Atlantic salmon (Salmo salar) waste as a unique source of biofunctional protein hydrolysates: Emerging productions, promising applications, and challenges mitigation.

The Atlantic salmon is an extremely popular fish for its nutritional value and unique taste among several fish species. Researchers are focusing on the utilization of Atlantic salmon waste for generating protein hydrolysates rich in peptides and amino acids and investigating their health benefits. Several technological approaches, including enzymatic, chemical, and the recently developed subcritical water hydrolysis, are currently used for the production of Atlantic salmon waste protein hydrolysates. Hydrolyzing various wastes, e.g., heads, bones, skin, viscera, and trimmings, possessing antioxidant, blood pressure regulatory, antidiabetic, and anti-inflammatory properties, resulting in applications in human foods and nutraceuticals, animal farming, pharmaceuticals, cell culture, and cosmetics industries. Furthermore, future applications, constraints several challenges associated with industrial hydrolysate production, including sensory, safety, and economic constraints, which could be overcome by suggested techno processing measures. Further studies are recommended for developing large-scale, commercially viable production methods, focusing on eradicating sensory constraints and facilitating large-scale application.

Subcritical Water Extraction of Undaria pinnatifida: Comparative Study of the Chemical Properties and Biological Activities across Different Parts.

The subcritical water extraction of Undaria pinnatifida (blade, sporophyll, and root) was evaluated to determine its chemical properties and biological activities. The extraction was conducted at 180 °C and 3 MPa. Root extracts exhibited the highest phenolic content (43.32 ± 0.19 mg phloroglucinol/g) and flavonoid content (31.54 ± 1.63 mg quercetin/g). Sporophyll extracts had the highest total sugar, reducing sugar, and protein content, with 97.35 ± 4.23 mg glucose/g, 56.44 ± 3.10 mg glucose/g, and 84.93 ± 2.82 mg bovine serum albumin (BSA)/g, respectively. The sporophyll contained the highest fucose (41.99%) and mannose (10.37%), whereas the blade had the highest galactose (48.57%) and glucose (17.27%) content. Sporophyll had the highest sulfate content (7.76%). Key compounds included sorbitol, glycerol, L-fucose, and palmitic acid. Root extracts contained the highest antioxidant activity, with IC50 values of 1.51 mg/mL (DPPH), 3.31 mg/mL (ABTS+), and 2.23 mg/mL (FRAP). The root extract exhibited significant α-glucosidase inhibitory activity with an IC50 of 5.07 mg/mL, indicating strong antidiabetic potential. The blade extract showed notable antihypertensive activity with an IC50 of 0.62 mg/mL. Hence, subcritical water extraction to obtain bioactive compounds from U. pinnatifida, supporting their use in functional foods, cosmetics, and pharmaceuticals is highlighted. This study uniquely demonstrates the variation in bioactive compound composition and bioactivities across different parts of U. pinnatifida, providing deeper insights. Significant correlations between chemical properties and biological activities emphasize the use of U. pinnatifida extracts for chronic conditions.

Protein and Polysaccharide Recovery from Shrimp Wastes by Natural Deep Eutectic Solvent Mediated Subcritical Water Hydrolysis for Biodegradable Film.

Environmental pollution is a significant problem due to the improper disposal of plastics and shrimp shells outdoors. Therefore, the synthesis of biodegradable film from waste materials is highly important. The novelty of this research lies in the extraction of protein hydrolysates and chitosan from shrimp shells, as well as the fabrication of biodegradable film from these materials. In this study, the composite films were produced using the solution casting method. Moreover, the combined effect of ultrasound pretreatments (UPT) and natural deep eutectic solvents (NADES) was investigated as extraction media, to determine their potential impact on shrimp waste subcritical water hydrolysis (SWH). Shrimp shells were submitted to UPT in NADES solution, followed by SWH at different temperatures ranging from 150 to 230 °C under 3 MPa for 20 min. Then, the physiochemical properties and bioactivities of the hydrolysates were assessed to determine their suitability for use in biodegradable packaging films. Additionally, the physiochemical properties and bioactivities of the resulting hydrolysates were also analyzed. The highest amount of protein (391.96 ± 0.48 mg BSA/g) was obtained at 190 °C/UPT/NADES, and the average molecular size of the protein molecules was less than 1000 Da with different kinds of peptide. Overall, combined UPT and SWH treatments yielded higher antioxidant activity levels than individual treatments. Finally, the application of composite films was evaluated by wrapping fish samples and assessing their lipid oxidation. The use of higher concentrations of protein hydrolysates significantly delayed changes in the samples, thereby demonstrating the film's applicability.

Subcritical water-assisted fish gelatin hydrolysis for astaxanthin-loaded fish oil emulsion stability.

Though gelatin emulsifying properties have been intensively studied, how low-molecular-weight (LMW) fish gelatin affects astaxanthin (AST)-loaded fish oil emulsion stability remains elusive. In this study, subcritical water hydrolysis (SWH)-modified LMW fish gelatin (SWHG) was produced from 110 °C to 180 °C and used to enhance the AST steadiness in oil/water emulsions in the presence of an emulsifier, lecithin. In the prepared emulsions, the surface charge increased while droplet size decreased with the decrease in gelatin MW due to the reduced thickness of the adsorbed gelatin membrane. LMW gelatin and lecithin could form a firm-absorbed layer on the droplet surface by electrostatic interaction between amide groups of gelatin molecules and phosphate groups of lecithin, thus stabilizing the emulsions. SWHG improved the creaming stability of the emulsions and hindered the oxygen- and light-induced AST degradation for 11 months compared to high MW gelatin. Whereas, the control emulsion showed noticeable phase separation after two weeks of storage. These findings prove the advantage of the SWH approach and propose the use of SWHG in oil-in-water emulsions for AST stabilization.

Optimization and evaluation of Atrina pectinata polysaccharides recovered by subcritical water extraction: A promising path to natural products.

In this study, the recovery of Atrina pectinata posterior adductor polysaccharides (APP-PS) using subcritical water extraction (SWE) was optimized by response surface methodology (RSM) and the physicochemical and biological properties of the recovered APP-PS were evaluated. The optimal extraction conditions, which resulted in a maximum yield of 55.58 ± 1.12 %, were temperature, 152.08 °C; extraction time, 10 min; solid-liquid ratio, 30 g/600 mL. The obtained APP-PS was found to be 88.05 ± 0.17 % total sugar. Fourier transform infrared (FT-IR) and Nuclear magnetic resonance (NMR) analyses confirmed the presence of the α-coordination of D-glucan in the polymer sample. The analysis of monosaccharide composition, along with thermogravimetric analysis, revealed the typical structure of the sample, composed of glucose alone. Total phenolic contents of APP-PS were measured as 5.47 ± 0.01 mg Gallic acid/g of dry sample and total flavonoids contents were determined to be 0.78 ± 0.06 mg Quercetin/g of dry sample. For biological activities, ABTS+, DPPH and FRAP antioxidant activities were measured to be 20.00 ± 0.71, 2.35 ± 0.05 and 4.02 ± 0.07 µg Trolox equivalent/100 g of dry sample, respectively. Additionally ACE inhibitory was confirmed to be 87.02 ± 0.47 %. These results showed that SWE is an effective method to recover biofunctional materials from marine organisms.

Trash to Treasure: An Up-to-Date Understanding of the Valorization of Seafood By-Products, Targeting the Major Bioactive Compounds.

Fishery production is exponentially growing, and its by-products negatively impact industries' economic and environmental status. The large amount of bioactive micro- and macromolecules in fishery by-products, including lipids, proteins, peptides, amino acids, vitamins, carotenoids, enzymes, collagen, gelatin, chitin, chitosan, and fucoidan, need to be utilized through effective strategies and proper management. Due to the bioactive and healthy compounds in fishery discards, these components can be used as functional food ingredients. Fishery discards have inorganic or organic value to add to or implement in various sectors (such as the agriculture, medical, and pharmaceutical industries). However, the best use of these postharvest raw materials for human welfare remains unelucidated in the scientific community. This review article describes the most useful techniques and methods, such as obtaining proteins and peptides, fatty acids, enzymes, minerals, and carotenoids, as well as collagen, gelatin, and polysaccharides such as chitin-chitosan and fucoidan, to ensure the best use of fishery discards. Marine-derived bioactive compounds have biological activities, such as antioxidant, anticancer, antidiabetic, anti-inflammatory, and antimicrobial activities. These high-value compounds are used in various industrial sectors, such as the food and cosmetic industries, owing to their unique functional and characteristic structures. This study aimed to determine the gap between misused fishery discards and their effects on the environment and create awareness for the complete valorization of fishery discards, targeting a sustainable world.

Exploring Bioactive Compounds in Brown Seaweeds Using Subcritical Water: A Comprehensive Analysis.

In this study, we characterized the bioactive properties of three important brown seaweed species, Sargassum thunbergii, Undaria pinnatifida, and Saccharina japonica, by subcritical water extraction (SWE), as these species are well known for their beneficial health effects. Their physiochemical properties, including potential antioxidant, antihypertensive, and α-glucosidase inhibitory activity, and the antibacterial activity of the hydroysates were also analyzed. The highest total phlorotannin, total sugar content, and reducing sugar content in the S. thunbergii hydrolysates were 38.82 ± 0.17 mg PGE/g, 116.66 ± 0.19 mg glucose/g dry sample, and 53.27 ± 1.57 mg glucose/g dry sample, respectively. The highest ABTS+ and DPPH antioxidant activities were obtained in the S. japonica hydrolysates (124.77 ± 2.47 and 46.35 ± 0.01 mg Trolox equivalent/g, respectively) and the highest FRAP activity was obtained in the S. thunbergii hydrolysates (34.47 ± 0.49 mg Trolox equivalent/g seaweed). In addition, the seaweed extracts showed antihypertensive (≤59.77 ± 0.14%) and α-glucosidase inhibitory activity (≤68.05 ± 1.15%), as well as activity against foodborne pathogens. The present findings provide evidence of the biological activity of brown seaweed extracts for potential application in the food, pharmaceutical, and cosmetic sectors.

In Vitro Biodegradation, Drug Absorption, and Physical Properties of Gelatin-Fucoidan Microspheres Made of Subcritical-Water-Modified Fish Gelatin.

This study aimed to prepare gelatin-fucoidan microspheres with enhanced doxorubicin binding efficiency and controllable biodegradation using fish gelatin combined with low molecular weight (LMW) gelatin and fucoidan at fixed ratios. The MW of gelatin was modified by subcritical water (SW), which is known as a safe solvent, at 120 °C, 140 °C, and 160 °C. In addition, gelatin-fucoidan microspheres were prepared using a solvent exchange technique. Our findings revealed that particle size decreased, the surface was rougher, the swelling ratio increased, and particle shape was irregular in microspheres composed of SW-modified gelatin. Doxorubicin binding efficiency was improved by fucoidan and SW-modified gelatin at 120 °C but not at 140 °C and 160 °C. Interestingly, an increase in in vitro enzymatic degradation was observed in the microspheres consisting of SW-modified fish gelatin, although the cross-linking degree between them was not significantly different. This is because LMW gelatin could form more cross-linked bonds, which might be weaker than the intramolecular bonds of gelatin molecules. Gelatin-fucoidan microspheres consisting of SW-modified fish gelatin with controlled biodegradation rates could be a candidate for a short-term transient embolization agent. In addition, SW would be a promising method to modify the MW of gelatin for medical applications.

Development of fish gelatin/carrageenan/zein bio-nanocomposite active-films incorporated with turmeric essential oil and their application in chicken meat preservation.

Gelatin/carrageenan (Ge/Car) active packaging films incorporated with turmeric essential oil (TEO) encapsulated in zein nanoparticles (ZNP) were developed. The efficacy of these active packaging films and their antimicrobial properties were also investigated to ensure their practical application. Three different types of nanocomposite films (Ge/Car, Ge/Car/TEO, and Ge/Car/ZNP) were prepared. The characterization of the films was elucidated using Fourier transform infrared (FTIR), X-ray diffraction analyses (XRD), and scanning electron microscope (SEM). Physicochemical and mechanical properties of the films were enhanced, owing to the application of TEO-containing nanocomposites. Supercritical-CO2 extracted TEO showed excellent biological activities, alongside GC-MS analysis identified that TEO contained 33 bioactive compounds where the major constituent was Zingiberene. ZNP proved an excellent carrier of TEO. The nanocomposite film sustainably released TEO, improving the shelf life of the chicken meat by reducing bacterial colonies from 3.08 log CFU/g to 2.81 log CFU/g after 14 days incubation against Salmonella enterica compared with 6.66 log CFU/g observed in the control film. The overall results of this study suggest that the nanocomposite active film is an excellent candidate for food packaging to ensure a better world.

Cellulose nanofibrils reinforced chitosan-gelatin based hydrogel loaded with nanoemulsion of oregano essential oil for diabetic wound healing assisted by low level laser therapy.

Diabetic foot ulcers are imperfections in the process of wound healing due to hyperglycemic conditions. Here, a nanoemulgel fabricated with oregano essential oil nanoemulsion, assisted by low-level laser therapy, was investigated for its efficacy in diabetic wound healing. A hydrogel- based healing patch, fabricated using biological polymers namely chitosan and gelatin and, polyvinyl pyrollidone. The hydrogel was reinforced with cellulose nanofibrils for enhanced stability and barrier properties. Nanoemulsion of oregano essential oil, with an average particle size of 293.7 ± 8.3 nm, was prepared via homogenization with chitosan as the coating agent. Nanoemulsion impregnated hydrogel, termed as the nanoemulgel, was assessed for its physio-mechanical properties and healing efficiency. The strong linkages in nanoemulgel demonstrated its large swelling capacity, high mechanical strength, and maximum thermal stability. The optimized conditions for low-level laser therapy using 808 nm were 1 W. cm-2 and 5 min. The optimized drug concentration of 128 µg. mL-1 exhibited viability of NIH/3 T3 fibroblasts as 75.5 ± 1.2 % after 24 h. Cell migration assay demonstrated that dual therapy facilitated wound healing, with a maximum closure rate of 100 % at 48 h. In vivo results revealed the rapid healing effects of the dual therapy in diabetic rat models with foot ulcers: a maximum healing rate of 97.5 %, minimum scar formation, increased granulation, enhanced reepithelialization, and a drastic decrease in inflammation and neutrophil infiltration within the treatment period compared to monotherapy and control. In summary, the combinatorial therapy of nanoemulgel and low-level laser therapy is a promising regimen for managing diabetic foot ulcers with a rapid healing effect.

Anticancer and apoptotic activity in neuroblastoma SK-N-SH using phospholipid extract from bone of Scomberomorus niphonius.

Among various types children's health challenges, neuroblastoma is the most serious solid neoplasm forming outside the cranium. Scomberomorus niphonius is a valuable edible fish that has been widely used for a meal. In this study, we obtained phospholipid extract from the bone of S. niphonius with the supercritical CO2 extraction method and tested anticancer activity with a cell viability assay. The phospholipid showed anticancer activity on neuroblastoma SK-N-SH cells, and the anticancer activity was presented with an IC50 of 710.25 ± 28.31 µg/ml, but did not show a significant toxicity on HUVEC cell lines. Western blot was used to detect signaling proteins; Bak, caspase-9, caspase-8, caspase-3, Bax, and IκBα were increased, whereas IKKß and NFκB were downregulated in experimental groups compared to untreated groups. Gene expression was revealed by RT-qPCR, and the fold ratio of Apaf-1, cytochrome-c, caspase-9, caspase-3, and Bax genes' expression was raised in treated groups, implying apoptosis. Gel electrophoresis revealed that the experimental groups had more fragmented DNA than the control group. The study shows that a phospholipid extract from S. niphonius' bone could be used as a biological origin of anticancer activity in neuroblastoma SK-N-SH cells.

Facile synthesis of black phosphorus-zinc oxide nanohybrids for antibacterial coating of titanium surface.

Bacterial infection is a major complication associated with bioimplant materials, including titanium (Ti) based orthopedic joints and dental implants. Thus, the fabrication of Ti surfaces with antibacterial activity is highly important. Black phosphorus (BP) is a recently discovered promising two-dimensional semiconductor for various biomedical applications due to its tunable bandgap and physicochemical properties. The present study aimed to synthesize zinc oxide (ZnO) laden BP nanohybrids (NH) and their coatings on a Ti bioimplant surface for improving the antibacterial activities against pathogenic bacteria with and without near-infrared (NIR) light irradiation. Nanohybrids were produced with the slightly oxidized BP NF and electrostatically laden ZnO NP. The produced BP-ZnO NH was a NIR active nanomaterial (up to ∼1000 nm), demonstrating a photothermal effect against bacterial infection and showing improved activity by damaging the cell membrane towards S. aureus in comparison to E. coli. Ti surface coated with BP-ZnO NH embedded chitosan (CS) demonstrated better antibacterial activity than BP NF, especially with NIR light treatment. Additionally, the produced BP nanoflakes and BP-ZnO NH, and their coatings over the Ti surface were found to be toxic at a negligible level. Electrochemical studies revealed the high corrosion resistance of the Ti surface coated with the synthesized antibacterial agents without altering its characteristic passive behavior. Owing to the interactions between the charged groups between chitosan and cell surfaces, a slight increase in antibacterial activities was noticed. Chitosan-based coating matrix embedded with nanoagents has adhered well over the Ti surface due to its inherent film-forming and high adhesion properties.

Anticancer and Apoptotic Activity in Cervical Adenocarcinoma HeLa Using Crude Extract of Ganoderma applanatum.

Cancer is currently one of the foremost health challenges and a leading cause of death worldwide. Cervical cancer is caused by cofactors, including oral contraceptive use, smoking, multiparity, and HIV infection. One of the major and considerable etiologies is the persistent infection of the oncogenic human papilloma virus. G. applanatum is a valuable medicinal mushroom that has been widely used as a folk medicine for the treatment and prevention of various diseases. In this study, we obtained crude extract from G. applanatum mushroom with a subcritical water extraction method; cell viability assay was carried out and the crude extract showed an antiproliferative effect in HeLa cells with IC50 of 1.55 ± 0.01 mg/mL; however, it did not show any sign of toxicity in HaCaT. Protein expression was detected by Western blot, stability of IκBα and downregulation of NFκB, IKKα, IKKß, p-NFκB-65(Ser 536) and p-IKKα/ß(Ser 176/180), suggesting loss of survival in a dose-dependent manner. RT-qPCR revealed RNA/mRNA expression; fold changes of gene expression in Apaf-1, caspase-3, cytochrome-c, caspase-9, Bax and Bak were increased, which implies apoptosis, and NFκB was decreased in a dose-dependent manner. DNA fragmentation was seen in the treatment groups as compared to the control group using gel electrophoresis. Identification and quantification of compounds were carried out by GC-MS and HPLC, respectively; 2(5H)furanone with IC50 of 1.99 ± 0.01 µg/mL could be the responsible anticancer compound. In conclusion, these findings suggest the potential use of the crude extract of G. applanatum as a natural source with anticancer activity against cervical cancer.

Subcritical Water Hydrolysis of Comb Pen Shell (Atrina pectinata) Edible Parts to Produce High-Value Amino Acid Products.

Artina pectinata (Comb pen shell, CPS) is a high-protein source that contains a variety of essential amino acids. Subcritical water hydrolysis (SWH) was used to recover amino acids from the posterior adductor muscle (PAM), anterior adductor muscle (ADM), and mantle. The temperatures ranged from 120 °C to 200 °C, and the pressure and time of hydrolysis were 3 MPa and 30 min, respectively. Further characterization of the hydrolysates was performed to ascertain amino acid profiles and biofunctional properties. The hydrolysates contained more free amino acids than the untreated samples. Antioxidant activity of treated samples increased as SW temperatures increased. At 200 °C, those inhibiting ACE had a maximum antihypertensive activity of 200 °C in 1% PAM, ADM, and mantle with 85.85 ± 0.67, 84.55 ± 0.18, and 82.15 ± 0.85%, respectively, compared to 97.57 ± 0.67% in 1% standard captopril. Perhaps the most significant finding was the predominance of taurine in the three parts following SW treatment at 120 °C. The hydrolysates may be of considerable interest for use in food or energy drinks. SWH demonstrates efficacy in recovering amino acids, particularly taurine, from edible parts of A. pectinata.

Extraction of edible oils and amino acids from eel by-products using clean compressed solvents: An approach of complete valorization.

Green extraction methodologies using supercritical carbon dioxide (SC-CO2) and subcritical water were used to valorize Conger myriaster skin (CMS). The omega-3 fatty acid content in CMS oil extracted using SC-CO2 was 18.62 ± 0.08%, and vitamin A, D, E, and K2 contents were 467.38 ± 0.46 µg/100 g, 8.31 ± 0.02 mg/100 g, 143.42 ± 4.61 mg/100 g, and 1.27 ± 0.05 mg/100 g, respectively. De-oiled CMS was hydrolyzed using subcritical water at temperatures ranging from 160 to 280 °C. Total protein, total sugar, and Maillard reaction product contents reached maximum values of 409.31 ± 2.86 mg bovine serum albumin (BSA)/g at 190 °C, 8.31 ± 0.31 mg glucose/g at 280 °C, and 0.240 ± 0.003 (Abs420nm) at 220 °C, respectively. The highest antioxidant activity was observed at 280 °C. Free amino acids were abundant in the hydrolysates. Oil extraction from CMS using supercritical and subcritical fluids represents an effective and economical source of functional materials.

Fabrication of chitosan-based food packaging film impregnated with turmeric essential oil (TEO)-loaded magnetic-silica nanocomposites for surimi preservation.

Successful modification of chitosan (CS) film using magnetic-silica nanocomposite to encapsulate turmeric essential oil (TEO) obtained by super critical CO2 extraction for enhanced preservation of surimi was performed. TEO exhibited antioxidant and antibacterial activities against Bacillus cereus. The core magnetic nanoparticles (MNPs) were capped with porous silica (Si) to form core-shell nanocomposites, into which TEO was loaded with 75.24% encapsulation efficiency. The fabricated nanocomposite was characterized, blended with CS to cast a bionanocomposite active film and characterized for efficient impregnation of bionanocomposite. The physical and mechanical properties of film were significantly improved after adding MNPs/Si/TEO nanocomposite. Uncontrolled release of TEO from CS film resulted in bacterial growth after 6 days of storage whereas bionanocomposites exhibited a sustained release of TEO that controlled the microbial load from 4.0 log CFU/g to 2.78 log CFU/g over 14 days. The overall study demonstrated that the CS/MNPs/Si/TEO bionanocomposite film was efficient as a packaging material for prolonged shelf-life of surimi.

Lipid Indexes and Quality Evaluation of Omega-3 Rich Oil from the Waste of Japanese Spanish Mackerel Extracted by Supercritical CO2.

Japanese Spanish mackerel (JSM) (Scomberomorus niphonius) is a marine fish species containing health-beneficial polyunsaturated fatty acids (PUFAs). In the present study, the quality of JSM by-products oils extracted by supercritical CO2 (SC-CO2) and organic solvent extraction was compared in terms of physico-chemical properties of the oils. Eicosapentaenoic acid (EPA) is one of the important polyunsaturated fatty acids present in SC-CO2-extracted skin and muscle oil 5.81 ± 0.69% and 4.93 ± 0.06%, respectively. The amount of docosahexaenoic acid (DHA) in SC-CO2-extracted skin and muscle oil was 12.56 ± 0.38% and 15.01 ± 0.28%, respectively. EPA and DHA are considered as important PUFAs for the development of brain function and the prevention of coronary heart diseases. Extracted oils showed considerable antioxidant activity. In the obtained oils, atherogenic index (AI) values varied from 0.72 to 0.93 and thrombogenic index (TI) ranged from 0.75 to 0.92, which is considered an acceptable level. Fatty acid composition, bio potentiality, thermogravimetric, and vitamin D analysis showed that oils extracted from JSM by-products can be a good source of oil for application in food, pharmaceutical and cosmetic industries. Therefore, the present research revealed the potentiality of green valorisation of S. niphonius by-products as a possible sustainable approach for targeting the era of zero waste.

Opto-chemical treatment for enhanced high-level disinfection of mature bacterial biofilm in a Teflon-based endoscope model.

Medical societies and public health agencies rigorously emphasize the importance of adequate disinfection of flexible endoscopes. The aim of this work was to propose a novel opto-chemical disinfection treatment against Staphylococcus aureus grown in mature biofilm on Teflon-based endoscope channel models. Laser irradiation using near-infrared and blue wavelengths combined with a low concentration of chemical disinfectant induced both irreversible thermal denaturation and intercellular oxidative stress as a combined mechanism for an augmented antimicrobial effect. The opto-chemical method yielded a 6.7-log10 reduction of the mature Staphylococcus aureus biofilms (i.e., approximately 1.0-log10 higher than current requirement of standard treatment). The proposed technique may be a feasible disinfection method for mitigating the risk associated with infection transmission.

Nutritional Value and Biofunctionalities of Two Edible Green Seaweeds (Ulva lactuca and Caulerpa racemosa) from Indonesia by Subcritical Water Hydrolysis.

Caulerpa racemosa (sea grapes) and Ulva lactuca (sea lettuces) are edible green seaweeds and good sources of bioactive compounds for future foods, nutraceuticals and cosmeceutical industries. In the present study, we determined nutritional values and investigated the recovery of bioactive compounds from C. racemosa and U. lactuca using hot water extraction (HWE) and subcritical water extraction (SWE) at different extraction temperatures (110 to 230 °C). Besides significantly higher extraction yield, SWE processes also give higher protein, sugar, total phenolic (TPC), saponin (TSC), flavonoid contents (TFC) and antioxidant activities as compared to the conventional HWE process. When SWE process was applied, the highest TPC, TSC and TFC values were obtained from U. lactuca hydrolyzed at reaction temperature 230 °C with the value of 39.82 ± 0.32 GAE mg/g, 13.22 ± 0.33 DE mg/g and 6.5 ± 0.47 QE mg/g, respectively. In addition, it also showed the highest antioxidant activity with values of 5.45 ± 0.11 ascorbic acid equivalents (AAE) mg/g and 8.03 ± 0.06 trolox equivalents (TE) mg/g for ABTS and total antioxidant, respectively. The highest phenolic acids in U. lactuca were gallic acid and vanillic acid. Cytotoxic assays demonstrated that C. racemosa and U. lactuca hydrolysates obtained by HWE and SWE did not show any toxic effect on RAW 264.7 cells at tested concentrations after 24 h and 48 h of treatment (p < 0.05), suggesting that both hydrolysates were safe and non-toxic for application in foods, cosmeceuticals and nutraceuticals products. In addition, the results of this study demonstrated the potential of SWE for the production of high-quality seaweed hydrolysates. Collectively, this study shows the potential of under-exploited tropical green seaweed resources as potential antioxidants in nutraceutical and cosmeceutical products.

In vivo protective effect against ethanol metabolism and liver injury of oyster (Crassostrea Gigas) extracts obtained via subcritical water processing.

The present study assesses hepatoprotective effects of raw oyster lyophilized powder (OP) and subcritical water treated oyster powder (SOP) on D-galactosamine (D-GalN)-induced toxicity and acute ethanol intoxication in mice. High-performance liquid chromatography analysis revealed that four phenolic compounds and glucose were identified from the SOP. The levels of aspartate aminotransferase, alanine aminotransferase, and malondialdehyde were considerably lower for the oyster extracts and the levels of glutathione, γ-glutamylcysteinesynthetase, glutathione S-transferase, and glutathione reductase were higher in the D-GalN induced mice compared with those in the controls. Histology analysis suggested that SOP can protect against and heal the D-GalN toxified liver. For the acute ethanol intoxication study, the enzymatic activity of acetaldehyde dehydrogenase and SOP's alcohol dehydrogenase appeared better than that of OP. Overall, SOP may protect the liver from acute ethanol intoxication and D-GalN persuaded hepatitis. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10068-021-00941-9.