20.500.12556/RUL-134188 Characterization of algae dietary supplements using antioxidative potential, elemental composition, and stable isotopes approach Dietary supplements based on algae, known for their nutritional value and bioactive properties, are popular products among consumers today. While commercial algal products are regarded safe by numerous studies, information about the production and origin of such products is scarce. In addition, dietary supplements are not as strictly regulated as food and medicinal drugs. We characterized different algal products (kelps: Laminariales, Spirulina spp., Chlorella spp., and Aphanizomenon flos-aquae), obtained on Slovenian market, based on their elemental composition (X-ray fluorescence, inductively coupled plasma–mass spectrometry), antioxidative potential [DPPH (2,2-diphenyl-1-picrylhydrazyl) assay, total phenolic content], and stable isotope values [carbon (C), nitrogen (N), and sulfur (S); elemental analyzer isotope ratio mass spectrometry (EA-IRMS) method]. Antioxidative potential is consistent among products of the same type, with A. flos-aquae samples having 4.4 times higher antioxidative potential compared to Chlorella spp. and 2.7 times higher compared to Spirulina spp. Levels of toxic trace elements (arsenic, cadmium, mercury, and lead) are below the maximum allowed values and as such do not pose risk to consumers' health. Samples of Spirulina spp. have relatively high δ$^{15}$N (7.4 ‰ ± 4.4‰) values, which indicate use of organic nitrogen sources in certain samples. Likewise, different elemental composition and isotopic ratios of stable elements (C, N, and S) for the samples with Spirulina spp. or Chlorella spp. are the consequence of using different nutrient sources and algae-growing techniques. Statistical analysis (principal component analysis) has confirmed that all tested A. flos-aquae samples originate from the same source, supposedly Klamath Lake (Oregon, USA). Hawaiian Spirulina pacifica can also be differentiated from all the other samples because of its characteristically high metal content (iron, manganese, zinc, cobalt, nickel, vanadium). Chlorella spp. and Spirulina spp. require further analyses with larger number of samples, as differentiation is not possible based on results of this study. algae Spirulina Chlorella Aphanizomenon flos-aquae antioxidative potential stable isotopes elemental composition toxic elements prehrana prehranska dopolnila alge antioksidativni potencial izotopska sestava elementna sestava true false true Angleški jezik Slovenski jezik Članek v reviji 2021-12-28 09:26:18 2021-12-28 09:26:18 2023-03-24 03:37:00 0000-00-00 00:00:00 2021 0 0 10 str. art. 618503 Vol. 7 2021 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 613.2:582.232:543.61 2296-861X 10.3389/fnut.2020.618503 49471491 RAZ_Kejzar_Jan_2021.pdf RAZ_Kejzar_Jan_2021.pdf 1 CC14D5DC3627AA890D42A57271190E56 16ebb7eeaf3423edd48df89a27b0b85d077bd6f7b33cf73e4a1d89d87f2c60bd 4139c81c-67b8-11ec-abdb-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=152522 https://www.frontiersin.org/articles/10.3389/fnut.2020.618503/full 0 327805cd-67b8-11ec-abdb-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=152521 Biotehniška fakulteta 0 0 0