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Effect of different temperature (30 to 90 °C), time (10 to 70 min) and pH (4 to 9) conditions were investigated on the extraction efficiency of polysaccharides from seaweed E. intestinalis. Results showed that the extraction temperature had the highest effect on the enhancement of polysaccharide content. The highest polysaccharide extraction yield was achieved at 90 °C, 30 min and pH 8. Therefore, antioxidant effects of polysaccharides obtained at temperatures 30, 70 and 90 °C, times 10, 30 and 50 min, and pH 4, 7 and 8 with significant yield differences were evaluated. DPPH radical scavenging activity, ferric reducing power and total antioxidant activity were employed in order to evaluate the antioxidant properties of polysaccharides. The maximum DPPH radical scavenging activity was obtained for polysaccharides of 30 °C (73.90%), 30 min (95.08%) and pH 7 (75.61%). The highest reducing power was achieved for polysaccharides of 70 °C (97.49%), 50 min (99.05%) and pH 8 (97.49%). The maximum total antioxidant activity was obtained for polysaccharides of 70 °C (49.97), 10 min (62.32) and pH 7 (59.11 mg ascorbic acid/ g dried seaweed powder?). Overall, findings of current study suggest that the polysaccharides from green seaweed E. intestinalis possess antioxidant capacity and that the use of high temperature, long time and acidic or basic pH in extraction process results in diminishing this antioxidant capacity.     

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This experiment evaluated the effect of soluble polysaccharides in Spirulina platensis microalgae on growth performance, body composition and immune response of rainbow trout (Oncorhynchus mykiss). In this regard, 180 rainbow trout (17.22 ± 0.5g) were selected and distributed in five experimental treatments (with three replications). Treatments included different levels of polysaccharide in dosage of 0 (control), 500, 1000, 2000 and 3000 mg / kg of feed. According to the results, in growth factors (final weight, body weight gain, specific growth factor, protein efficiency, feed conversion ratio and condition factor), no significant difference was observed. The highest and the lowest amount of carcass proteins were observed in the diet containing 500 mg polysaccharide and control, which showed a significant difference. The amount of fatty acids of the muscle of the fish body did not show any significant difference among the treatments. The highest and lowest levels of lysozyme activity were observed in treatments of 2,000 mg polysaccharide and control and the highest and lowest levels of complement activity were observed in treatments containing 3000 mg polysaccharide and control respectively (P <0.05). In general, the use of polysaccharide extracted from micro-algae did not significantly improve rainbow trout growth, but a slight improvement in growth and body composition (protein) in 500 mg polysaccharide per kg of diet was observed. In terms of safety indicators, treatments of 2,000 and 3,000 mg of polysaccharides per kg of diet had a good performance and could be used whenever needed.
 

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Finding natural, inexpensive and new polysaccharides resources is essential due to the high potential for utilization in the food and medicinal industries. Therefore, the current study was aimed to extraction optimization of polysaccharides from feijoa leaves in order to maximize extraction yield and, evaluate chemical, structural characteristics and antioxidant activity. In this regard, the effects of three independent parameters including extraction temperature (50-90°C), pH of water (3.5-5.5) and extraction time (1-4 h) on the extraction yield were studied. Optimum conditions were obtained at extraction temperature of 68°C, pH of 6.75 and extraction time of 2.96 h. Under optimum conditions, the predicted yield (3.38%) was consistent with the experimental yield (3.35±0.02%). The preliminary chemical characteristics of the polysaccharides extracted from the feijoa leaves were determined under optimum conditions. Based on the results obtained, total carbohydrate content was 54.77%, polyphenols and protein were 0.14 mg GAE and 0.18%, respectively. The FT-IR spectrum demonstrated obvious characteristic peaks of polysaccharides. Feijoa leave polysaccharides mainly consisted of glucose, ribose, mannose, arabinose and galactose. The results of antioxidant activity revealed the good ability of feijoa leave polysaccharides to scavenge DPPH free radicals and to reducing iron ions. Finally, the feijoa leave can be introduced as a natural, inexpensive and new resource for the extraction of polysaccharides with good biological activity for the production of functional foods or medicines.

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Sulfated polysaccharides presenting in the cell wall of seaweeds and aquatic plants exhibit a diverse range of biological functions mainly due to their particular structural and molecular properties. The aim of the current study was to evaluate the inhibition of oxidation reactions and activities of digestive enzymes including α-amylase and α-glucosidase by sulfated polysaccharides from aquatic plant Myriophyllum spicatum. After the removal of pigments and low molecular weight compounds, polysaccharides were extracted by distilled water at 60°C for 2 hours. Polysaccharide purification using DEAE Sepharose FF led to production of two fractions including F1 and F2. Obtained polysaccharides were considerably capable of scavenging DPPH free radicals (20.62-64.81%) and reducing Fe³⁺ ions (0.24-0.50 Abs) with F1 fraction exhibiting the greatest activity. Polysaccharides inhibitions against α-amylase activity were greatly different (22.50-63.20%) with the lowest IC₅₀ being 1.31 mg/mL for F2 fraction. α-glucosidase activity was reduced to various levels (1.30-89.5%) and the lowest IC₅₀ of 10.0 mg/mL was observed for crude polysaccharide. Overall, these findings indicated that sulfated polysaccharides from M. spicatum L. possess promising antioxidant, α-amylase and α-glucosidase inhibition potentials depending on their chemical and molecular structure and thus could be considered as antioxidant and anti-diabetic agents.

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Pomegranate peel is the main by-product during pomegranate processing that valuable source of bioactive compounds with health-beneficial effects. This study has comparatively assessed the effects of two extraction methods (enzymatic and acidic) on pomegranate peel by measuring their bioactivity in terms of total phenolic content (TPC), antioxidant activity, and antidiabetic properties using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging and 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) radical cation decolourization assays, and the α-amylase and α-glucosidase inhibition assays. The TPC mg gallic acid equivalents per g dry weight (GAE mg/g dw) of extracted pectin was ~ 243 and ~ 116 for enzymatic and acidic methods, respectively. The DPPH IC₅₀ of enzymatic pectin was significantly lower than that of acidic pectin (p < 0.05). The ABTS IC₅₀ of enzymatic pectin and acidic pectin was ~ 361 and ~ 945, respectively. The enzymatic pectin showed a significantly stronger α-amylase and α-glucosidase inhibition effect as compared to the acidic pectin. The α-amylase inhibition was stronger than α-glucosidase inhibition for all samples.
The results indicated that enzymatic extracted pectin showed antioxidant and antidiabetic potential, which could be considered as a promising candidate for functional foods in food formulation.

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In our previous studies, we prepared by mechanical treatment and tested several formulations of plant protection products based on Tebuconazole (TBC) with different delivery systems. As a result of those studies, polysaccharides showed high efficiency in increasing the solubility and the effectiveness of products based on these polymers. An important task in developing an effective seed treatment is to increase the efficiency of adhesion and penetration. However, the question arises as to which factor is more important for plant protection or which factor plays the main role in the activity of the protectants: the amount of dressing agent on the surface of the seed or the amount penetrated into the grain? This question remained unanswered in previous experiments and the purpose of this study was to find an answer to this question. For this purpose, protectants of various compositions based on TBС and polysaccharides were prepared and spring wheat seeds were treated with them. At the same time, these seeds were divided into two variants: seeds treated with protectant (TBС on the surface that managed to penetrate inside the seeds) and seeds whose surface was washed by water and, so, seeds were without sorbed Tebuconazole (TBС only inside the seeds). Thus, seeds were prepared that contained only the Adsorbed tebuconazole (SPrA) and seeds containing the drug that Penetrated into the grain (SPrP). These two types of seeds were used in biological tests and the results obtained were compared. An analysis of seed germination and infection with the main pathogens showed that SPrA seeds had an advantage over SPrP seeds both in germination and in protection from diseases. Further research in this direction will help to understand the effect of the penetration of drugs into plants on the possibility of increasing their efficiency and yield of grain crops.