Investigating the total antioxidant capacity of gluten-free grains with miniaturized near-infrared spectrometer

NIR news ◽  
2019 ◽  
Vol 30 (5-6) ◽  
pp. 35-38
Author(s):  
Verena Wiedemair ◽  
Christian Wolfgang Huck
Keyword(s):  
Antioxidant Capacity ◽  
Total Antioxidant Capacity ◽  
High Performance ◽  
Near Infrared ◽  
Least Squares Regression ◽  
Test Set ◽  
Total Antioxidant ◽  
Infrared Spectrometer ◽  
Near Infrared Spectrometer ◽  
Infrared Instruments

The use of ever smaller near-infrared instruments is becoming more and more prevalent, since they are cheaper, more versatile and often advertised as high-performance spectrometer. The last claim is rarely verified by independent researchers, which is why the presented work evaluates the performance of three hand-held spectrometers in comparison to a benchtop instrument. Seventy-seven samples comprising buckwheat, millet and oat were investigated for their total antioxidant capacity using Folin–Ciocalteu and near-infrared spectroscopy. Partial least squares regression models were established using cross- and test set validation. Results showed that all instruments were able to predict total antioxidant capacity to some extent. The coefficients of determinations ranged from 0.823 to 0.951 for cross-validated and from 0.849 to 0.952 for test set validated models. Errors for cross-validated models ranged from 1.11 to 2.08 mgGAE/g and for test set validated models from 1.02 to 1.86 mgGAE/g.

scholarly journals Investigations into the Performance of a Novel Pocket-Sized Near-Infrared Spectrometer for Cheese Analysis

Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 428 ◽  
Author(s):  
Verena Wiedemair ◽  
Dominik Langore ◽  
Roman Garsleitner ◽  
Klaus Dillinger ◽  
Christian Huck
Keyword(s):  
Data Analysis ◽  
Partial Least Squares Regression ◽  
Near Infrared ◽  
Coefficient Of Determination ◽  
Least Squares Regression ◽  
Analysis Software ◽  
Infrared Spectrometer ◽  
Automated Tools ◽  
Near Infrared Spectrometer ◽  
Data Analysis Software

The performance of a newly developed pocket-sized near-infrared (NIR) spectrometer was investigated by analysing 46 cheese samples for their water and fat content, and comparing results with a benchtop NIR device. Additionally, the automated data analysis of the pocket-sized spectrometer and its cloud-based data analysis software, designed for laypeople, was put to the test by comparing performances to a highly sophisticated multivariate data analysis software. All developed partial least squares regression (PLS-R) models yield a coefficient of determination (R2) of over 0.9, indicating high correlation between spectra and reference data for both spectrometers and all data analysis routes taken. In general, the analysis of grated cheese yields better results than whole pieces of cheese. Additionally, the ratios of performance to deviation (RPDs) and standard errors of prediction (SEPs) suggest that the performance of the pocket-sized spectrometer is comparable to the benchtop device. Small improvements are observable, when using sophisticated data analysis software, instead of automated tools.

scholarly journals Effect of Curcumin on Oxidative Stress in a Model of Turpentine Induced Acute Experimental Inflammation

2017 ◽  
Vol 45 (1) ◽  
pp. 65-74 ◽  
Author(s):  
Andrei CONEAC ◽  
Meda Sandra ORASAN ◽  
Daniel Corneliu LEUCUTA ◽  
Nicoleta DECEA ◽  
Miuta FILIP ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Antioxidant Capacity ◽  
Total Antioxidant Capacity ◽  
High Performance ◽  
Control Group ◽  
Group Iii ◽  
Group I ◽  
Total Antioxidant ◽  
Experimental Inflammation ◽  
Group Ii

Curcumin, a natural phenolic compound is an anti-tumor agent with anti-inflammatory and anti-oxidant properties. The aim of this research was to evaluate oxidative stress levels, the antioxidant activity and Curcumin concentrations by high performance liquid chromatography (HPLC) in an acute experimental inflammation induced by Turpentine oil (intramuscular 0.6 mg kg-1 body weight) and to compare a prophylactic versus a therapeutic regimen of Curcumin (oral suspension of 150 mg Curcumin kg-1 rat weight). Sixteen adult male Wistar rats were assigned to four groups: Control, Group I (Curcumin only), Group II (Curcumin administration, then induced inflammation after 1 hour) and Group III (induced inflammation then Curcumin administration after 2 hours). Oxidative stress was assessed by measuring serum malondialdehide and carbonylated proteins, while systemic and local total antioxidant capacity was determined by ABTS. Local tissue changes (muscle, kidney, liver) were analysed using histopathology. Results showed that acute inflammation significantly increased lipid peroxidation in Groups II and III compared to Control and Group I. A significantly reduced total antioxidant capacity (ATBS) was present in serum and kidney in Group II, also in muscle and kidney in Group III. ABTS levels were significantly increased only in the liver tissue of the animals in Groups II and III with induced inflammation as compared to Group I. This study proved the potential of Curcumin in reducing oxidative stress in both prophylactic and therapeutic regimens.

scholarly journals Discrimination and prediction of polyphenolic compounds and total antioxidant capacity in sorghum grains

2019 ◽  
Vol 27 (1) ◽  
pp. 46-53 ◽  
Author(s):  
Michela Alfieri ◽  
Giovanni Cabassi ◽  
Ephrem Habyarimana ◽  
Fabrizio Quaranta ◽  
Carlotta Balconi ◽  
...  
Keyword(s):  
Antioxidant Capacity ◽  
Total Antioxidant Capacity ◽  
Condensed Tannins ◽  
Near Infrared ◽  
Total Phenolics ◽  
Rapid Screening ◽  
Antioxidant Compounds ◽  
Total Flavonoids ◽  
Analysis Model ◽  
Total Antioxidant

One hundred and forty-seven sorghum samples, grown in 2015 and 2017, were used to build different near infrared spectroscopic calibration models able to predict total antioxidant capacity, total phenolics, total flavonoids and condensed tannins content. Samples were separated into calibration and validation sets using a nearest neighbours algorithm. The r2pred values ranged from 0.84 (condensed tannins) to 0.95 (total phenolics), whereas the Ratio of Performance to Deviation (RPD) values ranged from 1.9 (total flavonoids) to 3.0 (total phenolics). Comparison of prediction error estimates highlighted the best models with significant differences. Model robustness was tested through a reduction of sample numbers in the calibration set; the highest robustness was found for total antioxidant capacity and total flavonoids. In addition, a partial least squares discriminant analysis model to screen the samples for their tannins level was developed and resulted in good performance; it should be useful to select tannin-free genotypes for the food industry. These models could be used for rapid screening of sorghum breeding genotypes with high antioxidant compounds.

Calibration transfer across near infrared spectrometers for measuring hematocrit in the blood of grazing cattle

2017 ◽  
Vol 25 (1) ◽  
pp. 15-25 ◽  
Author(s):  
Xuan Luo ◽  
Akifumi Ikehata ◽  
Kunio Sashida ◽  
Shanji Piao ◽  
Tsutomu Okura ◽  
...  
Keyword(s):  
Latent Variables ◽  
Near Infrared ◽  
Least Squares Regression ◽  
Calibration Transfer ◽  
Grazing Cattle ◽  
Robust Model ◽  
Infrared Spectrometer ◽  
Near Infrared Spectrometer ◽  
Direct Standardization

For fast diagnosis of anemia for cattle farmed on pastures, portable short wavelength near infrared spectrometer instrument was built, and the feasibility of estimating hematocrit by partial least squares regression modeling was validated in our previous work. As a follow-up, the present study reports calibration transfer from one master instrument to two slave instruments. Different approaches, i.e. making robust models, skew and bias correction, and piecewise direct standardization, were compared. Our results show that making more use of simple models based on appropriate preprocessing, number of latent variables, and wavelength selection, can sometimes be as effective as applying standardization algorithm (e.g. piecewise direct standardization) when tackling the spectral differences between instruments. The importance of a robust model during the process of calibration transfer is shown. Application of standardization such as piecewise direct standardization could be risky when the model to be transferred is not robust enough.

scholarly journals Anaerobic Exercise Affects the Saliva Antioxidant/Oxidant Balance in High-Performance Pentathlon Athletes

2016 ◽  
Vol 17 (1) ◽  
Author(s):  
Marcelo de Lima Sant’Anna ◽  
Gustavo Casimiro-Lopes ◽  
Gabriel Boaventura ◽  
Sergio Tadeu Farinha Marques ◽  
Martha Meriwether Sorenson ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Uric Acid ◽  
Antioxidant Capacity ◽  
Total Antioxidant Capacity ◽  
High Performance ◽  
Anaerobic Exercise ◽  
Uric Acid Concentration ◽  
Before And After ◽  
Total Antioxidant ◽  
Anaerobic Test

AbstractPurpose. Investigate free radical production and antioxidant buffering in military pentathletes’ saliva after their performance of a standardized, running-based anaerobic sprint test (RAST). Methods. Seven members of the Brazilian Navy pentathlon team were recruited to perform a running-based anaerobic test (~90 sec). The participants provided samples of saliva before and after the test that were analyzed for biomarkers of oxidative stress such as lipid peroxidation, total antioxidant capacity and the quantity of two specific antioxidants, glutathione and uric acid. Results. The lipid peroxidation increased ~2 fold after RAST, despite an increase in total antioxidant capacity (46%). The concentration of reduced glutathione did not change, while the uric acid concentration increased by 65%. Conclusions. The evaluation in saliva following a sprint test that lasted no more than 90 sec was sensitive enough to reveal changes in redox state.

Rapid detection of the component contents in caryophylli flos by a handheld near infrared spectrometer based on digital light processing technology

2018 ◽  
Vol 26 (6) ◽  
pp. 389-397
Author(s):  
Hui Yan ◽  
Yue Ma ◽  
Bangxing Han
Keyword(s):  
Standard Error ◽  
Near Infrared ◽  
Processing Technology ◽  
Quantitative Detection ◽  
Least Squares Regression ◽  
Digital Light Processing ◽  
Standard Normal Variate ◽  
Eugenyl Acetate ◽  
Infrared Spectrometer ◽  
Near Infrared Spectrometer

A handheld and inexpensive near infrared spectrometer based on digital light processing technology was used to investigate the potential of fast quantitative detection of eugenol, beta-caryophyllene and eugenyl acetate in caryophylli flos. Gas chromatography was used to determine the reference values. The diffuse reflectance spectra of caryophylli flos powder were recorded and were pretreated by different methods, and then the partial least squares regression was applied to develop calibration models; furthermore, the competitive adaptive reweighted sampling was used for the wavelength selection to improve the performance of models. The results show that the best performance of the pretreatment methods is seen with the combination of the first derivative and standard normal variate, and the performance of calibration is improved by the competitive adaptive reweighted sampling. For the eugenol, the standard error of calibration and standard error of prediction are 0.46% and 0.60%, respectively, and the corresponding R-squares are 0.955 and 0.89; for beta-caryophyllene, the standard error of calibration and standard error of prediction are 0.11% and 0.14%, respectively, and the corresponding R-squares are 0.89 and 0.86; for eugenyl acetate, the standard error of calibration and standard error of prediction are 0.30% and 0.38%, respectively, and the corresponding R-squares are 0.89 and 0.80. The overall results of this work revealed the feasibility of the use of handheld near infrared spectrometers as a method for the quantitative on-site determination of eugenol, beta-caryophyllene and eugenyl acetate in caryophylli flos.

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