Protein Retention Rate Research Articles

Enhancing whipped cream anti-freeze properties: A dual plant system with aquafaba and mung bean protein

The objective of this study was to substitute sodium caseinate (SC) with a dual plant-based alternative to produce a refreshing sour whipped cream at pH 3.0, which could maintain stability when paired with low-pH foods. Aquafaba (AQ) was utilized as a novel foam booster, enhancing the whipped properties of the whipped cream, while pH12-shifting treated mung bean protein (BMBP) functioned as an interfacing stabilizer, improving its stability. Freeze-thaw stability of the aerated emulsion and the protein-protein interactions in the emulsion were characterized by analyzing water distribution, thermodynamics, serum loss, and protein retention rates. The high bound water content and dense bubble distribution of whipped cream prepared by AQ and native mung bean protein (NMBP) delivered superior freeze-thaw stability, shown as reduced serum loss, higher protein retention, and increased hardness. In addition, the internal fat network of the whipped cream made from a 1:1 combination of NMBP and BMBP showed moderate agglomeration with a comparable γmax value as SC-based whipped cream, indicating enhanced resistance to deformation and improved short-term shape retention. In conclusion, the combination of AQ and MBP provided viable options for the replacement of SC in commercial whipped cream.

Effect of Distiller's Dried Grain with Soluble (DDGS) in Artificial Feed on the Growth, Protein Retention, and Survival Rate of the Pacific White Shrimp (Litopenaeus vannamei)

Effect of Distiller's Dried Grain with Soluble (DDGS) in Artificial Feed on the Growth, Protein Retention, and Survival Rate of the Pacific White Shrimp (Litopenaeus vannamei)

Growth performance and intestinal histology of juvenile pirarucu fed with increasing levels of soybean meal

The aim of this study was to evaluate the inclusion of different levels of soybean meal in pirarucu’s diet. 200 pirarucu juveniles (152.15 ± 0.8 g) were distributed in 20 polyethylene tanks with a continuous water flow system. A completely randomized experimental design was used, with five treatments (n = 4) containing 0, 10, 20, 30 and 40% of soybean meal inclusion levels. Growth performance was measured as specific growth rate, feed conversion, weight gain and survival. Body composition, protein retention rate and histopathological changes in the intestine were analyzed. The different treatments did not affect weight gain, specific growth rate and survival. The body composition of the fish was affected by treatments for ash and ether extract and the IHS was also affected. The diet with 40% soybean meal compromised feed conversion rate. Additionally, the distal intestine of fish fed with the same diet showed a reduction in the height of mucosal folds and a loss of supranuclear vacuolation in enterocytes. Based on these results, the inclusion of up to 30% of soybean meal in the diet of juvenile pirarucu is possible without negative effects on performance and enteric morphology.

Effects of the Roasting-Assisted Aqueous Ethanol Extraction of Peanut Oil on the Structure and Functional Properties of Dreg Proteins.

The effects of the roasting-assisted aqueous ethanol extraction of peanut oil on the structure and functional properties of dreg proteins were investigated to interpret the high free oil yield and provide a basis for the full utilization of peanut protein resources. The roasting-assisted aqueous ethanol extraction of peanut oil obtained a free oil yield of 97.74% and a protein retention rate of 75.80% in the dreg. The water-holding capacity of dreg proteins increased significantly, and the oil-holding capacity and surface hydrophobicity decreased significantly, reducing the binding ability with oil and thus facilitating the release of oil. Although the relative crystallinity and denaturation enthalpy of the dreg proteins decreased slightly, the denaturation temperatures remained unchanged. Infrared and Raman spectra identified decreases in the C-H stretching vibration, Fermi resonance and α-helix, and increases in random coil, β-sheet and β-turn, showing a slight decrease in the overall ordering of proteins. After the roasting treatment, 62.57-135.33% of the protein functional properties were still preserved. Therefore, the roasting-assisted aqueous ethanol extraction of peanut oil is beneficial for fully utilizing the oil and protein resources in peanuts.

Effects of Enzyme Treatment and Carrier Agents on Chemical and Physical Properties of Almond Protein-Based Product

There has been an emerging trend towards the research of plant-based proteins over the past few years; however, there has been limited conductive observation of plant-based proteins from almond by-products, as well as the potential of using Flavourzyme and different carrier agents to obtain an instant protein-based powder. The purpose of this study was to investigate the effects of Flavourzyme at various concentrations (0, 0.5, 1, 1.5, 2, and 2.5%) and incubation times (30, 60, 90, 120, and 180 min), as well as carrier agents at different ratios with a 20% total concentration on the physicochemical properties of almond protein-based products using freeze-drying (FD). The results showed a higher protein content (p-value ≤ 0.05) using 1.5% Flavourzyme for 120 min compared to the other levels. There was no significant difference (p-value > 0.05) in the protein retention rate after freeze-drying of the samples. However, the addition of Maltodextrin (MA), Gum Arabic (GA), and Inulin (IN) encapsulants improved the physical and functional characteristics of freeze-dried almond protein-based powder (FDAP). However, the solubility of the powder is moderate. Water-holding-capacity (WHC) and Oil- Holding Capacity (OHC) are inversely proportional, where GA-coated powder is the most hydrophobic (17.72 ± 0.87 mL oil/g) and IN-encapsulated powder is the most hydrophilic (15.00 ± 0.87 mL water/g). In conclusion, IN could be a potential encapsulant for almond protein-based powder, because powder produced from IN or MA: IN is acceptable in terms of physical parameters, and IN can also enhance fiber content in the final product.

Dietary Effects of Lipid and Protein Levels on Growth, Feed Utilization, Lipid Metabolism, and Antioxidant Capacity of Triploid Rainbow Trout (Oncorhynchus mykiss).

This study investigated the dietary effects of lipid and protein levels on growth performance, feed utilization, body composition, lipid metabolism, and antioxidant capacity of triploid rainbow trout, Oncorhynchus mykiss. A 3 × 2 two-factor design was conducted with three crude lipid levels of 4%, 9%, and 14% (L4, L9, and L14) and two crude protein levels of 44%, 49% (P44, P49). Therefore, a total of six diets were prepared as P44/L4, P44/L9, P44/L14, P49/L4, P49/L9, and P49/L14. Triploid rainbow trout (initial body weight 65.0 ± 0.1 g) were fed one of the six diets for 80 days. The results showed that weight gain (WG), protein retention (PR), and protein efficiency rate (PER) significantly increased with increasing the dietary lipid level at the same crude protein level, while feed conversion ratio (FCR) and hepatosomatic index significantly decreased (P < 0.05). At the same lipid level, there was no difference in WG, FCR, PR, PER between 44% and 49% crude protein group (P > 0.05). The P49/L14 group had the highest WG (374.6%) and lowest FCR (1.25), while P44/L14 group had the highest PER (1.80) and PR (25.06%) with similar WG and FCR to P49/L14 group. The crude lipid contents in whole fish were significantly higher in the L14 group than those in the L4 and L9 groups (P < 0.05). Muscle n-3 PUFAs, n-6 PUFAs, and PUFAs levels were positively correlated with dietary lipid level, while n-6 PUFAs was negatively correlated with dietary protein level. Dietary protein, dietary lipid, and their interaction significantly affected hepatic malondialdehyde (MDA) content, aspartate aminotransferase, lipase (LPS), and fatty acid synthase (FAS) activities (P < 0.05). In both P44 and P49 groups, LPS and FAS activities increased with increasing the dietary lipid level. MDA content significantly decreased in the P44 group and increased in the P49 group with increasing the dietary lipid level (P < 0.05). As dietary protein level increased, serum total cholesterol level increased, while hepatic phosphoenolpyruvate carboxykinase activity decreased. With increasing the dietary lipid level, total superoxide dismutase, catalase, total nitric oxide synthase, and fructose-1,6-bisphosphatase activities showed an increasing trend, while the opposite was true for alanine aminotransferase activity. In conclusion, based on growth performance and feed utilization, dietary protein level of 44% and dietary lipid level of 14% (measured value, 43.71% and 13.62%) were suggested for young triploid rainbow trout.

The Linear-Logistic Model: A Novel Paradigm for Estimating Dietary Amino Acid Requirements.

This study aimed to determine whether current methods for estimating AA requirements for animal health and welfare are sufficient. An exploratory data analysis (EDA) was conducted, which involved a review of assumptions underlying AA requirements research, a data mining approach to identify animal responses to dietary AA levels exceeding those for maximum protein retention, and a literature review to assess the physiological relevance of the linear-logistic model developed through the data mining approach. The results showed that AA dietary levels above those for maximum growth resulted in improvements in key physiological responses, and the linear-logistic model depicted the AA level at which growth and protein retention rates were maximized, along with key metabolic functions related to milk yield, litter size, immune response, intestinal permeability, and plasma AA concentrations. The results suggest that current methods based solely on growth and protein retention measurements are insufficient for optimizing key physiological responses associated with health, survival, and reproduction. The linear-logistic model could be used to estimate AA doses that optimize these responses and, potentially, survival rates.

Gross energy levels in practical diets for the Amazon river prawn postlarvae, Macrobrachium amazonicum

The present study evaluated the effect of different energy levels (15.07, 15.91, 17.17, 18.00, and 19.68 kJ g-1 of diet) on isoproteic practical diets for Macrobrachium amazonicum during the nursery phase on the zootechnical performance and proximate composition of the whole body. Postlarvae with a mean weight of 0.043 ± 0.01 g were stored in 25 experimental units, at 150 animals per m2, in a completely randomized design with five treatments and five replicates. The post-larvae were evaluated at the end of the experimental period according to the pre-established performance parameters. The analysis of variance for regression (α = 0.05) allowed us to estimate that the maximum final weight was observed in the treatment with 16.74 kJ g-1. In contrast, the lowest apparent feed conversion was observed at the 16.43 kJ g-1 level. The best values were found in 17.29 and 17.50 kJ g-1, respectively, for the energy and protein retention rates. As the best fit of the equation was presented for the energy retention ratio (R2 = 0.63), which approached the treatment of 17.17 kJ g-1, this energy level is recommended in postlarvae diets.

The properties and formation mechanism of ovalbumin-fucoidan complex

The polymeric materials formed by proteins and polysaccharides through molecular interactions have attracted public attention. In this study, a novel binary complex consisting of ovalbumin (OVA) and fucoidan (FUC) was obtained by electrostatic self-assembly. The self-assembly properties and the formation mechanism of the OVA-FUC binary complex were investigated by changing the charging degree and density of complex through altering pH value and polysaccharides proportion. Structural changes during the OVA-FUC electrostatic self-assembly process were investigated by a phase diagram, ζ-potential, and particle size. The optimal conditions for preparing soluble OVA-FUC binary complex were determined by the protein retention rate and insoluble solids content. Results showed that the soluble OVA-FUC binary complex could be obtained at the pH of 3.5 to 5, and the insoluble OVA-FUC binary complex was generated at the pH of 2.5 to 3.5. The OVA-FUC binary complex (19 ± 0.29 mN/m) possessed a medium ability to reduce interfacial tension of the water-oil interface compared with OVA (15 ± 1.13 mN/m) and FUC (24 ± 0.3 mN/m), indicating that OVA-FUC binary complex has good amphiphilicity and can be applied as a potential pH-controlled emulsifier in function food systems for delivering bioactive substances.

Physicochemical properties of fluid milk with different heat treatments and HS-GC-IMS identification of volatile organic compounds

To improve understanding of the effects of industrial heating processes on its physiochemical and flavour properties, fluid milk was evaluated for protein denaturation and flavour volatiles after high-temperature short-time (HTST), indirect ultra-high temperature (IND-UHT) and direct ultra-high temperature with direct steam infusion (INF-dUHT) treatments. Protein denaturation was evaluated by particle size, free sulphydryl content, fluorescence spectra, native whey protein retention rate and microstructure. Volatile organic compounds (VOCs) were compared by headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS). HTST treatment exerted the lowest negative effect on the aggregation and denaturation of native whey proteins including α-lactalbumin, β-lactoglobulin and lactoferrin, followed by INF-dUHT. IND-UHT caused the most severe denaturation of native whey proteins. HTST-treated milk was characterised by a high level of low molecular weight ketones and INF-dUHT milk possessed the greatest abundance of aldehydes, whereas IND-UHT milk exhibited the highest contents of high molecular weight methyl ketones, which contributed to an unpleasant aroma.

A magnetic fluorescent spirochetes micromotor: Dynamic monitoring and in situ sterilization of foodborne pathogens

Foodborne disease caused by foodborne pathogens is one of the most common, widespread and influential diseases in the world and poses a great threat to food safety and human health. It is worth noting that nondestructive detection and in situ sterilization of foodborne pathogens are of great significance for food nutritional retention. In this research, we constructed an aptamer fluorescent micromotor based on spirulina (SP) using aptamers as molecular recognition elements, nontoxic carbon quantum dots (CQDs) as fluorescent signal carriers, and polydopamine (PDA) as a thermal element to realize the accurate detection and in situ sterilization of pathogens in liquid food through the magnetic actuation of magnetized SP. It was proven that the detection limit of the aptamer fluorescent micromotor is 4 CFU/mL, the bactericidal rate can reach 100 %, and the detection recovery of the micromotor in milk samples is 92.89–106.96 %. In addition, the results showed that the protein retention rate of the micromotor after 30 s of near-infrared irradiation (NIR) was better than that of traditional pasteurization, which protected the food substrate as much as possible and provided great potential for practical application in food.

Link between Energy Investment in Biosynthesis and Proteostasis: Testing the Cost-Quality Hypothesis in Insects.

The energy requirement for biosynthesis plays an important role in an organism's life history, as it determines growth rate, and tradeoffs with the investment in somatic maintenance. This energetic trait is different between painted lady (Vanessa cardui) and Turkestan cockroach (Blatta lateralis) due to the different life histories. Butterfly caterpillars (holometabolous) grow 30-fold faster, and the energy cost of biosynthesis is 20 times cheaper, compared to cockroach nymphs (hemimetabolous). We hypothesize that physiologically the difference in the energy cost is partially attributed to the differences in protein retention and turnover rate: Species with higher energy cost may have a lower tolerance to errors in newly synthesized protein. Newly synthesized proteins with errors are quickly unfolded and refolded, and/or degraded and resynthesized via the proteasomal system. Thus, much protein output may be given over to replacement of the degraded new proteins, so the overall energy cost on biosynthesis is high. Consequently, the species with a higher energy cost for biosyntheses has better proteostasis and cellular resistance to stress. Our study found that, compared to painted lady caterpillars, the midgut tissue of cockroach nymphs has better cellular viability under oxidative stresses, higher activities of proteasome 20S, and a higher RNA/growth ratio, supporting our hypothesis. This comparative study offers a departure point for better understanding life history tradeoffs between somatic maintenance and biosynthesis.

A high-protein retained PES hemodialysis membrane with tannic acid as a multifunctional modifier

A high protein retention polyethersulfone (PES) membrane was prepared by nonsolvent-induced phase separation and surface coating, which exhibited enhanced hemocompatibility and antioxidant stress performance. The cross-linked network was constructed by tannic acid (TA) and alpha-lipoic acid (α-LA) on the surface of the membrane, which controlled the pores to a reasonable size. The enrichment of heparin-like groups on the membrane surface, implemented by “hydrophobic interaction” and “click reaction”, confers anticoagulant properties; the presence of a large number of phenolic hydroxyl groups from TA and the introduction of α-LA allows the modified membranes to intervene in oxidative stress. The hemocompatibility characterizations included plasma recalcification time (PRT), activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT) and hemolysis rate (HR). Additionally, the DPPH ABTS radical scavenging capacity was tested to evaluate the antioxidant performance. The results show that the modified membrane presents an outstanding protein retention rate (99.3%) along with permeability. In addition, the PRT is prolonged to 341.7 s, and the DPPH• scavenging ability reaches 0.74 µmol•cm-2. The membranes can be easily prepared and present excellent comprehensive performance. This work provides a simple and facile strategy for the fabrication of hemodialysis membranes with controllable pore sizes.

Body yield, growth performance, and haematological evaluation of Nile tilapia fed a diet supplemented with Saccharomyces cerevisiae

The present study evaluated growth performance, body yield and blood samples of Nile tilapia (Oreochromis niloticus) after dietary supplementation with Saccharomyces cerevisiae. Sixty Nile tilapia (155.5 ± 2.15 g) were randomly distributed in ten experimental units of 800 L (six fish per unit) and divided into two groups with five replications each. One group of fish received a diet containing S. cerevisiae (SAC), while the control (CTL) group received a diet without the addition of the yeast. The fish remained in an experimental regime for 120 days. After this period, all fish were submitted to biometric analysis to determine growth performance, and blood samples were collected for haematological analysis. Subsequently, the fish were euthanized and eviscerated for further evaluation, including carcass weight, fillet yield, and centesimal fillet composition, as well as viscerosomatic, hepatosomatic and digestivesomatic indexes. Fish fed the diet containing S. cerevisiae showed a significant increase in the number of erythrocytes, lymphocytes, and monocytes, as well as weekly weight gain, feed efficiency, protein retention rate and productivity. Furthermore, in animals of the SAC group, pH in meat was reduced, and fillet yield was increased by 6.53 % compared to the control group. Therefore, dietary supplementation with S. cerevisiae showed probiotic properties in Nile tilapia during the fattening phase, along with the improvement of haematological indexes and optimization of zootechnical indicators relevant to the tilapia industry.

Holder Pasteurization: Comparison of Water-Bath and Dry-Tempering Devices.

BackgroundHuman milk (HM) for premature infants is frequently Holder pasteurized (heated at 62.5 ± 0.5°C for 30 min) despite its detrimental effects on heat-sensitive milk components. This tolerated compromise ensures HM's microbial safety while less detrimental methods like short-time HM treatments (HTST) are still being evaluated. Dry-tempering devices (DT-HoP) were recently introduced in clinical practice due to hygienic concerns about water-based Holder pasteurizers (WB-HoP). Evidence on the impact of such dry-tempering devices on HM quality is lacking. The aim of this study was to compare protein retention rates after DT-HoP, WB-HoP and HTST.MethodsWe colorimetrically determined alkaline phosphatase activity (ALP), concentrations of secretory immunoglobulin A (sIgA), and lactoferrin (LF) before and after DT-HoP, WB-HoP and HTST.ResultsALP was below the detection limit after HoP, but retained 52.8 ± 13% activity after HTST (p < 0.01). Secretory IgA (WB-HoP = 73.2 ± 13.5% vs. DT-HoP = 57 ± 14%, p = 0.0018) and LF retention (WB-HoP=47 ± 40% vs. DT-HoP=25 ± 8%, p = 0.07) differed between the two HoP modes. Again, retention was better maintained after HTST compared to HoP (80.4 ± 23% sIgA and 70 ± 42% LF concentration, all p < 0.01).ConclusionDry-tempering milk lowers even further the quality of HM when performing HoP compared to water-bath pasteurization, while HTST warrants continued evaluation for clinical application.

Effects of three feeding strategies (self‐feeders, automatic feeding and apparent satiety) on growth performance, haematological parameters, waste excretion and feed cost in Amazonian fish ( Colossoma macropomum )

A 127-day experiment was conducted to evaluate the effect of feeding strategies on juvenile tambaqui's (Colossoma macropomum) growth, body composition, haematological and biochemical parameters, excretion pattern and economic indices. Fifteen tanks randomly stocked 150 juvenile tambaqui (82.0 ± 0.8 g, mean ± SEM) subjected to three feeding strategies (n = 5): self-feeder system (T1); automatic-feeding with three set meals/day (T2) and apparent satiety with three meals/day (T3). The results revealed that fish T1 and T3 showed the best feed intake, feed conversion ratio, protein efficiency ratio and protein retention rate (p < 0.05). However, no significant differences were observed in growth, survival, haematological parameters, body composition and total ammonia nitrogen excretion among treatments (p > 0.05). Cortisol obtained a significantly higher value for fish T3 (122.92 ± 5.75 ng/ml), with a low water phosphorus value for fish T1 (0.43 ± 0.06 mg/L). Lastly, the feed cost based on the values deriving from diets revealed better indices (variable cost, unitary contribution margin and contribution margin index) for fish T1 and T3. In short, our findings suggest the benefits of using self-feeders for tambaqui aquaculture.

Effect of dietary fish meal replacement with spray dried chicken plasma on growth, feed utilization and antioxidant capacity of largemouth bass (Micropterus salmoides)

The present study was aimed to explore the influence of graded replacing fish meal (0.00%, 14.29%, 28.57%, 42.86%, and 57.14%) with spray dried chicken plasma (SDCP) on growth performance, feed utilization, and antioxidant capacity of largemouth bass. Triplicate groups of fish (initial weight: 10.05 ± 0.05 g) were fed experimental diets twice daily for 8 weeks. Results indicated that specific growth rate and feed intake of fish were not remarkably influenced with the replacement of fish meal. Meanwhile, no significant difference was observed in feed intake and feed efficiency ratio among treatments. The inclusion of SDCP significantly elevated crude protein content of muscle, liver and whole fish body, which resulted in the increased protein retention rate. Meanwhile, the lipid retention rate was also significantly increased with the replacement of fish meal. The replacement of 57.14% fish meal with SDCP significantly reduced the content of lipid peroxidation product malondialdehyde. Meanwhile, the total antioxidant capacity and catalase activity was significantly higher in fish fed the diet with replacement of 57.14% fish meal compared to the control group. In above, 57.14% fish meal could be substituted by SDCP in diets for largemouth bass under this experimental condition.

Flexible Zr-MOF anchored polymer nanofiber membrane for efficient removal of creatinine in uremic toxins

High-performance and low-cost hemodialysis membranes are urgently needed by patients suffering from end-stage renal disease. Here, we designed a flexible multifunctional Zr-MOF anchored polyacrylonitrile (PAN) nanofiber membrane (UAPNFM), which has good adsorption, dialysis, and regeneration ability. A novel adhesive layer modification method was used to make UIO-66-(COOH) 2 nanocrystals grow in-situ on the composite nanofibers. The UIO-66-(COOH) 2 nanocrystals were uniformly and stably anchored on the nanofibers with the content of 54.99 wt%. The obtained UAPNFM has the capability to effectively remove uremic toxins with excellent retain protein rate. The Langmuir isotherm and pseudo-second-order kinetic model can be applied to better describe the adsorption process. The maximum adsorption capacity of UAPNFM for creatinine reached 168.63 mg/g. After 4 h of simulate dialysis, the clearance rate of creatinine was 82.48% and the protein retention rate of bovine serum albumin (BSA) by the UAPNFM was 93.09%. In addition, after four cycles, the removal efficiency for creatinine still remained at 82.31%. The results show that the UAPNFM has good regenerability. Moreover, the composite nanofiber membrane exhibited satisfactory blood compatibility. Therefore, this unique flexible Zr-MOF anchored polymer composite nanofiber membrane with an outstanding creatinine removal performance provides a new opportunity for cost reduction for clinical hemodialysis. • A flexible multifunctional Zr-MOF anchored nanofiber membrane is prepared. • The UAPNFM has excellent blood compatibility. • The UAPNFM shows high adsorption capacity towards creatinine. • The UAPNFM could effectively remove uremic toxins with excellent retain protein rate. • The UAPNFM has great application prospect in low-cost clinical blood purification.

Effect of pond fertilization on growth performance of pirarucu (Arapaima gigas) during grow-out phase

Fertilization of aquaculture ponds has been pointed out as an efficient practice to improve fish feed conversion and growth performance. In this way, the present study aimed to assess the effect of pond fertilization on the growth performance, body composition, and water quality of juvenile pirarucu Arapaima gigas reared in earthen ponds (600 m²) during the grow-out phase. Two fertilized and two non-fertilized ponds were stocked with 208 juvenile pirarucus (19.9 ± 3.6 g and 15.0 ± 0.9 cm) and reared for 100 days. All four ponds were limed before the study. Ponds were fertilized before fish were stocked and weekly until the end of the experiment, and fish offered feed until apparent satiation. Pirarucu reared in fertilized ponds presented higher final weight (20%) and biomass (19%), further to lower feed intake and feed conversion rate (1.31) than fish reared in non-fertilized ponds (1.61). Pond fertilization did not affect the fish coefficient of variation, which was reduced over the culture cycle. The body composition of fish reared in fertilized ponds presented higher water content, protein, and energy retention rates and lowered crude fat and energy. Fertilized ponds presented lower transparency levels and higher pH from the 50th day of culture, whereas ammonia concentration was higher in the fertilized ponds in the first 25 days. Therefore, pond fertilization is a recommended practice for pirarucu during the grow-out phase.

The Addition of Immunostimulant in Self-Formulated Feed to Improve Immunity and Growth of Juvenile Cobia (Rachycentron canadum)

The aims of the experiment were to determine optimum dietary immunostimulant level in self-formulated on nonspecific immune response and growth performance of juvenile cobia fish. Fish were kept in net cages (0.8 x 0.8 x 0.6 m 3 ) installed in fiberglass tanks which were completed with aeration and flow-through water system for 30 days. Design of the study was completely randomized design with 4 treatments, each consisting of 3 replications. Initial density was 50 fish for each replication with average body weight 4.69 g. the self-formulated feed (crude protein 46% and lipid 9%) containing three levels of immunostimulant additional levels, namely A (0.3%), B (0.5%), and as control, K (commercial feed as first control) and M (0.0% as second control without added immunostimulant. The data observed were growth performance which were consisted of absolute weight, total feed consumption, survival rate, specific growth rate, feed conversion rate and protein retention and mortality rate after challenge test with LD50 (1.0 x 10 9 CFU/ml) of pathogenic bacteria Vibrio alginolyticus. The growth performances showed that fish fed with addition of immunostimulant 0,3% (A) obtained higher absolute weight values and significantly different (p&lt;0,05) from M, but not significantly different from K. Challenge test at the end of the study showed that treatment A had lower mortality compared to other treatments which was indicated had higher immunity level compare to other treatments. Based on the results above, it can be concluded that the self-formulated feed with added immunostimulant 0.3% (0.7% total in the feed) showed the survival rate and optimal growth performance of juvenile cobia .