The present study explores an alternative method for antioxidants determination in buckwheat (Fagopyrum) samples. Buckwheat contains different amounts of the antioxidants rutin, quercetin and quercitrin in different plant parts. Buckwheat seeds are most commonly used as food; however, preparations from the herb can also be used as a rich source of rutin. Infrared spectroscopy was used for individual and sum quantification of rutin, quercetin and quercitrin in whole and ground flowers and leaves of seven different buckwheat species. Correlation coefficients R of calibration and independent validation set for rutin, quercetin and quercitrin were 1.00 and 0.98, 0.94 and 0.99, 0.99 and 0.95, respectively. Some of the developed models had accuracy comparable to the reference HPLC method. Additionally many different parameters that give an important insight into the FTIR technique are discussed (different plant parts, whole and ground untreated samples, 3 different resolutions, 7 spectra pre-treatments, using individual or averaged spectra, reducing spectral data input, considering additional non-spectral data). The implemented technique used no sample preparation, is non-destructive and uses very little amounts of sample. Result show that infrared spectroscopy can be a fast and environmentally friendly alternative technique for routine analysis of main flavonoids in aerial parts of buckwheat.

The chemical composition of essential oils and hydrosols of immortelle (Helichrysum italicum) stems with leaves obtained by hydrodistillation was identified using gas chromatography coupled with mass spectrometry (GC-MS). One-year-old and two-year-old plants of the same immortelle population, and plants from three Croatian populations, all grown in Slovenia, were included in the study. The main compounds of essential oils of one-year-old and two-year-old plants were α-pinene, α-eudesmol, and rosifoliol. Among essential oils of the Croatian populations, three dominant components were found: α-pinene, geranyl acetate, and 2-phenylethyl tiglate. Both the essential oils and hydrosols of one-year-old plants were more diverse in their compositions than two-year-old plants. The predominant compounds of hydrosols of one- and two-year-old plants were pentan-3-one, 3-octanone, 2,2-dimethylnon-5-en-3-one, and α-terpineol, and in the Croatian populations α-terpineol, 2,6-octadien-1-ol, 2,2-dimethylnon-5-en-3-one, and α-terpineol.

No abstract

Hydrosols have been increasingly used in the food industries as drinks and as ingredients for seasoning and flavoring. Research has shown they have antimicrobial, antioxidative and anti-inflammatory effects and therefore have potential as food preservative agents and sanitizing agents for tools used in the food industry. The composition analysis of hydrosols is commonly conducted using extraction with organic solvents. However, some hydrophilic compounds are lost with this procedure, leading to issues in identifying native composition and potential adulteration. In this paper, different methods for hydrosol analysis are studied. The methods differ in sample preparation, number of detected compounds, repeatability and reliability. Direct hydrosol analysis and 1:1 extraction with organic solvent were determined to be the most appropriate in our experiments. However, the method implementation depends on the application. Direct hydrosol analysis is simple and does not change ratios among compounds; its drawback is poor repeatability. Using 1:1 extraction has good repeatability; however, some hydrophilic compounds are lost, and adulterations with cosolvents and the addition of solubilizers cannot be discovered.

Vegetable oils have been utilized for centuries in the food, cosmetic, and pharmaceutical industries, and they contribute beneficially to overall human health, to active skincare, and to effective treatments. Monitoring of the vegetable oils is carried out by the methods described in the European Pharmacopeia, which is time-consuming, has poor repeatability, and involves the use of toxic organic chemicals and expensive laboratory equipment. Many successful studies using IR spectroscopy have been carried out for the detection of geographical origin and adulteration as well as quantification of oxidation parameters. The aim of our research was to explore FT-IR spectroscopy for assessing the quality parameters and fatty acid composition of cranberry, elderberry, borage, blackcurrant, raspberry, black mustard, walnut, sea buckthorn, evening primrose, rosehip, chia, perilla, black cumin, sacha inchi, kiwi, hemp, and linseed oil. Very good models were obtained for the α-linolenic acid and linoleic acid contents, with R2 = 1.00; Rv2 values of 0.98, 0.92, 0.89, and 0.84 were obtained for iodine value prediction, stearic acid content, palmitic acid content, and unsaponifiable matter content, respectively. However, we were not able to obtain good models for all parameters, and the use of the same process for variable selection was found to be not suitable for all cases.