Grams ai 8

Mid-infrared absorption spectra were obtained with attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) using IRSpirit (Shimadzu, Kyoto, Japan) equipped with a DLATGS detector. The measurements were performed in ATR mode using the QATR™-S Single-Reflection Accessory with a Diamond Crystal (Shimadzu, Kyoto, Japan). Film samples were placed directly onto the crystal with a contact area diameter of 1.8 mm and pressed against its surface with a clamp mechanism. Spectra were recorded in the range of 4000–500 cm⁻¹ with 36 scans at a resolution of 4 cm⁻¹ from 5 locations for each film (1 in the center of the film and 4 around the perimeter). The spectra were baseline-corrected and vector-normalized; then, for each spectrum, ten individual samples were averaged. Spectral and data analysis were performed using the Grams/AI 8.0 software (Thermo Scientific, Waltham, MA, USA).

All Raman spectra were recorded with a Raman microscope inVia Reflex System from Renishaw (Renishaw Plc., Wotton-Under-Edge, UK), equipped with a charge-coupled device (CCD) detector with a resolution of 1 cm⁻¹. Spectra were collected in triplicate using a 50/0.75 × NA objective, with accumulation of 1 scan and 10 s exposure time. The excitation was provided by the 514 nm line of an argon ion laser with the power set as 1% or 10% from 5 mW (in this case the best spectra were selected). In every case the laser beam was focused on a surface of single crystal placed on an aluminum support. The spectra analysis and correction of a background signal originating from the fluorescence were performed using the Grams/AI 8.0 software (Thermo Scientific, Waltham, MA, USA). All Raman spectra were normalized to the intensity of the most intense band in the range 1750–600 cm⁻¹.

Another chemometrics method that can be a continuation of PCA classification is the hierarchical clustering analysis. HCA is an unsupervised method in which the focus is on the classification problem. The aim of the HCA is to detect similarities in the variables set and classification into clusters. Different classification algorithms can be applied in this method.
Principal component analysis (PCA) and hierarchical cluster analysis (HCA) were used to obtain Raman and FTIR spectra for the cocrystals and crystal form of xanthohumol. Before the data analysis, all spectra were subjected to pre-treatment (multi-point baseline correction, Savitzky-Golay smoothing with 11 points and Y offset correlation, points were set to zero) using the Grams/AI 8.0 software (Thermo Scientific, Waltham, MA, USA). The analysis was conducted in the range 1700–1000 cm⁻¹ for the Raman spectra and 3700–2700 cm⁻¹ and 1800–1000 cm⁻¹ for the FTIR spectra. In the principal component analysis the covariance matrices were used. In the hierarchical cluster analysis the Euclidean, Chebyshev, and Pearson correlation distance between the pairs of samples were used as a distance measure. Complete and average linkage criteria were used as an agglomeration method. The multivariate analysis was prepared using the Statistica 13 software (TIBCO Software Inc. Palo Alto, CA, USA).

FTIR spectra were measured using an IRSpirit FTIR spectrometer (Shimadzu, Kioto, Prefektura Kioto, Japan) equipped with a single reflection ATR accessory. Briefly, 5 μL of the fruit puree sample was spread on the surface of a ZnSe crystal with drying (N₂ gas). Each spectrum was investigated at a range of 4500–500 cm⁻¹ at 4 cm⁻¹ intervals of spectral resolution by averaging 30 scans. For the multivariate FTIR, spectral data were pre-processed using the Grams/AI 8.0 software (Thermo Scientific, Waltham, MA, USA).

Mid-infrared absorption spectra were acquired by Attenuated Total Reflectance-Fourier Transform Infrared spectroscopy (ATR-FTIR) IRSpirit (Shimadzu, Kyoto, Japan) equipped with a DLATGS detector. The measurements were performed in attenuated total reflectance mode using the QATR™-S Single-Reflection ATR Accessory with a Diamond Crystal (Shimadzu). A pinch of dried samples were placed directly onto the crystal (with a contact area diameter of 1.8 mm) and pressured against its surface with a swing clamp mechanism. Spectra were collected with 36 spectral scans at a resolution of 4 cm⁻¹ within the wavenumber range between 4000 and 500 cm⁻¹. The spectra were ATR, air vapour and baseline corrected and normalized. The spectral normalization was performed in terms of the equal area in the appropriate spectral range (3000–2800 cm⁻¹ for lipids, 1720–1500 cm⁻¹ for proteins, 1180–900 cm⁻¹ for carbohydrates). To gain more insight into cell structural components, second derivation procedure was performed. All spectral and data analysis were performed using the Grams/AI 8.0 software (Thermo Scientific, Waltham, MA, USA).

Multivariate analyses, including hierarchical cluster analysis (HCA), principal component analysis (PCA) and linear discriminant analysis (LDA), were performed for the pre-processed FTIR spectra of wines. Moreover, PCA was carried out also for the physicochemical composition. The Grams/AI 8.0 software (Thermo Scientific, Waltham, MA, USA) was applied for multi-point baseline correction, Savitzky–Golay smoothing, as well as Y offset correlation, and points were set to zero prior to the analysis. Data pre-processing such as mean centering was performed using OriginPro (OriginLab Corporation, Northampton, MA, USA). Chemometrics analysis was conducted in the broad range of spectra 1800–500 cm⁻¹. The Statistica 13 software (TIBCO Software Inc., Palo Alto, CA, USA) and OriginPro (OriginLab Corporation, Northampton, MA, USA) were applied for chemometrics analysis.

Electronic absorption spectra of NTBD were recorded on a double-beam UV–Vis spectrophotometer Cary 300 Bio (Varian) equipped with a thermostated tray holder with a 6 × 6 multi-cell Peltier block. The temperature was controlled with a thermocouple probe (Cary Series II from Varian) placed directly in the sample.
Cary Eclipse spectrofluorometer (Varian) was applied for recording fluorescence excitation, emission and synchronous spectra. All measurements were carried out at 22 °C. All the fluorescence spectra were recorded with 0.5 nm resolution together with the lamp and photomultiplier spectral characteristics corrections. Resonance light scattering (RLS) measurements were carried out according to the previously reported protocol with synchronous scanning of both the excitation and emission monochromators (there was no interval between excitation and emission wavelengths) and spectral resolution of 1.5 nm. Grams/AI 8.0 software (Thermo Electron Corporation; Waltham, Massachusetts, United States) was applied for an analysis of the recorded data.