matrices for honey authentication and adulteration detection. For this purpose, 4 types of authentic honeys (tilia, sunflower, acacia and rape) and samples adulterated with different adulteration agents (agave, maple, inverted sugar, corn and rice in different percentages - 5%, 10% and 20%) were analysed. Each honey type and each adulteration agent exhibit unique emission-excitation spectra that can be used for the classification according to the botanical origin and for the detection of adulteration. The principal component analysis clearly separated the rape, sunflower and acacia honeys. The partial least squares - discriminant analysis (PLS-DA) and support vector machines (SVM) were used in a binary mode to separate the authentic honeys from the adulterated ones, and the SVM proved to separate much better than PLS-DA.


Assuntos
Helianthus , Mel , Mel/análise , Quimiometria , Análise Discriminante , Carboidratos , Contaminação de Alimentos/análise
5.
Int J Biol Macromol ; 224: 739-753, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36302476

RESUMO

Pectin from grape pomace (Vitis vinifera var. Feteasca Neagra and Vitis vinifera var. Rara Neagra) was extracted by using different extraction techniques (conventional, microwave-assisted and pulsed ultrasound-assisted extraction). Microwave-assisted extraction showed highest yield (11.2 %) for Rara Neagra pectin, while conventional extraction presented highest yield (9.9 %) for Feteasca Neagra pectin. The yield was directly correlated with the galacturonic acid content, degree of esterification, molecular weight and functional features (water-holding, oil-holding and water-swelling capacity, emulsifying properties and rheological behavior of pectin emulsions). In addition, the FT-IR, morphological structure, thermal analysis and emulsion properties of obtained pectin samples from different extraction techniques revealed dissimilar results by comparing with commercial pectin.


Assuntos
Pectinas , Vitis , Pectinas/química , Vitis/química , Espectroscopia de Infravermelho com Transformada de Fourier , Peso Molecular , Emulsões/química , Água
6.
Foods ; 13(1)2023 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-38201126

RESUMO

The influence of particle size intervals (<125 µm, ≥125-<200 µm, and ≥200-<300 µm) of grape pomace (Vitis vinifera var. Babeasca Neagra) was analyzed in terms of the proximate composition, functional properties, and physicochemical parameters. The aim was to study the effect of the formulation variables (extract from grape pomace with different particle size intervals and gelatin doses-7, 8.5, and 10 g) on the mechanical properties (hardness, cohesiveness, adhesiveness, springiness, and gumminess), color, and sensorial, microbiological, and phytochemical parameters. The jelly candy formulated with grape pomace extract (<125 µm) and 7 g of gelatin showed the highest total phenolic content (156 mg GAE/g) and antioxidant activity (65.8% inhibition), while grape pomace jellies with a particle size of ≥125-<200 µm and different concentration of gelatin presented the greatest sensory acceptance in terms of sweetness, taste, odor, elasticity, color, and overall acceptability of the resulting jelly. The concluding observation was supported by the microbiological analysis, which also showed that there is no growth in jelly samples except the jelly candies prepared with a ≥200-<300 µm particle size interval of grape pomace extract.

7.
Foods ; 11(17)2022 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-36076817

RESUMO

Bee pollen represents an important bee product, which is produced by mixing flower pollens with nectar honey and bee's salivary substances. It represents an important source of phenolic compounds which can have great importance for importance for prophylaxis of diseases, particularly to prevent cardiovascular and neurodegenerative disorders, those having direct correlation with oxidative damage. The aim of this study was to characterize 24 bee pollen samples in terms of physicochemical parameters, organic acids, total phenolic content, total flavonoid content, individual phenolics compounds, fatty acids, and amino acids from the Nort East region of Romania, which have not been studied until now. The bee pollen can be considered as a high protein source (the mean concentration was 22.31% d.m.) with a high energy value (390.66 kcal/100 g). The total phenolic content ranged between 4.64 and 17.93 mg GAE/g, while the total flavonoid content ranged between 4.90 and 20.45 mg QE/g. The high protein content was observed in Robinia pseudoacacia, the high content of lipids was observed in Robinia pseudoacacia pollen, the high fructose content in Prunus spp. pollen while the high F/G ratio was observed in Pinaceae spp. pollen. The high TPC was observed in Prunus spp. pollen, the high TFC was observed in Robinia pseudoacacia pollen, the high free amino acid content was observed in Pinaceae spp. pollen, and the high content of PUFA was reported in Taraxacum spp. pollen. A total of 16 amino acids (eight essential and eight non-essential amino acids) were quantified in the bee pollen samples analyzed. The total content of the amino acids determined for the bee pollen samples varied between 11.31 µg/mg and 45.99 µg/mg. Our results can indicate that the bee pollen is a rich source of protein, fatty acids, amino acids and bioactive compounds.

8.
Foods ; 11(15)2022 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-35954041

RESUMO

The yield, physicochemical and rheological parameters of grape pomace pectin (Feteasca Neagra and Rara Neagra) obtained by conventional extraction (CE) were compared to those acquired by pulsed ultrasound-assisted extraction (PUAE). Extraction temperature (70-90 °C), pH (1-3) and time (1-3 h) were considered as independent variables for CE, while amplitude (20-100%), pH (1-3) and time (20-60 min) for PUAE. The optimal conditions for maximum yield and physicochemical parameters of pectin samples extracted by CE were temperature of 90 °C, pH 1.9 for 164 min (9.96% yield, 79.91 g/100 g of galacturonic acid (GalA) content, 81.28% of degree of esterification (DE) and 5.52 × 104 g/mol of molecular weight (Mw) for Feteasca Neagra (FN) pectin; 11.08% yield, 80.05 g/100 g of GalA content, 80.86% of DE and 5.59 × 104 g/mol of Mw for Rara Neagra (RN) pectin), while for PUAE they were amplitude of 100%, pH 1.8 for 60 min (8.83% yield, 80.24 g/100 g of GalA content, 81.07% of DE and 4.19 × 104 g/mol of Mw for FN pectin; 8.94% yield, 78.64 g/100 g of GalA content, 80.04% of DE and 4.23 × 104 g/mol of Mw for RN pectin). The yield and physicochemical parameters of CE pectin were higher than PUAE pectin. The FT-IR spectra of pectin samples revealed the occurrence of polysaccharide compound, while rheology characteristics confirming its application in different food products.

9.
Sci Rep ; 12(1): 12722, 2022 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-35882905

RESUMO

The utilization of microwave technique for the pectin extraction from grape pomace (Feteasca Neagra and Rara Neagra), its influence on yield, galacturonic acid content, degree of esterification and molecular weight of pectin were analyzed. The optimal conditions of the extraction process were microwave power of 560 W, pH of 1.8 for 120 s. The pectin samples extracted by MAE in optimal conditions were analyzed by comparing with commercial apple and citrus pectin based on FT-IR analysis, thermal behavior, rheological characteristics and microstructure. The FT-IR analysis established the presence of different functional groups which are attributed to the finger print region of extracted pectin, while the rheological behavior presented a good viscoelasticity of pectin solutions. The obtained data assumes that grape pomace has a great potential to be a valuable source of pectin which can be extracted by simple and quick techniques, while maintaining analogous quality to conventional sources of pectin.


Assuntos
Micro-Ondas , Vitis , Esterificação , Pectinas/química , Espectroscopia de Infravermelho com Transformada de Fourier
10.
Polymers (Basel) ; 14(7)2022 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-35406252

RESUMO

Grape pomace is one of the most abundant by-products generated from the wine industry. This by-product is a complex substrate consisted of polysaccharides, proanthocyanidins, acid pectic substances, structural proteins, lignin, and polyphenols. In an effort to valorize this material, the present study focused on the influence of extraction conditions on the yield and physico-chemical parameters of pectin. The following conditions, such as grape pomace variety (Feteasca Neagra and Rara Neagra), acid type (citric, sulfuric, and nitric), particle size intervals (<125 µm, ≥125−<200 µm and ≥200−<300 µm), temperature (70, 80 and 90 °C), pH (1, 2 and 3), and extraction time (1, 2, and 3 h) were established in order to optimize the extraction of pectin. The results showed that acid type, particle size intervals, temperature, time, and pH had a significant influence on the yield and physico-chemical parameters of pectin extracted from grape pomace. According to the obtained results, the highest yield, galacturonic acid content, degree of esterification, methoxyl content, molecular, and equivalent weight of pectin were acquired for the extraction with citric acid at pH 2, particle size interval of ≥125−<200 µm, and temperature of 90 °C for 3 h. FT-IR analysis confirmed the presence of functional groups in the fingerprint region of identification for polysaccharide in the extracted pectin.

11.
Plants (Basel) ; 11(7)2022 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-35406834

RESUMO

Usnea genus (Parmeliaceae, lichenized Ascomycetes) is a potent phytomedicine, due to phenolic secondary metabolites, with various pharmacological effects. Therefore, our study aimed to explore the antioxidant, cytotoxic, and rheological properties of Usnea barbata (L.) Weber ex F.H. Wigg (U. barbata) extract in canola oil (UBO) compared to cold-pressed canola seed oil (CNO), as a green solvent used for lichen extraction, which has phytoconstituents. The antiradical activity (AA) of UBO and CNO was investigated using UV-Vis spectrophotometry. Their cytotoxicity was examined in vivo through a brine shrimp lethality (BSL) test after Artemia salina (A. salina) larvae exposure for 6 h to previously emulsified UBO and CNO. The rheological properties of both oil samples (flow behavior, thixotropy, and temperature-dependent viscosity variation) were comparatively analyzed. The obtained results showed that UBO (IC50 = 0.942 ± 0.004 mg/mL) had a higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity than CNO (IC50 = 1.361 ± 0.008 mg/mL). Both UBO and CNO emulsions induced different and progressive morphological changes to A. salina larvae, incompatible with their survival; UBO cytotoxicity was higher than that of CNO. Finally, in the temperature range of 32-37 °C, the UBO and CNO viscosity and viscoelastic behavior indicated a clear weakening of the intermolecular bond when temperature increases, leading to a more liquid state, appropriate for possible pharmaceutical formulations. All quantified parameters were highly intercorrelated. Moreover, their significant correlation with trace/heavy minerals and phenolic compounds can be observed. All data obtained also suggest a possible synergism between lichen secondary metabolites, minerals, and canola oil phytoconstituents.

12.
Foods ; 11(7)2022 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-35407027

RESUMO

The aim of this study was to evaluate the influence of synbiotic microcapsules on oat yogurt's properties. For this study, four different microcapsules were added into the oat yogurt and the modifications were studied for 28 days. Microbiological analysis was used to analyze the effect of different factors on the microencapsulated probiotic population in the product. Those factors are: the technological process of obtaining microcapsules; the type of prebiotic chicory inulin (INU), oligofructose (OLI) and soluble potato starch (STH); the prebiotic concentrations in the encapsulation matrix; the technological process of obtaining yogurt; and the yogurt storage period, gastric juice action and intestinal juice action. The experimental data show that oat yogurt containing synbiotic microcapsules has similar properties to yogurt without microcapsules, which illustrates that the addition of synbiotic microcapsules does not change the quality, texture or rheological parameters of the product. Oat yogurt with the addition of synbiotic microcapsules can be promoted as a functional food product, which, in addition to other beneficial components (bioactive compounds), has in its composition four essential amino acids (glycine, valine, leucine and glutamine acids) and eight non-essential amino acids (alanine, serine, proline, asparagine, thioproline, aspartic acid, glutamic acid and α-aminopimelic acid). After 28 days of storage in refrigerated conditions, the cell viability of the microcapsules after the action of the simulated intestinal juice were: 9.26 ± 0.01 log10 cfu/g, I STH (oat yogurt with synbiotic microcapsules-soluble potato starch); 9.33 ± 0.01 log10 cfu/g, I INU, 9.18 ± 0.01 log10 cfu/g, I OIL and 8.26 ± 0.04 log10 cfu/g, IG (oat yogurt with microcapsules with glucose). The new functional food product provides consumers with an optimal number of probiotic cells which have a beneficial effect on intestinal health.

13.
Sci Rep ; 11(1): 23408, 2021 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-34862474

RESUMO

The aim of this study was to assess the influence of different adulteration agents (agave, maple, corn, rice and inverted sugar) on honey rheology. There was studied the influence of different percentages of adulteration agent on steady state and dynamic state rheology but also on rheology in the negative temperature domain. The authentic honey and adulterated ones behaved as a Newtonian fluid with a liquid-like behavior (G">>G'). Regarding the physicochemical parameters analyzed (moisture and sugar content), significant changes depending on the adulteration agent/degree used were observed. The viscoelastical parameters (η*-complex viscosity, G' -elastic modulus and G"-viscous modulus) and glass transition temperature (Tg) were predicted in function of the chemical composition (moisture content, glucose, fructose, sucrose, maltose, raffinose, trehalose, turanose, melesitose, and F/G ratio) using the PLS-R (partial least square regression). All parameters analyzed had a high regression coefficient for calibration (> 0.810) and validation (> 0.790), except for the elastic modulus.


Assuntos
Acer/química , Agave/química , Contaminação de Alimentos/análise , Mel/análise , Oryza/química , Zea mays/química , Fenômenos Químicos , Módulo de Elasticidade , Análise dos Mínimos Quadrados , Reologia , Viscosidade
14.
Sensors (Basel) ; 21(15)2021 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-34372298

RESUMO

The aim of this study is to establish the usefulness of an electronic tongue based on cyclic voltammetry e-tongue using five working electrodes (gold, silver, copper, platinum and glass) in honey adulteration detection. Authentic honey samples of different botanical origin (acacia, tilia, sunflower, polyfloral and raspberry) were adulterated with agave, maple, inverted sugar, corn and rice syrups in percentages of 5%, 10%, 20% and 50%. The silver and copper electrodes provided the clearest voltammograms, the differences between authentic and adulterated honey samples being highlighted by the maximum current intensity. The electronic tongue results have been correlated with physicochemical parameters (pH, free acidity, hydroxymethylfurfural content-5 HMF and electrical conductivity-EC). Using statistical methods such as Linear discriminant analysis (LDA) and Support vector machines (SVM), an accuracy of 94.87% and 100% respectively was obtained in the calibration step and 89.65% and 100% respectively in the validation step. The PLS-R (Partial Least Squares Regression) model (constructed from the minimum and maximum current intensity obtained for all electrodes) was used in physicochemical parameters prediction; EC reached the highest regression coefficients (0.840 in the calibration step and 0.842 in the validation step, respectively), being followed by pH (0.704 in the calibration step and 0.516 in the validation step, respectively).


Assuntos
Mel , Análise Discriminante , Contaminação de Alimentos/análise , Mel/análise , Análise dos Mínimos Quadrados , Língua
15.
Foods ; 10(4)2021 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-33921097

RESUMO

Grape pomace is one of the most abundant solid by-products generated during winemaking. A lot of products, such as ethanol, tartrates, citric acid, grape seed oil, hydrocolloids, bioactive compounds and dietary fiber are recovered from grape pomace. Grape pomace represents a major interest in the field of fiber extraction, especially pectin, as an alternative source to conventional ones, such as apple pomace and citrus peels, from which pectin is obtained by acid extraction and precipitation using alcohols. Understanding the structural and functional components of grape pomace will significantly aid in developing efficient extraction of pectin from unconventional sources. In recent years, natural biodegradable polymers, like pectin has invoked a big interest due to versatile properties and diverse applications in food industry and other fields. Thus, pectin extraction from grape pomace could afford a new reason for the decrease of environmental pollution and waste generation. This paper briefly describes the structure and composition of grape pomace of different varieties for the utilization of grape pomace as a source of pectin in food industry.

16.
Foods ; 10(4)2021 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-33810507

RESUMO

As the production and maintenance of a sufficient number of microencapsulated probiotics is still a test for the food industry, the present study addressed the testing of three prebiotics: chicory inulin, soluble potato starch, oligofructose and a control carbon source, namely glucose, as a component part of the encapsulation matrix. Using the extrusion encapsulation technique, it was possible to obtain microcapsules whose matrix composition and dimensions correspond to the requirements of the food industry. The microcapsules obtained showed significantly different physicochemical properties, with different survival rates during processing, storage and in simulated gastrointestinal conditions. The encapsulation efficiency was very high in relation to the dimensions of the microcapsules and the technique used (between 87.00-88.19%). The microcapsules obtained offered a very good viability (between 8.30 ± 0.00-9.00 ± 0, 02 log10 cfu/g) during the 30 days of storage at 2-8 degrees and also in the simulated gastrointestinal conditions (between 7.98-8.22 log10 cfu/g). After 30 days, the lowest viability was registered in the microcapsules with glucose 6.78 ± 0.15 log10 cfu/g. It was found that after 4 h of action of gastrointestinal juices on the microcapsules stored for 30 days, cell viability falls within the limits recommended by the Food and Agriculture Organization of the United Nations (FAO) (106-107 CFU/mL or g of food. This study demonstrated that using prebiotic encapsulation matrix increases cell viability and protection and that the extrusion encapsulation method can be used in the production of probiotic microcapsules for the food industry.

17.
Ultrasonics ; 110: 106298, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33227685

RESUMO

The aim of the study was to analyse the effect of osmotic treatment assisted by ultrasound on the physico-chemical properties of blueberries from Suceava county, Romania. Ultrasound treatment was conducted at the frequency of 25 kHz (using different values of amplitude - 20, 60 and 100%, respectively) in 61.5% sucrose solution at 30, 40 and 50 °C for 20, 40 and 60 min. The Box-Behnken design was used to investigate the influence of independent variables (time, temperature and amplitude) on the osmotic dehydration. The results showed that for physico-chemical characteristics (mass transfer parameters; moisture content; total content of anthocyanins, flavonoids and polyphenols; DPPH assay scavenging activity) that optimal conditions were obtained at 30 °C for 40 min at a 100% amplitude. Ultrasound treatment stimulated changes in the main characteristics, especially of colour leading to a higher lightness (L*), decreasing AsA-POD and water activity. The results indicated that the higher the values of independent variables are, the more representative is the correlation between them.


Assuntos
Ultrassom , Vaccinium myrtillus/química , Osmose , Romênia
18.
Foods ; 9(10)2020 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-32987873

RESUMO

Beebread or ambrosia is a unique product for humans and bees, which is the result of lactic fermentation on pollen in honeycombs. Bee bread is a rich source of nutrients (proteins, vitamins) and polyphenols (such as flavonoids, flavonols, phenolic acids). This study aimed to characterize bee bread in terms of physicochemical properties: pH, free acidity, glucose, fructose, sucrose, raffinose and melesitose content, total phenolic content (TPC), total flavones content (TFC), fatty acids and individual phenolics (gallic acid, protocatechiuc acid, p-hydroxybenzoic acid, caffeic acid, vanillic acid, chlorogenic acid, p-coumaric acid, rosmarinic acid, myricetin, luteolin, quercetin and kaempferol). The main phenolic compound identified in the bee bread was kaempferol, followed by myricetin and luteolin. The TPC, TFC and extraction yield were optimized in function of ultrasonic amplitude, temperature and time and the suitable conditions for achieving the maximum level were 87.20% amplitude of ultrasonic treatment, 64.70 °C and 23.10 min, respectively for reaching 146.2 mg GAE/L of TPC, 1231.5 mg QE/g of TFC and a 5.72% extraction yield. The most abundant fatty acids were C18:3 (all-cis-9,12,15) octadeca-6,9,15-trienoic acid, followed by C16:1 (9Z)-hexadec-9-enoic acid, C21:0 heneicosanoic acid and C18:2 (all-cis-9,12) (9Z,12Z)-octadeca-9,12-dienoic acid, respectively.

19.
Sensors (Basel) ; 20(9)2020 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-32365978

RESUMO

The aim of this study was to authenticate five types of Romanian honey (raspberry, rape, thyme, sunflower and mint) using a voltammetric tongue (VE tongue) technique. For the electronic tongue system, six electrodes (silver, gold, platinum, glass, zinc oxide and titanium dioxide) were used. The results of the melissopalynological analysis were supplemented by the data obtained with the electronic voltammetric tongue system. The results were interpreted by means of principal component analysis (PCA) and linear discriminant analysis (LDA). In this way, the usefulness of the working electrodes was compared for determining the botanical origin of the honey samples. The electrodes of titanium dioxide, zinc oxide, and silver were more useful, as the results obtained with these electrodes showed that it was achieved a better classification of honey according to its botanical origin. The comparison of the results of the electronic voltammetric tongue technique with those obtained by melissopalynological analysis showed that the technique was able to accurately classify 92.7% of the original grouped cases. The similarity of results confirmed the ability of the electronic voltammetric tongue technique to perform a rapid characterization of honey samples, which complements its advantages of being an easy-to-use and cheap method of analysis.

20.
Antioxidants (Basel) ; 9(4)2020 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-32316244

RESUMO

The aim of this study was to evaluate the extraction efficiency of polyphenols from crude pollen by an ultrasonic process. Prior to the polyphenols extraction, the crude pollen was defatted. The extraction from defatted pollen was carried out by varying four extraction parameters: ultrasonic amplitude (20%, 60% and 100%), solid/liquid ratio (10 g/L, 20 g/L and 30 g/L), temperature (35, 50 and 65 °C) and time (10, 20 and 30 min). The extracts were analyzed in terms of extraction yield (%), total phenolic content (TPC) and total flavones content (TFC). The extracted oil was analyzed in terms of fatty acids composition; myristic acid (159.1 µg × g-1) and cis-14-pentadecenoic acid (106.6 µg·g-1) were found in the highest amount in the pollen oil. The optimum conditions of extraction were determined and were, as follows: 100% amplitude of ultrasonic treatment, 30 g/L solid/liquid ratio, 40.85 °C and 14.30 min, which led to the extraction of 366.1 mg GAE/L of TPC and 592.2 mg QE/g of TFC, and also to an extraction yield of 1.92%.

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