1. The extraction process, separation, and identification of curcuminoids from turmeric curcuma longaGal Slaček, Petra Kotnik, Azra Osmić, Vesna Postružnik, Željko Knez, Matjaž Finšgar, Maša Knez Marevci, 2023, original scientific article Abstract: Turmeric Curcuma longa is a well-known spice with various health benefits, attributed primarily to curcumin. Soxhlet extraction, cold maceration, ultrasound-assisted extraction (UAE), and supercritical fluid extraction were performed, and the content of total phenols, proanthocyanidins, and antioxidants was analysed by UV/VIS spectrophotometry. High-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was employed to identify and quantify the curcumin content. Supercritical extracts had the highest total phenolic content (538.95 mg GA/100 g material), while the Soxhlet extracts had the highest content of proanthocyanidins (4.77 mg PAC/100 g of material). Extracts obtained by UAE and supercritical extraction have the highest antioxidant potential. Antioxidant activity measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH center dot) was 64.27% and 1750.32 mg Trolox per g dry weight by 2,2-azinobis(3-ethylbenzothiazoline 6 sulphonic acid) (ABTS(+center dot)) for the extract obtained by supercritical extraction. The UAE resulted in the highest amount of curcumin (1.91 mg curcumin/g material). A kinetic study showed that extraction yield in supercritical extracts decreased with increasing temperature and that the content of isolated curcumin was inversely proportional to solvent-to-feed ratio (S/F). The present study has confirmed that turmeric is an excellent source of antioxidants, such as curcumin, that play an important role in reducing cellular stress by neutralising free radicals.
Keywords: turmeric, curcumin, total phenols, proanthocyanidins, antioxidants
Published in DKUM: 09.02.2024; Views: 361; Downloads: 50
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2. Variations in leaf total protein, phenolic and thiol contents amongst old varieties of mulberry from the Gorizia regionTina Ugulin, Tamas Bakonyi, Rebeka Lucijana Berčič, Andreja Urbanek Krajnc, 2015, original scientific article Abstract: Preserving the plant genetic resources of genus Morus is insuffcient but undoubtedly vital for conservation of the world’s germplasm for our successors. This research was focused on old mulberry varieties from the Gorizia region in Slovenia which were assessed for their contents on crucial metabolites (proteins, phenolics and thiols) in leaves regarding their antioxidant and nutraceutical potentials. Total proteins were measured spectrophotometrically by following the procedure of Bradford, the total phenolic contents were determined using the Folin-Ciocalteu method and thiols were established with monobromobimane fluorescent dye. The presented metabolite screening showed that some of the evaluated genotypes had higher concentrations of glutathione and were superior in contents of proteins and phenolics when compared to the results of other authors and could be propagated as highly recommendable feed for silkworms, and other animals.
Keywords: feeds, glutathione, Morus, phenols, proteins
Published in DKUM: 14.11.2017; Views: 1822; Downloads: 530
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