Search results for "Chemometric"

Classification of persimmon fruit origin by near infrared spectrometry and least squares-support vector machines

2014

Abstract The main objective of this work has been the authentication by Fourier transform near infrared (FT-NIR) spectrometry of the origin of persimmon fruits cultivated in different regions of Spain. In order to achieve this goal, 166 persimmon samples from 7 different regions of Spain were analyzed by FT-NIR spectrometry. By splitting the spectral data in training and independent test sets, a classification model was built using least squares support vector machines chemometric technique. Orthogonal signal correction and principal component analysis were performed prior to conduct the classification strategy. The verified model was applied for the prediction of the origin of 50 samples f…

Characterization of petroleum-based products by infrared spectroscopy and chemometrics

2012

Abstract The role of fossil fuels in providing the energy required for automobiles, factories and daily life has seriously concerned the authorities. Consistency of the quality of petroleum-based products is an important aspect of social and environmental criteria in a developed society. High-quality petroleum-based fuels would have several benefits (e.g., reduction in rate of consumption, less environmental pollution and durability of hardware). We review recent advances in the application of infrared spectroscopy in the petroleum industry. We focus on the methods proposed for the determination of a wide range of characteristics in petroleum-based products. We discuss methods based on the …

2018

Whisky can be described as a complex matrix integrating the chemical history from the fermented cereals, the wooden barrels, the specific distillery processes, aging, and environmental factors. In this study, using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) and liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS), we analyzed 150 whisky samples from 49 different distilleries, 7 countries, and ranging from 1 day new make spirit to 43 years of maturation with different types of barrel. Chemometrics revealed the unexpected impact of the wood history on the distillate's composition during barrel aging, regardless of the whisky origin. Flavonols, ol…

Vibrational spectroscopy in soil and sediment analysis

2014

The literature concerning the use of vibrational spectroscopy for soil and sediment analysis, published in the last years, has been revised in order to provide a picture of the strengths and weaknesses of these direct techniques to characterize soil composition and properties. Many soil components as water, organic matter, like humic substances, and minerals, can be determined together with physicochemical parameters as pH, conductivity or redox potential. The main strategies to obtain sample spectra and to extract, as many as possible, useful information were evaluated, taking into account the progress on chemometrics and discussing the whole analytical process, from sampling to sample pre…

New chemiometric technique applied to traceability of Sicilian honey of Sulla (Hedysarum coronarium L.)

The consumers have an increasing interest about food traceability with respect to safety, quality and typicality issues. Food traceability is an important issue in food safety and quality control, with impacts on food security, its quantity and overall availability. Furthermore, the possibility of tracing the origin of foodstuff is assuming an increasingly important role at the legislative level, as a tool that may allow to prove on product authenticity and to control adulteration. So, establish systems to trace food products through specified stages of production, processing and distribution play a key role also to ensure food safety. In the last years, several of analytical techniques hav…

Adulteration detection of argan oil by inductively coupled plasma optical emission spectrometry

2010

Abstract The singularity of the trace element profile of argan oil has been demonstrated by means of inductively coupled plasma optical emission measurement in combination with different chemometric approaches. The ability of multivariate analysis methods; such as hierarchical cluster analysis (HCA), principal component analysis (PCA), classification trees using Chi -squared Automatic Interaction Detector (CHAID) and discriminant analysis (DA) to achieve edible oils classification based on its type or variety from their elemental content have been investigated. The calculations were performed using 16 variables (contents of Na, Mg, Al, K, Ca, Ti, Fe, Co, Ni, Cu, Zn, Cd, Pr, Sm, Er and Bi at…

1H NMR-based metabolic profiling for evaluating poppy seed rancidity and brewing

2015

Poppy seeds are widely used in household and commercial confectionery. The aim of this study was to demonstrate the application of metabolic profiling for industrial monitoring of the molecular changes which occur during minced poppy seed rancidity and brewing processes performed on raw seeds. Both forms of poppy seeds were obtained from a confectionery company. Proton nuclear magnetic resonance (1H NMR) was applied as the analytical method of choice together with multivariate statistical data analysis. Metabolic fingerprinting was applied as a bioprocess control tool to monitor rancidity with the trajectory of change and brewing progressions. Low molecular weight compounds were found to be…

Fusion of the 1H NMR data of serum, urine and exhaled breath condensate in order to discriminate chronic obstructive pulmonary disease and obstructiv…

2015

Chronic obstructive pulmonary disease, COPD, affects the condition of the entire human organism and causes multiple comorbidities. Pathological lung changes lead to quantitative changes in the composition of the metabolites in different body fluids. The obstructive sleep apnea syndrome, OSAS, occurs in conjunction with chronic obstructive pulmonary disease in about 10–20 % of individuals who have COPD. Both conditions share the same comorbidities and this makes differentiating them difficult. The aim of this study was to investigate whether it is possible to diagnose a patient with either COPD or the OSA syndrome using a set of selected metabolites and to determine whether the metabolites t…

Differentiation among dairy products by combination of fast field cycling NMR relaxometry data and chemometrics

2021

A set of commercial milk and Sicilian cheeses was analysed by a combination of fast field cycling (FFC) nuclear magnetic resonance (NMR) relaxometry and chemometrics. The NMR dispersion (NMRD) curves were successfully analysed with a mathematical model applied on Parmigiano-Reggiano (PR) cheese. Regression parameters were led back to the molecular components of cheeses (water trapped in casein micelles, proteins and fats) and milk samples (water belonging to hydration shells around dispersed colloidal particles of different sizes and bulk water). The application of chemometric analysis on relaxometric data enabled differentiating milk from cheeses and revealing differences within the two sa…