Squalen, Buletin Pascapanen dan Bioteknologi Kelautan dan Perikanan
Current issue: 2025: Squalen Bulletin Volume 20 Issue 2 Year 2025 (August)| ISSN: 2089-5690 (print) ISSN: 2406-9272 (online) Accreditation Number ("KEMENRISTEK"):"169/E/KPT/2024" Squalen publishes original and innovative research to provide readers with the latest research and knowledge on, emerging technologies of marine and fisheries postharvest and biotechnology from tropical waters. The Journal also publishes review articles by invitation that providing an overview and discussion of the latest developments in topics of specific interest to researchers in this field of activity. Scope : 1) Marine and fisheries postharvest, preservation and processing, including mechanization engineering 2) Fish and fishery products quality and safety 3) Marine ecology and pollution related to fish and fishery products 4) Biodiscovery/marine natural products 5) Marine biotechnology and bioprocess engineering Editor in Chief: Dr. Tatty Yuniarti, ST. M.Si More info about Editorial Team here. International Diversity of Editors/Editorial Board: 12 Editors in 8 countries. Indonesia (5); Malaysia (1); United States (1); Iran (1); Germany (1); Japan (1); Mexico (1); Australia (1). | Time to First Decision = 1 week | Review Time = 8 weeks | Publication Time = 3 weeks | Current Acceptance Rate = 30% | Time to First Decision is the average number of weeks it takes for an article to go from manuscript submission to the initial decision on the article whether it will be rejected, revised before review, or continued to review process, including standard and desk rejects. Review Time is the average number of weeks it takes for an article (after the first decision) to go through the editorial review process for this journal, including standard and desk rejects. Publication Time is the average number of weeks it takes to reach from manuscript acceptance, layouting process, to the first appearance of the article PDF fulltext online (with DOI). Current Acceptance Rate is percentage of submitted articles accepted during a calendar year; the total number of articles accepted out of the total number of articles submitted in the same year.
:Agency for Marine and Fisheries Research and Human Resources, Indonesia
Policy for Journals That Offer Open Access
Characterization of Cellulose Fibers Extracted from Ulva lactuca with Various NaOH Concentrations
As demand for sustainable biopolymers is growing, Ulva lactuca has emerged as a promising macroalgal source of cellulose. Alkaline hydrolysis using sodium hydroxide (NaOH) is widely applied in cellulose extraction to remove lignin; however, the influence of NaOH concentration during delignification process of U. lactuca remains insufficiently understood. This study aimed to identify the optimal NaOH concentration for cellulose extraction from U. lactuca and to characterize the resulting fibers. Alkaline treatments were performed using NaOH concentrations of 10%, 20%, 30%, and 40%. The extracted cellulose was evaluated for yield, functional groups, thermal stability, crystallinity index (CrI), and morphology using FTIR, XRD, simultaneous thermal analysis, and FE-SEM. Results showed that cellulose yields ranged from 4.38% to 5.44%, with no significant differences among treatments. In contrast, NaOH concentration significantly affected cellulose morphology, with enhanced delignification and fibrillar refinement observed at higher alkali levels. FTIR spectra confirmed cellulose purity through characteristic O–H and C–H stretching vibrations, β-glycosidic linkages, and the absence of hemicellulose-related peaks. XRD analysis showed that 30% NaOH treatment produced the highest CrI (84.09%), while higher concentrations induced structural degradation. Thermal analysis revealed a two-stage degradation process, consisting of moisture loss at 120–150 °C followed by major cellulose decomposition at 250–300 °C. Overall, 30% NaOH was identified as the optimal concentration for extracting α-cellulose from U. lactuca.
Hak Cipta (c) 2025 Squalen, Buletin Pascapanen dan Bioteknologi Kelautan dan Perikanan
Effect of Sodium Alginate Coating Incorporated with Epigallocatechin Gallate and Peanut Oil on Refrigerated Hilsa (Tenualosa ilisha) Chunk
Hilsa, the national fish of Bangladesh, is highly perishable despite its high nutritional value. Low-temperature preservation, salting, and synthetic preservatives are used to extend the shelf life of hilsa. Nowadays, researchers are searching for safer alternatives. Edible coatings are a safe and effective method for extending the shelf life of fish. This research aims to assess the efficacy of a sodium alginate-based edible coating enriched with the antioxidant and antimicrobial agent epigallocatechin gallate (EGCG) and peanut oil for preserving the quality and extending the shelf life of refrigerated hilsa fish chunks (HFC). In the experiment, HFC samples were divided into four treatment groups: T1 (sodium alginate, 2%), T2 (sodium alginate 2% with peanut oil 1%), T3 (sodium alginate 2%, peanut oi 1%, and EGCG 0.2%), and a control group (CON) treated with distilled water. Samples were stored at 4±1 °C and evaluated over 12 days for biochemical parameters, including pH, total volatile base nitrogen (TVB-N), thiobarbituric acid reactive substances (TBARS), and microbial counts on tryptic soy agar (TSA) and violet-red bile agar (VRB). Initial pH values (5.73±0.03 to 5.74±0.04) were not significantly different (p>0.05), but T3 exhibited a significant increase by day 12 (6.54±0.04, p<0.05). TVB-N levels showed that T3 remained within acceptable limits until day 9, while CON and T1 exceeded spoilage limits by day 6. TBARS values surpassed the oxidative rancidity threshold of 2 mg MDA/kg by day 6 in CON and day 9 in T1 and T2, while T3 remained acceptable until day 9. Sensory evaluation indicated that T3 maintained its quality longer than the other treatments. These findings suggest that sodium alginate coatings with EGCG and peanut oil effectively extend the shelf life of refrigerated HFC, offering a sustainable alternative to synthetic preservatives.
Nutritional Composition, Amino Acid Profiles, and Protein Digestibility of Indonesian Smoked Eel, Shirayaki, and Kabayaki
Eel (Anguilla sp.) is a catadromous fish with high nutritional value, originating in freshwater and migrating to spawn, producing glass eel larvae. In Indonesia, processed eel products such as kabayaki, shirayaki, and smoked eel, which are popular in Japan, have not been widely developed. Comprehensive data on the nutritional composition and protein quality of these products are essential for product development and nutritional improvement. This study aims to determine the nutritional composition, amino acid profiles, and in vitro protein digestibility of Indonesian smoked eel, shirayaki, and kabayaki. Analyses included nutritional composition, amino acid profiles using high-performance liquid chromatography (HPLC), and in vitro protein digestibility for processed eel products. The results indicated that the processing method affected the nutritional value, albumin, minerals, and amino acids. Fresh eel had the highest protein content, followed by smoked eel, while there was no significant difference between shirayaki and kabayaki. The protein digestibility was highest in smoked (67.59%), but there was no significant difference among the others (63.30-64.44%). Calcium (Ca), magnesium (Mg), and potassium (K) contents were highest in smoked eel compared to fresh eel and decreased significantly in shirayaki and kabayaki, but for zinc (Zn), shirayaki and kabayaki tend to be higher than smoked eel. An analysis of essential amino acids showed no significant difference between the processing methods. Leucine had the highest concentration, followed by valine, threonine, and isoleucine, with concentrations ranging from 4.02% to 7.83%. The research found that the best processing method was smoked, and there was no significant difference between kabayaki and shirayaki.
In Vivo Study of Fish Meal-Based RUFF (Ready-To-Use Fish Food) on Growth and Cognitive Development
The prevalence of global malnutrition among children under 5 remains far from the SDG 30 target. As a countermeasure, RUTF (Ready to Use Therapeutic Food) was developed as an intervention and recovery measure. However, RUTF formulations use milk as the primary source of protein, which is scarce in some countries. That is why RUFF (Ready to Use Fish Food) is made, as a development of RUTF, using fish meal to create an even paste, improve formulations, and maximize the utilization of natural resources. This study aimed to create mackerel and pangas catfish RUFF and assess the impact of diet on growth and cognitive development in rodents. RUFFs were produced by preparing fish meals, which were then used to prepare RUFF formulations and were administered to rats for 28 days. Throughout the intervention, rats were counted for food consumption, weighed weekly, and subjected to the classic labyrinth. The pangas catfish and mackerel groups had the most significant weight gain. After 28 days, the rats were sacrificed to analyze brain development by weight and volume, as well as fatty acid profiles in blood plasma using GC-FID. The mackerel group had the largest brain weight and volume, at 1.747 g and 1.833 ml. The mackerel group also had the best cognitive performance and fastest average time in the labyrinth test. This supports that the mackerel group had the highest omega-3 content in both fish powder and blood plasma. The study concluded that experimental animals fed mackerel RUFF showed the best growth and cognitive development.
Response Surface MethodologyBased Optimization of Rusip Fermentation Conditions and Characterization of Bioactive Peptide Fractions with Antioxidant and Antimicrobial Properties
Optimization of raw materials and processing conditions in rusip, a traditional fermented anchovy, has the potential to enhance its bioactive properties. This study consisted of two stages, including optimization of rusip processing parameters (salt, sugar, and fermentation time) using Response Surface Methodology (RSM) based on a Central Composite Design to enhance bioactivity, and physicochemical and microbiological characterization, and bioactivity evaluation of the rusip optimized formulation, including ultrafiltration-based fractionation of its water-soluble extract. The rusip optimized formulation was determined as 5% sugar, 18% salt, and 12 days of fermentation with antioxidant activity of 60.50% (DPPH assay) and inhibition zones of 4.13 mm against Escherichia coli and 3.27 mm against Staphylococcus aureus (agar well diffusion assay), with model validation ranging from 95.86% to 98.03%. Subsequently, the optimized rusip formula was analyzed for physicochemical and microbiological characteristics. The water-soluble extract of rusip optimized formulation was separated using an ultrafiltration membrane, which showed that the <3kDa fraction demonstrated the highest antioxidant (46.09%) and antimicrobial activity (4.9 mm against E. coli and 4.7 mm against S. aureus). Proteolytic enzyme sensitivity analysis showed that exposure to enzymes significantly reduced and eliminated the bioactivity of the rusip fraction, thus indicating the compounds responsible for the bioactivity were proteins or peptides. Qualitative HPLC profiling showed the <3 kDa fraction exhibited an intense peak at 214 nm with early retention time, suggesting the presence of abundant low-molecular-weight peptide compounds. This study provides a scientifically optimized formulation and production method for rusip, revealing its potential as a functional food with natural antioxidant and antimicrobial peptides.
Hak Cipta (c) 2026 Squalen, Buletin Pascapanen dan Bioteknologi Kelautan dan Perikanan
Bioprospecting Marine Endophytic Fungi from Buton Island: Antibacterial Activity and Cellulase Production for Sustainable Blue Economy
Marine-derived endophytic fungi represent an underexplored reservoir of biologically active metabolites and enzymes with industrial relevance. This study investigated the fungal diversity associated with seaweed, seagrass, and mangrove leaf tissues collected from Buton Island, Southeast Sulawesi, with particular emphasis on antibacterial properties and cellulolytic activity. Thirty-two fungal isolates were successfully recovered and characterized based on morphological features. Antibacterial assays against Vibrio harveyi showed that several isolates, notably WB 1-2, WB 6-2, and SM 27-2, produced clear inhibition zones ranging from 11 to 13 mm, demonstrating notable antibacterial efficacy. Among all isolates, Aspergillus terreus (WB 1-2) exhibited the highest cellulase activity and was therefore selected for further enzymatic evaluation. The crude cellulase displayed maximum activity at pH 4 and a temperature of 70 °C. Hydrolysis products were qualitatively analyzed using HPLC, confirming the presence of glucose. These results highlight the dual potential of marine endophytic fungi as sources of antibacterial agents and thermostable cellulases. This work lays the groundwork for future development of eco-friendly enzyme production and marine-based antimicrobial resources, supporting sustainable biotechnological innovation within the blue economy framework.
Effectiveness of Chitosan and Ariid Catfish Swim Blader Gelatine as Edible Coating on the Preservation of White Shrimp Litopenaeus vannamei
White shrimp (Litopenaeus vannamei) is a high-value fishery commodity that is highly perishable due to rapid microbial growth, enzymatic activity, and lipid oxidation during storage. Chitosan is widely recognized for its antimicrobial and antioxidant properties, while gelatine derived from Ariid catfish swim bladders represents an underutilized fishery by-product with excellent film-forming, gelling, and oxygen-barrier properties. This study aimed to evaluate the effectiveness of a composite edible coating based on shrimp chitosan and Ariid catfish swim bladder gelatine at different ratios in preserving the quality of white shrimp during chilled storage. Treatments consisted of chitosan–gelatin ratios of K (0:0), P1 (3:7), P2 (5:5), and P3 (7:3), with storage durations of 0, 24, 48, and 72 hours. Quality parameters assessed included thiobarbituric acid (TBA), total plate count (TPC), peroxide value (PV), total volatile basic nitrogen (TVBN), pH, weight loss, sensory attributes (appearance, texture, odor), and melanosis. The results demonstrated that edible coating application significantly affected TBA, TPC, PV, TVBN, pH, sensory quality, and melanosis (p < 0.05), while no significant effect was observed on weight loss. The chitosan–gelatine coatings effectively inhibited microbial proliferation, oxidative degradation, and enzymatic activity, thereby extending shrimp freshness. The P3 formulation (7:3) showed the most optimal preservation performance, with TPC of 59.33 × 10³ CFU/g, PV of 3.33 meq/kg, TVBN of 24.31 mg N/100 g, pH of 7.14, and a melanosis score of 2.82 after 72 hours of storage. The synergistic combination of shrimp chitosan and Ariid catfish swim bladder gelatine provides an effective, biodegradable edible coating for extending the shelf life of white shrimp. This study highlights the potential application of fishery by-products as functional biopolymers, contributing to sustainable seafood preservation, value-added processing, and circular bioeconomy development.
Effects of Transglutaminase on the Gel Properties of Indonesian Catfish Surimi Using Response Surface Methodology
Surimi is a myofibrillar fish protein, extracted mainly from marine fish, which is commonly used to produce fish balls, crab imitation products, and various other seafood substitutes. However, finding an alternative fish from freshwater, such as freshwater catfish, is important, although its drawbacks include low gel strength and water-holding capacity. To address this problem, transglutaminase addition can maintain the surimi quality. This study aimed to improve catfish surimi characteristics by optimizing surimi production with various transglutaminase concentrations and incubation times. It used Response Surface Methodology (RSM) with Central Composite Design (CCD) to evaluate the effect of Enzyme Concentration and Incubation Time. The result showed that the catfish surimi gel strength, chewiness, whiteness, and water-holding capacity were respectively 927.513 g.cm, 3,747.18 g, 79.95 %, and 91.37 %. It was obtained by the optimum condition of surimi production with the addition of 0.85 % w/w transglutaminase and an incubation time of 36 minutes. The overall study provides insight for surimi producers to maintain surimi characteristics from freshwater fish, such as catfish.
Antioxidant Bioactive Peptides from By-Product Canned Yellowfin Tuna (Thunnus sp.) through an Enzymatic Membrane Reactor (EMR)
As a by-product of the pre-cooking phase, canned yellow fin tuna (Thunnus sp.) is processed into body juice. A bioactive peptide derived from an organism&#39;s body juice was developed to create a functional food. Hence, the purpose of the research was to evaluate the biological activity of antioxidant bioactive peptides prepared from body juice. Three stages were conducted to determine the substrate-to-enzyme and enzyme-to-substrate ratios for the production of antioxidative bioactive peptides in a batch reactor. These stages include the production of antioxidative bioactive peptides in an automated EMR with a constant flux and residence time, as well as the production of bioactive peptides using ultrafiltration with membranes of 10, 5, 4, and 2 kDa. The process was conducted at a temperature of 50°C, pH level of 7, constant flux of 8.08 L/m 2 /h, enzyme concentration of 15%, and substrate concentration of 2%. Furthermore, the optimal treatment implemented an automated EMR and filtered through a membrane of size 4 kDa, generating an IC 50 value of 0.604 mg/mL for antioxidant activity. The LC–MS analysis results indicated that the bioactive peptide, which passed through a 4 kDa membrane, contained the amino acid phenylalanine. Therefore, it can be inferred that an automated EMR could potentially be applied to create bioactive peptides from the body juice of by-products of canned yellow fin tuna (Thunnus sp.) that exhibit antioxidant activity.
Formulation of nutritious biscuits fortified with minced catfish and Ulva sp for malnourished children
Stunting is a critical problem that deserves attention and has become a global problem. The approach to reducing stunting is to provide nutritious supplementary food in the form of biscuits for children, especially those who are malnourished. The purpose of this study is to formulate nutritious biscuits enriched with minced catfish as a source of amino acids and Ulva sp as a source of dietary fiber. Design expert software (DX13) ® was used to analyze sensory data gathered from a hedonic scale assessment with 25 trained panelists to determine the best formulation for the fortified biscuit product. Taste and texture were among the sensory qualities that were assessed. In addition, physical aspects such as hardness and color (L, a, and b) are analyzed to determine the quality of the biscuit formula. The best formulas based on sensory evaluation and physical analysis undergo further analysis of their nutritional composition, including proximate analysis and amino acid profile.The best quality products found are biscuits fortified with a formula consisting of 33% wheat flour, 14% chopped catfish, and 1% Ulva flour.The state of the art of this research is the development of functional biscuits fortified with a combination of animal protein (catfish) and dietary fiber as well as antioxidants form Ulva sp., using an RSM-based formulation optimization approach to produce a highly nutritious product that is acceptable to children.
Extraction of Eutectogel-Carrageenan from Kappaphycus alvarezii using Natural Deep Eutectic Solvent (NADES) Assisted by Ultrasonication
The extraction process of carrageenan from red seaweed (Kappaphycus alvarezii) still predominantly employs conventional solvents, which leave residues that pose potential risks to human health and the environment. Natural Deep Eutectic Solvents (NADES) are green solvents that are biodegradable, biocompatible, and sustainable, offer a promising alternative. The process of extracting carrageenan polysaccharides using NADES enables simultaneous synthesis-extraction (SSE). This process operates through supramolecular interactions and facilitates in situ gel formation, resulting in a Marine Eutectogel based on carrageenan, referred to as Eutectogel-Carrageenan. This study aims to determine the optimal extraction conditions, in terms of temperature and time, for the characteristics of the Eutectogel-Carrageenan-NADES (ECN) produced, and to compare them with those of the Eutectogel-Carrageenan-Commercial (ECC). The research process includes sample preparation, NADES preparation, Eutectogel- Carrageenan extraction using NADES assisted by ultrasonication, and characterization. The optimal condition was established at 80°C for 60 minutes, yielding ECN with a moisture content of 18.93%, yield of 28.81% (db), and viscosity of 5.82 cP. Comparative analyses showed that ECN had a slightly lower sulfate content (3.96% db) and nearly identical functional group spectra compared to ECC, along with rheological properties of lower rigidity and a lower melting point. These findings confirm that ECN produced under optimal NADES-assisted ultrasonication exhibits comparable quality to ECC. This study demonstrates, for the first time, feasibility of simultaneous synthesis–extraction of carrageenan eutectogels using NADES, offering a sustainable approach with concrete prospects for food, pharmaceutical, and biomedical applications.
Viability of Encapsulated Bacteria using Gel Particle and Foam-Mat Drying with k-carrageenan/Chitosan and i-carrageenan/Chitosan
The study aimed to determine the effect of using a mixture of kappa-carrageenan/Chitosan and Iota carrageenan/Chitosan as encapsulating materials for Lactobacillus acidophilus and Bifidobacterium bifidum on viability, encapsulation yield, moisture content and aw of microcapsules. The research method is an experimental laboratory design, ANOVA, LSD using the Excel program. The results showed that using chitosan with a DD of 83.5% in the i-carrageenan/Chitosan mixture gave the highest viability of Bifidobacterium bifidum. The combination of i-carrageenan/chitosan coating ingredients with a concentration ratio of 0.5%:1.5% produced probiotic viability (L aci + B bifi) of 6.56 log CFU/g, while probiotic viability (B bifi) was the highest with a viability 6.70 log CFU/g. The highest probiotic encapsulation yield (L aci+B bifi) was 72.85%. The water content of the microcapsules (L aci+B bifi) was 8.96%, and the aw value was 0.63. It is recommended to carry out further testing using a processing factor for its viability.
Formulation of Carrageenan and Sodium Chloride in Edible Coatings for Enhanced Tilapia Fillet Preservation
While carrageenan coatings offer promising preservation for fish, limitations like water absorption and insufficient antimicrobial strength necessitate more investigation on combining them with natural substances. This study aimed to extend the shelf life of tilapia fillets using an edible coating made from carrageenan and sodium chloride (NaCl). Response Surface Methodology (RSM) was employed to optimize the coating formulation, considering film properties such as thickness, swelling index, opacity, and water vapor transfer rate. A Central Composite Design (CCD) identified the optimal composition as 1.4 grams of carrageenan and 0.6 grams of NaCl, minimizing undesirable characteristics. The optimized coating was applied to fresh tilapia fillets and compared to uncoated controls during five days of refrigerated storage (4.5 oC). Quality parameters, including bacterial count, total volatile basic nitrogen (TVB-N), pH, weight loss, and color, were monitored. The carrageenan-NaCl coating significantly reduced bacterial growth, with values increasing from log 6.31 CFU/ml on day 0 to log 6.34 CFU/ml on day 5, compared to uncoated fillets exhibiting TNTC (too numerous to count) bacteria by the end of storage. Additionally, the coated fillets displayed a lower increase in TVB-N (22.50%) compared to uncoated samples (31.38%), maintaining a stable pH and experiencing less weight loss (27.54%) compared to uncoated controls (32.96%). The coating also effectively preserved color, indicating its potential to maintain sensory attributes. These findings suggest that the optimized carrageenan-NaCl edible coating offers a promising strategy for extending the shelf life and maintaining the quality of fresh tilapia fillets, potentially reducing losses within the seafood supply chain.
Antioxidant Activity and Lipid Content of Aurantiochytrium sp. from Raja Ampat and Kepulauan Seribu
Raja Ampat (Southwest Papua Province) and Kepulauan Seribu (Jakarta Raya Province) are part of Indonesia&#39;s territory, which includes the mangrove forest area. This habitat supports a diverse array of animals, plants, and microalgae, including Aurantiochytrium sp. It has antioxidant activity related to lipid content. This study aims to identify the lipid content and the antioxidant effects of the microalgae Aurantiochytrium sp.’s extract isolated from the mangrove forest areas of Raja Ampat and Kepulauan Seribu. The extraction process was conducted using the Folch method, which involves a 2:1 (v/v) chloroform-methanol solvent ratio. The microalgae Aurantiochytrium sp. extract of Raja Ampat (MAERA) and microalgae Aurantiochytrium sp. extract of Kepulauan Seribu (MAEKS) were analyzed using GC-MS, antioxidant potential tested in silico by target proteins (5ZLG, 2A1X, 3VLN, and 1EEM) using Autodock Tools, and in vitro by DPPH and ABTS radicals and the carotenoid bleaching method. The results showed that total squalene and fatty acids in MAERA and MAEKS were at different levels. Squalene as a ligand had the lowest binding energy (-9.4, -6.6, -7.7, and -6.5) compared to the native ligand (-5.6, -4.4, -5.2, and -5.2) and ascorbic acid (-5.6, -4.8, -5.3, and -4.9) by in silico antioxidant activity. The in vitro antioxidant activities by DPPH, ABTS, and ß-caroteen bleaching were 103.00 ± 3.75, 216.39 ± 367, 214.62 ± 7,07 (MAERA); and 131.85 ± 23.48, 225.50 ± 3.36, 251.69 ± 5.39 (MAEKS) were not significantly different (p&gt;0.05) by all methods. These findings showed that the Aurantiochytrium sp. strains Raja Ampat and Kepulauan Seribu contained diverse levels of fatty acids and squalene. In the in silico study, squalene was evaluated and in vitro, the MAERA and MAEKS extracts showed moderate antioxidant activity.
PHYSICAL PROPERTIES OF CHINESE HERRING (Hilsentoli sp.) LEATHER TANNED WITH CHROME AND RETAINED WITH SYNTHETIC AGENT
When the scales of Chinese herring (Hilsentoli sp.), like those of snakes or monitor lizards, are tanned, they exhibit a unique scaly texture with an attractive natural pattern. This study aimed to evaluate the physical properties of Chinese herring skin tanned with chrome and retained with a synthetic agent. The treatments consisted of a combination of chrome and tanning agents at various concentrations, ie. Chrome (C) 6% and tanning agent (S) 0% (C6S0), Chrome 8% and tanning agent 0% (C8S0), Chrome 10% and tanning agent 0% (C10S0), Chrome 6% and tanning agent 4% (C6S4), Chrome 8% and tanning agent 4% (C8S4), Chrome 10% and tanning agent 4% (C10S4), Chrome 6% and S 6% (C6S6), Chrome 8% and S 6% (C8S6), and Chrome 10% and tanning agent 6% (C10S6). Observations were conducted based on descriptive sensory, physical, and chemical tests, identification of functional groups of the leather, and morphology analysis of the skin leather. The results showed that a combination of chrome and synthetic tanning produced leather with a denser and fuller texture than leather tanned with the chrome tanning agent. C10S6 treatment produced the best physical properties of tanned skin of Chinese herring in terms of its high tensile strength, tear strength, stitch strength, and shrinkage temperature, along with the lowest elongation. The values are well within the Indonesian standard of SNI 0253:2009 for leather with fancy motifs on finished leather goods. The analysis of the cross-section of skin at various treatments using Scanning Electron Microscope (SEM) analysis indicates that retanning with synthetic tanning agents strengthened the collagen matrix, producing denser, more compact structures. This density is caused by the presence of collagen compound bonds and synthetic tanning materials, such as phenol and formaldehyde, which were detected as 2,4-dimethyl phenol in the Raman spectra shift at 208, 35 – 2445.87 cm -1 .
In-Silico Approach of Mole Crab (Emerita sp.) Peptides Produced by Alcalase Hydrolysis
One type of mole crab in Indonesia is Emerita sp., which has a fatty acid content of 3.57% and crude protein content of 32.42% (100 mg). The use of mole crabs is currently limited to food sources; therefore, it is necessary to conduct research to optimize the use of mole crabs, which are a source of protein hydrolysate. The samples were used under fresh conditions and stored at −20°C before processing. This study aimed to produce protein hydrolysates from moles of crabs. This hydrolysate is produced by enzymatic hydrolysis of marine back-down raw materials using alcalase. In silico analyses have identified the potential of marine-receding protein hydrolysates. The results of in silico analysis using BIOPEP and Peptide Ranker revealed that these peptides exhibited multiple bioactivities, including ACE inhibition, DPP-IV inhibition, and antioxidative and anti-inflammatory effects. The dipeptide PW (Pro-Trp) achieved the highest Peptide Ranker score of 0.993, with a predicted dual function as an antioxidant and DPP-IV inhibitor. Molecular docking confirmed strong binding affinities to target receptors, with the AF peptide displaying the best interaction against ACE (−129.70 kcal/mol) and GH peptide against DPP-IV (−113.68 kcal/mol). These results suggest that mole crab hydrolysate contains promising peptides with potential applications as nutraceuticals, particularly in the management of hypertension and type 2 diabetes mellitus. The highest potency based on the in-silico peptide hydrolysate has a strong antihypertensive effect. Further in vivo research is needed to explain the potential of sea retreat peptides as bioactive antihypertensive agents in peptide form.
Antibacterial Activity of Chlorophyta, Phaeophyta, and Rhodophyta Using Various Antibiotics as Positive Controls: A Systematic Review and Meta-Analysis
Different species of marine macroalgae have been reported to demonstrate antimicrobial activities against numerous bacteria, with varying results. According to the studies, other antibiotics have been used as positive controls. This study evaluated the effect of crude extracts and sulphated polysaccharides from Chlorophyta, Phaeophyta, and Rhodophyta in inhibiting bacterial growth in terms of the diameter of inhibition zones (DIZ) using a systematic review and meta-analysis approach. A total of 835 data, extracted from 23 selected articles, were analyzed using OpenMee software by comparing the standardized mean difference (SMD) and 95% confidence interval (CI). The largest DIZ that Chlorophyta showed was 35 mm, Phaeophyta was 27.3 mm, and Rhodophyta was 25.66 mm, which was categorized as a very strong activity. The crude extract revealed a better inhibitory activity than the sulphated polysaccharides. The overall effect size for crude extracts was with SMD = -1.72 (CI = -1.96 to -1.48, I2 = 84.65%, p <0.000) and for sulphated polysaccharides with SMD = -13.07 (CI = -16.00 to -10.14, I2 = 85.8%, p < 0.000), respectively. Subgroup analysis showed that when ciprofloxacin was used, the SMD value was -12.88 (CI = -14.50 to -11.25), whereas if ampicillin was used, the SMD value was 1.81 (CI = 1.27 to 2.35). This study proved that Chlorophyta, Phaeophyta, and Rhodophyta revealed promising antibacterial activities. However, the overall effect size was affected by the antibiotic used when comparing the SMD of the DIZ using a meta-analysis approach. Other factors, such as extraction methods and bacterial strains that likely affect the overall effect size, are subjected to further analysis in the next study.
The Effect of Aeration and Chlorella vulgaris Initial Cell Density on Mercury Removal
Research on Chlorella vulgaris is vital due to its rapid growth and versatile habitat adaptability. C. vulgaris is a fast-growing green microalga used for phycoremediation of heavy metals such as mercury which is usually found in gold mining wastewater. This research aims to determine the best mercury removal efficiency with variations in aeration rate, medium concentration, and C. vulgaris inoculum concentration. This research was conducted by cultivating C. vulgaris and examining its response to various parameters in an artificial mercury (II) chloride (HgCl2) solution. Moreover, other parameters such as cell density, pH, temperature, bicarbonate, and dissolved oxygen were monitored over a seven-day experimental period. The highest removal efficiency (61.34%) at a mercury concentration of 0.3 mg/L was found in the variant with a walne medium dose of 1 mL/L, inoculum concentration of 10%, and aeration rate of 3 L/min. This study confirmed the potential of C. vulgaris as an effective agent for heavy metal removal, particularly mercury, and contributed to bioremediation.
Marine Bacteria Producing L-Asparaginase with Low Glutaminase and Urease Co-Activity from Pangandaran East Coast Indonesia
acterial L-asparaginase is a therapeutic enzyme widely used in the treatment of Acute Lymphoblastic Leukemia (ALL). Although L-asparaginase is prominent in treating ALL, its use is limited due to its side effects caused by its dual substrate specificity towards both asparagine and glutamine. This study aimed to isolate and identify marine bacteria from the East Coast of Pangandaran capable of producing L-asparaginase with low glutaminase and urease co-activities. A semi-quantitative approach was employed, involving the isolation and screening of seawater bacteria using Zobell Marine media supplemented with L-asparagine, glutamine or urea and phenol red as a pH indicator to determine the enzymatic activity. Molecular identification was performed by amplifying and sequencing the 16S rRNA gene, followed by phylogenetic analysis using the neighbor-joining method with 1,000 bootstrap replicates. The results indicated that the bacterial isolate designated PT3 exhibited a high enzymatic index of 4.2 for L-asparaginase, surpassing that of the positive control (E. coli), which had an index of 1.4. Sequence analysis revealed that PT3 shared 99.58% identity with Marinobacterium georgiense strain NBRC 102606, an earlier synonym of Marinobacterium iners. Therefore, PT3 was identified as a strain of Marinobacterium iners, with potential as a novel source of L-asparaginase and displayed significant L-asparaginase activity with minimal co-activity of glutaminase and urease, highlighting its potential as a safer alternative for therapeutic enzyme development.
Antimicrobial ointment based on Bacillus subtilis subsp. subtilis HSFI-9 isolated from Sea Cucumber of Kodek Bay Lombok Indonesia
The ethyl acetate extract of Bacillus subtilis subsp. subtilis HSFI-9, a bacteria isolated from intestinal fermentation of sea cucumbers (Holothuria scabra) is known to have antimicrobial properties. This research aimed to determine the activity of HSFI-9 extract ointment against Staphylococcus aureus and Candida albicans. Extract ointment is a topical preparation for skin infections made from a mixture of Vaseline Alba and Adeps lanae bases. The extract ointment was prepared into four concentrations of 0.003%, 0.03%, 0.3%, and 1% w/v using HSFI-9 as active ingredient. Antimicrobial assay was carried out in vitro using the disc diffusion method. The extract ointment was evaluated based on organoleptic, homogeneity, spreadability, adhesion characteristics, and pH tests. The optimal concentration of the extract ointment to inhibit the growth of S. aureus 0.3% (inhibition zone of 11.67±1.26 mm) and against C. albicans is 0.03% (inhibition zone of 10.16±1.50 mm). The activity of the extract ointment was categorized as strong although not as strong as the antibiotic control ointment Mupirocin 2% or Ketoconazole 2%. The extract ointment organoleptic indicated a characteristic odor of ethyl acetate, was yellowish-white ointment, and had a homogeneous and smooth consistency. The extract ointment also had properties such as good spreadability but poor adhesion and tended to have an acidic pH (< 4.5). The HSFI-9 extract can be declared feasible for the development of topical antimicrobials. The ointment still needs to be optimized, especially regarding improving the adhesion characteristic and pH to be safe for the skin and mucosa.
Antioxidant Profiling of Botryocladia leptopoda Based on In Silico and In Vitro Studies
Seaweed has long been recognized as an excellent source of antioxidants. The presence of antioxidant activity from Botryocladia leptopoda was investigated. The study aims to estimate the potential antioxidative peptides released by B. leptopoda sequences using an in-silico approach and to explore the antioxidant capacities revealed by different extracts. In silico studies using the ProtParam and BIOPEP-UWM databases showed that B. leptopoda proteins are potential sources of antioxidative peptides. Glycine and leucine were identified as the primary amino acids detected in the sequences. The antioxidant capacities of various seaweed extracts at different drying temperatures (60 °C and 70 °C) and solvents (alkaline-ethanol, ethanol, and water) were further observed in vitro. The fraction from alkaline-ethanol extraction of seaweed dried at 60 °C (BL-A, 1 mg/mL) produced a high phenolic concentration of 6.44 mg GA/g (p < 0.05). It exhibited superior reducing power activity, with an absorbance of 0.29 at 700 nm (p < 0.05) and ferrous ion chelating activity of 99.64% (p < 0.05). In comparison, significant DPPH radical scavenging activities were observed in the ethanol extracts of seaweed dried at 60 °C (BL-B) and 70 °C (BL-C), with 46.08% and 33.74%, respectively, at a 1 mg/mL concentration (p < 0.05). At a 10 mg/mL concentration, BL-B and BL-C optimally scavenged DPPH radicals (96.61% and 94.79%, respectively). Overall, this study showed that in silico and in vitro analyses yielded similar results. Thus, B. leptopoda can be considered a promising source of antioxidative products in the functional food and pharmaceutical industries.
Microbial and Amino Acid Changes in Pre and Post- Fermentation Shrimp Paste from Cirebon, West Java
This study investigates the changes in microbial communities and amino acid profiles in shrimp paste (terasi) from Cirebon, West Java, before and after fermentation. Samples were collected from two traditional processors, representing different stages of shrimp paste processing. The microbial diversity was analyzed using 16S rRNA gene sequencing, revealing significant shifts in bacterial populations during fermentation. Processor A’s shrimp paste showed a dominance of Bacilli, with Staphylococcus becoming more prevalent post-fermentation, while Processor B’s paste exhibited a more diverse microbial community, including Empedobacter and Acinetobacter. The study identified 60 and 64 genera in Processor A’s samples before and after fermentation, respectively, and 26 and 41 genera in Processor B’s samples. Vibrio, initially present in the raw material, was eliminated post-fermentation. Amino acid analysis indicated an increase in key amino acids such as glutamic acid and leucine post-fermentation, contributing to the enhanced flavor profile of the shrimp paste. Processor A’s shrimp paste showed significant increases in amino acids, with glutamic acid reaching 64,249 mg/kg, Processor B’s paste had a more moderate increase, with glutamic acid at 10,714 mg/kg post fermentation. These findings highlight the significant influence of fermentation conditions on the microbial and biochemical composition of shrimp paste, emphasizing the importance of standardized processing methods to ensure consistent product quality and safety.
Tyrosinase Inhibitory Activity of Methanolic Extract and Fractions from Green Seaweed Ulva lactuca
Ulva lactuca, a widely available green seaweed, has demonstrated promising bioactivity as a tyrosinase inhibitor. This study aimed to evaluate the tyrosinase inhibitory activity of U. lactuca extracts and identify the active compounds responsible. The seaweed was extracted using methanol via maceration, followed by partitioning with hexane, chloroform, and water. Total phenolic and flavonoid contents were determined using UV-VIS spectrophotometry, and tyrosinase inhibition was assessed in vitro. Among the tested fractions, the hexane fraction exhibited the highest tyrosinase inhibitory activity with an IC50 value of 584.34 ± 35.07 µg/mL, classifying it as an active inhibitor. Although this activity was weaker than kojic acid (IC50 = 11.07 ± 0.86 µg/mL), the hexane fraction showed relatively high phenolic (11.66 ± 0.53 mg GAE/g) and flavonoid (9.75 ± 0.30 mg QE/g) contents. Gas Chromatography-Mass Spectrometry (GC-MS) analysis identified several bioactive compounds, notably 2,4-dimethoxycinnamic acid, chalcone, and derivatives such as 2,6-dihydroxybenzoic acid and phloretin. These findings highlight the potential of U. lactuca, particularly its hexane fraction, as a source of natural tyrosinase inhibitors. This opens avenues for its application in the pharmaceutical and cosmetic industries, especially in formulations targeting hyperpigmentation and skin brightening.
Prospecting New Antimicrobial Peptide from Gracilaria spp. Active-peptide Hydrolysate against Pathogenic Bacteria using Proteomic Approach
Our study focused on unveiling the tropical red algae Gracilaria spp. Active-peptide materials from the central region of Java Island, Indonesia. We described the protein isolation, hydrolysis, purification, and method to test its potency against pathogen Staphylococcus aureus IFO 12576 and Eschericia coli IFO 3301, followed by molecular docking analysis. TCA/acetone precipitation was used to isolate Gracilaria spp. proteins, and the hydrolysis was done by trypsin digestion with an effective yield to provide antibacterial activity. The disk diffusion method showed promising inhibition and continued with a confirmation test using microdilution, which implied bacteriostatic inhibition with a minimum concentration of 40 µg/ml, from one potent fraction. Further characterizations were conducted using a proteomic approach. LC-HRMS was used for peptide sequencing in the potent fraction with prospective peptides identified along with its physical properties. Molecular docking simulations were used to investigate the degree of interactions using binding affinities score (kcal/mol), with the target of receptor DraE adhesin subunit (2JKJ) of Escherichia coli binds chloramphenicol. We proposed the interactions model of peptides GP1 and GP4 against targeted peptides. Our model GP4.1 and GP4.2 model (VVINADAK) were found to have high binding affinities with the energy score of -10,6 and -10,8 kcal/mol, respectively by the different sites of binding than chloramphenicol succinate.
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Functional Properties of Protein Hydrolysates from Skipjack Tuna Byproducts Using Response Surface Methodology
Protein hydrolysates from skipjack tuna by-products are rich in protein and excellent in functional properties, making them a valuable source of nutrients for humans. This research sought to determine the optimal pH, temperature, and hydrolysis time for producing protein hydrolysates from skipjack tuna byproducts (PHST) using Response Surface Methodology (RSM). A total of 20 g of PHST was prepared from frames and trimmings, samples were hydrolyzed under the following conditions: pH of 6 (P1) and 7 (P2), temperatures of 50°C (S1), 60°C (S2), and 70°C (S3), and hydrolysis times of 90 minutes (T1), 180 minutes (T2), and 270 minutes (T3). The hydrolysis process was terminated by inactivating the enzyme at 80°C for 30 minutes. The filtrate was ready for further analysis in the laboratory. Data and design experiments were analyzed using Box-Behnken Design (BBD) with the Design-Expert (DX) 13® software (Stat-Ease Inc. Minneapolis) to determine the optimum conditions for higher PHST production. A quadratic model was developed to predict the production of PHST. The RSM recommendation was to perform hydrolysis at pH 6.386 and a temperature of 61.190°C for a hydrolysis time of 228.540 minutes to result in a desirability of 0.906 in producing PHST with 85.680% DH, a protein solubility of 51.538%, and a viscosity of 3.587%. The study results showed that PHST can be used as a promising food ingredient and protein source in the food system.
The Marine Actinobacterium Streptomyces sp. BTA 1-131 as a Potential Producer of Anti-Nontuberculous Mycobacterial (Anti-NTM)
Nontuberculous mycobacteria (NTM) are environmental microorganisms, also known as opportunistic pathogens, found in patients with pulmonary tuberculosis. The emergence of antibiotic resistance is increased by prolonged antibiotic treatment for NTM infections. Therefore, alternative sources of new antibiotics are essential for the treatment of NTM infections. A marine actinobacterium, Streptomyces sp. BTA 1-131, isolated from a marine sponge, Melophlus sarasinorum, has been reported as a potential source of antibacterials and anticancer agents. The present study aimed to investigate the potential of Streptomyces sp. BTA 1-131 against two NTMs: Mycobacterium smegmatis and Mycobacterium fortuitum. Streptomyces sp. BTA 1-131 was fermented in three cultivation media (SYP, ISP2, and YS), and the secondary metabolites were extracted using methanol. The bioactivity screening showed inhibition of all methanolic extracts against the growth of M. smegmatis and M. fortuitum. The methanolic extract, which could inhibit both mycobacteria, was a crude extract derived from SYP liquid medium fermentation. The isolated compounds in this study were preliminarily identified using thin-layer chromatography (TLC). The TLC results showed different potential compounds in the crude extracts of Streptomyces sp. BTA 1-131 also highlighted the impact of the fermentation medium on the production of metabolites from Streptomyces. This study also added knowledge about the importance of the Indonesian marine actinobacterium Streptomyces sp. BTA 1-131 as a promising producer of anti-NTM compounds.
Characteristics of Pindang Boiling Water and Its Use to Produce Antioxidative Peptides through Trypsin Hydrolysis
Pemindangan is a traditional fish processing method in Indonesia, where fish are preserved by boiling in saltwater. This process results in a liquid as a by-product, which is often discarded without any further processing. The liquid contains a substantial amount of protein, reaching 1.04±0.03 mg/mL, which make it a potential source of bioactive peptides. This study aimed to produce bioactive peptides from pindang liquid which was hydrolysed by enzymes isolated from skipjack viscera. The hydrolysates were prepared by using extracted trypsin, which was also from a fish by-product. The trypsin-assisted hydrolysis was carried out at a temperature 60 °C and pH 8.0, while for the semi-purified trypsin, the process was run at 50 °C and pH 8.0. The hydrolysis time was operated at different periods of 15, 30, and 60 min. The results showed that the pindang liquid dominantly contained hydrophobic amino acids and the hydrolysate was still rich in protein content ranging from 0.56 to 0.65 mg/mL. Furthermore, hydrolysis time significantly influenced antioxidant activity of the peptide. The best antioxidant activity was shown at hydrolysis time of 15 min by crude extract enzymes, resulting in antioxidant activity of 0.90±0.01 mg ascorbic acid equivalent antioxidant capacity (AEAC)/mg protein and reducing power of 4.49±0.60 mg trolox equivalent antioxidant capacity (TEAC)/mg protein. Hydrolysis by using semi-purified trypsin showed antioxidant activity equivalent to 0.73±0.05 mg AEAC/mg protein and reducing power 6.54±0.34 mg TEAC/mg protein. Overall, the results revealed the conversion of pindang liquid into bioactive peptides showing antioxidant activity, and therefore, they might be potentially developed as functional foods.
Antioxidant and Antibacterial Activity of Suaeda maritima from Karangantu Waters, Serang-Indonesia
Suaeda maritima or locally called Alur in Indonesia is a water-based plant that has high nutritional content and commonly consumed as fresh vegetables or urap. Therefore, this study aimed to determine the content of phytochemicals, antioxidants and antibacterial activities in Suaeda maritima extracts. Fresh Suaeda maritima was analyzed for its proximate content then it was dried by hot air dryer at 40°C until the moisture content reached ≤10%. The dried Suaeda maritima was extracted by maceration and ultrasonication method using three different solvents, namely methanol, ethanol, acetone. The extracts then were analyzed for the phytochemical compounds, total phenolics content, antioxidant activity (FRAP methods), and antibacterial activity. The results showed that fresh Suaeda maritima comprised of moisture 86.74±0.58%; ash 2.76±0.17%; protein 1.08±0.33%, lipid 0.47±0.11%; and carbohydrate 8.94±0.82%. It was also revealed that overall extracts, both in maceration and ultrasonication methods, comprised of alkaloids, flavonoids, phenolics, steroids, tannins, and saponins. The ethanol extract by the maceration methods had the highest total phenolic contents among the other extracts, which was 6.20±0.27 mg GAE g-1 (P<0.05). The highest antioxidant activity was 85.04±4.01 mM FeSO4/g also found in ethanol extract by maceration method. It was proven that there was high relationship between the total phenolic content and antioxidant activity, which the R2 was 0.9242. However, the antibacterial activity for inhibiting Escherichia coli and Staphylococcus aureus on Suaeda maritima was categorized as weak due to its clear zone was <5 mm. In conclusion, Suaeda maritima extract would be potential as natural source of antioxidant.
STRATEGY FOR MAINTAINING THE QUALITY OF CATCHES BY IMPLEMENTING QUOTA AND ZONE BASED FISHING IN ZONE 3
The quality of catches is determined by how the best fishing practices are conducted. A program or policy is needed to support the achievement of high-quality catches. Ministry of Marine Affairs and Fisheries implements quota and zone-based fishing, one of the objectives of this policy is to have catches with high quality. This study aims to develop strategies to maintain the quality of catches at Ports in Zone 3 where fishing vessels are required to land their catches at ports within the same zone. The methodology in this research is the Soft System Methodology (SSM) approach with CATWOE analysis. The study identifies various issues related to fish handling on vessels, fish handling facilities and infrastructure, as well as fish distribution and processing, all of which impact the quality of the catch. The results find that improving product quality is closely linked to onboard fish handling practices, fish processing units, and the development of fish industries. This relationship is described by the eigenvector, with downstream industry strengthening scoring 0.438, quota and zone-based fishing management scoring 0.348, and human resource capacity scoring 0.248. Based on these findings, strengthening downstream industries is crucial to supporting the quality of catches within the quota and zone-based fishing. This is further evidenced by laboratory test results showing that distribution from Tual Fishing Port to Karangsong Fishing Port a 28.57% decline in organoleptic tests, a 92.31% increase in Escherichia coli, and a 40% increase in Total Plate Count (TPC). The study also highlights the fishermen's proficiency, skills, and expertise in handling fish catches and implementing cold chain systems up to the consumer level, which significantly influence the quality of fish catches. To realize these findings, it is recommended to provide training for fishermen, supply cooling facilities and vessels, and develop cold chain systems up to the consumer level. This study shows that the zoning system will help maintain fish quality. Additionally, strengthening supporting infrastructure is essential to improve fish quality in the capture fisheries sector.
Variations in Milling Time and Their Impact on the Bio-Calcium Properties of Red Snapper Fish Bones
Calcium is a macromineral essential by human body, with deficiencies often leading to bone-related issues. Red snapper bone waste is a source of calcium. The bioavailability of calcium is maximized when present in microscopic particles, such as bio-calcium. This study aims to identify the optimal milling time to produce bio-calcium from red snapper bones, evaluating parameters such as water content, particle size, and yield. Biocalcium was extracted from red snapper bone meal using a 1 N NaOH solution (1:3 ratio) with milling times of 1, 2, and 3 h. Analysis of the red snapper bone meal including yield, particle size, chemical composition, calcium, and phosphorus content. The bio-calcium was characterized based on water content, particle size, yield, Fourier-transform infrared spectroscopy (FTIR), and morphological structure using a scanning electron microscope (SEM). The results demonstrated that a 3-hour milling time yielded bio-calcium with a particle size of 410.8 nm, a water content of 4.51 ± 0.15%, and a yield of 4.12 ± 0.03%. SEM revealed a uniform morphology. FTIR spectra indicated the presence of carbonate, amine, hydrocarbon, and hydroxyl groups, suggesting residual organic substances such as protein, fat, and water. The uniform spectra across all samples highlight the consistency of the extraction process, ensuring a similar chemical composition.