Periaswamy Sivagnanam Saravana

Structural, antioxidant, and emulsifying activities of fucoidan from Saccharina japonica using pressurized liquid extraction

Pressurized liquid extraction (PLE) was utilized to extract sulfated polysaccharides (fucoidan) from brown seaweed Saccharina japonica. Various conditions of temperature (80-200°C), pressure (5-100bar), and solvents (water, 0.1% sodium hydroxide, 0.1% formic acid, 70% ethanol, 50% ethanol, and 25% ethanol) were assessed; the best crude fucoidan (CF) yield was 8.23%, obtained from 140°C and 50bar (sodium hydroxide). Compositional analysis, FT-IR, molecular weight, monosaccharides, TGA, UV-vis, XRD, and elemental analysis confirm that extracted polysaccharides revealed the features of fucoidan. Fucose was the main monosaccharide present in CF obtained by various solvent systems. All CF showed antioxidant activities as measured by DPPH radical and ABTS(+) radical scavenging. CF demonstrates good emulsion-stabilizing capacities, especially with vegetable oils. This study demonstrates that PLE is an efficacious method for enhancing the yield of polysaccharides from S. japonica and that it could be a potential source of natural antioxidants and emulsifiers.

Effects of process parameters on EPA and DHA concentrate production from Atlantic salmon by-product oil: Optimization and characterization

Supercritical carbon dioxide (SC-CO2) extracted Atlantic salmon frame bone oil (SFBO) was used for Eicosapentaenoic acid and Docosahexaenoic acid (EPA-DHA) concentrate production by urea complexation. Urea/fatty acids (2.5 to 4.0 w/w), crystallization temperature (−24 to −8 °C) and crystallization time (8 to 24 h) were studied by Box-Behnken Design (BBD) to maximize EPA-DHA content. Highest EPA-DHA content was 60.63% at urea/fatty acids 4.0 w/w, crystallization temperature −15.67 °C and crystallization time 8 h. EPA-DHA concentrate showed improvement of EPA-DHA from 6.39% in SFBO to 62.34%, increase of astaxanthin content from 21.33 μg/g in SFBO to 44.69 μg/g in EPA-DHA concentrate, no residual urea and reduction of many off-flavor compounds. The EPA-DHA yield showed an inverse relation with the urea/fatty acids, whereas its concentration increased proportionally with urea/fatty acids. Therefore, EPA-DHA concentrate produced from SFBO by urea complexation may be an efficient technique to provide ω-3 polyunsaturated fatty acids to the consumers.

Deep eutectic solvent-based extraction and fabrication of chitin films from crustacean waste

In this study, chitin was exclusively extracted from shrimp shells (Marsupenaeus japonicas) through a green solvent called deep eutectic solvent (DES), and various types of DES were utilized to extract chitin. The physicochemical properties of the obtained chitin were compared with the conventional method. A high purity of chitin was obtained while using DES-8 (choline chloride-malonic acid) with a yield of 19.41% ± 1.35%, and purity was confirmed using 13C nuclear magnetic resonance. The DES-produced chitin was utilized to produce chitin films and was compared with standard chitin films. The obtained films were characterized by SEM, AFM, TGA, DSC, FTIR, mechanical properties, moisture sorption, swelling behavior, and biodegradation. The DES film showed similar properties to the standard film, while the mechanical properties, swelling behavior, and biodegradation of the DES chitin films proved to be similar to standard chitin film. These chitin films can be used as wound healing resources.

Omega-3 fatty acids concentrate production by enzyme-catalyzed ethanolysis of supercritical CO 2 extracted oyster oil

The separation of oil by a suitable technique from the Pacific oyster muscle is important for the utilization of the oil as a ω-3 polyunsaturated fatty acids (ω-3 PUFAs) source and production of bio-functional peptides/ oligosaccharides from oil-free residue. This study was conducted to prepare ω-3 PUFAs concentrate from supercritical carbon dioxide (SC-CO2) extracted Pacific oyster oil by enzyme-catalyzed ethanolysis reactions. SC-CO2 extractions were done at different temperatures and pressures to optimize suitable extraction conditions and extracted oils were compared with Soxhlet (n-hexane) extracted oil to evaluate the yield and quality. Oil extracted by SC-CO2 at optimized conditions was used for ethanolysis reaction catalyzed by immobilized sn-1,3 specific lipases, namely Novozymes-435, Lipozyme TLIM, and Lipozyme RMIM to produce 2-monoacylglycerols (2-MAG) rich in ω-3 PUFAs. The optimum temperature and pressure for SC-CO2 extractions of oyster oil was 50°C and 30 MPa. In this condition, the yield of oil was 5.96% and the acid, peroxide, free fatty acid, and p-anisidine values were 4.49 mg KOH/g, 4.72 meq/kg, 3.42%, and 10.03, respectively. The ω-3 PUFAs content significantly increased in 2-MAG obtained from Novozymes 435, Lipozyme TLIM, and Lipozyme RMIM to 43.03 ± 0.36, 45.95 ± 0.29, and 40.50 ± 0.77%, respectively (p < 0.05). A thin layer chromatography (TLC) analysis confirmed the production and separation of 2-MAG in the ethanolysis process. The ratio of total ω-3 to ω-6 fatty acids was almost twice in 2-MAG of SC-CO2 extracted oyster oil. SC-CO2 extracted Pacific oyster oil can be used for sn-1,3 specific lipases catalyzed ethanolysis to produce ω-3 PUFAs rich in 2-MAG.

Fabrication of multifunctional chitosan-based nanocomposite film with rapid healing and antibacterial effect for wound management

A nanocomposite film, chitosan (CS)-polyvinylpyrrolidone (PVP)-bentonite (BN) was fabricated to enhance wound healing processes as a new nanoplatform for wound dressing. Both physical properties and antibacterial activity of the proposed film were examined to validate its applicability and inhibitory effect for wound management. In vitro cytotoxicity was evaluated by using MTT assay on L929 and NIH3T3 cells to identify the toxicity level of the film. In vivo wound healing test assessed the wound healing performance in animal models. The results confirmed a strong interaction between surface functional groups among CS, PVP and BN with suitable surface morphology and high thermal stability. The CS-PVP-BN film improved various material features such as including mechanical property, tensile strength, pH and porosity, inhibitory activity on bacterial organisms, and collagen deposition. The animal study confirmed that the fabricated film yielded a rapid healing rate of 97%, less scarring, thick granulation at the 11th day, regeneration of epidermis at the 16th day, and abundant deposition of collagen and fibroblast, compared with control. The non-toxic nanocomposite film can be a promising antibacterial wound dressing with rapid wound healing effects in wound care management.

Hydrothermal degradation of seaweed polysaccharide: Characterization and biological activities

Fucoidan is a marine sulfated polysaccharide that possesses various biological activities. To enhance the functional properties of fucoidan, it was depolymerized using a green technique viz. subcritical water treatment (SCW) to produce a low molecular weight fucoidan. In this study, response surface methodology (RSM) was used to study the influence of different influences for instance temperature, pressure, liquid to solid ratio, and agitation speed to depolymerize fucoidan. RSM was used to focus on the antioxidant activity and chemical composition of SCW-treated fucoidan. Further, resulting SCW-treated fucoidan was investigated by UV-Vis, FT-IR, Thermal gravimetric analysis (TGA), DSC, Elemental analysis, and ESI-MS. Moreover, the optimized SCW-treated fucoidan was checked for cytotoxicity, antimicrobial, antidiabetic, and anticoagulant activity compared with the untreated fucoidan. The obtained values displayed that SCW treatment breakdowns polymer chain and so it produces low molecular weight fucoidan. Biological activities were improved as the molecular weight was reduced.

Astaxanthin-alpha tocopherol nanoemulsion formulation by emulsification methods: Investigation on anticancer, wound healing, and antibacterial effects

Emulsion-based delivery systems have been fabricated and developed to increase the bioavailability of astaxanthin and alpha-tocopherol as active compounds for various biomedical applications. Astaxanthin-alpha tocopherol nanoemulsion (ATNE) is well known for its potential 6.-6.30 effect. The current study investigated ATNE by spontaneous (SENE) and ultrasonication emulsification (USNE) methods to optimally fabricate oil/water nanoemulsion characterized for biomedical applications. The two methods were compared by using a response surface method of 3-level Box-Behnken design (BBD) with significant factors. Transmission electron microscopy (TEM) confirmed spherical-shaped nanoemulsion from SENE and USNE methods and dynamic light scattering (DLS) proved the good stability of the fabricated nanoemulsion. Cytotoxicity studies on three different cancer cells confirmed that the nanoemulsion at higher concentrations was more toxic than one at lower concentrations by accompanying a significant decrease in the cellular viability after 24 and 48 h of exposure. The wound-healing potential using scratch assay evidenced faster healing effect of the nanoemulsion. Both minimal inhibitory concentration (MIC) and minimum bactericidal concentrations (MBC) methods confirmed significant antibacterial activity to disrupt the integrity of the bacterial cell membrane. The current results suggested that ATNE act as effectively targeted drug delivery vehicles in the future for cancer treatment applications due to its significant results of anticancer, wound healing, and antimicrobial effects.

Seaweed Polysaccharide Isolation Using Subcritical Water Hydrolysis

Abstract Seaweed contains several important polysaccharides. The major polysaccharides are agar, carrageenan, and alginates, while the minor polysaccharides comprise of fucose, cellulose, laminarin, floridean, and xylan. To obtain these compounds with the principle of green chemistry, subcritical water extraction (SWE) is the most promising technique. SWE of biomass presents several advantages as compared with traditional technologies (acid, alkali, and enzymatic hydrolysis). Its main advantage is that, it does not use solvents, which is a factor of major importance in any process. In the current chapter, the extraction and characterization of polysaccharides from seaweeds using SWE are discussed.