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In this study, different extraction methods and conditions were used for the extraction of antioxidants from brown macroalgae Fucus spiralis. The extraction methodologies used were ultrasound-assisted extraction (ultrasonic bath and ultrasonic probe), extraction with a vortex, extraction with an Ultra-Turrax® homogenizer, and high-pressure-assisted extraction. The extracts were analyzed for their total phenolic content (TPC) and their antioxidant activity, and evaluated through the 2,2-difenil-1-picrilhidrazil (DPPH) free radical scavenging method and ferric reducing antioxidant power (FRAP) assay. Ultrasonic probe-assisted extraction yielded the highest values of TPC (94.78–474.16 mg gallic acid equivalents/g extract). Regarding the antioxidant activity, vortex-assisted extraction gave the best DPPH results (IC50 1.89–16 µg/mL), while the highest FRAP results were obtained using the Ultra-Turrax® homogenizer (502.16–1188.81 μmol ascorbic acid equivalents/g extract). For each extraction method, response surface methodology was used to analyze the influence of the experimental conditions “extraction time” (t), “biomass/solvent ratio” (R), “solvent” (S, water % in water/ethanol mixture), and “pressure” (P) on TPC, DPPH, and FRAP of the F. spiralis extracts. In general, higher TPC content and higher antioxidant capacity (lower IC50 and higher FRAP) were obtained with higher R, t, and P, and lower S (higher ethanol %). The model regarding the combined effects of independent variables t, R, and S on the FRAP response values for vortex-assisted extractions best fitted the experimental data (R2 0.957), with optimal extraction conditions of t = 300 s, R = 50 g, and S = 25%.

AbstractBackground: Iron deficiency is one of the leading causes of anaemia, with those most affected being children and women of childbearing age, in Brazil there is a scarcity of studies involving the local prevalence of anaemia. Aim: To evaluate anaemia and associated factors in schoolchildren in Santa Cruz do Sul through the analysis of biochemical and haematological markers and parasitological examination of faeces. Subjects and methods: School children from 10 to 12 years of age were evaluated through complete blood count, serum ferritin, C-reactive protein and stool parasitological examination, as well as socio-demographic characteristics and prophylaxis with ferrous sulphate in childhood. Results: It was found that 13.0% of the population was anaemic, girls were very slightly overrepresented among the anaemic children. Only 5.3% had altered haematocrit levels; 26.6% had low Mean Corpuscular Volume levels; 18.4% had low ferritin levels; 2.4% had increased C-reactive protein levels, and 21.7% had altered eosinophils. As for the socioeconomic level, classes A2 and D presented lower haemoglobin levels, as well as class D presenting lower ferritin levels, although without statistical significance. Only 6.0% of the population presented iron-deficiency anaemia and 46.0% of the schoolchildren had used ferrous sulphate supplementation in childhood. Conclusion: The prevalence of anaemia in the studied municipality is low, probably due to the high municipal human development index. Epidemiological studies are essential to characterise the population in a systematic form, to prevent future problems.