Search Results (49)

The growing demand for sustainable food sources requires the efficient use of aquaculture by-products. This study aimed to optimize enzymatic hydrolysis conditions for the simultaneous recovery of fish protein hydrolysate (FPH) and oil from rainbow trout (Oncorhynchus mykiss) processing by-products. Hydrolysis was performed at different temperatures (30–50 °C), enzyme concentrations (0.5–1.5%), and durations (30–90 min), and the optimal conditions were determined as 40 °C, 1% enzyme concentration, and 60 min. Under these conditions, oil yield reached 11.46%, while quality indices remained within acceptable limits (peroxide value: 1.78–3.47 meq O₂/kg; thiobarbituric acid reactive substances: 0.41–1.41 mg MDA/kg; free fatty acids: 0.27–4.12%). Fatty acid analysis revealed 22.5% saturated, 46.31% monounsaturated, and 23.52% polyunsaturated fatty acids, including notable levels of EPA and DHA. The protein hydrolysates obtained under optimized conditions contained 22.61% protein and essential amino acids, accounting for 52.4% of the total amino acid content, confirming their high nutritional value. Overall, the findings demonstrate that rainbow trout by-products can be effectively valorized through enzymatic hydrolysis to produce oil and protein hydrolysates of acceptable quality, which may serve as alternative ingredients for food and feed applications. Full article

Hydrolyzed protein is increasingly used in pet food, especially for animals with adverse reactions to food or gastrointestinal issues. This randomized, double-blind controlled trial evaluated the effects of a diet containing hydrolyzed anchovy protein on the gut health of healthy adult West Highland white terriers (5 males, 25 females; 5.6–9 kg). The dogs were randomly assigned to a control group (CTR, n = 15), receiving a standard commercial diet, or a treatment group (TRT, n = 15), fed a diet partially replacing anchovy meal with hydrolyzed anchovy protein for 42 days. All the dogs underwent a veterinary health check at baseline (T0) and remained healthy throughout the study. The food and water intake were recorded daily. The body weight (BW), body condition score (BCS, 1–9), and fecal score (FS, 1–7) were assessed at days 0, 21, and 42. Fecal samples were collected at T0 and T42 to measure calprotectin, cortisol, and putrefactive compounds (indole and skatole). No significant differences were found between the groups in the BW, BCS, FS, calprotectin, or cortisol. However, the TRT group showed a significant reduction in fecal indole and skatole. The results suggest that hydrolyzed anchovy protein may improve gut fermentation and support better digestive health in dogs, leading to reduced fecal odor and increased owner satisfaction. Full article

Soybean flours are widely used as a protein-rich ingredient in fish aquafeeds, and to obtain value-added compounds after a previous treatment with proteases. Additionally, non-starch polysaccharidases (NSPases) enhance dietary protein bioaccessibility and have been used as feed additives. In this study, defatted soybean flour was hydrolyzed using Sparus aurata gastric proteases and varying doses of a commercial blend of acidic NSPases. Reactions occurred at 25 °C for 3 h under typical fish stomach pH conditions (3.5–5.6). We modeled the hydrolytic process using response surface methodology, focusing on the released peptides and carbohydrates. The main finding was the efficient control of the degree of protein hydrolysis. We achieved 6–25% hydrolysis for peptides below 10 kDa by adjusting the carbohydrase dose and reaction pH. This work confirms that acidic commercial NSPases improve soybean flour protein hydrolysis when combined with S. aurata gastric proteases. Full article

This study was conducted to investigate the effects of the addition of dried mealworm, hydrolyzed mealworm, fermented poultry by-product meal (FPBM), and hydrolyzed fish soluble protein (HFSP) on the growth performance, nutrient digestibility, fecal score, and blood profiles of weaning pigs. A total of 40 (21-day-old) weaned piglets ([Yorkshire × Landrace] × Duroc) with an initial average body weight (BW) of 7.14 ± 1.29 kg were randomly assigned to one of four treatments for 35 days. There were four treatment groups with five replicates and two pigs (male and female) per pen. The dietary treatment included TRT1, a basal diet + 10% dried mealworm; TRT2, a basal diet + 10% hydrolyzed mealworm; TRT3, a basal diet + 10% fermented poultry by-product meal (FPBM); and TRT4, a basal diet + 10% hydrolyzed fish soluble protein (HFSP). The inclusion of FPBM in weaning pig diets had a significant effect on the blood profile with blood urea nitrogen (BUN) levels (p < 0.05), but not on other blood profiles of serum IGF-1, IgG, and IgA concentrations. BUN concentration decreased in response to the dietary inclusion of FPBM (p = 0.019). BUN concentration decreased and was at its lowest with FPBM (6.3 mg/dL), followed by hydrolyzed mealworm (7.3 mg/dL), while increasing with dried mealworm and HFSP (8.5 mg/dL). There was no significant difference in the growth performance, nutrient digestibility, and fecal score of piglets fed a basal diet with dried mealworm, hydrolyzed mealworm, FPBM, and HFSP. Hence, the addition of fermented poultry by-products in weaning pigs’ diets decreases the blood urea nitrogen, without any detrimental effect on performance, nutrient digestibility, or fecal score. Full article

As the global demand for aquafeed ingredients continues to rise, sourcing sustainable alternatives is crucial for aquaculture industries. This study aimed to explore the potential of enzymatic hydrolysate as a substitute for traditional fishmeal and soybean meal in diets for juvenile sea cucumbers (Apostichopus japonicus). Three isonitrogenous (15% crude protein) and isolipidic (2.4% crude lipid) diets were formulated: a control diet containing 10% fishmeal and 5% soybean meal and two experimental low-fishmeal (8%) and low-soybean meal (0%) diets, supplemented with either 8% enzymatically hydrolyzed fish stickwater (EFS) or 8% enzymatically hydrolyzed chicken pulp (ECP), designated as Control, EFS, and ECP, respectively. Juvenile sea cucumbers (initial body weight, 0.25 ± 0.01 g) were fed these diets for 84 days to evaluate the effects of ECP and EFS on their growth performance, antioxidant capacity, and inflammatory responses. The results revealed significantly higher final weights and specific growth rates in both experimental groups than the control (p < 0.05). The proximate chemical compositions of sea cucumber were less affected by the diets (p > 0.05). Compared with the control group, significantly elevated levels of digestive enzymes, antioxidants, and lysozyme, together with lower malondialdehyde levels, were recorded in the experimental groups (p < 0.05). ECP appeared to exhibit greater potency than EFS in enhancing growth performance and antioxidant capacity. Similar trends were observed in the mRNA expression of SOD, CAT, and inflammation-related genes across the groups. In a nutshell, both ECP and EFS supplemented in a low-fishmeal and low-soybean meal diet could effectively promote the growth and health of A. japonicus, with ECP showing a superior effect over EFS. These findings suggest that enzymatic hydrolysate demonstrates potential as a viable alternative to traditional fishmeal and soybean meal in diets for sustainable sea cucumber aquaculture. Further investigations are warranted to reveal its underlying mechanism. Full article

Marine-derived foods, often called blue foods, are promising sustainable alternatives to conventional food sources owing to their abundant amino acids and high protein content. Current treatments for hyperuricemia, a chronic condition attributed to purine metabolism disorders, are associated with various side effects. Novel peptide xanthine oxidase inhibitors have been discovered in the hydrolyzed products of marine fish and invertebrate proteins, which have demonstrated promising therapeutic potential by reducing uric acid levels in vitro and in vivo. This review explores the potential therapeutic effects of xanthine oxidase inhibitors derived from marine fish and invertebrates, summarizes the methods for extracting bioactive peptides from marine organisms, and emphasizes the impact of different proteases on the structure–activity relationship of bioactive peptides. The hypouricemic effects of these bioactive peptides warrant further verification. There is consensus on the in vitro chemical methods used to verify the xanthine oxidase inhibitory effects of these peptides. Considering several cell and animal model development strategies, this review summarizes several highly recognized modeling methods, proposes strategies to improve the bioavailability of bioactive peptides, and advocates for a diversified evaluation system. Although the screening and evaluation methods for antihyperuricemic peptides have been shown to be feasible across numerous studies, they are not optimal. This review examines the deficiencies in bioavailability, synthesis efficiency, and evaluation mechanisms in terms of their future development and proposes potential solutions to address these issues. This review provides a novel perspective for the exploration and application of marine-derived hypouricemic bioactive peptides. Full article

Fish protein hydrolysates used in larval diets have been prepared from a variety of fish species, with different enzymes used to hydrolyze the protein. This study’s objectives were to determine the effect of the dietary inclusion of fish muscle hydrolysates obtained from species-specific muscle/enzymes—versus hydrolysates produced from muscle/enzymes of a different species—on the growth performance, survival, skeletal development, intestinal peptide uptake, and muscle-free amino acid (FAA) composition of larval Walleye (Sander vitreus). Eight protein products were obtained for this study, comprising an unhydrolyzed and hydrolyzed product from each combination of muscle/enzymes from Walleye and Nile tilapia (Oreochromis niloticus). Four diets were produced, and the dietary protein was provided in a 50/50 ratio of unhydrolyzed and hydrolyzed protein from the respective muscle/enzyme combination. Four groups were fed one of the corresponding formulated diets, and two groups of larvae, fed a commercial starter diet and Artemia, respectively, served as reference groups. Larval Walleye fed the diet containing protein produced with the species-specific muscle and enzymes had a significantly higher weight after the study—30% higher than any other group. A significant interaction effect between muscle and enzyme sources on the growth of Walleye larvae was observed. The species-specific combination also led to a significant increase in postprandial FAA and indispensable amino acid concentrations in muscle. No significant differences were observed between the hydrolysate-fed groups in survival, deformity occurrence, or peptide uptake. Each hydrolysate-based diet significantly reduced skeletal deformities and survival compared to the commercial diet. The results of this study suggest that species-specific muscles and enzymes produce a more optimal dietary protein source for larval fish than non-species-specific products. Further research should focus on improving the physical properties of the formulated diets to reduce possible leaching of hydrolyzed protein and improve the survival of fish larvae. Full article

Among 79 Bacillus spp. isolated from Miang, a fermented tea in north Thailand, 17 Bacillus strains were selected with probiotic potential in Nile tilapia culture based on the capabilities of bacteriocin production and associated antimicrobial activities against fish pathogens, Aeromonas hydrophila and Streptococcus agalactiae. However, only six isolates were selected for further extensive studies based on the strength of their antimicrobial activities and their tolerance against simulated gastrointestinal conditions. The molecular identification by 16S rRNA gene sequence analysis revealed that five isolates, K2.1, K6.1, K7.1, K15.4, and K22.6, were Bacillus tequilensis, and the isolate K29.2 was Bacillus siamensis. B. siamensis K29.2 showed complete susceptibility to antibiotics tested in this study, while B. tequilensis K 15.4 showed moderate resistance to some antibiotics; therefore, both strains were selected as potential probiotic bacteria. B. tequilensis K15.4 and B. siamensis K29.2 were capable of the production and secretion of extracellular protease and polysaccharide degrading enzymes, including cellulase, xylanase, and β-mannanase. The tannin tolerant test also demonstrated their ability to grow on selective agar plates and secrete cellulase and β-mannanase in the presence of hydrolyzable tannin. In addition, in vitro digestion of commercial fish substrate revealed that the extracellular enzymes produced by both strains efficiently reacted with feed protein and polysaccharides. Based on the results from this study, B. siamensis K29.2 was deemed to have the highest potential multifunctional probiotic qualities for application in Nile tilapia culture, while the antibiotic-resistant gene in B. tequilensis K15.4 must be clarified before field application. Full article

In Experiment 1, a total of eighteen crossbred ([Landrace × Yorkshire] × Duroc) barrows with an initial body weight of 6.74 ± 0.68 kg were randomly divided into three dietary treatments (one pig per cage and six replicates per treatment) and housed in metabolic cages that were equipped with a feeder and slatted floor to collect urine and feces. In Experiment 2, a total of 96 crossbred ([Landrace × Yorkshire] × Duroc) barrows with an initial body weight of 8.25 ± 0.42 kg were used in the 6-week trial. The pigs were randomly divided into three dietary treatments (three pigs per pen and eight replicates per treatment). In Experiment 1, nutrient composition of defatted black soldier fly larvae meal (BLM) was superior to that of hydrolyzed BLM but lower than that of fish meal (FM). Also, defatted BLM and FM had better apparent total track digestibility (ATTD) of crude protein (CP) and better nitrogen retention (p < 0.05) than hydrolyzed BLM, but there was no significant difference (p > 0.05) between defatted BLM and FM. In Experiment 2, defatted BLM improved (p < 0.05) average daily gain (ADG), feed conversion ratio (FCR), and feed cost per kg gain (FCG) compared with FM. Defatted BLM could replace soybean meal and fish meal as an alternative protein source for weaning pigs. Full article

The aim of this research is to explore the potential effects of two microalgae-based additives included in finishing feeds on the quality and shelf-life of seabream fillets. In a 41-day feeding trial, seabream specimens were fed with experimental aquafeeds containing 10% of the bioactive supplements. These additives consisted of a blend of Nannochloropsis gaditana and Arthrospira platensis biomass, which was utilized as either raw (LB-CB) or enzymatically hydrolyzed (LB-CBplus). A control group received a microalgae-free diet. The results showed that the functional aquafeeds improved the nutritional profile of seabream fillets, increasing protein and PUFA-n3 contents while reducing the atherogenic index, especially for the LB-CBplus treatment. LB-CBplus also enhanced the texture parameters (hardness and chewiness) of fillets during the initial 5 days under cold storage. Regarding skin pigmentation, fillets showed increased greenish and yellowish coloration compared to control fish, mostly attributed to the inclusion of crude algal biomass (LB-CB). Moreover, diets enriched with microalgae additives effectively delayed muscle lipid oxidation processes under refrigeration for up to 12 days, with LB-CBplus exhibiting higher antioxidant effects. These findings highlight the potential of microalgae-based additives to enhance both the nutritional and organoleptic quality of seabream fillets. Full article

The enzymatic extraction of proteins from fish biomasses is being widely investigated. However, little or almost no research has paid attention to the exploitation of unsorted fishery biomasses. This work is part of a larger study, Part I of which has already been published, and focuses on an extensive characterization of two collagenous samples, namely gelatin (G) and hydrolyzed gelatin peptides (HGPs), extracted from a dehydrated fish biomass coming from unsorted canned yellowfin tuna side streams. The results indicate crude protein fractions of 90–93%, pH values between 3 and 5, white–yellow colors, collagen-like FTIR spectra, and 17% in terms of total amino acid content. Viscosity and the study of dynamic viscous–elastic behavior were analyzed. Thermo-gravimetric analysis was performed to assess the residual ashes. Both samples were investigated to determine their molecular weight distribution via size-exclusion chromatography, with a higher total average molecular weight for G compared to HGPs, with values of 17,265.5 Da and 2637.5 Da, respectively. G demonstrated technological properties similar to analogous marine gelatins. HGPs demonstrated antioxidant activity as per FRAP assay. All the results open up new perspectives for the potential use of these substances in biodegradable packaging, dietary supplements, and skin care cosmetics. Full article

This study investigated the antioxidant, antimicrobial, and anti-atopic dermatitis (AD) effects of a novel peptide (CP) derived from a Chromis notata by-product hydrolysate. Alcalase, Flavourzyme, Neutrase, and Protamex enzymes were used to hydrolyze the C. notata by-product protein, and the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical-scavenging activity was measured. Alcalase hydrolysate exhibited the highest ABTS radical-scavenging activity, leading to the selection of Alcalase for further purification. The CHAO-1-I fraction, with the highest ABTS activity, was isolated and further purified, resulting in the identification of the peptide CP with the amino acid sequence Ala-Gln-Val-Met-Lys-Leu-Pro-His-Arg-Met-Gln-His-Ser-Gln-Ser. CP demonstrated antimicrobial activity against Staphylococcus aureus, inhibiting its growth. In a 2,4-dinitrochlorobenzene (DNCB)-induced AD-like skin model in mice, CP significantly alleviated skin lesions, reduced epidermal and dermal thickness, and inhibited mast cell infiltration. Moreover, CP suppressed the elevated levels of interleukin-6 (IL-6) in the plasma of DNCB-induced mice. These findings highlight the potential of CP as a therapeutic agent for AD and suggest a novel application of this C. notata by-product in the fish processing industry. Full article

Considering the global increase in fish consumption, the growing side-streams coming from the fish supply chain (e.g., skin, fins, tail, heads…), also including undersized or “unwanted catches”, have been recently proposed as source of high-value bioactive compounds (e.g., peptides and fatty acids). In this case study, hydrolyzed collagen peptides (HCPs) were extracted from different parts of Mugil cephalus L. using environmentally friendly techniques such as ultrasounds and enzymatic treatments. Both a mixed biomass derived from the skin, fins, and tail, and a whole fish, were considered as starting biomass, simulating the unsorted processing side-streams and an undersized/unwanted catch, respectively. The extracted HCPs were purified in fractions (<3 KDa and >3 KDa) whose yields (about 5% and 0.04–0.3%, respectively) demonstrated the efficiency of the hydrolysis process. The extraction protocol proposed allowed us to also isolate the intermediate products, namely the lipids (about 8–10%) and the non-collagenous proteins (NCs, 16–23%), whose exploitation could be considered. Each sample was characterized using Sircol, UltraViolet-Spectra, and hydroxyproline assay, and the viability of their collagen fractions was tested on human endothelial cells. Significant effects were obtained at a fraction of <3 KDa, in particular at a concentration of 0.13 µg/mL. The T-scratch test was also performed, with positive results in all fractions tested. Full article

To assess the possibility of using a formulated diet instead of an iced trash fish diet for feeding spotted mandarin fish (Siniperca scherzeri), a 20-week feeding trial was conducted. The objective of the study was to examine the effects of the formulated diet (FG) and the iced trash fish diet (XG) on the growth performance and muscle nutrient composition of the fish. The results showed that the spotted mandarin fish fed with an XG had slightly higher survival rates, weight gain rate, fullness, hepatic index, and viscera index compared to those fed with an FG, although the differences were not significant (p > 0.05). Additionally, in terms of muscle composition, the FG group had higher levels of crude protein and ash content in the fish muscle compared to the XG group (p < 0.05). On the other hand, the crude fat content showed the opposite trend. Among the seventeen amino acids analyzed, only lysine and proline levels differed significantly between the FG and XG groups (p < 0.05). In terms of muscle-hydrolyzed fatty acids, fifteen fatty acids were detected in both groups, with arachidonic acid being exclusive to the FG group. Furthermore, significant differences in the levels of thirteen fatty acids were observed between the two groups (p < 0.05). The FG group had lower levels of saturated fatty acids compared to the XG group (p < 0.05), while monounsaturated fatty acids, polyunsaturated fatty acids, and EPA + DHA contents were higher. This study demonstrates the potential of using a formulated diet as a substitute for an iced trash fish diet in the rearing of spotted mandarin fish. However, further optimization of the formulated diet is necessary to improve the growth of spotted mandarin fish in future research. Full article

A large amount of fish side streams are produced each year, promoting huge economic and environmental problems. In order to address this issue, a potential alternative is to isolate the high-added-value compounds with beneficial properties on human health. The objectives of this study were to determine the effect of hydrolyzed fish protein and collagen samples on cell proliferation, as well as to determine the specific influence of minerals and metals on this effect and whether dietary antioxidants can enhance cell proliferation. The results of hydrolyzed fish protein and collagen samples showed negative effects on Caco-2 cell proliferation at the highest concentrations tested. Moreover, the pre-treatment of these hydrolyzates with vitamin C and E, quercetin and resveratrol increased the proliferation of bioaccessible fractions of hydrolyzated fish protein and collagen samples compared to the bioaccessible fractions without pre-treatment. The highest mineral concentrations were found for P, Ca and Mg. The metals found in the pure hydrolyzates were As, Cd, Hg and Pb; however, they appeared at almost undetectable levels in bioavailable fractions. It can be concluded that the consumption of hydrolyzates of fish by-products is an interesting strategy for complying with EFSA recommendations regarding fish consumption while at the same time reducing fish waste. Full article