scholarly journals Physicochemical characterization and bioactive compounds of stalk from hot fruits of Capsicum annuum L.

2016 ◽  
Vol 35 (2) ◽  
pp. 199 ◽  
Author(s):  
Jana Simonovska ◽  
Mojca Škerget ◽  
Željko Knez ◽  
Marija Srbinoska ◽  
Zoran Kavrakovski ◽  
...  
Keyword(s):  
Particle Size ◽  
Ftir Spectroscopy ◽  
Volatile Compounds ◽  
Capsicum Annuum ◽  
Bioactive Compounds ◽  
Physicochemical Characterization ◽  
Hot Pepper ◽  
Particle Sizes ◽  
Degradation Temperature ◽  
Residual Weight

In stalk of red hot pepper (<em>Capsicum annuum</em> L.) with 0.25 mm, 0.5 mm and 1.0 mm particle sizes, the quantities of nutritive and volatile compounds, bioactive capsaicin and carotenoids were determined. Furthermore, the stalk was characterized using TGA, DSC and FTIR spectroscopy. The influence of the particle size on the content of proteins, ash and cellulose is insignificant. Compared to 0.5 and 1.0 mm, stalk with 0.25 mm particle size was darker with a deeper yellow-brown color, and richer in microelements. Among the quantified volatile compounds, 6 were esters, 2 terpenoids, and 1 acid. The highest quantity of extract rich fats was obtained from stalk with 0.25 mm particle size by using ethanol, which is more efficient for capsaicin extraction, while <em>n</em>-hexane is efficient for extraction of carotenoids. Stalk with 0.25 mm particle size was characterized with a higher degradation temperature and residual weight.

Effects of Particles Size of Nanosilica on Properties of Polybenzoxazine Nanocomposites

2015 ◽  
Vol 659 ◽  
pp. 394-398 ◽  
Author(s):  
Nutthaphon Liawthanyarat ◽  
Sarawut Rimdusit
Keyword(s):  
Particle Size ◽  
Silica Nanoparticles ◽  
Primary Particle ◽  
Mechanical And Thermal Properties ◽  
Particle Sizes ◽  
Barrier Effect ◽  
Degradation Temperature ◽  
Maximum Value ◽  
Wetting Behaviors ◽  
Composite Samples

Polybenzoxazine nanocomposites filled with three different sizes of silica nanoparticles are investigated for their mechanical and thermal properties. In this research, silica nanoparticles with primary particle sizes of 7, 14 and 40 nm were incorporated in polybenzoxazine matrix at a fixed content of 3% by weight. From the experimental results, the storage modulus of the polybenzoxazine nanocomposite was found to systematically increase with decreasing the particle sizes of nanosilica suggesting better reinforcement of the smaller particles. Glass transition temperature was found to slightly increase with the addition of the silica nanoparticles. The uniformity of the composite samples were also evaluated by thermogravimetric analysis to show good dispersion of the silica nanoparticles in the composite samples as a result of high processability of the benzoxazine resin used i.e. low A-stage viscosity with good wetting behaviors. Degradation temperature at 5% weight loss (Td,5) of polybenzoxazine nanocomposites filled with different particle sizes of silica nanoparticles was found to increase from the value of 325 °C of the neat polybenzoxazine to the maximum value of about 340 °C with an addition of the nanosilica of the smallest particle size used. Finally, the smaller nanosilica particle size was also found to show more pronounced effect on Td,5enhancement of the composite samples as a result of greater barrier effect from larger surface area of the smaller particles.

Capsicum annuum (hot pepper): An ancient Latin‐American crop with outstanding bioactive compounds and nutraceutical potential. A review

2020 ◽  
Vol 19 (6) ◽  
pp. 2972-2993
Author(s):  
Talía Hernández‐Pérez ◽  
María del Rocío Gómez‐García ◽  
María Elena Valverde ◽  
Octavio Paredes‐López
Keyword(s):  
Capsicum Annuum ◽  
Bioactive Compounds ◽  
Latin American ◽  
Hot Pepper

scholarly journals Physicochemical Characterization of a Dental Eggshell Powder Abrasive Material

2017 ◽  
Vol 15 (4) ◽  
pp. e341-e346 ◽  
Author(s):  
Stanley C. Onwubu ◽  
Anisa Vahed ◽  
Shalini Singh ◽  
Krishnan M. Kanny
Keyword(s):  
Surface Roughness ◽  
Particle Size ◽  
Ftir Spectroscopy ◽  
Physicochemical Characterization ◽  
Xrd Analysis ◽  
Physicochemical Characteristics ◽  
Threshold Limit Value ◽  
Abrasive Material ◽  
Limit Value ◽  
Transmission Electron

Background This study aimed to determine the physicochemical characteristics of an eggshell-based dental abrasive material. Methods The eggshell powder abrasive material (EPAM) was synthesized by ball milling eggshell powder and surfactants. Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM) and a laser diffraction particle size analyzer (PSA) were used to characterize EPAM. In addition, the abrasive characteristics of EPAM were evaluated by comparison using poly(methyl methacrylate) (PMMA) resins. Surface roughness (Ra) was measured using a profilometer. Results The FTIR spectroscopy and XRD analysis confirmed that the carbonate product was primarily calcite (97.3%) with traces of graphite 2H (1.3%) and thenardite (1.4%). The TEM imagery revealed irregular particles in EPAM. The PSA analysis of the particle size distribution showed EPAM to be a superfine powder (0.3 μm to 50 nm). In addition, the 50-nm EPAM (Ra = 0.04 μm) measured the lowest Ra value when compared with pumice (Ra = 0.08 μm). Conclusions The salient features of this study indicate that EPAM can naturally replace calcite, which is generally mined and used as a dental abrasive material. In addition, and regarding the abrasive characteristics of EPAM in reducing the surface roughness of PMMA resin specimens, this study conclusively showed that EPAM effectively reduces the surface roughness below the threshold limit value of 0.2 μm. Potentially, EPAM could reduce waste disposal problems while enabling an economic benefit from using eggshell waste material.

scholarly journals Reduction of antinutrients and maintenance of bioactive compounds in flour from agro-industrial residue of acerola (Malpighia emarginata D.C.)

2020 ◽  
Vol 9 (9) ◽  
pp. e980998054
Author(s):  
Viviane Martins Barros ◽  
Jane de Jesus da Silveira Moreira ◽  
Maria Terezinha Santos Leite Neta ◽  
Tatiana Pacheco Nunes ◽  
Evelyn Horanyi Silva Costa Vasvary ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Volatile Compounds ◽  
Bioactive Compounds ◽  
Physicochemical Characterization ◽  
Significant Loss ◽  
Alternative Source ◽  
Malpighia Emarginata ◽  
Industrial Residue ◽  
Drying Conditions ◽  
The Impact

This study was aimed at analyzing the reduction of antinutrients, preserving apparent phenolic compounds in acerola flour residue by employing drying techniques. The optimal drying conditions were then determined in the wet residue, analyzing antinutrient concentration and apparent phenolic compounds in the residue and subsequently in the acerola flour. The physicochemical characterization of the flour was carried out, determining its antioxidant activity, thereby assessing the impact of the drying process on the composition of volatile compounds. The optimal drying conditions were found for a temperature of 65ºC for 120 min, reducing water activity by 0.3 and moisture content by 13.89%, which are considered adequate conditions for flours. Carbohydrate content represented 68.72 g/100g, while proteins represented 12.55 g/100g of the centesimal composition of the flour. Significant reductions (p<0.5) of antinutrients were observed in saponins (35.9%), followed by phytates (32.8%) and condensed tannins (11.52%). Losses of 18.7% of apparent phenolic compounds were also observed. For volatile compounds, a significant loss of esters with a significant increase in alcohol content was noticed. Thermal processing reduced aroma complexity, but maintained important bioactive compounds, such as linalool and caryophyllene. In this regard, taking into account the results of the present study, the agro-industrial residue of acerola proved to be an alternative source of antioxidants with a reduced antinutritional impact and may be incorporated as an ingredient in the formulation of new food products. Moreover, this agro-industrial residue reduces the environmental impact caused by the fruit pulp processing industry.

Surface energy of cellulosic materials: The effect of particle morphology, particle size, and hydroxyl number

TAPPI Journal ◽  
2015 ◽  
Vol 14 (9) ◽  
pp. 565-576 ◽  
Author(s):  
YUCHENG PENG ◽  
DOUGLAS J. GARDNER
Keyword(s):  
Particle Size ◽  
Surface Energy ◽  
Particle Morphology ◽  
Nanofibrillated Cellulose ◽  
Particle Sizes ◽  
Hydroxyl Number ◽  
Small Individual ◽  
Dispersion Component ◽  
Commercial Applications ◽  
Lower Temperature

Understanding the surface properties of cellulose materials is important for proper commercial applications. The effect of particle size, particle morphology, and hydroxyl number on the surface energy of three microcrystalline cellulose (MCC) preparations and one nanofibrillated cellulose (NFC) preparation were investigated using inverse gas chromatography at column temperatures ranging from 30ºC to 60ºC. The mean particle sizes for the three MCC samples and the NFC sample were 120.1, 62.3, 13.9, and 9.3 μm. The corresponding dispersion components of surface energy at 30°C were 55.7 ± 0.1, 59.7 ± 1.3, 71.7 ± 1.0, and 57.4 ± 0.3 mJ/m2. MCC samples are agglomerates of small individual cellulose particles. The different particle sizes and morphologies of the three MCC samples resulted in various hydroxyl numbers, which in turn affected their dispersion component of surface energy. Cellulose samples exhibiting a higher hydroxyl number have a higher dispersion component of surface energy. The dispersion component of surface energy of all the cellulose samples decreased linearly with increasing temperature. MCC samples with larger agglomerates had a lower temperature coefficient of dispersion component of surface energy.

scholarly journals Effect of particle size on phytochemical composition and antioxidant properties of Sargassum cristaefolium ethanol extract

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
E. S. Prasedya ◽  
A. Frediansyah ◽  
N. W. R. Martyasari ◽  
B. K. Ilhami ◽  
A. S. Abidin ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Particle Size ◽  
Antioxidant Activities ◽  
Antioxidant Properties ◽  
Ethanol Extract ◽  
Total Phenolic ◽  
Particle Sizes ◽  
Epicatechin Gallate ◽  
Particle Size Reduction ◽  
Phytochemical Composition

AbstractSample particle size is an important parameter in the solid–liquid extraction system of natural products for obtaining their bioactive compounds. This study evaluates the effect of sample particle size on the phytochemical composition and antioxidant activity of brown macroalgae Sargassum cristaefolium. The crude ethanol extract was extracted from dried powders of S.cristeafolium with various particle sizes (> 4000 µm, > 250 µm, > 125 µm, > 45 µm, and < 45 µm). The ethanolic extracts of S.cristaefolium were analysed for Total Phenolic Content (TPC), Total Flavonoid Content (TFC), phenolic compound concentration and antioxidant activities. The extract yield and phytochemical composition were more abundant in smaller particle sizes. Furthermore, the TPC (14.19 ± 2.08 mg GAE/g extract to 43.27 ± 2.56 mg GAE/g extract) and TFC (9.6 ± 1.8 mg QE/g extract to 70.27 ± 3.59 mg QE/g extract) values also significantly increased as particle sizes decreased. In addition, phenolic compounds epicatechin (EC), epicatechin gallate (ECG), epigallocatechin (EGC), and Epigallocatechin gallate (EGCG) concentration were frequently increased in samples of smaller particle sizes based on two-way ANOVA and Tukey’s multiple comparison analysis. These results correlate with the significantly stronger antioxidant activity in samples with smaller particle sizes. The smallest particle size (< 45 µm) demonstrated the strongest antioxidant activity based on DPPH, ABTS, hydroxyl assay and FRAP. In addition, ramp function graph evaluates the desired particle size for maximum phytochemical composition and antioxidant activity is 44 µm. In conclusion, current results show the importance of particle size reduction of macroalgae samples to increase the effectivity of its biological activity.

scholarly journals Experimental Analysis of the Mechanical Properties and Resistivity of Tectonic Coal Samples with Different Particle Sizes

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2303
Author(s):  
Congyu Zhong ◽  
Liwen Cao ◽  
Jishi Geng ◽  
Zhihao Jiang ◽  
Shuai Zhang
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
Uniaxial Compressive Strength ◽  
Coalbed Methane ◽  
Coal Sample ◽  
Fine Particles ◽  
Particle Sizes ◽  
Tectonic Coal

Because of its weak cementation and abundant pores and cracks, it is difficult to obtain suitable samples of tectonic coal to test its mechanical properties. Therefore, the research and development of coalbed methane drilling and mining technology are restricted. In this study, tectonic coal samples are remodeled with different particle sizes to test the mechanical parameters and loading resistivity. The research results show that the particle size and gradation of tectonic coal significantly impact its uniaxial compressive strength and elastic modulus and affect changes in resistivity. As the converted particle size increases, the uniaxial compressive strength and elastic modulus decrease first and then tend to remain unchanged. The strength of the single-particle gradation coal sample decreases from 0.867 to 0.433 MPa and the elastic modulus decreases from 59.28 to 41.63 MPa with increasing particle size. The change in resistivity of the coal sample increases with increasing particle size, and the degree of resistivity variation decreases during the coal sample failure stage. In composite-particle gradation, the proportion of fine particles in the tectonic coal sample increases from 33% to 80%. Its strength and elastic modulus increase from 0.996 to 1.31 MPa and 83.96 to 125.4 MPa, respectively, and the resistivity change degree decreases. The proportion of medium particles or coarse particles increases, and the sample strength, elastic modulus, and resistivity changes all decrease.

scholarly journals Investigation of the kinetics of spontaneous combustion of the major coal seam in Dahuangshan mining area of the Southern Junggar coalfield, Xinjiang, China

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Li Shen ◽  
Qiang Zeng
Keyword(s):  
Particle Size ◽  
High Temperature ◽  
Coal Seam ◽  
Spontaneous Combustion ◽  
Heating Temperature ◽  
Characteristic Temperature ◽  
Mining Area ◽  
Particle Sizes ◽  
Coal Oxidation ◽  
Increasing Temperature

AbstractIn the present paper, with using diverse methods (including the SEM, the XRD, the TPO, the FTIR, and the TGA) , the authors analysed samples of the major coal seam in Dahuangshan Mining area with different particle sizes and with different heated temperatures (from 50 to 800 °C at regular intervals of 50 °C). The results from SEM and XRD showed that high temperature and high number of pores, fissures, and hierarchical structures in the coal samples could facilitate oxidation reactions and spontaneous combustion. A higher degree of graphitization and much greater number of aromatic microcrystalline structures facilitated spontaneous combustion. The results from TPO showed that the oxygen consumption rate of the coal samples increased exponentially with increasing temperature. The generation rates of different gases indicated that temperatures of 90 °C or 130 °C could accelerate coal oxidation. With increasing temperature, the coal oxidation rate increased, and the release of gaseous products was accelerated. The FTIR results showed that the amount of hydroxide radicals and oxygen-containing functional groups increased with the decline in particle size, indicating that a smaller particle size may facilitate the oxidation reaction and spontaneous combustion of coal. The absorbance and the functional group areas at different particle sizes were consistent with those of the heated coal samples, which decreased as the temperature rose. The results from TGA showed that the characteristic temperature T3 declined with decreasing particle size. After the sample with 0.15–0.18 mm particle size was heated, its carbon content decreased, and its mineral content increased, inhibiting coal oxidation. This result also shows that the activation energy of the heated samples tended to increase at the stage of high-temperature combustion with increasing heating temperature.

scholarly journals 3D Printing of Drug Nanocrystals for Film Formulations

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3941
Author(s):  
Giorgia Germini ◽  
Leena Peltonen
Keyword(s):  
Particle Size ◽  
3D Printing ◽  
Polymer Films ◽  
Film Studies ◽  
Polymer Concentration ◽  
Physicochemical Characterization ◽  
Methyl Cellulose ◽  
Polymeric Film ◽  
Content Uniformity ◽  
3D Printed

The aim of the study was to prepare indomethacin nanocrystal-loaded, 3D-printed, fast-dissolving oral polymeric film formulations. Nanocrystals were produced by the wet pearl milling technique, and 3D printing was performed by the semi-solid extrusion method. Hydroxypropyl methyl cellulose (HPMC) was the film-forming polymer, and glycerol the plasticizer. In-depth physicochemical characterization was made, including solid-state determination, particle size and size deviation analysis, film appearance evaluation, determination of weight variation, thickness, folding endurance, drug content uniformity, and disintegration time, and drug release testing. In drug nanocrystal studies, three different stabilizers were tested. Poloxamer F68 produced the smallest and most homogeneous particles, with particle size values of 230 nm and PI values below 0.20, and was selected as a stabilizer for the drug-loaded film studies. In printing studies, the polymer concentration was first optimized with drug-free formulations. The best mechanical film properties were achieved for the films with HPMC concentrations of 2.85% (w/w) and 3.5% (w/w), and these two HPMC levels were selected for further drug-loaded film studies. Besides, in the drug-loaded film printing studies, three different drug levels were tested. With the optimum concentration, films were flexible and homogeneous, disintegrated in 1 to 2.5 min, and released the drug in 2–3 min. Drug nanocrystals remained in the nano size range in the polymer films, particle sizes being in all film formulations from 300 to 500 nm. When the 3D-printed polymer films were compared to traditional film-casted polymer films, the physicochemical behavior and pharmaceutical performance of the films were very similar. As a conclusion, 3D printing of drug nanocrystals in oral polymeric film formulations is a very promising option for the production of immediate-release improved- solubility formulations.

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