scholarly journals Potential of Ultraviolet-Visible Spectroscopy for the Differentiation of Spanish Vinegars According to the Geographical Origin and the Prediction of Their Functional Properties

Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1830
Author(s):  
Raúl González-Domínguez ◽  
Ana Sayago ◽  
Ángeles Fernández-Recamales
Keyword(s):  
Functional Properties ◽  
Geographical Origin ◽  
Low Cost ◽  
Classification Performance ◽  
Total Phenolic ◽  
Least Squares Regression ◽  
Visible Spectroscopy ◽  
Linear Discriminant ◽  
Organoleptic Characteristics ◽  
Vis Spectroscopy

High-quality wine vinegars with unique organoleptic characteristics are produced in southern Spain under three Protected Designations of Origin (PDO), namely “Jerez”, “Condado de Huelva” and “Montilla-Moriles”. To guarantee their authenticity and avoid frauds, robust and low-cost analytical methodologies are needed for the quality control and traceability of vinegars. In this study, we propose the use of ultraviolet-visible spectroscopy in combination with multivariate statistical tools to discriminate Spanish wine vinegars according to their geographical origin, as well as to predict their physicochemical and functional properties. Linear discriminant analysis provided a clear clustering of vinegar samples according to the PDO with excellent classification performance (98.6%). Furthermore, partial least squares regression analysis demonstrated that spectral data can serve as accurate predictors of the total phenolic content and antioxidant activity of vinegars. Accordingly, UV-Vis spectroscopy stands out as a suitable analytical tool for simple and rapid authentication and traceability of vinegars.

scholarly journals Determination of Total Phenolic Content and NIR-Chemometrics Classification Model of Queen and Local Varieties of Soursop (Annonamuricata L.) Leaf Powder

2020 ◽  
Vol 20 (3) ◽  
pp. 520
Author(s):  
Lestyo Wulandari ◽  
Mellda Kusuma Candra Dewi ◽  
Nia Kristiningrum ◽  
Yashinta Nirmala Siswanti
Keyword(s):  
Total Phenolic Content ◽  
Phenolic Content ◽  
Nir Spectroscopy ◽  
Classification Model ◽  
Total Phenolic ◽  
Support Vector ◽  
Local Varieties ◽  
Linear Discriminant ◽  
Phytochemical Content ◽  
Vis Spectroscopy

The leaves of soursop (Annonamuricata L.) are commonly used for health because of their antioxidant activity from its highest phytochemical content, namely phenolic compound, which is influenced by the varieties of this plant. In Indonesia, there are two soursop varieties, namely ‘queen’ and ‘local’ varieties which are difficult to determine morphologically. The aim of this study was to determine the total phenolic content of soursop leaves of both varieties and to establish a classification model of NIR spectroscopy combined with chemometrics for the identification of the varieties of soursop leaves. After the soursop leaves were dried and grinded, they were then scanned to obtain the spectra of NIR spectroscopy. NIR spectras were combined with chemometrics to classify the varieties of the soursop. The classification models used were Linear Discriminant Analysis (LDA), Support Vector Machines (SVM) and Soft Independent Modelling of Class Analogies (SIMCA). Total phenolic content of the soursop leaves was determined by UV-Vis spectroscopy using Folin-Ciocalteau reagent and gallic acid as reference. The result showed that the local variety had higher total phenolic content than the queen variety. NIR spectroscopy combined with chemometrics was able to classify the varieties of soursop leaves with 100% accuracy using LDA and SVM.

scholarly journals Chemometric Classification of Cocoa Bean Shells Based on Their Polyphenolic Profile Determined by RP-HPLC-PDA Analysis and Spectrophotometric Assays

Antioxidants ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1533
Author(s):  
Olga Rojo-Poveda ◽  
Giuseppe Zeppa ◽  
Ilario Ferrocino ◽  
Caroline Stévigny ◽  
Letricia Barbosa-Pereira
Keyword(s):  
Geographical Origin ◽  
Radical Scavenging Activity ◽  
Low Cost ◽  
Radical Scavenging ◽  
Cocoa Bean ◽  
Total Phenolic ◽  
Screening Methods ◽  
Rp Hplc ◽  
Polyphenolic Profile

The cocoa bean shell (CBS), a byproduct from the cocoa industry, was recently proposed as a functional and low-cost ingredient, mainly because of its content in polyphenols. However, vegetal food products could significantly differ in their chemical composition depending on different factors such as their geographical provenience. This work is aimed to determine the polyphenolic and methylxanthine profile of different CBS samples and utilize it for achieving their differentiation according to their geographical origin and variety. RP-HPLC-PDA was used to determine the CBS polyphenolic profile. Spectrophotometric assays were used to obtain the total phenolic, flavonoid, and tannin contents, as well as to evaluate their radical scavenging activity. The results obtained from both methods were then compared and used for the CBS differentiation according to their origin and varieties through chemometric analysis. RP-HPLC-PDA allowed to determine 25 polyphenolic compounds, as well as the methylxanthines theobromine and caffeine. Polyphenolic profile results highlighted significant differences among the analyzed samples, allowing for their differentiation based on their geographical provenience. Similar results were achieved with the results of the spectrophotometric assays, considered as screening methods. Differentiation based on CBS variety was instead obtained based on the HPLC-determined methylxanthine profile.

scholarly journals Classifying Diverse Physical Activities Using “Smart Garments”

Sensors ◽  
2019 ◽  
Vol 19 (14) ◽  
pp. 3133 ◽  
Author(s):  
Mohammad Iman Mokhlespour Esfahani ◽  
Maury A. Nussbaum
Keyword(s):  
Health Promotion ◽  
Nearest Neighbor ◽  
Low Cost ◽  
Initial Step ◽  
Classification Performance ◽  
Physical Activities ◽  
K Nearest Neighbor ◽  
Linear Discriminant ◽  
Physical Disorders ◽  
Smart Garments

Physical activities can have important impacts on human health. For example, a physically active lifestyle, which is one of the most important goals for overall health promotion, can diminish the risk for a range of physical disorders, as well as reducing health-related expenditures. Thus, a long-term goal is to detect different physical activities, and an important initial step toward this goal is the ability to classify such activities. A recent and promising technology to discriminate among diverse physical activities is the smart textile system (STS), which is becoming increasingly accepted as a low-cost activity monitoring tool for health promotion. Accordingly, our primary aim was to assess the feasibility and accuracy of using a novel STS to classify physical activities. Eleven participants completed a lab-based experiment to evaluate the accuracy of an STS that featured a smart undershirt (SUS) and commercially available smart socks (SSs) in discriminating several basic postures (sitting, standing, and lying down), as well as diverse activities requiring participants to walk and run at different speeds. We trained three classification methods—K-nearest neighbor, linear discriminant analysis, and artificial neural network—using data from each smart garment separately and in combination. Overall classification performance (global accuracy) was ~98%, which suggests that the STS was effective for discriminating diverse physical activities. We conclude that, overall, smart garments represent a promising area of research and a potential alternative for discriminating a range of physical activities, which can have positive implications for health promotion.

scholarly journals Evaluation of Geographic Origin of Torrontés Wines by Chemometrics

2013 ◽  
Vol 2 (5) ◽  
pp. 48 ◽  
Author(s):  
Silvana Mariela Azcarate ◽  
Miguel Angel Cantarelli ◽  
Eduardo Jorge Marchevsky ◽  
José Manuel Camiña
Keyword(s):  
Discriminant Analysis ◽  
Geographical Origin ◽  
Uv Spectroscopy ◽  
Geographic Origin ◽  
Principal Component ◽  
San Juan ◽  
Electromagnetic Spectrum ◽  
Linear Discriminant ◽  
Rio Negro ◽  
Vis Spectroscopy

<p>This work discusses the determination of the provenance of commercial Torrontés wines from different Argentinean provinces (Mendoza, San Juan, Salta and Rio Negro) by the use of UV-vis spectroscopy and chemometric techniques. In order to find classification models, wines (n = 80) were analyzed using UV-Vis region of the electromagnetic spectrum. Principal component analysis (PCA), linear discriminant analysis (LDA) and partial least squares discriminant analysis (PLS-DA) were used to classify Torrontés wines according to their geographical origin. Classification rates obtained were highly satisfactory. The PLS-DA and LDA calibration models showed that 100% of the Mendoza, San Juan, Salta and Rio Negro Torrontés wine samples had been correctly classified. These results demonstrate the potential use of UV spectroscopy with chemometric data analysis as a method to classify Torrontés wines according to their geographical origin, a procedure which requires low-cost equipment and short-time analysis in comparison with other techniques.</p>

scholarly journals Volatile Profiling of Strawberry Fruits Cultivated in a Soilless System to Investigate Cultivar-Dependent Chemical Descriptors

Foods ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 768
Author(s):  
Raúl González-Domínguez ◽  
Ana Sayago ◽  
Ikram Akhatou ◽  
Ángeles Fernández-Recamales
Keyword(s):  
Volatile Compounds ◽  
Food Industry ◽  
Geographical Origin ◽  
Solid Phase ◽  
Principal Component ◽  
Linear Discriminant ◽  
Organoleptic Characteristics ◽  
Great Utility ◽  
Methyl Butyrate ◽  
Chemical Descriptors

Volatile compounds are essential for food organoleptic characteristics and of great utility for the food industry as potential markers for authenticity purposes (e.g., variety, geographical origin, adulteration). The aim of this study was to determine the characteristic volatile compounds of strawberry samples grown in a soilless system by using headspace solid phase micro-extraction coupled with gas chromatography and to investigate the influence of cultivar (Festival, Candonga, Camarosa) on this volatile profile. We observed that Festival and, to a lesser extent, Candonga varieties were characterized by the richest aroma-related profiles, including higher levels of esters, furanones and terpenes. In particular, methyl butyrate, hexyl hexanoate, linalool, geraniol and furaneol were the most abundant aromatic compounds detected in the three varieties of strawberries. Complementarily, the application of pattern recognition chemometric approaches, including principal component analysis and linear discriminant analysis, demonstrated that concentrations of specific volatiles can be employed as chemical descriptors to discriminate between strawberry cultivars. Accordingly, geraniol and hexyl hexanoate were found to be the most significant volatiles for the discrimination of strawberry varieties.

scholarly journals Low-cost, simple and eco-friendly biosynthesis of CeO2-NPs using extract of Pelargonium hortorum for the photocatalytic and antioxidant applications

2021 ◽  
Author(s):  
Ali Ganbarianzade Mahabadi ◽  
Abbas Mirzakhani ◽  
Amir Azizi ◽  
Saied Chavoshi ◽  
Shahab Khaghani
Keyword(s):  
Low Cost ◽  
Total Pore Volume ◽  
Bet Surface Area ◽  
Total Phenolic ◽  
Volatile Constituent ◽  
Volatile Constituents ◽  
Practical Applications ◽  
Good Ability ◽  
Vis Spectroscopy ◽  
Average Size

Abstract In this paper, firstly the phytochemical composition in the aqueous extract of Pelargonium, growing wildly in the center of Iran, was studied. Folin–Ciocalteu and Aluminum chloride methods and the GC/MS technique were used to determine the total phenolic, flavonoid contents, and volatile constituents in the extract, respectively. The amounts of the total phenolic and flavonoid contents in the extract were found to be 136.5 mg GA/g and 63.9 mg RU/g, respectively. Twenty-one compounds, representing 15 (about 80.0%) of the total volatile constituents were identified. The main components of the volatile constituent were α-pinene (25.28%) and fenchyl acetate (20.63%). Secondly, a fast, simple, and eco-friendly biosynthesis of cerium oxide nanoparticles (CeO2-NPs) were investigated using the extract of Pelargonium as a natural reducing and stabilizing agent. Several advance techniques such as Ultraviolet-Visible (UV–Vis) spectroscopy, X-ray diffraction (XRD), Scanning electron microcopy (FESEM), Dynamic light scattering (DLS), and Brunaure Emmett-Teller (BET) were used for the analysis and characterization of the synthesized nanoparticles. The results of the characterization analysis showed that the prepared nanoparticles were spherical in shape, with an average size of 28 nm and zeta potential of -25.8 mV, and had 33.84 m2/g BET surface area, 9.31 nm mane diameter pore, and a total pore volume of 0.078 cm3/g. Finally, the practical applications including the antioxidant and photocatalyst activity of the biosynthesized CeO2-NPs were evaluated. An analysis of antioxidant and catalytic activities showed that the biosynthesized CeO2-NPs have a good ability of scavenging of 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical with the IC50 value of 42.7 µg/mL and also good reduction ability of hexavalent chromium {Cr(VI)} ions with a reduction efficiency of 94% in an aqueous solution containing 10 mg/L of Cr(VI) of ion with natural pH of 5.5 and CeO2-NPs dose of 200 mg/L during 60 min.

scholarly journals Lifetime of electrochromic optical transition cycling of ethyl viologen diperchlorate-based electrochromic devices

2021 ◽  
Vol 3 (5) ◽  
Author(s):  
Logan G. Kiefer ◽  
Christian J. Robert ◽  
Taylor D. Sparks
Keyword(s):  
Optical Transition ◽  
Low Cost ◽  
Cycling Performance ◽  
Power Measurement ◽  
Electrochromic Devices ◽  
Metal Oxide Films ◽  
Cycle Times ◽  
Vis Spectroscopy ◽  
Multiple Devices ◽  
Measurement Devices

AbstractElectrochromic materials and devices are enabling a variety of advanced technologies. Gel-based organic electrochromic molecules such as ethyl viologen diperchlorate are attractive options due to their simple device design and low cost processing options relative to the more expensive and complex transition metal oxide films. However, electrochromic devices are subject to extensive cycling in which failure and fatigue can eventually occur. This work presents the lifetime cycling performance of ethyl viologen diperchlorate-based electrochromic devices using two different anodic compounds, hydroquinone and ferrocene, which are cycled at different voltages, 3 V and 1.2 V, respectively. Multiple devices are cycled until failure with periodic device characterization via UV–Vis spectroscopy, electrical resistance and power measurement, and transition duration measurement. Devices with hydroquinone can transition quickly. Cycle times are $$\sim$$ ∼ 30 s in these samples, however, these samples also typically fail before 3000 cycles. On the other hand, devices using ferrocene transition more slowly (total cycle time $$\sim$$ ∼ 2 min), but have superior cycling performance with all samples surviving beyond 10,000 cycles while complying with ASTM E2141-14 standard.

scholarly journals UV-A Treatment of ZrO2 Thin Films Fabricated by Environmental Friendlier Water-Based Solution Processing: Structural and Optical Studies

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 821
Author(s):  
Aneeqa Bashir ◽  
Mehwish Farooq ◽  
Abdul Malik ◽  
Shahzad Naseem ◽  
Arshad Saleem Bhatti
Keyword(s):  
Optical Properties ◽  
Low Cost ◽  
Annealed Film ◽  
Optical Transmittance ◽  
Amorphous Structure ◽  
Solution Processing ◽  
Vis Spectroscopy ◽  
Water Based ◽  
Free Films ◽  
Quartz Substrates

An environmentally friendlier solution processing has been introduced to fabricate zirconium oxide (ZrO2) films on quartz substrates, using spin coating of simple water-based solution. The films cured with UV-A = 330 nm for different times (40, 80, 120 min) were investigated for structural and optical properties and compared with thermally annealed film (at 350 °C). XRD and Raman spectroscopy showed amorphous structure in all the samples with no significant phase transformation with UV-A exposure. AFM microscopy showed smooth and crack free films with surface roughness ≤2 nm that reduced with UV-A exposure. Ultraviolet-visible (UV–Vis) spectroscopy demonstrated optical transmittance ≥88% and energy band gap variations as 4.52–4.70 eV. Optical constants were found from spectroscopic ellipsometry (SE). The refractive index (n) values, measured at 470 nm increased from 1.73 to 2.74 as the UV-A exposure prolonged indicating densification and decreasing porosity of the films. The extinction coefficient k decreased from 0.32 to 0.19 indicating reduced optical losses in the films under the UV-A exposure. The photoluminescence (PL) spectra exhibited more pronounced UV emissions which grew intense with UV-A exposure thereby improving the film quality. It is concluded that UV-A irradiation can significantly enhance the optical properties of ZrO2 films with minimal changes induced in the structure as compared to thermally treated film. Moreover, the present work indicates that water-based solution processing has the potential to produce high-quality ZrO2 films for low cost and environmental friendlier technologies. The work also highlights the use of UV-A radiations as an alternate to high temperature thermal annealing for improved quality.

scholarly journals Ripeness Prediction of Postharvest Kiwifruit Using a MOS E-Nose Combined with Chemometrics

Sensors ◽  
2019 ◽  
Vol 19 (2) ◽  
pp. 419 ◽  
Author(s):  
Dongdong Du ◽  
Jun Wang ◽  
Bo Wang ◽  
Luyi Zhu ◽  
Xuezhen Hong
Keyword(s):  
Prediction Models ◽  
Extraction Methods ◽  
Oxide Semiconductor ◽  
Soluble Solids ◽  
Support Vector ◽  
Least Squares Regression ◽  
Accuracy Rate ◽  
Linear Discriminant ◽  
The Difference ◽  
Ripe Stage

Postharvest kiwifruit continues to ripen for a period until it reaches the optimal “eating ripe” stage. Without damaging the fruit, it is very difficult to identify the ripeness of postharvest kiwifruit by conventional means. In this study, an electronic nose (E-nose) with 10 metal oxide semiconductor (MOS) gas sensors was used to predict the ripeness of postharvest kiwifruit. Three different feature extraction methods (the max/min values, the difference values and the 70th s values) were employed to discriminate kiwifruit at different ripening times by linear discriminant analysis (LDA), and results showed that the 70th s values method had the best performance in discriminating kiwifruit at different ripening stages, obtaining a 100% original accuracy rate and a 99.4% cross-validation accuracy rate. Partial least squares regression (PLSR), support vector machine (SVM) and random forest (RF) were employed to build prediction models for overall ripeness, soluble solids content (SSC) and firmness. The regression results showed that the RF algorithm had the best performance in predicting the ripeness indexes of postharvest kiwifruit compared with PLSR and SVM, which illustrated that the E-nose data had high correlations with overall ripeness (training: R2 = 0.9928; testing: R2 = 0.9928), SSC (training: R2 = 0.9749; testing: R2 = 0.9143) and firmness (training: R2 = 0.9814; testing: R2 = 0.9290). This study demonstrated that E-nose could be a comprehensive approach to predict the ripeness of postharvest kiwifruit through aroma volatiles.

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