scholarly journals FTIR-ATR Spectroscopy Combined with Multivariate Regression Modeling as a Preliminary Approach for Carotenoids Determination in Cucurbita spp.

2020 ◽  
Vol 10 (11) ◽  
pp. 3722
Author(s):  
Natalia Quijano-Ortega ◽  
Carlos Alberto Fuenmayor ◽  
Carlos Zuluaga-Dominguez ◽  
Consuelo Diaz-Moreno ◽  
Sanín Ortiz-Grisales ◽  
...  
Keyword(s):  
Organic Solvents ◽  
Carotenoid Content ◽  
Future Application ◽  
Attenuated Total Reflectance ◽  
Total Reflectance ◽  
Total Carotenoid Content ◽  
Three Samples ◽  
Freeze Dried ◽  
Using Data ◽  
Atr Spectroscopy

Quantitative analysis of carotenoids has been extensively reported using UV-Vis spectrophotometry and chromatography, instrumental techniques that require complex extraction protocols with organic solvents. Fourier transform infrared spectroscopy (FTIR) is a potential alternative for simplifying the analysis of food constituents. In this work, the application of FTIR with attenuated total reflectance (ATR) was evaluated for the determination of total carotenoid content (TCC) in Cucurbita spp. samples. Sixty-three samples, belonging to different cultivars of butternut squash (C. moschata) and pumpkin (C. maxima), were selected and analyzed with FTIR- ATR (attenuated total reflectance). Three different preparation protocols for samples were followed: homogenization (A), freeze-drying (B), and solvent extraction (C). The recorded spectra were used to develop regression models by Partial Least Squares (PLS), using data from TCC, determined by UV-Vis spectrophotometry. The PLS regression model obtained with the FTIR data from the freeze-dried samples, using the spectral range 920–3000 cm−1, had the best figures of merit (R2CAL of 0.95, R2PRED of 0.93 and RPD of 3.78), being reliable for future application in agriculture. This approach for carotenoid determination in pumpkin and squash avoids the use of organic solvents. Moreover, these results are a rationale for further exploring this technique for the assessment of specific carotenoids in food matrices.

scholarly journals Phytochemicals Content, Antioxidant Activity and Acetylcholinesterase Inhibition Properties of IndigenousGarcinia parvifoliaFruit

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Siti Hawa Ali Hassan ◽  
Jeffrey R. Fry ◽  
Mohd Fadzelly Abu Bakar
Keyword(s):  
Methanol Extract ◽  
Radical Scavenging ◽  
Acetylcholinesterase Inhibition ◽  
Carotenoid Content ◽  
Total Phenolic ◽  
Garcinia Mangostana ◽  
Total Carotenoid Content ◽  
Freeze Dried ◽  
Gallic Acid Equivalent ◽  
Phenolic And Flavonoid

Garcinia parvifoliabelongs to the same family as mangosteen (Garcinia mangostana), which is known locally in Sabah as “asam kandis” or cherry mangosteen. The present study was conducted to determine the phytochemicals content (total phenolic, flavonoid, anthocyanin, and carotenoid content) and antioxidant and acetylcholinesterase inhibition activity of the flesh and peel ofG. parvifolia. All samples were freeze-dried and extracted using 80% methanol and distilled water. For the 80% methanol extract, the flesh ofG. parvifoliadisplayed higher phenolic and flavonoid contents than the peel, with values of7.2±0.3 mg gallic acid equivalent (GAE)/g and5.9±0.1 mg rutin equivalent (RU)/g, respectively. Anthocyanins were detected in the peel part ofG. parvifoliabut absent in the flesh. The peel ofG. parvifoliadisplayed higher total carotenoid content as compared to the flesh part with the values of17.0±0.3and3.0±0.0 mgβ-carotene equivalents (BC)/100 g, respectively. The free-radical scavenging, ferric reducing, and acetylcholinesterase inhibition effect of the flesh were higher as compared to the peel in both extracts. These findings suggested that the edible part ofG. parvifoliafruit has a potential as a natural source of antioxidant and anti-Alzheimer’s agents.

scholarly journals The Influence of Curing Regimes in Self-Healing of Nano-Modified Cement Pastes

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5301
Author(s):  
Maria Stefanidou ◽  
Eirini-Chrysanthi Tsardaka ◽  
Aspasia Karozou
Keyword(s):  
Sem Analysis ◽  
Attenuated Total Reflectance ◽  
Self Healing ◽  
Nano Silica ◽  
Cement Pastes ◽  
Curing Conditions ◽  
Total Reflectance ◽  
Atr Spectroscopy ◽  
Curing Regimes ◽  
Early Healing

The present study proposes nano-calcium oxide (NC) and nano-silica (NS) particles as healing agents in cement pastes, taking into account the curing conditions. Two series of specimens were treated in water and under wetting-drying cycles. The addition of NC (1.5%wt of binder) triggered early healing since cracks were healed within 14 days in underwater immersion and before 28 days at wetting-drying cycles. Attenuated Total Reflectance (ATR) spectroscopy and SEM analysis revealed that the healing products were mainly aragonite and calcite in water conditions and more amorphous carbonates under wetting-drying cycles. The combination of NS and NC (3.0%wt in total) offered healing under both curing conditions before 28 days. The presence of NS assisted toward porosity refinement and NC increased the carbonates’ content. The newly formed material was dense, and its elemental analysis by SEM revealed the C-S-H compounds that were also verified by ATR.

Milk Inspection by THz Attenuated Total Reflectance (THz-ATR) Spectroscopy

2011 ◽  
Author(s):  
Hirotaka Naito ◽  
Yuichi Ogawa ◽  
Tetsuhito Suzuki ◽  
Naoshi Kondo
Keyword(s):  
Attenuated Total Reflectance ◽  
Total Reflectance ◽  
Atr Spectroscopy

Removal of Organic Dyes by Using Cellulose-Chitosan-Nanowires Hybrid Composition Beads

2020 ◽  
Vol 1002 ◽  
pp. 468-477
Author(s):  
Alarqam Zyaad Tareq
Keyword(s):  
Organic Dyes ◽  
Hybrid Composites ◽  
Attenuated Total Reflectance ◽  
Mechanical And Thermal Properties ◽  
Anionic Dyes ◽  
Chitosan Beads ◽  
Total Reflectance ◽  
Removal Capacity ◽  
Atr Spectroscopy ◽  
Dyes Removal

Organic dyes are mostly used in textile, paper, plastic, and other industries. These industries can be toxic and harmful to environment and human. Adsorption is the most efficient method to control wastewater that contains dyes. Cellulose-Chitosan beads was mainly used in the adsorption. To increase and enhance the organic dyes removal capacity of these beads, titanium dioxide nanowires (TiO2Nw) as used to achieve novel Cs-Cell-nanowires hybrid composites. Ultralong hydroxyapatite nanowires was prepared and used to enhance the mechanical and thermal properties of beads. On the other hand, the beads composition was prepared with spherical white shape. Internal structure of beads and other composition were studied by using Attenuated Total Reflectance (ATR) spectroscopy, scanning electron microscopy (SEM), lazer diffraction (LD), thermal analysis (TG, DSC, DTG, and DTA). The beads are tested with five different organic dyes which include Methyl blue (MB), Acid alizarin Black (AAB) as cationic dyes, and Methyl orang (MO), Methyl red (MR) and Eriochrome black T (EBT) as anionic dyes. The results indicate that the beads have the ability to remove MB, EBT,AAB but do not have the ability to remove MO and MR. So, the Cell-CS- HAPNw- TiO2Nw beads can be considered as the promising adsorption for MB, EBT, and AAB from aqueous solutions.

Multivariate Determination of Sugar Powders by Attenuated Total Reflectance Infrared Spectroscopy

1993 ◽  
Vol 47 (4) ◽  
pp. 452-457 ◽  
Author(s):  
N. Dupuy ◽  
M. Meurens ◽  
B. Sombret ◽  
P. Legrand ◽  
J.P. Huvenne
Keyword(s):  
Quantitative Analysis ◽  
Attenuated Total Reflectance ◽  
Infrared Spectrometry ◽  
Infrared Analysis ◽  
Total Reflectance ◽  
Regression Methods ◽  
Peak Resolution ◽  
Atr Spectroscopy ◽  
Time Required

Thanks to what has been achieved by Fourier transformation, infrared analysis can now become a state-of-the-art device in quality control laboratories if we consider its precision and the gain in time it ensures. Moreover, an increasing number of new mathematical regression methods such as partial least-squares (PLS) regression allow multicomponent quantitative analysis in mixtures. Nevertheless, the efficiency of infrared spectrometry as a quantitative analytical method often depends on the choice of an adequate presentation for the sample. For quantitative analysis of powders, sampling appears difficult in the mid-IR. We have developed a method built on three advantages: the rapidity of Fourier transform spectroscopy, fast solvent elimination, and good peak resolution. For enhancing peak intensity on attenuated total reflectance (ATR) spectroscopy we use nondissolving and evaporating liquids. For instance, the analysis of three components (glucose, fructose, and sucrose) can be done with a precision in the range of 4%, whereas the time required to obtain an analysis report is about 5 min.

Small Molecule Diffusion and Solubility in Adhesives Used for Transdermal Drug Delivery: Infrared-Attenuated Total Reflectance (IR-ATR) Studies.

2000 ◽  
Vol 662 ◽  
Author(s):  
Adam S. Cantor
Keyword(s):  
Drug Delivery ◽  
Small Molecule ◽  
Diffusion Coefficients ◽  
Transdermal Drug Delivery ◽  
Attenuated Total Reflectance ◽  
Transdermal Drug Delivery System ◽  
Total Reflectance ◽  
Adhesive Matrix ◽  
Atr Spectroscopy ◽  
Receptor Layer

AbstractA key factor in designing a drug-in-adhesive transdermal drug delivery system is to understand the rate at which the drug and small-molecule excipients can diffuse in the adhesive matrix. The solubility of these components in the adhesive matrix is also of great importance. Results will be presented discussing the use of infrared-attenuated total reflectance (IR-ATR) spectroscopy as a method to measure both diffusion and solubility of small molecules in adhesives. In this method, the donor layer is either a doped adhesive or a free liquid that is placed in contact with a receptor layer which is an undoped adhesive in contact with an IR-ATR crystal. The IR-ATR crystal detects as a function of time any molecules that diffuse from the donor layer into and through the receptor layer.Examples will be discussed of several different experiments that can be performed with this technique. Diffusion coefficients are presented here for testosterone and terpineol in an isooctyl acrylate based adhesive using a doped adhesive donor layer. Diffusion and solubility of liquids in several adhesives has been determined using the experiment where a free liquid is used as the donor. Solubility and diffusion coefficients determined using an oversaturated doped layer containing dispersed, as well as dissolved solute, are presented here for testosterone and for progesterone. Finally diffusion from a doped layer of one adhesive to an undoped layer of a different adhesive was performed as a partition measurement. The parameters that can be extracted from each of these experiments, as well as the limitations of each type of experiment will be discussed.

Studies of the Dynamics of Thin Ion Exchange Films by Spectroscopic Ellipsometry and Attenuated Total Reflectance Spectroscopy

2006 ◽  
Vol 518 ◽  
pp. 431-438
Author(s):  
N. Pantelić ◽  
A. Piruska ◽  
Carl J. Seliskar
Keyword(s):  
Mass Transport ◽  
Spectroscopic Ellipsometry ◽  
Structural Changes ◽  
Electrochemical Sensors ◽  
Optical Quality ◽  
Attenuated Total Reflectance ◽  
Total Reflectance ◽  
Non Invasive ◽  
Invasive Method ◽  
Atr Spectroscopy

A chemically selective film, usually of optical quality, is a key component of optical and electrochemical sensors. We have examined the dynamics of various thin selective films by spectroscopic ellipsometry and attenuated total reflectance (ATR) spectroscopy. Spectroscopic ellipsometry provided a non-invasive method for measurement of optical constants (n(λ), refractive index; k(λ), extinction coefficient) and thicknesses of thin selective films which were conditioned in time by solvent and penetrant mass transport. The methods we have developed allowed us to characterize film dynamic response, stability, and chemically specific mass transport even to the point of quantitatively modeling both transport and structural changes. The ATR spectra of thin, highly absorbing films are distorted both by reflectance and interference phenomena. Enhanced absorbance was observed under film leaky mode conditions.

scholarly journals Effects of drying methods on the physicochemical properties and antioxidant capacity of Kuini powder

2021 ◽  
Vol 24 ◽  
Author(s):  
Gan Wei Shuen ◽  
Lew Yan Yi ◽  
Thor Sing Ying ◽  
Germaine Chng Yu Von ◽  
Yus Aniza Binti Yusof ◽  
...  
Keyword(s):  
Freeze Drying ◽  
Colour Change ◽  
Carotenoid Content ◽  
Total Phenolic ◽  
Drying Methods ◽  
Vacuum Oven ◽  
Oven Drying ◽  
Convection Oven ◽  
Total Carotenoid Content ◽  
Freeze Dried

Abstract Kuini powders were obtained through spray-drying, freeze-drying, vacuum oven drying and convection oven drying. Colour, water activity (Aw), moisture content, hygroscopicity, wettability, flowability, degree of caking, water solubility index (WSI), total colour change, total phenolic content and total carotenoid content of Kuini powders were determined and compared. Convection oven drying resulted in the highest yield (46.97%), moisture content (4.91%), Aw (0.55) and WSI (74.33%) among all the drying methods. However, convection oven-dried Kuini powder had the lowest hygroscopicity and wettability, which were 18.66% and 12.04 s, respectively. Spray drying resulted in poor hygroscopicity (22.41%), degree of caking (22.16%), wettability (275s), WSI (45.67%) and higher colour change (59.81). Least total colour change (19.05) and higher yellowness (57.31) were observed in freeze-drying. In addition, freeze-dried Kuini powder had the highest total phenolic content (24.76 mg/100 g) and total carotenoid content (1.61 mg/100 g). Drying temperature had a negative and significant correlation with the retention of color pigments and antioxidant content. The physicochemical properties and antioxidant content of freeze-dried Kuini powder were preferred over spray-dried, vacuum oven-dried and convection oven-dried powders. Hence, freeze-drying offers potential application in the food products.

scholarly journals Идентификация Н-связей кальцинированного аортального клапана

2019 ◽  
Vol 45 (18) ◽  
pp. 24
Author(s):  
В.И. Иванов-Омский ◽  
К.С. Рутковский ◽  
Н.И. Гуляев ◽  
А.С. Галенко ◽  
С.Г. Ястребов
Keyword(s):  
Aortic Valve ◽  
Attenuated Total Reflectance ◽  
Hydroxyl Groups ◽  
Frequency Interval ◽  
Ir Absorption ◽  
Spectroscopy Technique ◽  
Healthy Human ◽  
Total Reflectance ◽  
Ir Absorption Spectra ◽  
Atr Spectroscopy

AbstractThe IR absorption spectra of subendothelial regions of the aortic valve cusps of a patient with calcified aortic stenosis diagnosis were measured by the attenuated total reflectance (ATR) spectroscopy technique in a frequency interval of 2500–3600 cm^–1 and analyzed in comparison to the spectra of healthy human tissues and reference spectra of a pig’s healthy bone and aortic valve. The IR absorption band structure in this spectral region was studied by means of expansion into Gaussian components. The energies of hydrogen bonds (H-bonds) involving O–H groups were estimated. It is established that, among all samples studied, the energy of H-bonds between hydroxyl groups reaches maximum in the bone tissue.

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