Journal Articles

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    A Complete Analysis Pipeline for the Processing, Alignment and Quantification of HPLC–UV Wine Chromatograms
    (Springer-Verlag GmbH Germany, 2024-03) Ianeselli A; Longo E; Poggesi S; Montali M; Boselli E
    Elucidating the chemistry of wine would help defining its quality, chemical and sensory characteristics and optimise the wine-making processes. High-performance liquid chromatography coupled with UV–Vis spectroscopy (HPLC–UV–Vis) is a common analysis method used to obtain the molecular profile of wine samples. We propose a complete procedure for the analysis of wine chromatograms. Data are pre-processed using standard methods of down-sampling, smoothing and baseline subtraction. Multiple samples are then merged in a three-dimensional tensor, decomposed using parallel factor analysis (PARAFAC2) into three factors: (i) one reduced (rank-one) chromatogram per sample, (ii) an estimate of the samples’ spectral UV–Vis profile and (iii) an estimate of the samples’ concentrations. If the decomposition is performed on a single peak of the tensor, the second and third factors correspond to the representative wavelength spectrum and to the relative concentrations of the samples, respectively. Otherwise, when multiple peaks are analysed, further processing is required. In the latter case, the decomposed rank-one chromatograms are peak-detected and aligned, clustered and integrated. A table containing the concentration of the peaks at different retention times is obtained. The pipeline proposed in this study is a guideline for a quantitative and reproducible chemical analysis of wine, or other samples, via the HPLC–UV–Vis method.
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    Non-invasive discrimination of roasted and unroasted cocoa bean shell of cocoa clones in Ghana and quantification of nutritional and bioactive components: a chemometric approach
    (Springer Nature, 2024-10-09) Ampomah KA; Attakora R; Zaukuu J-LZ; Agbolegbe RK; Diako C; Aduama-Larbi MS; Atta O; Mensah ET; Amoah I
    Cocoa bean shell (CBS) remains a commonly produced by-product of cocoa bean processing. It is usually obtained from fermented and dried cocoa beans that are roasted. The study investigated the potential use of Near-infrared spectroscopy (NIRS) analysis for discriminating roasted and unroasted CBS among cocoa clones and quantifying some nutritional and bioactive components in Ghana. Five clones, comprising four important seed gardens clones used across West Africa and one criollo were evaluated. Cocoa beans from the different clones (T60/887, VENC 4, MO 20, PA 150 and T60/887 × POUND 7) were divided into two parts, with one part roasted at a temperature of 120 °C for 50 min while the other part was kept unroasted. The CBSs were milled and passed through a 425 μm pore-sized sieve to obtain the powder. A handheld portable NIRS was used to scan the CBS powder in Ziplock bags. The nutritional and bioactive characterisation was carried out using official methods. NIRS discriminated the various clones of roasted and unroasted CBS. Carbohydrate was the predominant macronutrient, and ash content ranged from 5.25 to 8.24%. The CBS was high in potassium (2382–3144 mg/100 g) and low in sodium (25.67–51.33 mg/100 g). Total flavonoids and phenolics ranged from 8.61 to 40.71 mgQE/g and 6.34–12.25 mgGAE/g, respectively, for the roasted and unroasted CBS. To ensure better differentiation of cocoa beans from different clones using NIRS, incorporating roasting as a processing parameter is recommended.
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    Monitoring the mode of action of synthetic and natural biocides against Aeromonas hydrophila by Raman spectroscopy and chemometrics
    (BioMed Central Ltd, 2021-12) Mehta M; Liu Y; Waterland M; Holmes G
    We have investigated the mode of action of synthetic biocides, (2-(thiocyanomethylthio) benzothiazole(TCMTB), dichlorophen, (commonly used in leather industry for preservation) and natural biocides, oregano and eucalyptus oils, on Aeromonas hydrophila using Raman spectroscopy in collaboration with multivariate analysis and 2D correlation spectroscopy to evaluate whether Raman spectra acquired contained valuable information to study the action of biocides on bacterial cells. The growth of A. hydrophila in clear and outer edge zone of inhibition differ in their reaction with different biocides, which allows us to highlight the differences as a characteristic of two kinds of bacteria. Such classification helps identify oregano oil as the most effective biocide by altering clear and outer edge zone of bacteria. Standard disk diffusion assay method was used for screening biocide bacteria interactions and later analysed by Raman spectroscopy. The paper also presents the introduction of TCMTB and oregano oil into leather processing stages to examine and determine the antimicrobial effect as an application to real-world setting. Therefore, we conclude that Raman spectroscopy with appropriate computational tools constitutes a powerful approach for screening biocides, which provide solutions to all the industries using biocides including leather industry, considering the potentially harmful effect of biocides to humans and the environment.