Production Of Fish Protein Hydrolysates Research Articles

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.

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 < 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.

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.

Review of fish protein hydrolysates: production methods, antioxidant and antimicrobial activity and nanoencapsulation.

Marine products have gained popularity due to their valuable components, especially protein, despite generating significant waste. Protein hydrolysates are widely recognized as the most effective method for transforming these low-value raw materials into high-value products. Fish protein hydrolysate (FPH), sourced from various aquatic wastes such as bones, scales, skin, and others, is rich in protein for value-added products. However, the hydrophobic peptides have limitations like an unpleasant taste and high solubility. Microencapsulation techniques provide a scientific approach to address these limitations and safeguard bioactive peptides. This review examines current research on FPH production methods and their antioxidant and antibacterial activities. Enzymatic hydrolysis using commercial enzymes is identified as the optimal method, and the antioxidant and antibacterial properties of FPH are substantiated. Microencapsulation using nanoliposomes effectively extends the inhibitory activity and enhances antioxidant and antibacterial capacities. Nevertheless, more research is needed to mitigate the bitter taste associated with FPH and enhance sensory attributes.

Optimization of the Refining Process for a Fraction Rich in Crude Common Pony Fish (Leiognathus equulus) Oil as a By-product of Fish Protein Hydrolysate Processing Using The Response Surface Method

The production of fish protein hydrolysate from common pony fish yields a fraction rich crude fish oil as a by-product. To utilize this by-product, refining is necessary to obtain common pony fish oil. This research aims to use a fraction rich crude fish oil from fish protein hydrolysate by-products to obtain fish oil and to determine the optimal conditions for the refining process using the response surface method (RSM) in the degumming, neutralization, and bleaching processes. The experimental design used was the Box–Behnken design, with the responses used to determine the optimum conditions at the degumming stage were water content and total dissolved solids. The response used to determine the optimum conditions at the neutralization stage was the refining factor, and at the bleaching stage was color (L, a*, b*). Parameters studied for each purification process include heating temperature (50-80°C), contact time between fraction rich crude fish oil with auxiliary materials (10-20 minutes) and the length of time for centrifugation (5-15 minutes) with a rotation speed of 10,062 G. The optimal conditions obtained in the degumming, neutralization, and bleaching processes for heating temperature, contact time between fraction rich crude fish oil with auxiliary materials, and centrifugation time, respectively, were 50°C, 10 min, 5 min; 50°C, 20 min, 5 min; and 80°C, 10 min, 15 min. Verification of the optimum conditions resulted in a free fatty acid value of 8.25% ± 0.01%, an acid value of 1.87 ± 0.02 mg KOH/g oil, a peroxide value of 1.04 ± 0.01 meq/Kg, an anisidine value of 11.11 ± 0.01 meq/Kg, a total oxidation value of 13.21 ± 0.01 meq/Kg and water content 6.052 ± 0.02 %. These results indicate a reduction in free fatty acids, acid number, peroxide number, anisidine number and water content by 66%, 90%, 73.5%, 61%, 63%, and 92% respectively. Our results showed that the purified fraction rich crude fish oil has met the SNI standards in parameter acid number, peroxide number, iodine number, anisidine number, and total oxidation value. The purification process that has been carried out can improve the quality fraction rich crude fish oil, but further processing still needs to be carried out to reduce water content and free fatty acid value

Optimization and Characterization of Fish Protein Hydrolysate (FPH) from Milkfish Scales (Chanos chanos Forsskal) Using Papain Enzyme

This study determined that optimum fish protein hydrolysed (FPH production results from milkfish scales using crude extract of papain can be achieved by mixing 0.305 units of papain crude extract with 1 g of milkfish scales previously treated with 0.1 M NaOH (1:10 w/v). The incubation process comprised three stages: incubation at room temperature for 3 h, incubation at 75 °C for 1 h, and continued incubation at 90 °C for 5 min, with a resulting FPH yield of 45.70%. FTIR characterization revealed that FPH derived from milkfish scales includes amide A, amide I, amide II, and amide III groups. Additionally, SDS-PAGE analysis indicated that the FPH molecules measure between 10-35 kDa. The results of the study showed that FPH can inhibit the activity of E. coli and S. aureus, forming clear zones measuring 2.438 mm and 1.563 mm, respectively. Furthermore, FPH exhibited antioxidant activity against DPPH with an IC50 value of 81.91 ppm.

Fish Protein Hydrolysates: Bioactive Properties, Encapsulation and New Technologies for Enhancing Peptides Bioavailability.

Fish protein hydrolysates (FPHs) can be obtained from substrates such as fish muscle, skin, and wastes and assign value to these fish by-products. Proteolytic enzymes catalyze the hydrolysis of these fish substrates' peptide bonds resulting in smaller peptides that present several bioactive properties. Hydrolysates' bioactive properties are a function of the fish species used as the substrate, the enzyme selectivity or specificity, pH and temperature applied in the reaction, etc. Furthermore, many pre-treatment methods are being applied to fish protein substrates to improve their enzyme susceptibility and increase the number of smaller bioactive peptides. This review addresses the production of FPHs and the main bioactive properties evaluated recently in the literature and emphasizes the substrate treatments by high-pressure processing, microwave, ultrasound, and thermal treatments to achieve better bioactivity making essential amino acids more available in peptides. The bioactive properties most found in FPHs were antioxidants, antimicrobials, anticancer, and antihypertensive. These bioactivities may vary depending on the conditions of hydrolysis, fish species, and fractionation and isolation of specific peptides.New technologies for the treatment of by-products can reduce process losses and achieve better results by cleavage of proteins. Conversely, encapsulation and film utilization can improve bioactivity, bioavailability, and controlled release when applied to foods, resulting in improved health.

Avances tecnológicos en la obtención, identificación y producción de hidrolizados proteicos de residuos de pescado por acción enzimática: propiedades bioactivas y tecnofuncionales, aplicación en alimentos, mercado y regulación

At present, numerous methodologies have been developed to obtain the maximum use of fish proteins, to satisfy human nutritional demand, this use has been made both from whole fish and from its residues or by-products (liver, head, skin, gonads, skeleton, and viscera) which represent up to 60% of the whole fish. Whole fish and by-products can potentially be used as sources of essential amino acids, collagen, gelatin, polyunsaturated lipids, and enzymes. Using enzymatic technology, protein hydrolysates have been obtained with ample potential for their application as ingredients in the development and production of fortified foods, due to their functional properties (antihypertensive, antioxidant, antimicrobial and immunomodulatory), which can reduce the risk of cancer, aging, diabetes, and cardiovascular diseases. In addition, these hydrolysates have important techno-functional properties (foaming, solubility, emulsification, gelation, water, and oil retention) that provide desirable technological characteristics for processing, storage and product quality, as well as for behavior during processing. and storage. This review analyzes the advances in the technology for obtaining, identifying, and producing fish protein hydrolysates (FPH) by enzymatic action, with an emphasis on fish residues, highlighting the application of FPH in food, market analysis and global regulations. It is recommended to continue the studies to optimize the enzymatic production of FPH to improve the flavor and its application in the fortification of mass consumption foods.

Production of fish protein hydrolisates from Oreochromis niloticus fillet trimmings

Process optimization is essential for the large-scale viability of the food industry. Central composite rotational design (CCRD) followed by response surface analysis was used to optimize the production of fish protein hydrolysate (FHP). FHP was obtained from tilapia filet trimmings hydrolyzed subjected using Alcalase 2.4L™, Neutrase™, and Novo-Pro™ D enzymes under temperature, enzyme concentration, and pH-controlled conditions. A 23-3 full factorial design (FFD) was initially employed to select the most influential variables in the process (with each enzyme used in the CCRD). From the FFD, temperature and enzyme concentration for Alcalase 2.4L™ and Novo-Pro™ D, and temperature and pH for Neutrase™ were selected. The estimated maximum degree of hydrolysis (DHmax) using Alcalase 2.4L™ was 60.05% during 180 min of processing at 39.03°C and 0.65% enzyme concentration. A DHmax of 56.96% was reached using Neutrase™ during 120 min at 39.46°C and 6.039 pH. Novo-Pro™ D was associated with a DHmax of 54.76% during 60 min at 47.95°C and 0.866% enzyme concentration. The three enzymes showed promising results for obtaining FHP with high DH from Nile tilapia filet trimmings.

Antioxidant activity of protein hydrolysate from snakehead fish (Channa striata) viscera obtained by enzymatic process

Snakehead fish (Channa striata) in South Sumatra, Indonesia has been widely used as a raw material in the processing of typical Palembang food industry, namely pempek, kemplang, and kerupuk. During its processing, not all parts of the fish can be utilized. In general, only 40% of the fish is used for consumption and 60% is wasted as by-products. One of the by-product produced during processing is viscera which can still be used as value-added products. One alternative is to use viscera as raw material in the production of fish protein hydrolysate (FPH) which is well known to have functional properties such as antioxidant, antibacterial, antihypertensive, and anticancer. This research was aim to determine the antioxidant activity of FPH made from snakehead fish viscera as a source of natural antioxidants. The research was conducted by papain treatments with the concentration of enzymes used were 1%, 2% and 3%. Evaluation of the hydrolysis process was done by measure the soluble protein and DH (degree of hydrolysis) while antioxidant activity was carried out by DPPH (1,1-diphenyl-2-picrylhydrazyl) and ABTS (2,2-Azinobis 3-ethyl benzothiazoline6-sulfonic acid) assay. DH of fish protein hydrolysate was found to be 68.79%, 77.06% and 72.63%, respectively while protein solubility gave values of 5.69%, 6.15% and 6.56% respectively. The highest antioxidant activity was attained at enzyme concentration of 3% with DPPH (1,1-diphenyl-2-picrylhydrazyl) and ABTS (2,2-Azinobis 3-ethyl benzothiazoline 6-sulphonic acid) value were 37.26% and 58.58% respectively.

Production and characteristics of sailfin catfish (Pterygoplichthys pardalis) protein hydrolysate

Background: The sailfin catfish (Pterygoplichthys pardalis) is a freshwater fish from the Loricariidae family, and is considered an invasive species in Indonesia. The fish is usually neglected and discarded. Its protein hydrolysate is the product of the breakdown of proteins into amino acids through the hydrolysis of acids, bases, or enzymes. Therefore, this study aims to determine the hydrolysate characteristics of sailfin catfish (Pterygoplichthys pardalis) proteins, produced with different pH and hydrolysis durations. Methods: The hydrolysis was carried out with variable pH (control, 5, 7, 9) and hydrolysis durations (12 and 24 hours) in three replicates. Results: The hydrolysis duration, pH, and interaction of both variables had significant effects (p<0.05) on the parameters of yield, antioxidant activity, degree of hydrolysis, protein levels, and ash content. Similarly, the moisture content, hydrolysis duration, and pH were significantly affected (p<0.05), while their interactions were not (p>0.05). The pH treatment had a significant effect on fat content (p<0.05), while the hydrolysis length and the interaction between the two had no significant effect (p>0.05). Based on this study, the best resulting production of fish protein hydrolysate (FPH) from sailfin catfish were a for a combination of pH 9 and a hydrolysis duration of 24 hours. The characteristics of FPH produced were as follows: a yield of 57.39%, antioxidant activity 63.99%, degree of hydrolysis 40.67%, water content 7.28%, ash content 7.63%, fat content 5.10%, protein content 34.51%, molecular weight 6.14 -118.17 KDa, total essential amino acids 49.30%, and nonessential amino acids 50.71%. Conclusions: Two factors affected FPH characteristics in sailfin catfish (Pterygoplichthys pardalis). The best processing conditions to obtain optimal characteristics for FPH were a yield of 57.39%, antioxidant levels of 63.99%, a DH of 40.67%, a moisture content of 7.28%, ash content of 7.63%, fat content of 5.10%, and protein content of 34.51%.

Fish protein hydrolysate production, treatment methods and current potential uses: A review

About 20 per cent of the live weight of freshwater fish is visceral mass is a rich source of protein, lipids, polyunsaturated fatty acids, soluble vitamins, phospholipids etc having very great source of agro industrial products. Any scientific technique that uses strong squanders coming about because of fish harvesting by recuperating biomolecules like lipids and proteins brings about extra income as well as helps to reduce the dumping issues related therewith. Visceral fish hydrolysate (also known as fish protein hydrolysate; FPH) has drawn the interest of many researchers in recent years due to its great utility in the fields of food, pharmaceuticals, cosmetics and nutrition. The extraction or production of FPH including predefined sequential steps like collection of raw materials, pretreatment (alcohols, heat treatment, press technique coupled with heat treatment), hydrolysis (acidic, alkaline, enzymatic) and recovery of FPH using spray drying, lyophilisation, centrifugation or nanofiltration. The extracted FPH is characterized for molecular mass, protein content, structure of protein, IR, XRD etc to analyse the chemical nature of the FPH. It is widely used as emulsifier, binder, gelling agent, fertilizer, crayoprotectant and dietary additives in various industries. FPH has been used as potential source of microbial growth media for gram positive and negative microbes, nutritional supplement due to higher protein content (60-90%), and antioxidant, antihypertensive and antimicrobial agent. FPH is also used as nutriceuticals and some of the products are commercially available in various countries including US, Canada, UK. Considering the physicochemical difficulties associated with FPH, its excellent nutritional and functional properties generate possibilities for its usage in both the food and health industries.

Optimization and Characterization Freeze Dried Fish Protein Hydrolysate Production

The production of fish protein hydrolysate from underutilized fish species is attracting the industrial interest for increasing the rich protein values. The central composite design was used to optimize the degree of enzymatic hydrolysis of freeze-dried fish protein hydrolysate (FPH) production by the application of commercial Alcalase on the recovery mixed small fish protein. The effects of time, temperature, pH and enzyme concentration on the degree of hydrolysis (DH) of five strains of fish as Rastrelliger brachysoma (short-bodied mackerel), Rastrelliger kanagurta (Indian mackerel), Leiognathidae (Ponyfish), Amblygaster leiogaster (Smooth belly sardinella) and Selaroides leptolepis (yellow-stripe scad) were experimented. Result showed that the FSH production was optimized at 2.85%v/w enzyme concentration at 61 °C, pH 8.50 for 27 min with 89.42% DH. Mathematical model was proposed and validated under the optimum condition. The high proportion (46.43%) of smaller molecular weight <1 kDa was found in hydrolysate. Freeze-dried fish protein hydrolysate was produced and revealed that three predominant amino acids as glutamine, lysine and alanine. Based on amino acid compositions, the waste fish hydrolysate showed nutritional value and high potential for the applications of feed supplementation.

The Hydrolysis of Fish Protein from Giant Mudskipper (Periophthalmodon Schlosseri) using Alcalase Enzyme

Giant mudskippers (Periophthalmodon schlosseri) are amphibious fish and considered as endemic fish, so it can not be found in any other place and they live in a typical habitat in a tidal area with the mud of mangroves. Mudskipper These fish is relatively untapped as food source. This research aims to obtain the optimum conditions of enzyme concentration, pH, temperature, and hydrolysis incubation time on the degress of hydrolysis of alcalase enzyme in giant mudskipper (P. schlosseri). The production of fish protein hydrolysate was conducted by varying one parameter at a time to determine its effect without considering interactions with other parameters. The results obtained optimum hydrolysis at 1.5% alcalase concentration of protein weight, pH 7.5, temperature 50°C, and the duration of hydrolysis 2 hours. The degree of hydrolysis produced at the optimum condition was 67.44%.

Optimization of the Enzymatic Protein Hydrolysis of By-Products from Seabream (Sparus aurata) and Seabass (Dicentrarchus labrax), Chemical and Functional Characterization.

Valorization of seabass and seabream by-products is becoming increasingly relevant, as marketing of these species moves from selling whole fish to filleting for convenience products. With this aim, we optimized for the first time the production of fish protein hydrolysates (FPH) by enzymatic hydrolysis from filleting by-products of these commercially relevant aquaculture species, isolating fish oil at the same time. On the whole, both fish yielded similar amounts of protein, but frames and trimmings (FT) were the best source, followed by heads and viscera. In vitro antioxidant and antihypertensive activities showed similar figures for both species, placing FPHs from FT as the most active. Molecular weights ranged from 1381 to 2023 Da, corresponding to the lowest values of FT, in line with the higher hydrolysis degrees observed. All FPHs reached high digestibility (>86%) and displayed an excellent amino acid profile in terms of essential amino acids and flavor, making them suitable as food additives and supplements.

Enzymatic fish protein hydrolysates in finfish aquaculture: a review

AbstractIn intensive farming systems, fish are held at high densities, which may increase stress, leading to susceptibility to diseases that result in economic losses. Therefore, effective feeding practices incorporating health‐promoting compounds such as proteins, hydrolysates and bioactive peptides that can stimulate the defence mechanisms of fish and achieve better growth are some of the priorities for sustainable aquaculture development. Globally, the fish processing industries generate and discard a large volume of waste every year, estimated at up to 60% of the harvested biomass. This waste can be converted to value‐added products such as fish protein hydrolysate (FPH) with the addition of various proteolytic enzymes. FPH from fish processing waste including skin, heads, muscle, viscera, liver and bones is a good source of protein, amino acids, peptides and antioxidants and has been found to possess desirable functional and bioactive peptides. A moderate inclusion of FPH in aquafeeds has the potential to improve growth, feed utilization, immune functions and disease resistance of fish. Production of FPH, targeted to more precise molecular weight ranges, has superior functionalities that are in high demand. With interest in FPH as an aquafeed supplement, this review aimed to summarize the source, production processes and functional properties of FPH and the reported impact of FPH in aquafeed supplement on fish growth, survival, feed utilization, immune response and disease resistance. Possible limitations of using FPH and future research potential as an opportunity for the use of processing fish waste are also discussed.

Optimization of production parameters of fish protein hydrolysate from Sarda Orientalis black muscle (by-product) using protease enzyme

Fish protein hydrolysate, which is released to the environment as tuna processing waste during the hydrolysis reaction of Sarda Orientalis’ black muscle, could be used as a nutritional source of nitrogen for food products because of its valuable properties in antioxidant effects. This study used Protamex protease (endopeptidase) to hydrolyze the tuna’s black muscle (TBM) and to produce fish protein hydrolysate (FPH) for producing nutritional food powder. To access the FPH production, optimized conditions of reaction in hydrolyzing TBM were determined by factorial experimental design with the Box–Behnken model at a ratio of 0.45% enzyme/substrate, 100% added water content and temperature of 56 °C for 4.0 h. Consequently, the FPH obtained with the optimized condition resulted in an average degree of hydrolysis of 7.72% in response to the required range of 5–20%. Moreover, this FPH was detected for compositions of amino acids and peptides with low molecular weight less than 14 kDa and was tested in high antioxidant activity of 70% at its concentration of 500 µg mL−1. This study has provided an efficient procedure to solve the solid waste of TBM from the seafood manufacturing factories and transformed it into valuable products in the food industry.

Valorization of Aquaculture By-Products of Salmonids to Produce Enzymatic Hydrolysates: Process Optimization, Chemical Characterization and Evaluation of Bioactives.

In the present manuscript, various by-products (heads, trimmings, and frames) generated from salmonids (rainbow trout and salmon) processing were evaluated as substrates for the production of fish protein hydrolysates (FPHs), potentially adequate as protein ingredients of aquaculture feeds. Initially, enzymatic conditions of hydrolysis were optimized using second order rotatable designs and multivariable statistical analysis. The optimal conditions for the Alcalase hydrolysis of heads were 0.1% (v/w) of enzyme concentration, pH 8.27, 56.2°C, ratio (Solid:Liquid = 1:1), 3 h of hydrolysis, and agitation of 200 rpm for rainbow trout and 0.2% (v/w) of enzyme, pH 8.98, 64.2 °C, 200 rpm, 3 h of hydrolysis, and S:L = 1:1 for salmon. These conditions obtained at 100 mL-reactor scale were then validated at 5L-reactor scale. The hydrolytic capacity of Alcalase and the protein quality of FPHs were excellent in terms of digestion of wastes (Vdig > 84%), high degrees of hydrolysis (Hm > 30%), high concentration of soluble protein (Prs > 48 g/L), good balance of amino acids, and almost full in vitro digestibility (Dig > 93%). Fish oils were recovered from wastes jointly with FPHs and bioactive properties of hydrolysates (antioxidant and antihypertensive) were also determined. The salmon FPHs from trimmings + frames (TF) showed the higher protein content in comparison to the rest of FPHs from salmonids. Average molecular weights of salmonid-FPHs ranged from 1.4 to 2.0 kDa and the peptide sizes distribution indicated that hydrolysates of rainbow trout heads and salmon TF led to the highest percentages of small peptides (0–500 Da).

Enzymatic Production of Fish Protein Hydrolysates in A Pilot Plant Scale

Protease enzyme produced from Bacillus sp was employed to hydrolyze fish protein hydrolysates (FPH) under controlled conditions at a batch-pilot plant scale-process. Thirty kilograms of fish meat was mincedand mixed with 60 liters of water in 100 liters stainless steel vessel and 20,000 units of protease enzyme was added per kg of fish. Hydrolysis of fish was carried out at 55 oC for 6 hours. Multi stage of filtration were done to separate the FPH from unhydrolized fish residue. Mass balance were carried out to determine the rate of hydrolysis and yields. W ithout pH adjustment, 80% of substrate hydrolyzed could be achieved in 6 hour at 55 °C. Three kinds of products were recovered from the process, i.e solid residue, liquid FPH as filtration product, and spray dried FPH. Hydrolysis of 30 kg of fish meat substrate producing 1.7-2.0 kg of unhydrolyzed residue and 70 L of liquid FPH. Afterspray drying process of liquid FPH, 13 kg of FPH powder was recovered. The proximate and amino acid analysis of spray dried FPH showed that the FPH containing 20% of protein, rich in amino acids especially lysine and leucineand the residue still had 85,36% of protein (dry basis) that could be utilized for other purpose.

Kinetics of enzymatic reactions in the production of fish protein hydrolysates

ABSTRACTThe kinetic laws of enzyme hydrolysis of waste products (heads, fins, bones, and muscle tissue) of the Atlantic cod Gadus morhua have been investigated. An enzyme specimen hepatopancreatine was used for the hydrolysis reaction (proteolysis). A kinetic model describing the mechanism of enzyme hydrolysis of fish proteins as a second-order reaction was developed. The proteolysis model was based on the existence of easily hydrolysed and hydrolysis-resistant protein fractions. Autolysis of the enzyme was also taken into consideration. In the context of the developed kinetic model, the second-order rate constants of the intermediate stages of proteolysis were calculated.