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Proteínas y péptidos de residuos líquidos pesqueros: Obtención, bioactividad y uso en la alimentación acuícola
Abstract and Figures
La industria procesadora de productos pesqueros, derivado de sus actividades productivas, genera una importante cantidad de residuos líquidos, los cuales son comúnmente conocidos como efluentes pesqueros. Muchos de estos efluentes, son descargados al medio ambiente sin recibir algún tratamiento, generando un impacto negativo en los cuerpos de agua y zonas costeras donde son vertidos. Por otro lado, estudios han determinado que estos efluentes poseen concentraciones importantes de materia sólida, principalmente proteínas. Dicha proteína es de alta calidad considerando su perfil de aminoácidos, por lo cual es de interés emplear tecnologías para poder concentrarlas y recuperarlas. Una vez recuperada la fracción proteica de los efluentes pesqueros, a partir de esta se pueden obtener productos con alto valor agregado (p.ej. hidrolizados proteicos y péptidos bioactivos) aplicando tecnología enzimática. Las aplicaciones de estos nuevos productos en la industria alimentaria (humana o animal), pueden ser amplias y de importante valor económico. En esta revisión, se discutirá lo relacionado a alternativas de aprovechamiento de los efluentes generados en la industria pesquera, enfocándose en la recuperación y la utilización de fracciones proteicas.
Se incluyen algunas técnicas empleadas para su obtención, mencionando sus ventajas y requerimientos; así como las propiedades tecno-funcionales y biológicas de las proteínas o sus hidrolizados proteicos obtenidos a partir de los efluentes pesqueros, y finalmente, se discutirá los usos y aplicaciones de efluentes pesqueros y sus hidrolizados como
reemplazo de harina de pescado para la formulación de alimentos acuícolas, lo cual acarrea ventajas sobre el desempeño productivo y/o sobre distintos indicadores de la salud de los organismos.
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PurposeHigh amounts of rich-protein liquid wastes are produced during seafood processing. The effluent called stickwater resulting from the processing of Pacific thread herring (Ophistonema libertate) into fishmeal, was evaluated as protein source to produce bioactive protein hydrolysates by using Alcalase as enzyme source.Methods
The effect of degree of hydrolysis on biochemical properties (proximate analysis, molecular weight, and amino acid composition) and antioxidant and antihypertensive activities of stickwater protein hydrolysates obtained with Alcalase was determined.ResultsDegree of hydrolysis (DH) of samples (5%, 10%, 15% and 20%) influences its biochemical and bioactive properties. The maximum ABTS and FRAP activity values (P < 0.05) were exhibited by hydrolysates at 15% DH (EC50 = 2.8 mg/mL and TEAC = 1.16 ± 0.03 mM TE/mg, respectively). Whereas the highest DPPH scavenging activity (P < 0.05) was found for hydrolysates at 5 % and 10 % of DH (EC50 = 34.7 mg/mL and 37 mg/mL respectively). Furthermore, enzymatic hydrolysis enhanced angiotensin converting enzyme (ACE)-inhibitory activity, being those at 5 and 10% of DH, which exhibited lower IC50 values (P < 0.05) compared to non-hydrolyzed stickwater. Peptide distribution of protein hydrolysates at < 1.35 kDa was in a range of 47–62% of total peptides and the presence of amino acids related to antioxidant activity such as His, Lys, Met, Tau, Tyr and Trp was detected in stickwater and protein hydrolysates.Conclusions
The production of protein hydrolysates from Pacific thread herring stickwater, represents an alternative to obtain added-value products with potential antioxidant and antihypertensive activity.Graphic Abstract
The seafood industry generates large volumes of waste. These include processing discards consisting of shell, head, bones intestine, fin, skin, voluminous amounts of wastewater discharged as effluents, and low-value under-utilized fish, which are caught as by-catch of commercial fishing operations. The discards, effluents, and by-catch are rich in nutrients including proteins, amino acids, lipids containing good proportions of polyunsaturated fatty acids (PUFA), carotenoids, and minerals. The seafood waste is, therefore, responsible for loss of nutrients and serious environmental hazards. It is important that the waste is subjected to secondary processing and valorization to address the problems. Although chemical processes are available for waste treatment, most of these processes have inherent weaknesses. Biological treatments, however, are environmentally friendly, safe, and cost-effective. Biological treatments are based on bioconversion processes, which help with the recovery of valuable ingredients from by-catch, processing discards, and effluents, without losing their inherent bioactivities. Major bioconversion processes make use of microbial fermentations or actions of exogenously added enzymes on the waste components. Recent developments in algal biotechnology offer novel processes for biotransformation of nutrients as single cell proteins, which can be used as feedstock for the recovery of valuable ingredients and also biofuel. Bioconversion options in conjunction with a bio-refinery approach have potential for eco-friendly and economical management of seafood waste that can support sustainable seafood production.
The industrial mussel processing generates significant quantities of waste. Nearly 30% of one metric tonne of processed mussel is finally destined for human consumption. Regardless of the mussel commodities, an important quantity of waste is concentrated at several sub-processes, such as input reception, washing and declumping shells, and mussel meat extraction stages, or by means of the rejection of mussels only due to a size characteristic criterion established by the target market. Despite the main segregated waste comprising shells, byssus threads, residual meat and wastewater, a heterogeneous composition must be taken into account, since much of the solid waste is commonly gathered and compacted for landfill transportation purposes. This paper reviews the sustainable management strategies for mussel by-products, addressing their limitations for an industrial implementation to obtain value-added products. It is concluded that, although there is a well-known diversity of waste sustainable management alternatives, several proposed products (e.g., collagen, bio-adhesives, biopolymer, and adsorbent for pollutants) still remain in a potential framework, circumscribed into laboratory results, subject to an optimization process, to a validation by industrial pre-scale trials, or even limited by the associated production costs. Future researches should focus on reducing the uncertainties linked with their technical-economic feasibility for an industrial scale development.
Global demand for fresh water is rising at a rapid rate and is struggling to keep pace with water requirements of increasing population. Against this scenario, the seafood industry including aquaculture routinely uses voluminous amounts of fresh water and discharges large volumes of post-process wastewater as effluents. The presence of proteins, oil, carotenoids, minerals, and other compounds in the effluents make them high in biological oxygen demand and chemical oxygen demand, and hence, responsible for significant environmental hazards. Therefore, appropriate treatments of the effluents are essential before they are discharged or disposed off to mitigate the environmental problems. Besides, there are good potentials to recover various ingredients from the effluents for uses as food additives, nutraceuticals, nutritional supplements, flavoring agents, fertilizers, plant bio-stimulants, animal and aqua feed. Recent developments in microbial technology, particularly, algal biotechnology has potentials for cost-effective and eco-friendly treatments of the effluents together with the recovery of various biomolecules. Cultivation of microalgae in the effluents provide single cell proteins (SCP) that can have applications as animal feed including feed for the rising aquaculture industry. The SCP is also sources of proteins, oils, carotenoids and other compounds. The rich contents of oil in SCP can be resource for biofuel. In addition, the treated wastewaters can also be used as fertilizer. Recent developments in effluent treatments have potentials to improve water security, protect the environment, support food and nutraceutical industries, and enhance seafood sustainability, thereby contributing an interesting value chain for a circular bioeconomy.
Large volumes of liquid waste are generated in processing operations of seafood industry. Such effluents have high
concentrations of soluble protein, but it is necessary to concentrate it for utilization. Therefore, the present study investigated
the effects of the use of hydrochloric (HCl) and trichloroacetic (TCA) acids on biochemical and antioxidant properties of
recovered solids from sardine stickwater (SSW) and tuna cooking water (TCW). After centrifugation of both raw effluents,
solids recovery was performed with the pH-shift method separately using 5 N HCl and 40% TCA as precipitating agents.
Specifically, protein recovery was effective (> 80%) only for SSW when both acids were used. An increasing of highmolecular-
weight peptides (17 to 158 kDa) in recovered solids resulted from a protein aggregation boosted by the precipitating
agents. Concentration of some essential amino acids (Lys, Leu, Ile, Phe and Val) were increased in recovered solids. Except
to recovered solids of TCW at pH 11, a low protein solubility (20 to 13%) was observed after treatment with both acids.
Elimination of low-molecular-weight peptides and some antioxidant AAs result in a loss of free-radical-scavenging activity,
but an increase in ferric reducing antioxidant power was registered for protein concentrates of TCW.
Enormous amounts of by-products and waste are generated during the processing of seafood, sometimes representing about 65% of the raw material employed. Seafood by-products (SB) include solid waste such as skin, head, viscera, trimmings, and bones; however, liquid wastes (effluents) derived from operations such as washing, thawing, cooking and the production of fishmeal are also produced. SB contain considerable amounts of protein and others biomolecules, which has been regularly processed as food ingredients for animal nutrition. But also, sometimes SB are used as fertilizers or discarded to environment without a previous treatment. Nowadays, there is an increasing interest in adding value to the protein material within SB by improving their properties through hydrolysis and thus releasing of peptides with bioactive properties. Thus, this review aims to present an overview of the potential of SB, focused on effluents, as a source of protein hydrolysates, summarizing their methods of production, bioactive property evaluation and structural characteristics.
Recovery, physicochemical and functional characteristics of proteins recovered from different meat processing wastewater streams were revealed in the present study. Wastewaters from surimi processing (SPW) and slaughterhouses, namely fish (FSW), cattle (CSW), poultry (PSW), and goat (GSW), exhibited protein, fat, ash, moisture, and microbial load in the range of 1.28–7.04%, 0.86–2.34%, 0.02–0.80%, 89.81–97.44%, and 5.33–5.81 CFU/mL, respectively. Among the wastewaters, SPW presented slightly higher protein (7.04%), fat (2.34%), and ash (0.80%) contents (P < 0.05). Furthermore, proteins recovered from SPW (SPWP) and FSW (FSWP), CSW (CSWP), PSW (PSWP), and GSW (GSWP) presented yield, protein, fat, ash, and moisture content in the range of 55.54–76.81%, 65.86–78.22%, 7.26–11.45%, 4.58–11.75%, and 5.67–14.79%. All protein samples displayed higher essential amino acid (EAA) content with leucine (8.47–14.52 g/100 g) as a predominant amino acid. GSWP and SPWP scored the highest and lowest EAA contents, respectively. SPWP displayed myofibrillar proteins as dominant proteins, while slaughterhouses’ wastewater proteins showed blood proteins as major proteins. β-Sheet is the major secondary structure presented by all protein samples. SPWP showed the highest lightness value as compared to other protein counterparts (P < 0.05). All protein samples from slaughterhouse wastewaters had the lowest protein solubility at pH 4.5. However, SPWP presented minimum solubility at pH 5.5. Among all protein samples, SPWP presented slightly higher water holding capacity and foaming property (P < 0.05), whereas FSWP displayed slightly higher emulsion property (P < 0.05). Overall, all meat processing wastewater streams served as good sources of high-quality proteins, which could be used as protein ingredients in animal feed formulation.
Se evaluó el efecto de la centrifugación complementaria en la composición química y reológica parcial, así como la biodegradabilidad del agua de cola de sardinas Monterey y sardina crinuda como alternativa en la recuperación de sólidos. Se utilizó agua de cola y se centrifugó para posteriormente aplicarle los análisis respectivos. Es de resaltar que la centrifugación complementaria reduce significativamente la concentración de sólidos totales, viscosidad, demanda bioquímica de oxígeno (DBO5) y demanda química de oxígeno (DQO) a valores cercanos al 50 %. La concentración de colágeno en el agua de cola (11.7 mg/g y 3 mg/g) fue más alta que las observadas después de centrifugar (3.3 y 0.87 mg/g), además, la viscosidad presentó una relación con la concentración de colágeno/gelatina, que ayuda a calcular la biodegradabilidad. Esta, se calculó mayor de 2.5 pero menor de 5. Se concluye que la centrifugación complementaria como operación unitaria aumenta la recuperación de sólidos y mejora del tratamiento agua de cola.
Se evaluó el efecto de las enzimas de vísceras de sardina Monterey en el tratamiento del agua de cola producida por sardinas crinuda y Monterey y, se compararon con enzimas de un extracto comercial. Además, se aplicó una centrifugación complementaria al ensayo. La enzima comercial tuvo mayor actividad proteasa que la enzima de víscera de sardina (0.65 U/mg vs. 0.35 U/mg) y que la actividad colagenasa (0.022 Hyp/mg/min vs. 0.0102 Hyp/mg/min). Se observaron grados de hidrolisis mayores sobre agua de cola de sardina crinuda (16.1 %), y no se registraron diferencias significativas (P≥0.05) en el agua de cola de sardina Monterey por el uso de las enzimas de vísceras de sardina Monterey y enzimas comercial. Se obtuvo mayor hidrolisis al aplicar la enzima de víscera de sardina Monterey sobre el agua de cola centrifugada (57.1 % vs. 17.4 %) sin importar la especie de sardina utilizada. La enzima comercial disminuyó la viscosidad sobre el agua de cola, mientras que la enzima de víscera de sardina Monterey lo hizo sobre el agua de cola centrifugada. La electroforesis mostró una disminución de la fracción PM>220 kDa en el agua de cola. Lo anterior, indicó que la enzima comercial tuvo una mayor actividad sobre agua de cola, mientras que la enzima de víscera de sardina Monterey lo tuvo en agua de cola centrifugada, sin importar el tipo de sardina utilizada para la elaboración del agua de cola.
Enzymatic protein hydrolysis of fish processing by-products offers an alternative option to valorise this raw material. Monkfish heads originating from fish processors presents such an opportunity, as the heads constitute a significant portion of the total fish (approximately 30%) and are currently processed into relatively low-value fish meal or even discarded. In this study, the reaction conditions for enzymatic protein hydrolysis of monkfish heads were optimised by varying the reaction pH and temperature using the Alcalase proteolytic enzyme. A mixed 2-factor, 3-level factorial design was employed to determine significant factors and interactions and was followed by response surface optimisation to determine optimal enzymatic hydrolysis conditions, which were shown to occur at 62°C and a pH of 8.2. In addition, proximate analysis of the raw material and functional property characterisation of both the aqueous fish protein hydrolysate (FPH) phase and the insoluble sediments were performed to maximise the possibility of total raw material utilisation. Both the FPH and sediment displayed functional and bioactive properties, including emulsion stabilisation, fat absorption and antioxidant activity; only the FPH displayed foaming capacity, while the sediment displayed a reasonable emulsion activity index. In addition, high levels of essential amino acids (EAA) were found in the sediment (49.5% of the total amino acids), and all EAA were present (except tryptophan, which was not analysed for), which confirmed the high quality of the protein contained in the sediment. Overall, this work successfully optimised hydrolysis conditions for the Alcalase/monkfish system and confirmed the potential of enzymatic protein hydrolysis as an upgrading strategy to better utilise monkfish processing by-products.
An eight-week feeding experiment was conducted to evaluate the effects of replacing fish meal with stickwater hydrolysate (SWH) on the growth, serum biochemical, immune indexes, intestinal health of Monopterus albus. The control diet was produced using fish meal (FM), and the other three diets replaced the fish meal with 5.0% (SWH5.0), 10.0% (SWH10.0), and 15.0% (SWH15.0) SWH. The results showed that the weight gain rate (WGR) of the SWH10.0 and SWH15.0 groups was significantly higher than that of the FM group, while the opposite result was found for feed conversion ratio (FCR). The activities of trypsin and amylase were significantly higher in the SWH10.0 groups than in the FM group. There were no significant differences in serum triglyceride (TG), complement 3 (C3) and malondialdehyde (MDA) contents and lysozyme (LZM), alkaline phosphatase (AKP) and superoxide dismutase (SOD) activities among all treatment groups. With increasing SWH replacement, the glucose (GLU) and alanine aminotransferase (ALT) contents were increased, and the SWH10.0 and SWH15.0 groups had a significant increase compared with the FM group. The serum aspartate aminotransferase (AST), immunoglobulin M (IgM) and C4 contents were significantly higher in the SWH10.0 group than that in the FM group. The villi length, goblet cell quantity and muscle thickness were significantly higher in the SWH10.0 groups than in the FM group. Furthermore, we observed that SWH replacement can decrease the richness and diversity of the intestinal microbiota. The dominant phylum and genus in the intestine of M. albus were Firmicutes and Clostridium, respectively. The partial replacement of fish meal with SWH increased the richness of Firmicutes and decreased the richness of Edwardsiella, which promoted the growth and immune performance of M. albus. Therefore, it could be inferred that the partial replacement of fish meal with SWH can improve the growth performance, immune function and intestinal health of M. albus. The optimal replacement ratio is 10%.
BACKGROUND
Seafood processing generates significant amounts of solid and liquid waste in the environment. Such waste represents a potential source of high‐value biomolecules for food, pharmaceutic and cosmetic applications. There are very few studies on the valorization of wastewaters compared to solid by‐products. However, cooking waters are characterized by a high organic polluting load, which could contain valuable molecules such as proteins, pigments and flavor compounds. Snow crab (Chionoecetes opilio) processing is included among the most important processes in Canadian fisheries, although its cooking effluent composition is not well characterized.
RESULTS
The present study concentrated and valorized the biomass in snow crab cooking wastewaters for the development of products for food applications. A membrane process was designed and optimized to concentrate the effluents. The chemical composition of the concentrates was analyzed, including characterizing the flavor profile compounds. The extracts were mainly composed of proteins (592 g kg⁻¹) and minerals (386 g kg⁻¹) and contained desirable flavor compounds. Their functional properties (solubility, water‐holding capacity, oil‐holding capacity) and antioxidant activities were also assessed, and their safety was verified.
CONCLUSION
The cooking effluents generated by snow crab processing facilities, usually considered as waste, can be concentrated and turned into a natural aroma for the food industry. © 2019 Society of Chemical Industry
The effects of replacing fish meal (FM) protein with stick water (SW) were investigated during the market stage of sex-reversed Nile tilapia, Oreochromis niloticus (18.49 ± 0.31 g initial body weight). The FM protein was replaced with SW for 10% (10SW), 20% (20SW), 30% (30SW) and 50% (50SW) of the FM. The completely randomized design was conducted in outdoor 15 floating baskets (1.5 × 1.5 × 2 m), comprising three replications with 50 fish each, over an 8 month trial. At the end of the experiment, no differences in survival, growth performance or feed utilization were observed across the dietary treatments (p > 0.05). A significant change in lipase-specific activity was caused by the replacement, without changes to trypsin, chymotrypsin or amylase activities. The fish in all dietary groups exhibited normal liver histopathology, but the fish fed a diet containing SW showed higher numbers of cells accumulating lipids as compared to fish fed the baseline 0SW dietary treatment. Hematological parameters were similar across the five dietary groups. Only fish fed the 20SW diet had superior carcass quality compared to the baseline 0SW group, in terms of crude protein and lipids, but lower or higher replacement levels had negative effects on carcass quality. Findings from the current study support the replacement of FM protein with SW at a level of 20% in the diet of sex-reversed Nile tilapia reared to the market stage. Higher replacement levels might be possible with the supplementation of fatty acids.
Background: Seafood is one of the primary sources of nutrients and bioactive compounds for human consumption throughout the world. Processing of seafood is accompanied by the generation of a tremendous quantity of by-products and discards. These non-edible residues contain a considerable amount of biomolecules such as proteins, polysaccharides, lipids, carotenoids, vitamins, minerals, and so on. Recovering of these biomolecules can be an important way to improve global food security and mitigate environmental problems associated with seafood by-products/discards. Scope and approach: The present review deals with an overview of biomolecules contained in the seafood by-products and discards. Also, an overview of new extraction techniques which have been applied for the recovery of biomolecules from seafood by-products and discards will be discussed. Key findings and conclusions: Green extraction techniques constitute a hopeful tool for industrial recovery of biomolecules from seafood by-products and discards. However, the extraction efficiency can vary highly depending on the matrix, the target compounds, extraction methods, and conditions. Therefore, the choice of green extraction techniques and the extractions conditions depend essentially on the matrix and the target compound features.
This study evaluated the protein recovery, functional properties and biological activity of isolate processed water (IPW) generated in the preparation of protein isolates from fish roes (BH, bastard halibut Paralichthys olivaceus; ST, skipjack tuna Katsuwonus pelamis; YT, yellowfin tuna Thunnus albacares) by an isoelectric solubilization and precipitation process. The IPWs contained 2.7-5.4 mg/mL of protein, and the protein losses were 8-21% (P<0.05). The form capacity of IPW-3 for BH and ST, and IPW-4 for YT was 155, 194, and 164%, respectively. The emulsifying activity index (27-43 m2/g) of the YT-IPWs was the strongest, followed by ST (7-29 m2/g) and BH (10-19 m2/g). The 2,2-diphenyl-1-picrylhydrazyl scavenging activities of IPW-1 and -3 were higher than those of IPW-2 and -4. The 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid scavenging activity (IC50, mg/mL) of IPW-2 and -4 was 0.03 mg/mL for BH, 0.04-0.08 mg/mL for ST, and 0.04-0.07 mg/mL for YT. BH IPW-3 had the strongest reducing power (0.41 mg/mL) and superoxide dismutase-like activity (1.68 mg/mL). The angiotensin-I converting enzyme inhibitory activity of IPW-3 was the highest for ST (1.52 mg/mL), followed by BH and YT. The common predominant amino acids in the IPWs were the essential amino acids Val, Leu, Lys, and Arg and the non-essential amino acids Ser, Glu, and Ala.
This study evaluated the protein recovery and functional properties and biological activity of boiled and steamed process water (BPW and SPW, respectively) generated from the preparation of concentrated roe of bastard halibut (BH; Paralichthys olivaceus), skipjack tuna (ST; Katsuwonus pelamis), and yellowfin tuna (YT; Thunnus albacares) using the cook-dry process. The protein loss from the water extracts (EXT) of 100 g of roe protein was 15.05-19.71% and was significantly (P<0.05) higher than that of BPW (5.47-10.34%) and SPW (3.88-8.18%). The foam capacity of BPW (166-203%) and SPW (15-194%) was better than that of EXT. The emulsifying activity index of the original samples was lower than those (15.40-107.86 m2/g) of diluted protein samples. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and the reducing power of BPW and SPW were stronger than those of EXT. The 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS+) radical scavenging activity of EXT (0.028-0.045mg/mL) was significantly higher those of BPW and SPW. The angiotensin I-converting enzyme (ACE) inhibitory activity of SPW was the highest for BH (1.04 mg/mL), followed by YT and ST. The predominant amino acids in SPW were Glu, Ala, Leu, and His. These results demonstrate that processing water containing diluted organic components, including protein, can be consumed directly by humans as a functional reinforcing material after appropriate concentration processes.
Abstract:
The use of microorganisms to degrade or reduce the concentration of hazardous wastes on a contaminated site is called bioremediation. Such a biological treatment system has various applications, such as cleanup of contaminated sites such as water, soil, sludge, and streams. Rapid industrialization, urbanization, intensive farming and other human activities have resulted in land degradation, environmental and aquatic pollution. Human activities have increased pressure on the natural resources, which in turn has resulted in myriad of pollutants. There has always been interest in developing efficient and effective techniques for the treatment of ever growing types of wastes. Bioremediation is one such process which involves detoxification, wherein the wastes detoxified and mineralized, are converted into inorganic compounds such as carbon dioxide, water and methane. There is a general interest in studying the diversity of indigenous microorganisms capable of degrading different pollutants because of their green value with regard to the environment. Seafood processing plant waste water management has been one of the serious problems faced by the seafood industry especially fish meal plants which face serious problems with public resistance for dumping of wastes into the environment. This article discusses the role of microbes in the treatment of seafood processing waste water and puts forward thoughts and scope for further research in the field.
Taurine is a sulfonic acid found in high concentrations in animal tissues. In recent years, a number of studies have demonstrated the essentiality of dietary taurine for many commercially relevant species, especially marine teleosts. Consequently, the removal of taurine-rich dietary ingredients such as fishmeal may create a deficiency, of which symptoms include reduced growth and survival, increased susceptibility to diseases, and impaired larval development. These symptoms emphasize the systemic role of taurine in the animal’s physiology and provide few clues as to the underlying mechanisms of taurine function. In fact, a myriad of roles have been attributed to taurine in mammals, ranging from bile salt conjugation to membrane stabilization, osmoregulation, anti-oxidation, immunomodulation, calcium-signaling, and neuroprotection. This review describes the current knowledge of taurine physiology and metabolism in fish and requirement levels in relevant species, and highlights possible parallels with mammalian taurine metabolism. In addition, the effects of ingredient processing and feed manufacturing on taurine bioavailability are discussed. Finally, regulatory aspects are brought to the forefront: although the supplementation of taurine will be necessary to further reduce the use of ingredients such as fishmeal, taurine is not currently approved by the FDA in the USA for fish feeds. Obtaining approval in the United States to utilize taurine in fish feeds can improve the environmental and economic sustainability of fish feeds nation-wide.
Anchovy (Engraulis japonicus) cooking wastewater (ACWW) is a by-product resulted from the production of boiled–dried anchovies in the seafood processing industry. In this study, the protein hydrolysate of ACWW (ACWWPH) was found to have antimicrobial activity after enzymatic hydrolysis with Protamex. For the targeted screening of antibacterial peptides, liposomes constructed from Staphylococcus aureus membrane lipids were used in an equilibrium dialysis system. The hydrolysate was further purified by liposome equilibrium dialysis combined with high performance liquid chromatography. The purified antimicrobial peptide (ACWWP1) was determined to be GLSRLFTALK, with a molecular weight of 1104.6622 Da. The peptide exhibited no haemolytic activity up to a concentration of 512 μg/ml. It displayed a dose-dependent bactericidal effect in reconstituted milk. The change in cell surface hydrophobicity and membrane-permeable action of the purified ACWWP1 may have contributed to the antibacterial effect. This study suggests that liposome equilibrium dialysis can be used for the targeted screening of antimicrobial peptides.
The aim of this work was the purification and identification of the major angiotensin converting enzyme (ACE) inhibitory peptides produced by enzymatic hydrolysis of a protein concentrate recovered from a cuttlefish industrial manufacturing effluent. This process consisted on the ultrafiltration of cuttlefish softening wastewater, with a 10 kDa cut-off membrane, followed by the hydrolysis with alcalase of the retained fraction. Alcalase produced ACE inhibitors reaching the highest activity (IC50 = 76.8 ± 15.2 μg mL-1) after 8 h of proteolysis. Sequential ultrafiltration of the 8 h hydrolysate with molecular weight cut-off (MWCO) membranes of 10 and 1 kDa resulted in the increased activity of each permeate, with a final IC50 value of 58.4 ± 4.6 μg mL-1. Permeate containing peptides lower than 1 kDa was separated by reversed-phase high performance liquid chromatography (RP-HPLC). Four fractions (A-D) with potent ACE inhibitory activity were isolated and their main peptides identified using high performance liquid chromatography coupled to an electrospray ion trap Fourier transform ion cyclotron resonance-mass spectrometer (HPLC-ESI-IT-FTICR) followed by comparison with databases and de novo sequencing. The amino acid sequences of the identified peptides contained at least one hydrophobic and/or a proline together with positively charged residues in at least one of the three C-terminal positions. The IC50 values of the fractions ranged from 1.92 to 8.83 μg mL-1, however this study fails to identify which of these peptides are ultimately responsible for the potent antihypertensive activity of these fractions.
Membrane technology has revolutionized the dairy sector. Different types of membranes are used in the industry for various purposes like extending the shelf life of milk without exposure to heat treatment, standardization of the major components of milk for tailoring new products as well increasing yield and quality of the dairy products, and concentrating, fractionation and purification of milk components especially valuable milk proteins in their natural state. In the cheese industry, membranes increase the yield and quality of cheese and control the whey volume, by concentrating the cheese milk. With the advancement of newer technology in membrane processes, it is possible to recover growth factor from whey. With the introduction of superior quality membranes as well as newer technology, the major limitation of membranes, fouling or blockage has been overcome to a greater extent.
This study aimed to evaluate the effects of alternative feed ingredients: Insect meal (DI) using non-defatted meal obtained from Acheta domesticus, Microalgae (DM) using a mix of four marine microalgae ((Nannochloropsis gaditana, Tisochrysis lutea, Rhodomonas lens, Isochrysis galbana), Protein and oil from water of tuna canning process (DP&L) and a Mixture (DMix) of the three ingredients, on the growth, feed utilisation, digestibility and composition of meagre juveniles, and the results obtained were compared with a feed similar to a commercial feed used as a control (DC). Results show that the formulated alternative feeds had different effects on fish growth. DMix have a similar growth performance than the control, whereas the other treatments (DI, DM and DP&L) showed a lower final weight. Hepatosomatic and viscerosomatic indices did not show differences among the treatments. Muscle protein content was higher for fish fed with DMix group whereas lipids were significantly higher in DI. In the case of the liver, protein was higher in the liver of fish fed with DI, DM and DP&L, whereas lipids were higher in fish fed with DI and DM, a result that was confirmed with the results obtained in hepatocyte size and lipid accumulation.
The nutritional value of the meagre muscle at the end of the study showed that meagre fed with DM and DI diets contained a significantly higher content of monounsaturated and n-6 PUFA, whereas fish from the groups fed with DP&L and DMix had a significantly higher content of DHA and n-3 PUFA with the liver showing similar results. In view of the results obtained, the ingredients assayed in this study might be used as alternative sources of protein and lipids in aquafeeds since no negative effects were detected neither on fish growth, muscle composition or final nutritional value, except in the case of the diet with microalgae (DM), which inclusion rate in the feed must be adjusted and needs more research.
The mechanical deboning of fish carcasses generates large volumes of water with proteins and other nutrients that are directly discarded. This study aimed to demonstrate the industrial value of minced tilapia wash-water (MTW-W) by determining its proximate composition and amino acid content, functional properties (solubility, foaming and emulsifying properties), antioxidant activity and potential as microbial growth medium. MTW-W showed a high crude protein content and a high content in essential amino acids for human and animal nutrition. A high protein diversity was detected in MTW-W by SDS-PAGE, including low-molecular-weight proteins that could serve as nitrogen source in bioprocesses. MTW-W demonstrated a high solubility in water and remarkable foaming properties over a wide pH range, but a limited emulsifying activity. A high antioxidant activity in terms of 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging was also detected, probably due to the high content in hydrophobic amino acids and those containing sulphur. Moreover, MTW-W showed a high efficiency for the growth of Escherichia coli, Listeria monocytogenes and Staphylococcus aureus. Therefore, the present study demonstrated the potential of MTW-W as functional additive with antioxidant activity and nitrogen source in bioprocesses, which would increase the sustainability of the tilapia processing and reduce the environmental impact.
Nile perch wastewater was biodegraded using two Bacillus species to recover bioactive substances to enhance its reutilization value. The two Bacillus species successfully produced low-molecular-weight substances with a 47.8% degree of hydrolysis. The antioxidant activities of the Nile perch wastewater increased as the biodegradation proceeded, and the culture supernatant exhibited the highest DPPH (80.1%), ABTS (93.1%) and Fe²⁺ chelating (88.5%) antioxidant activities at 60 h. The antioxidant potential of the biodegraded Nile perch wastewater was found to be higher than those of other fish hydrolysates. Moreover, the biodegraded Nile perch wastewater exhibited effective antimicrobial activity against Vibrio vulnificus, exhibiting a minimal inhibitory concentration of 585 μg mL⁻¹. Two-dimensional thin layer chromatography analysis revealed the specific amino acids responsible for the antioxidant activity, and molecular-weight cut-off ultrafiltration revealed that the <2-kDa fraction exhibited the highest antioxidant activity with the lowest IC50 values (0.43 and 0.22 mg mL⁻¹ for DPPH and ABTS antioxidant activities, respectively). This is the first report of the reutilization of Nile perch wastewater as a natural antioxidant and antimicrobial ingredient for nutraceuticals.
Fish industry has been growing continuously over the last decades and generates huge amounts of by-products. These by-products come from fish head, skin, bones, thorns and viscera. Part of them are processed for feed, collagen and oil production, and to a lesser extend to produce biofuels and fertilizers, but many other high-value bioactive
compounds can be recovered. Fish fermentation, which is traditionally used to increase fish shelf-life, results into the formation of bacteria metabolites of interest. Applied to by-products, fermentation increases the quality of protein hydrolysates, oil and produces
antioxidant compounds. This technology, which is safe, environmental-friendly and poor energy consuming, presents advantages for future applications.
Flocculation and sedimentation of a protein-rich biomass from shrimp boiling water (SBW) using food grade polysaccharides (carrageenan, alginate and carboxymethyl cellulose (CMC)) as flocculants was investigated at different pH-values. The effect of flocculant concentration on particle size and viscosity of SBW was also evaluated. Flocculation with carrageenan (0.45 g/L) at pH = 4 exhibited the most efficient protein sedimentation; protein concentration of the upper phase was here reduced by 77%, allowing 86% protein to be sedimented from SBW. Flocculation by alginate and CMC at pH = 4 showed 67% and 60% protein reduction of the upper phase at concentrations of 0.5 and 0.2 g/L, respectively. Contrary to alginate and CMC, carrageenan concentration affected the size distribution of flocs. Finally, carrageenan at 0.45 g/L and pH = 4 was successfully tested in a scaled up trial (5L) providing 78.5% protein recovery and a biomass with 75% protein on dry weight basis.
This study determined some antioxidative activities and functional properties of hydrolyzed proteins prepared from kilka (Clupeonella sp.) meat (KMH), kilka fishmeal (KFH), and stickwater (SWH). The highest degree of hydrolysis (DH) was 25.02% (p < 0.05) in SWH; however, the difference in DH between KMH and KFH was not significant. KFH had the highest protein content (85.69%) compared with other hydrolysis samples. The Fourier transform infrared spectra of KFH had the highest amide absorption picks (p < 0.05). Solubility at neutral pH was 84.09%, 86.00%, and 93.08% for KMH, KFH, and SWH, respectively. The highest fat absorption capacity was obtained with KFH (204 mg/50 mg). KFH also showed the best foaming properties with 25.66% foaming capacity and proper stability during 60 min (p < 0.05). The highest and lowest whiteness values were obtained in KMH (72.33%) and SWH (36.54%), respectively (p < 0.05). The highest 2,2-diphenyl-1-picrylhydrazyl (DPPH) (IC50 value of 1.99 mg/mL) and 2,2ʹ-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) (IC50 value of 2.00 mg/mL) radical scavenging activities were measured at the highest concentrations (40 mg/mL) in KFH (p < 0.05). KFH had the best functional and antioxidant properties, while SWH had a strong ability to inhibit lipid oxidation. Therefore, stickwater from fishmeal production factories is a potential resource for use in developing value-added products instead of being discarded.
The intention of this study is to investigate the effects of stickwater hydrolysates on growth performance for yellow catfish (Pelteobagrus fulvidraco) fed with non-fish meal diets. Two experiments were designed. Experiment (A) was conducted to evaluate the effects of stickwater hydrolysates which were prepared by different methods. Ten diets were prepared: the control diet used fish meal as the main protein source and other nine non-fish meal diets were formulated with stickwater (SW), stickwater hydrolysate (HSW) or stickwater hydrolysate meal (HSM), supplying approximate 25%, 50% or 75% of fish meal protein in the control diet. Experiment (B) was conducted to determine how peptide and free amino acid content of HSW influence growth performance of fish. Ten diets were prepared: the control diet used fish meal as the main protein source and other nine non-fish meal diets were formulated with low degree of hydrolyzed stickwater hydrolysate (L-HSW), middle degree of hydrolyzed stickwater hydrolysate (M-HSW) or high degree of hydrolyzed stickwater hydrolysate (H-HSW), supplying approximate 15, 30 or 45% of fish meal protein in the control diet. All diets were fed to three replicate groups of yellow catfish (initial body weight of 15.67 ± 0.11 g for experiment A and 18.67 ± 0.11 g for experiment B) for 60 days. High weight gain was achieved in yellow catfish fed with HSW25 and M-HSW30, in which the fish in-fish out values (FIFO) were only about 27% to 32% of control diet. Growth performance of fish fed SW diets was significantly reduced compared to the control diet. No significant (P > 0.05) differences in SGR, FCR, PRR, and FRR were found in the fish fed with the HSW diets compared to the control diet. The weight gain had no significant (P > 0.05) differences among fish fed L-HSW30, M-HSW30, and basal diet, but it significantly reduced in fish fed H-HSW diets. Decreasing tendency of fish growth performance was obtained when we increase the content of SW, SHW, and SHM in diets, while the relative expression of PepT1 was significantly down-regulated. The present work gives evidence on the multi-dimensional effects of different SW hydrolysates on fish growth performance. These results suggest that in the commercial diet pattern containing same nitrogen, energy, phosphorus, and sum amino acid, we observed the equivalent biological valve between fish fed with HSW25 or M-HSW30 and basal diet. This indicates that stickwater hydrolysate is a promising fish meal replacement and the optimal level in diet is approximately 80 to 90 g kg⁻¹ (dry matter), in which the FIFO value was only about 27% to 32% of the control diet. Poorer growth performance was observed in the fish fed with diets contain SW and hydrolysates (dry matter) >130 g kg⁻¹. Besides, the H-HSW was not a good option for yellow catfish. It may be because of the considerable small nitrogen compounds of lower than 500 Da, which lead to high serum free amino acid and eventually result in the low digestion and absorption of protein by modulating the mRNA expression levels of PepT1.
La presente edición de El estado mundial de la pesca y de la acuicultura se destaca el papel fundamental de la pesca y la acuicultura en la seguridad alimentaria y la nutrición, así como la expansión económica. El sector sigue siendo un proveedor importante de proteína animal de alta calidad y es compatible con los medios de vida y el bienestar de más de diez por ciento de la población mundial. El comercio internacional de pescado ha alcanzado nuevos máximos ya que la producción total ha seguido aumentando. Sin embargo, como subraya el documento, una serie de problemas - que van desde la necesidad de una gobernanza más eficaz a la de garantizar la sostenibilidad del medio ambiente - amenaza con socavar la valiosa contribución del sector a la reducción del hambre y la reducción de la pobreza.
In this chapter a brief overview of membrane processes is presented, where the most significant parameters and processes have been pointed out, including descriptions of the industrial applications of membrane processes, membrane configurations and membrane operations.
In recent years, functional foods and nutraceuticals have attracted much attention, particularly in regard to their impact on human health and prevention of certain diseases. Consequently, the production and properties of bioactive materials has received an increasing scientific interest over the past few years. Membrane processing offers several advantages over conventional methods for separation, fractionation, and recovery of those bioactive components. Membrane separation is a useful technique to extract, concentrate, separate, or fractionate the compounds. The use of membrane bioreactors to integrate a reaction vessel with a membrane separation unit is emerging as a beneficial method for producing bioactive materials such as peptides, chitooligosaccharides, and polyunsaturated fatty acids (PUFAs) from diverse seafood by-products. In this review, membrane applications of lipid-, carbohydrate-, and protein-based nutraceuticals and some minor bioactive components have been critically evaluated. This article discusses recent membrane technology related to the production of bioactive materials for health benefits from marine organisms and their processing by-products. © Springer Science+Business Media New York 2014. All rights are reserved.
It is possible to recover muscle protein isolates from food processing by-products and under-utilized or difficult to process sources that otherwise would be discarded or diverted from direct human consumption by using isoelectric solubilization/precipitation (ISP). ISP selectively induces water solubility of muscle proteins by changing pH. When muscle proteins are dissolved, they are separated from lipids and other insoluble fractions such as skin, bones, scales, etc. Following separation, the dissolved proteins are subjected to subsequent pH change that causes protein precipitation and yields protein isolate. ISP processing efficiently recovers protein isolates of high quality from both nutritional and technological stand point. However, attempts at commercializing food products developed from the ISP-recovered protein isolates have been very limited. Results from laboratory-scale product development research demonstrate the potential for the use of ISP-recovered protein isolates as a base and functional ingredient for prototypes of nutraceutical foods with specific health benefits. This article reviews ISP as an innovative means to recover functional protein isolates from low-value sources. It also covers recent attempts to develop prototypes of nutraceutical food products using the ISP-recovered protein isolates targeting diet-driven cardiovascular disease.
Background
Ultrafiltration has led to the recovery of valuable products from seafood processing wastes. However, the use of crustacean process wastewaters as a source of bioactive compounds with application in the chemical, pharmaceutical and food industries has been scarcely studied to date.ResultsThis study reports the recovery of high concentrations of astaxanthin (10–13 µg mL−1) by 300 kDa ultrafiltration of shrimp cooking wastewater, indicating astaxanthin is somehow associated to high MW retained proteins. Individual UF with 300, 100 and 30 kDa MWCO membranes and the sequential UF 100 30 kDa were the most effective configurations for protein concentration. Besides, hydrolysates from these three protein-concentrated fractions showed very potent ACE-inhibitory (1.98, 9.87 and 23.10 µg mL−1IC50 values) and ß- carotene bleaching activities compared to hydrolysates from other fish and seafood species.Conclusions
According to these results, shrimp cooking wastewater is a good source of astaxanthin and bioactive peptides. This approach based on the ultrafiltration of shrimp cooking wastewaters contributes towards the depuration of this by-product, while enabling the recovery and production of high value-added products.
This review intended to give a brief idea of the importance of proteases applications. Processes that involve protein hydrolysis steps find wide ranging utilizations, such as cleaning process, proteomic studies, or food biotechnology process. Many positive effects hoped for with food processing can be achieved by protein hydrolysis using specific proteases, changing nutritional, bioactive and functional properties of food proteins, which include improved digestibility, modifications of sensory quality (such as texture or taste), improvement of antioxidant capability or reduction in allergenic compounds. Protease
applications in industrial processes are constantly being introduced and can be advantageous compared to chemical processes, by increasing hydrolysis specificity, product preservation and purity, and reducing environmental impact. Differences in specificity between proteases are very important to take in to consideration as a guide for the choice of protease according to the protein source to be hydrolyzed or predicted products. In this present review, some aspects of the processes that involve protein hydrolysis
steps are discussed, especially considering the application of specific proteases as a tool on food
biotechnology.
Galicia (NW Spain) is an ideal environment for mussel culture owing to its excellent natural conditions. It is the first Spanish and European mussel producer and the second worldwide after China. More than 50% of the mussel collected in Galicia is used in the processing industry, which produces different products, as cooked mussel that is canned, frozen or used in the food industry.In this paper a methodology based on Life Cycle Thinking has been applied to a mussel processing plant. The methodology combines Material and Energy Flow Analysis (MEFA) and BAT (Best Available Techniques) Analysis to detect the Improvable Flows (IF) of the process and to propose techniques that enhance the process. The results obtained after the application of the methodology will be used to improve the performance of the plant. It will also be considered the suitability of the methodology for being applied to other plants of the sector.
: Protease XXIII, from Aspergillus oryzae, was used to hydrolyze tuna cooking juice at 37°C for up to 6 h. The hydrolyzate obtained at the degree of hydrolysis of 25.68% (after hydrolysis for 2.5 h) displayed the highest 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging effect, reaching 82.19%. Six major fractions (A, B, C, D, E, and F) of this hydrolyzate were obtained by Sephadex G-25 column chromatography using a 0.05 M phosphate buffer (pH 6.5) as the mobile phase. All six fractions displayed a scavenging effect for the DPPH radical, but the scavenging effect was only obvious in two fractions (B and C). After the solid content of hydrolyzates was concentrated from one to five times, the scavenging effect of the DPPH radical increased from 17% to 75% for fraction B, and from 13% to 66% for fraction C. Seven anti-oxidative peptides were isolated from the hydrolyzates (mixture of B and C fractions) by reversed-phase HPLC. The peptide sequences comprised four to eight amino acid residues, including Val, Ser, Pro, His, Ala, Asp, Lys, Glu, Gly, or Tyr.
This article details recent research conducted on the complexation between milk proteins and polysaccharides and the properties of the complexes, and the application of such relationships to the food industry. Complexation between proteins and polysaccharides through electrostatic interactions gives either soluble complexes in a stable solution or insoluble complexes, leading to phase separation. The formation and the stability of these complexes are influenced by pH, ionic strength, ratio of protein to polysaccharide, charge density of protein and polysaccharide as well as processing conditions (temperature, shearing and time). The functional properties of milk proteins, such as solubility, surface activity, conformational stability, gel-forming ability, emulsifying properties and foaming properties, are improved through the formation of complexes with polysaccharides. These changes in the functional properties provide opportunities to create new ingredients for the food industry.
A fish canning facility processes 1900–2000 tons of mackerel and sardine annually at arate of 10–15 tons per day for a total of 200 days yr-1. This factory generates an average of 20 m3 of industrial wastewaters per day. The objective of our study, which was carried out on a bimonthly basisfrom December 1995 to November 1996, was to determine the overall pollutant load associated with this effluent in relation to the applicable Egyptian Standards and to propose methods for pollutant load reduction before discharging it to the local sewer. The methods were to benefit through the recovery of wasted organic load and transform it into an environmentally safe residue amenable for either immediate reuse or final disposal thereafter. Five chemical coagulation/flocculation treatments were tried using ferric chloride, alum, lime, ferric chloride and lime, and alum and lime. The best method involved the use of FeCl3 and Ca(OH)2 (0.4 g Fe L-1 and 0.2 g Ca L-1, respectively) which reduced the average influent BOD5 from 989 to 204 mg L-1, the COD from 1324 to 320 mg L-1, TSS from 4485 to 206 mg L-1, total protein content from 812 to 66 mg L-1 and oil and grease from 320 to 66 mg L-1. The separated dried precipitate averaged 50 g L-1 which was found to contain 40% by weight recovered protein and 20% recovered fat. The solid was ideal for on-site reprocessing as animal feed. As well, the final effluent, if not discharged to the area sewer, was safe for controlled use in some irrigation applications or forestry projects at the desert area surrounding the factory.
In this study, increasing levels of stickwater (SW) separated during the fish meal production process were added back to produce 5 experimental fish meals. Five experimental diets were prepared which consisted of 50 g commercial fish meal and 50 g of the different experimental fish meals with graded inclusion levels of SW kg− 1 diet. The remaining dietary protein sources consisted of a mixture of plant protein sources (soy protein concentrate; 215 g kg− 1 diet, corn gluten; 215 g kg− 1 diet; field beans 140 g kg− 1 diet; wheat gluten 55 g kg− 1 diet) giving 17% of the total dietary protein from marine sources. All the experimental diets were isonitrogenous, isolipidic and isoenergetic. Two more low fish meal diets were prepared containing the low (permeate) or high (retentate) molecular weight fraction of fractionated and ultrafiltrated SW. A control diet containing 300 g commercial fish meal kg− 1 diet was prepared. The diets were fed to 8 triplicate groups of salmon (initial body weight 137 g) for 74 days. Fish growth was positively affected by the increasing inclusion level of SW in the low fish meal diets. The low fish meal diets that were supplemented with SW performed the same, both in terms of growth and feed utilization, as the control diet. The growth parameters were also positively correlated to the dietary levels of taurine and hydroxyproline but it is not known if this is because of taurine and hydroxyproline themselves or if taurine and hydroxyproline are indicators for other functional water soluble components present in the marine raw materials. No significant differences were found in feed intake or feed efficiency, nor was there any difference in ADC of protein, lipid, gross energy or phosphorus (P) among the diets containing the experimental fish meals, except for the control diet which had a lower ADC of protein compared to the high plant protein diets. Whole body proximate composition and total and soluble P content of fish were not affected by the inclusion level of SW in the diets. Significant effects were identified in the free amino acid profile in the fillet of fish fed the different experimental diets. The present work gives further evidence for the importance of marine water-soluble fractions and small marine water-soluble components in high plant protein diets for salmon. The present results may be a significant contribution in explaining why marine protein sources are important in feed for carnivorous fish species. By the addition of SW to the diets higher flexibility in the choice of protein sources may be obtained.
Muscle proteins were recovered from rainbow trout processing by-products (fish meat leftover on bones, head, skin, and etc.) by isoelectric solubilization/precipitation. Muscle proteins precipitated at pH 5.5 are typically recovered by high-speed centrifugation at a laboratory scale, which appears to impede process scale-up. Our objective was to investigate the effect of flocculants on separation of precipitated proteins from process water (supernatant). Flocculants with different surface charge properties and molecular weights (Mw) were added to precipitated proteins. Protein separation was evaluated by determining optical density (OD) of the supernatant using Bradford dye-binding method. A high Mw anionic flocculent at 100 mg/L resulted in excellent protein separation following 10 min reaction. The OD of the supernatant was comparable to that of clear water, suggesting that even water-soluble fish muscle proteins were removed from the process water. Freeze–thaw cycles, commonly encountered in the fish processing industry, resulted in even more rapid flocculation reaction. This flocculent could be added to a bio-reactor that precipitates muscle proteins at pH 5.5 in a continuous isoelectric solubilization/precipitation system. However, effects of the flocculants on human and animal health should be determined and appropriate approvals obtained before the recovered muscle proteins can be used in human food products and/or animal feeds.