Fish Protein Hydrolysate Research Articles

Exploring the Physicochemical Characteristics of Marine Protein Hydrolysates and the Impact of In Vitro Gastrointestinal Digestion on Their Bioactivity.

Fish protein hydrolysates (FPHs) were obtained from different fish sources using a combination of microbial enzymes. The industrially produced FPHs from blue whiting (Micromesistius poutassou) and sprat (Sprattus sprattus) were compared to freeze-dried FPHs generated in-house from hake (Merluccius merluccius) and mackerel (Scomber scombrus) in terms of their physicochemical composition and functionality. Significant differences (p < 0.05) were observed in the protein, moisture, and ash contents of the FPHs, with the majority having high levels of protein (73.24-89.31%). Fractions that were more extensively hydrolysed exhibited a high solubility index (74.05-98.99%) at different pHs. Blue whiting protein hydrolysate-B (BWPH-B) had the highest foaming capacity at pH 4 (146.98 ± 4.28%) and foam stability over 5 min (90-100%) at pH 4, 6, and 8. The emulsifying capacity ranged from 61.11-108.90 m2/g, while emulsion stability was 37.82-76.99% at 0.5% (w/v) concentration. In terms of peptide bioactivity, sprat protein hydrolysate (SPH) had the strongest overall reducing power. The highest Cu2+ chelating activity was exhibited by hake protein hydrolysate (HPH) and mackerel protein hydrolysate (MPH), with IC50 values of 0.66 and 0.78 mg protein/mL, respectively, while blue whiting protein hydrolysate-A (BWPH-A) had the highest activity against Fe2+ (IC50 = 1.89 mg protein/mL). SPH scavenged DPPH and ABTS radicals best with IC50 values of 0.73 and 2.76 mg protein/mL, respectively. All FPHs displayed noteworthy scavenging activity against hydroxyl radicals, with IC50 values ranging from 0.48-3.46 mg protein/mL. SPH and MPH showed the highest scavenging potential against superoxide radicals with IC50 values of 1.75 and 2.53 mg protein/mL and against hydrogen peroxide with 2.22 and 3.66 mg protein/mL, respectively. While inhibition of α-glucosidase was not observed, the IC50 values against α-amylase ranged from 8.81-18.42 mg protein/mL, with SPH displaying the highest activity. The stability of FPHs following simulated gastrointestinal digestion (SGID) showed an irregular trend. Overall, the findings suggest that marine-derived protein hydrolysates may serve as good sources of natural nutraceuticals with antioxidant and antidiabetic properties.

The use of protein hydrolysate from fish waste as part of microbiological culture media

The need to involve in the processing of significant amount of secondary protein-containing raw materials formed during fish cutting, on the one hand, and on the other hand, the shortage of a source of the protein component of microbiological nutrient media determines the relevance of the work. The goal was to study the possibility of using fish protein hydrolyzate obtained by enzymatic hydrolysis from secondary fish raw materials in microbiological nutrient media. Microbiological and physicochemical methods were used to conduct research. When optimizing the developed algorithm for the fermentation process, a mathematical model of the experiment was used with a minimum number of experiments. An algorithm has been developed for obtaining fish protein hydrolyzate from meat and bone waste from cutting pelagic fish (cod). The hydrolysis parameters were optimized: the concentration of the enzyme preparation is 1.33 % of the total mass of waste, the duration of the fermentation process – 3 hours. The characteristics of the resulting fish hydrolyzate are determined: the mass fraction of total nitrogen – 13 %, amine – 3.6 %, water – 4.6 %, sodium chloride – 2.7 %, fat – 0.3 %. An experimental fish hydrolyzate has been studied as a source of protein nitrogen in accordance with the formulation of a microbiological medium used for counting when growing colonies of microorganisms. The effectiveness of the prepared nutrient media was assessed by comparing the performance coefficients of the experimental and control nutrient media, as well as by identifying test microorganisms grown on the experimental medium. It was established that the growth pattern of test cultures both on the studied nutrient medium and on the control medium was almost the same. Test microorganisms retained their biochemical, morphological and cultural characteristics. The research results showed the possibility of using fish protein hydrolyzate obtained by enzymatic hydrolysis from secondary fish raw materials in microbiological nutrient media.

From Waste to Value: Fish Protein Hydrolysates as a Technological and Functional Ingredient in Human Nutrition.

Fish provides a low-caloric content, polyunsaturated fatty acids, many essential trace elements and is also a rich source of protein, ranging from 10% to 25%. Therefore, the production of FPH (fish protein hydrolysates) is of great interest, as the resulting products exhibit a variety of important bioactive and technological properties, making them potential ingredients for new functional foods and supplements. The aim of this review was to compile and analyze information on enzymatic hydrolysates, with particular emphasis on those derived from fish by-products, as a potential ingredient in human nutrition. Their nutritional characteristics, food safety aspects, bioactive properties, technological attributes, key influencing factors, and applications in food products were evaluated. The findings revealed that these properties are influenced by several factors, such as the raw material, enzymes used, degree of hydrolysis, and the molecular weight of the peptides, which need to be considered as a whole. In conclusion, the gathered information suggests that it is possible to obtain high-value products through enzymatic hydrolysis, even when using fish by-products. However, although numerous studies focused on FPH derived from fish muscle, research on by-products remains limited. Further investigation is needed to determine whether the behavior of FPH from by-products differs from that of muscle-derived FPH.

Sensory Analysis of Chocolate Cakes Enriched with Fish Protein Hydrolyzate (HPP)

Sensory Analysis of Chocolate Cakes Enriched with Fish Protein Hydrolyzate (HPP)

Antioxidative, Glucose Management, and Muscle Protein Synthesis Properties of Fish Protein Hydrolysates and Peptides.

The marine environment is an excellent source for many physiologically active compounds due to its extensive biodiversity. Among these, fish proteins stand out for their unique qualities, making them valuable in a variety of applications due to their diverse compositional and functional properties. Utilizing fish and fish coproducts for the production of protein hydrolysates and bioactive peptides not only enhances their economic value but also reduces their potential environmental harm, if left unutilized. Fish protein hydrolysates (FPHs), known for their excellent nutritional value, favorable amino acid profiles, and beneficial biological activities, have generated significant interest for their potential health benefits. These hydrolysates contain bioactive peptides which are peptide sequences known for their beneficial physiological effects. These biologically active peptides play a role in metabolic regulation/modulation and are increasingly seen as promising ingredients in functional foods, nutraceuticals and pharmaceuticals, with potential to improve human health and prevent disease. This review aims to summarize the current in vitro, cell model (in situ) and in vivo research on the antioxidant, glycaemic management and muscle health enhancement properties of FPHs and their peptides.

Half substitution of mineral N with fish protein hydrolysate enhancing microbial residue C and N storage and climate benefits under high straw residue return

The widespread utilization of straw return was a popular practice straw disposal for highly intensive agriculture in China, which has brought about some negative impacts such as less time for straw complete biodegradation, aggravation of greenhouse gas evolution, and lower efficient of carbon accumulation. It was urgent to find an eco-friendly N-rich organic fertilizer instead of mineral N as activator to solve the above problems and lead a carbon accumulation in long tern management. Besides, microbial necromass was considered as a crucial contributor to persistent soil carbon (C) and nitrogen (N) pool. How organic fertilizer activators influence microbial residue under different amount of crop residues input remained unclear. Thus, soils incorporating moderate and high rate of rice straw residue with additions of half and full of organic activators (fish protein hydrolysates vs. manure) were incubated for measuring carbon dioxide (CO2) and nitrous oxide (N2O) emission, microbial community and necromass. It was found that soil CO2 emission was rapidest during the first 13 days of straw decomposition but remained lowest in the treatments of 50% mineral N substituted by fish protein hydrolysate. There were that 81%–89% of total CO2 release and 59%–65% of total N2O emission occurred within 60 days of incubation period, and bacterial community and nitrate positively affected soil CO2 and N2O release respectively. Straw incorporation amount and organic activator application interactively influenced soil CO2 emission but not affected soil N2O emission. After 360 days of incubation, the difference of bacterial necromass was noticeable but fungal necromass remained almost unaltered across all treatments. All treatments showed generally comparable contribution of microbial necromass N to the total N pool. The treatment of 50% mineral N substituted by fish protein hydrolysate under high rate of straw input (HSF50) promoted the highest proportion of microbial necromass C in soil organic C because of alleviating N limitation for microorganisms. Finally, HSF50 was recommended as an eco-friendly strategy for enhancing microbial necromass C and N storage and climate benefits in agroecosystems.

Strategies for the valorization of fish by-products: Fish balls formulated with mechanically separated amberjack flesh and mullet hydrolysate

The aim of the present study was to valorise fish by-products by developing fish balls obtained using mechanically separated amberjack (Seriola dumerili) flesh and the optimized fish protein hydrolysate prepared from mullet (Mugil cephalus) by-products. Shelf life of the developed products was also evaluated during refrigerated storage. The fish by-products hydrolysate (FBH) was added to the basic formulation at a concentration of 1.5%. All fish balls were packed under modified atmosphere (80% N2/20% CO2) and stored at 4 °C for 20 days. Physico-chemical and microbiological analyzes were performed. The addition of FBH significantly extended the shelf life to more than 12 days, compared to less than 8 days for conventional products. FBH also effectively prevented the accumulation of histamine and ensured that the EU limits were met throughout the 12-day (137.84 mg/kg). The addition of 1.5% of the FBH promoted a reduction of lipid oxidation, observed by volatile analysis, however, this difference was not perceived by sensorial analysis. The innovative amberjack fish balls can be considered an interesting new fish product obtained by the valorization of fish by-products (mechanically separated meat and FBH).

Effect of ultrasound treatment on quality parameters and health promoting activity of fish protein hydrolysates extracted from side streams of Atlantic mackerel (Scomber scombrus).

Fish protein hydrolysates (FPH) obtained by enzymatic hydrolysis allows for smart valorization of fish side streams. However, further treatments are normally needed to enhance bioactive and functional properties of the obtained FPH. At present, the commonly used methods to improve functional properties of FPH include chemical and enzymatic modification. Chemical treatments often cause environmental problems, while the enzymatic modification method requires the use of quite expensive enzymes. In recent years, emerging technologies such as ultrasound treatment (US-treatment) have shown great potential in protein modification with high efficiency and safety, low energy consumption, and low nutritional destructiveness. In this study, high-power ultrasound treatments were applied to fish protein hydrolysates (FPH) extracted from Atlantic mackerel (Scomber scombrus) side streams to improve their quality parameters. The effect of three different treatments of 300 W, 450 W and 600 W at the operating frequency of 20 kHz for 10 min on the physicochemical, structural, and functional characteristics of FPH, were examined. The results have shown that with an increase in ultrasound power, the protein solubility of FPH increased linearly, and the changes were significant for all US-treated samples compared to control (untreated) samples. US-treatment significantly increased the degree of hydrolysis of FPH samples treated with 450 W and 600 W compared to control samples. The carbonyl content of FPH increased (significantly for 450 W and 600 W), while thiol groups decreased (significantly for 300 W and 450 W). This indicated that some US-treatments induced oxidation of FPH, however the values of the protein oxidation were low. Amino acid composition of FPH revealed that US-treatment increased the proportion of essential amino acids in the sample treated with 300 W and 450 W, but the increase was not significant. After the US-treatment, all FPH samples became lighter and less yellowish and reddish, which suggest potentially higher attractiveness to consumers. In addition, the in vitro antioxidant activity was assessed using the DPPH, FRAP, and ABTS assays and the cell-free dipeptidyl peptidase IV (DPP-IV) inhibitory activity was also measured. Moreover, these biological activities were measured at cellular level utilizing human intestinal Caco-2 cells. Specifically, the FPH capacity to lower H2O2-induced reactive oxygen species (ROS) and lipid peroxidation levels was used to measure its antioxidant activity. The findings suggest that Scomber scombrus hydrolysates could find use as ingredients for promoting health.

Польза элиминационной диеты из гидролизованной рыбы и рисового крахмала для диагностики неблагоприятных пищевых реакций у кошек: открытое клиническое исследование

Background: diagnosis of adverse food reaction (AFR) is based on an eight week elimination diet (ED) and is confirmed by relapse upon re-challenge with the previously fed diet. Hydrolysed EDs are commonly used for this purpose. Objective: to evaluate the commercially available hydrolysed fish protein and rice starch ED Farmina UltraHypo (FUH) for the diagnosis of feline AFR. Animals: thirty-two nonseasonally pruritic cats. Materials and methods: pruritus was assessed with a new dual Visual Analog Scale, lesions with the Scoring Feline Allergic Dermatitis scale and Quality of Life with a validated questionnaire on days 0 and 56. Short-acting corticosteroids or oclacitinib were permitted during the first six weeks. Cats showing 50% pruritus and/or lesional improvement were separately challenged with their prior diet, fish and rice. Cats not responding to the study diet were fed another hydrolysed diet for two months. Results: 25 cats completed the ED: four dropped out due to vomiting and/or diarrhoea, one owing to low palatability and two were lost to follow-up. In 17 cats, pruritus improved by &gt;50% and these underwent dietary challenges. Of these, nine reacted to their prior diet and/or fish and/or rice and were diagnosed with AFR, while eight did not relapse (and a diagnosis of AFR was considered to be doubtful). Of the eight cats in which pruritus did not improve, four underwent a second ED with no improvement. Conclusion and clinical importance: FUH may be a useful ED for the diagnosis of feline AFR, even in cats reacting to fish or rice

Enhancement of fish protein hydrolysates for salad dressing through high shear and sterilization pre‐treatments

Enhancement of fish protein hydrolysates for salad dressing through high shear and sterilization pre‐treatments

The Effect of the Species Source of Muscle and/or Digestive Enzymes on the Utilization of Fish Protein Hydrolysates as a Dietary Protein Source in First Feed for Larval Walleye (Sander vitreus).

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.

Protein Hydrolysates from Salmon Heads and Cape Hake By-Products: Comparing Enzymatic Method with Subcritical Water Extraction on Bioactivity Properties.

Fish by-products can be converted into high-value-added products like fish protein hydrolysates (FPHs), which have high nutritional value and are rich in bioactive peptides with health benefits. This study aims to characterise FPHs derived from salmon heads (HPSs) and Cape hake trimmings (HPHs) using Alcalase for enzymatic hydrolysis and Subcritical Water Hydrolysis (SWH) as an alternative method. All hydrolysates demonstrated high protein content (70.4-88.7%), with the degree of hydrolysis (DH) ranging from 10.7 to 36.4%. The peptide profile of FPHs indicated the breakdown of proteins into small peptides. HPSs showed higher levels of glycine and proline, while HPHs had higher concentrations of glutamic acid, leucine, threonine, and phenylalanine. Similar elemental profiles were observed in both HPHs and HPSs, and the levels of Cd, Pb, and Hg were well below the legislated limits. Hydrolysates do not have a negative effect on cell metabolism and contribute to cell growth. HPSs and HPHs exhibited high 2,2'-azino-bis(3 ethylbenzthiazoline-6)-sulfonic acid (ABTS) radical scavenging activity, Cu2+ and Fe2+ chelating activities, and angiotensin-converting enzyme (ACE) inhibitory activity, with HPHs generally displaying higher activities. The α-amylase inhibition of both FPHs was relatively low. These results indicate that HPHs are a promising natural source of nutritional compounds and bioactive peptides, making them potential candidates for use as an ingredient in new food products or nutraceuticals. SWH at 250 °C is a viable alternative to enzymatic methods for producing FPHs from salmon heads with high antioxidant and chelating properties.

Novel ACE inhibitory peptides from enzymatic hydrolysate of Channa punctata protein: In vitro and In silico assay of structure-activity relationship

Channa punctata flesh meat is well known for its ethnomedicinal values. The objective of this study was to isolate and identify peptides having Angiotensin-Converting Enzyme (ACE) inhibitory potential from the Channa punctata fish protein hydrolysates (FPH) and to investigate the inhibitory mechanism by docking study. ACE inhibitory potential of the ultrafiltrate of C. punctata 240 min protein hydrolysates was analysed. The PrAHyd240 (<3 kDa) had the strongest ACE inhibitory potential as it has the lowest IC50 value i.e., 66.08 μg/ml. To identify the ACE inhibitory peptides, PrAHyd240 (<3 kDa) was evaluated by LC ESI mass spectrometer. The amino acid residues of 3 peptides within the intensity count 100–250 were determined by de novo sequencing.The docking analysis reveals that the peptides were deeply buried in the active site of ACE. Thr 5 of ISISTSGGSFR, Val 3 of SLVNLGGSK, and Val 6, Ala 7 of SISISVAR form highly stable metal coordination bonds with the Zn cofactor present in the binding site of ACE. Similar to captopril, the peptide SISISVAR interacted with the amino acids His 353 and His 513 of the binding sites of ACE via H-bond interactions. The MD simulation study reveals that the peptides ISISTSGGSFR, SLVNLGGSK, and SISISVAR interacted with the Zn+ ion via H-bond with 100% occupancy respectively. The above study reveals that Channa punctata protein hydrolysate is a rich source of ACE inhibitory peptides and the isolated peptides ISISTSGGSFR, SLVNLGGSK, and SISISVAR are potential ingredients in the preparation of functional foods.

Optimization of the autolysis of rainbow trout viscera for amino acid release using response surface methodology

Background Due to the huge amounts of their production in Europe, their environmental impact, and the difficulty in processing them, there is a clear necessity for the valorization of rainbow trout viscera. Considering that the production of fishmeal with viscera can be problematic, and in order to make viscera more profitable, the production of fish protein hydrolysates has been considered. Although silage and enzymatic hydrolysis are the most common methods for obtaining hydrolysates, autolysis has emerged as an alternative method that uses endogenous enzymes of the viscera. Methods Considering the stability and characteristics of the enzymes, a factorial design was carried out using three variables: pH, temperature, and water content. The design resulted in 15 experiments, and the results were analyzed using response surface methodology. The optimum parameters were validated by comparing the predicted outcomes with experimental results. Additionally, a kinetics study was conducted to shorten the autolysis time. Results from autolysis were compared with those from silage and enzymatic hydrolysis in a previous study. Results The optimal conditions for achieving the highest degree of hydrolysis and yield of free amino acids (FAAs) per 100 g of viscera and per total protein were determined to be a pH of 8, a temperature of 40 ºC, and a water content of 6.85%. The pH and content of the added water were found to be significant variables during autolysis (p &lt; 0.05). The kinetic study showed that 7 h was still required to be effective. Conclusions Autolysis achieved a lower degree of hydrolysis than silage; however, as it solubilized more protein, the global yield of free amino acids per 100 g of viscera was slightly higher. It was concluded that endogenous alkaline proteases could be used in an autolytic process to obtain a free amino acid-rich hydrolysate from trout viscera.

A hyperstable, low-salt adapted protease from halophilic archaeon with potential applications in salt-fermented foods

Salt-tolerant proteases with remarkable stability are highly desirable biocatalysts in the salt-fermented food industry. In this study, the undigested autocleavage product of HlyA (halolysin A), a low-salt adapted halolysin from halophilic archaeon Halococcus salifodinae, was investigated. HlyA underwent autocleavage of its C-terminal extension (CTE) at temperatures over 40 °C or NaCl concentrations below 2 M to yield HlyAΔCTE. HlyAΔCTE demonstrated robust stability over a wide range of −20–60 °C, 0.5–4 M NaCl, and pH 6.0–10.0 for at least 72 h. Notably, HlyAΔCTE is the first reported halolysin with such exceptional stability. Compared with HlyA, HlyAΔCTE preferred high temperatures (50–75 °C), low salinities (0.5–2.5 M NaCl), and near-neutral (pH 6.5–8.0) conditions to achieve high activity, consistently with its production conditions. HlyAΔCTE displayed a higher Vmax value against azocasein than HlyA. During fish sauce fermentation, HlyAΔCTE significantly enhanced fish protein hydrolysis, indicating its potential as a robust biocatalyst in the salt-fermented food industry.

Valorization of fish processing by-products for protein hydrolysate recovery: Opportunities, challenges and regulatory issues

Protein-rich fish processing by-products, often called rest raw materials (RRM), account for approximately 60% of the total fish biomass. However, a considerable amount of these RRM is utilized for low-value products such as fish meal and silage. A promising and valuable approach for maximizing the utilization of RRM involves the extraction of bioactive fish protein hydrolysate (FPH). This review assesses and compares different hydrolyzation methods to produce FPH. Furthermore, the review highlights the purification strategy, nutritional compositions, and bioactive properties of FPH. Finally, it concludes by outlining the application of FPH in food products together with various safety and regulatory issues related to the commercialization of FPH as a protein ingredient in food. This review paves the way for future applications by highlighting efficient biotechnological methods for valorizing RRM into FPH and addressing safety concerns, enabling the widespread utilization of FPH as a valuable and sustainable source of protein.

Nutritional enrichment of cereal foods: feasibility study and characterisation of biscuits fortified with seabass by‐products

SummaryIndustrial fish processing generates large amounts of fish by‐products. Therefore, this research aimed to explore alternatives that allow better exploitation of these by‐products and promote sustainability and a circular economy. To achieve this, the possibility of producing and using fish meal (FM) and fish protein hydrolysates (FPH) from seabass was studied for the nutritional fortification of biscuits. The results showed that the heat applied in the production of FPH was a factor that negatively affected the lipidic fraction, reducing the proportion of polyunsaturated fatty acids but also producing a product with darker shades. The incorporation of FM and FPH into the biscuits produced nutritional enrichment, especially in protein and polyunsaturated fatty acids, but also caused colour changes, which were more intense due to the increase of Maillard reaction, and changes in sensory perception, where higher intensities of colour and toasted flavour were perceived (especially when including FPH), but also fish flavours. Scanning electron microscopy made possible the visualisation of differences in the internal structure, which could be related to differences found in instrumental texture measurements. In conclusion, this research demonstrated that using fish by‐products to enrich biscuits is possible from a nutritional perspective. However, other techniques such as the use of antioxidant substances to preserve the fish's fatty acid profile or the combination of enzymes to reduce fish flavours should be considered for future research.

Optimal and sustainable production of tailored fish protein hydrolysates from tuna canning wastes and discarded blue whiting: Effect of protein molecular weight on chemical and bioactive properties

Thousands tons of discards of blue whiting (BW) and tuna heads (YT) by-products are generated each year in Europe. BW is the species most discarded by European fishing fleet and, in some canning factories, YT are processed for the retrieval of oil rich in omega-3, but producing a huge amount of solid remains and effluents disposal as wastes. The development of optimal and sustainable processes for both substrates is mandatory in order to reach clean solutions under the circular economy precepts. This work focused on the mathematical optimization of the production of tailored fish protein hydrolysates (FPH), from blue whiting and tuna residues, in terms of controlling average molecular weights (Mw) of proteins. For the modeling of the protein depolymerization time-course, a pseudo-mechanistic model was used, which combined a reaction mechanistic equation affected, in the kinetic parameters, by two non-lineal equations (a first-order kinetic and like-Weibull formulae). In all situations, experimental data were accurately simulated by that model achieving R2 values higher than 0.96. The validity of the experimental conditions obtained from modeling were confirmed performing productions of FPH at scale of 5 L-reactor, without pH-control in most of cases, at the different ranges of Mw selected (1–2 kDa, 2–5 kDa and 5–10 kDa). The results showed that FPH from BW with lower Mw led to a remarkable yield of production (12 % w/w of substrate), largest protein contents (77 % w/w of BW hydrolysate), greatest in vitro digestibility (>95 %), highest essential amino acid presence (43 %) and the best antioxidant (DPPH = 62 %) and antihypertensive (IC50-ACE = 80 mg/L) properties. Our results prove that the proposed procedure to produce sustainable FPH, with specific Mw characterisitics, could be extended to other fish waste substrates. Tailored FPH may have the potential to serve as valuable ingredients for functional foods and high-quality aquaculture feed.

A comprehensive investigation of the use of freeze concentration appro aches for the concentration of fish protein hydrolysates

Fish protein hydrolysates (FPH) are inherently unstable in their liquid form, necessitating either freezing or dewatering for stabilization. Gentle methods such as freeze concentration can be used to remove water, this can be achieved by freezing water in solution by decreasing the bulk temperature below freezing point and separating pure ice crystals from concentrated solution. This approach serves as an alternative to techniques like evaporation and reverse osmosis for concentrating solutions that have high water content, significant nutritional value, and thermolabile compounds. This is crucial as many bioactive compounds degrade when exposed to elevated temperatures. Another notable advantage of this technology is its potential to reduce energy consumption by up to 40% when integrated into the FPH drying process. Although this technology is currently industrialized primarily for juices, it can achieve concentrations of up to 60°Brix and manage viscosities up to 400 mPa.s. Numerous studies have been dedicated to enhancing design and processes, leading to a 35% reduction in the system's capital cost and a 20% reduction in energy consumption. Moreover, freeze concentration can synergize with other concentration techniques, creating more efficient hybrid processes. This review aims to introduce freeze concentration as a superior option for preserving fish protein hydrolysates, enhancing their stability, and maintaining their nutritional and bioactive qualities.

Utilization and application of bioactive compounds generated from Fish waste and by product as Functional Food Ingredient: A review

The quest for novel functional food ingredients from natural sources is one of the most important discuss in food science and technology. Food industries dispose their valuable waste and some food industries re-process their wastes and used them as functional food ingredients, thereby developed their economy to survive in the neck cutting competition of the market. Enormous volumes of food processing by-products (FPBs) are produced from food manufacturing industries, accounting it as the second-largest quota of food waste generation. Fish known as ‘rich food for poor people,’ supplies good quality of fats, minerals vitamins and proteins to billions of populaces across the globe. However, the fish processing industry on daily basis generates huge wastes leading to the quest for management of these wastes. These wastes which can be referred to as by-products are generated during removal of head; gutting of the fish and during other secondary processing carried out either onboard in fishing vessels or at processing plants on the shores. Over the years there are bids for utilization of fish wastes and by products for production of functional food ingredients using bioactive compounds produced from them. This was aimed at reduction of processing waste, creation of sustainable economic boost, environmental safety while formulating value added functional food which could be of importance to human and animal health or wellbeing. By-products from fish processing such as blood, fleshy chunks of fatty fish, tails, liver from white lean fish, Fish heads, offal, viscera (gut, intestines, etc.), skin and shells have potentials utilization as raw materials for production of value-added functional food ingredients. Bioactive peptides isolated from various fish protein hydrolysates have reported to have several bioactivities such as immunomodulatory, antioxidative antihypertensive, antithrombotic, anticoagulant activities among others Hence from the review, the recovery of bioactive compound and utilization of these by-products are untapped sources for functional ingredients which can be applied in several aspects of food processing for the benefit of manufactures, supply series of nourishments, and consequently advancing the usefulness of the fish waste in consumers’ health and economic benefits of all stakeholders.