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1.
This study aimed to investigate the effects of process extrusion on the characteristics of Sargassum cristaefolium sodium alginate (SCSA) extracted using twin-screw extruder. Box-Behnken Design (BBD) from response surface methodology (RSM) was established to understand the effects of temperature, screw speed, and pH on the multiple-responses of alginate characteristics including intrinsic viscosity, yield, and molecular weight. The results revealed that temperature, screw speed, and pH significantly affected ( P < .05) all responses. The optimum extraction condition was found at temperature of 58.18°C, screw speed of 77.99 rpm, and pH 10.11. At this condition, the response of residence time distribution was 7.07 ± 0.029 min, yield of 34.01 ± 0.12%, intrinsic viscosity of 460.13 ± 14.75 mL/g, and molecular weight of 217.94 ± 7.14 × 10 3 g/mol. This alginate had mannuronic acid to guluronic acid (M/G) ratio of 0.28, and the L-guluronic acid block was 0.78, which was higher than the D-mannuronic acid block. Rheological characterization of SCSA in aqueous solution was shear-thinning pseudoplastic, and alginate gel in 1 M CaCl 2 was more elastic than liquid. 相似文献
2.
Eight tropical marine macro algae were investigated for in-vitro antioxidant, antibacterial, and biochemical properties. The moisture content [% DW (dry weight)] ranged from 7.21 to 14.72%; ash, 24.92 to 47.04%; lipids, 0.73 to 2.67%; protein, 4.56 to 12.59%; and carbohydrate, 30.1 to 48.51%. The % sum of polyunsaturated fatty acids (PUFAs) ranged from 21.71 to 78.22%, while omega-6/omega-3 (ω6/ω3) ratio was from 0 to 2.08, which remained within the prescribed World Health Organization (WHO) standards (<10). The % sum of essential amino acids (EAAs) ranged from 86.18 to 204.66, and Na/K ratio ranged from 0.37 to 2.85. The extracts exhibited significant ( P < 0.05) values for total phenol (7.25–16.0 µg PGE mg –1 DW) and total flavonoid (4.06–15.63 µg QE mg –1 DW) at 200 µg/ml. Antibacterial activity was tested against the selected food spoilage and pathogenic bacteria. The principal component analysis (PCA) confirmed a positive correlation between total phenolic content, 1, 1-diphenyl-2-picryl-hydrazyl (DPPH) radical-scavenging activities, and ferric reducing antioxidant power (FRAP), which supports the integration of seaweeds as ingredients in functional foods. 相似文献
3.
ABSTRACTResponse surface methodology was used to investigate the effect of ultrasound-assisted extraction conditions including solvent:seaweed ratio (10:1–30:1), extraction temperature (30–50°C), and extraction time (30–60 min) on the total phenolic compounds and antioxidant activity of red seaweed ( Laurencia obtuse) extracts. The optimum extraction parameters for maximum phenolic content were as follows: solvent:seaweed ratio, 30:1; extraction temperature, 50°C; and extraction time, 42.8 min. The experiment results showed that the solvent:seaweed ratio was the most significant parameter for the extraction. The optimum extraction conditions for maximum antioxidant activity were as follows: solvent:seaweed ratio, 24.3:1; extraction temperature, 45.3°C; and extraction time, 58 min. Under the above-mentioned conditions, the experimental total phenolic content and antioxidant activity value were 26.23 ± 0.75 mg GAE/g seaweed and 120.89 ± 0.81 TEAC, respectively, of seaweed tested, which are well compatible with the predicted contents. 相似文献
4.
Utilization of shrimp head waste from the processing industry offers a solution to environmental pollution and also produces valuable bioactive peptides. The present study was aimed to optimize the alcalase assisted extraction conditions by response surface methodology (RSM) to obtain protein hydrolysates from shrimp ( Metapenaeus dobsoni) head waste with maximum antioxidant activity. Based on the models derived by RSM, the optimized conditions for maximum degree of hydrolysis (DH) were pH 8.2, temperature of 45.4°C, and enzyme/substrate (E/S) of 1.8%. Meanwhile, the optimized conditions for maximum antioxidant activity of protein hydrolysates as measured by 2, 2-diphenyl-1-picrylhydrozyl (DPPH) and ferric reducing antioxidant power (FRAP) assays were pH 8.2 and 8.1, temperatures of 49.7 and 59.4°C, and E/S of 2.1 and 2.7%, respectively. The maximum predicted values for DH, DPPH, and FRAP were 42.44%, 39.64% inhibition, and 8.3 μM Fe (II)/g wet wt. of sample, respectively. The extraction of protein hydrolysates at optimal conditions derived by these models resulted in DH, DPPH, and FRAPs of 40.31%, 38.93%, and 8.21 μM Fe (II)/g of sample, respectively, demonstrating the fitness of the models. The present study demonstrates the potential of Metapenaeus dobsoni head waste as a source of protein hydrolysates with prospective antioxidant activity. 相似文献
5.
Sulfated polysaccharides (SP) from seaweeds exhibit numerous biological activities and are less toxic than conventional antiviral drugs. However, little is known about their mode of action. This study aims at extracting the polysaccharides from brown seaweed Sargassum ilicifolium and then evaluating its antiviral activity against fish Betanodavirus. The extracted SP was characterized through FT-IR, 1H NMR, and thermal gravimetric analysis (TGA). The antiviral activity of SP was tested on SGA cell line by syncytia reduction and the polysaccharide represented a prominent antiviral activity to Betanodavirus by reducing the cytopathic effect (CPE) formation in vitro. The study revealed that SP effectively blocked viral attachment and entry. Moreover, during the in vivo challenge experiment in Gambusia affinis, SP treatment showed a significant decrease in the viral titers. Hence, these results indicate that the polysaccharides obtained from S. ilicifolium exhibited the high antiviral potential to Betanodavirus infection in fishes both in vitro and in vivo. 相似文献
6.
Seven species of cultivated and edible seaweeds found in Southern Taiwan—including Enteromorpha intestinalis, Monostorma nitidum, Ulva lactuca, Dictyopteris undulata, Sargassum hemiphyllum var. chinense, Laurencia intermedia, and Porphyra dentate—were used to determine their antioxidant activity by different extraction methods. All seaweeds were extracted using water at 90°C, sterilization at 121°C, homogenization, or enzymatic hydrolysis. Extracts were evaluated for their free radical-scavenging capacity using 1,1-diphenyl-2-pricrylhydrazyl (DPPH), their reducing power, and their superoxide anion scavenging activity. The DPPH-scavenging capacity of S. hemiphyllum var. chinense extracts produced by sterilization (98.59%), homogenization (94.72%), and carbohydrate-degrading enzyme treatment was higher than that of protease extracts, except for U. lactuca. The reducing power of S. hemiphyllum var. chinense water extracts and M. nitidum Viscozyme extracts was better than that of a commercial antioxidant. S. hemiphyllum var. chinense exhibited higher superoxide anion scavenging activity than the other species. The results demonstrate that different extracts of some of the seaweeds showed remarkable antioxidant activity in different assays. The results also provide important information for the marine food industry and suggest that seaweed might be a valuable source of natural antioxidants. 相似文献
7.
Fish processing by-products may become more than 50% of the starting material. If mismanaged, these large quantities of discarded fish can create serious pollution problems and can also generate cost associated with their disposal. Enzymatic hydrolysis is one of the techniques that is currently being developed in order to recover and add value to these biomolecules. There is an increasing interest in natural antioxidants that are safer for consumers compared with synthetic antioxidants. In this study, common carp by-product was hydrolyzed using the enzymes Alcalase (A) and Protamex (P) to reach degrees of hydrolysis (DH) of 10 and 15%, respectively. Antioxidant capacity against peroxyl radicals (ACAP); 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging; and the measurement of intracellular reactive oxygen species (ROS) concentration after exposure to common carp protein hydrolysates were investigated. The results revealed that the hydrolysate A15 exhibited significantly ( p < 0.05) higher antioxidant activity against the DPPH radical. A15 showed the highest in vitro antioxidant competence against peroxyl radicals, whereas P15 showed the lowest activity against peroxyl radicals ( p < 0.05). Hydrolysates having the highest and the lowest in vitro antioxidant activity (A15 and P15, respectively) were selected for the determination of antioxidant activity in the HT-22 cells system. Measurement of intracellular ROS concentration revealed that P15 at the concentration of 1.25 mg/mL significantly ( p < 0.05) reduced the intracellular ROS concentration. These results showed that common carp by-product protein hydrolysates are a source of antioxidant peptides with a high potential for food and pharmaceutical industries to develop new nutraceuticals and functional foods. 相似文献
8.
Global warming increases seawater temperature, causing high temperature stress to marine organisms, including algae. This study aimed to explore the global proteomic response of Sargassum fusiforme under high temperature stress. Sargassum fusiforme seedlings were cultured in natural seawater for 24 hr and subjected to different temperatures (22°C, control group; 27°C and 32°C, high temperature stress group) for 1, 3, 5 and 7 days. Changes in their membrane lipid peroxidation after high temperature stress were investigated. Proteomic changes in the air bladders of S. fusiforme were analysed using isobaric tags for relative and absolute quantification, along with liquid chromatography–tandem mass spectrometry. Data were analysed using bioinformatics methods. Results showed that high temperature stress destroyed the cell membrane of the air bladders. Further, 28 and 53 differentially expressed proteins (DEPs) were found in the 27°C and 32°C treatment groups respectively. These DEPs were mainly involved in glycolysis, single‐organism catabolism, purine nucleoside diphosphate metabolism and carbohydrate catabolism. In addition, DEPs were significantly enriched in 10 pathways, such as glycolytic process, biosynthesis of antibiotics, ribosome, biosynthesis of secondary metabolites and biosynthesis of amino acids. Proteomics analyses indicated that proteins associated with synthesis, folding, degradation, photosynthesis and energy and carbohydrate metabolism are differentially expressed under high temperature stress and normal conditions. 相似文献
9.
Among 51 marine algae distributed along the Korean coast, Sargassum muticum (Yendo) Fensholt, Ishige okamurae Yendo, Ecklonia cava Kjellman, Polysiphonia morrowii Harvey, Dictyopteris undulata Holmes, Sargassm micracanthum (Kutzing) Endlicher, and Sargassum macrocarpum C. Agarch were found to have potent antioxidant activity. Additionally, the reducing power of marine algae-extracts was consistent with diphenyl-1-picryl hydrazyl (DPPH) radical scavenging activity. Because little is known about Sargassum muticum (Yendo) Fensholt, Ishige okamurae Yendo, Ecklonia cava Kjellman, Polysiphonia morrowii Harvey, Dictyopteris undulata Holmes, Sargassm micracanthum (Kutzing) Endlicher, and Sargassum macrocarpum C. Agarch, these marine algae may act as candidates for potent antioxidant food materials and are expected to have functional activity for foods and pharmaceuticals for treating oxidative diseases. 相似文献
10.
对鼠尾藻有性繁育规律进行观察、研究。鼠尾藻雌、雄异株,在黄海北部其生殖季节是7月上中旬,高光照和升温可促进精卵成熟,鼠尾藻在海区和室内都可正常完成受精。干露1~2h能促进幼孢子体生长,幼孢子体在实验范围的光照强度(1000~4000lx)下,光照越强生长越快;在试验盐度(21~40)范围内均可正常生长。在此基础上建立起了鼠尾藻人工苗种繁育技术,并对鼠尾藻有性繁育技术中存在的问题及今后研究的方向进行了分析。 相似文献
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