Search

The rising protein demand in the aquaculture sector has significantly impacted fishmeal supply and pricing. Excessive use of fishmeal can lead to environmental issues and negatively impact marine biodiversity and human food security. Consequently, finding alternative fishmeal in aquaculture is crucial for economic and environmental sustainability. The present study aimed to determine how Bacillus cereus (MT355408) could enhance nutritional value of Sardine fish waste, which could replace fish meal in the market. Solid-state fermentation (SSF) represents a biotechnological method that utilizes microbes to convert discarded fish byproducts into valuable products. The bacterial ability to produce enzymes was studied and optimised for its maximum production to be used as an inoculum for the SSF technique. Different prebiotic sources were also studied for better upliftment of bacteria in the solid-state surface. A single-factor analysis was conducted to investigate the influence of varying prebiotic concentrations, inoculum quantity, and fermentation duration on protein breakdown. After studying the single-factor tests, a further response surface model was employed for better yield. The results indicated that the highest protein yield could be achieved with a fermentation time of 132.893 hours, a prebiotic quantity of 25%, and an inoculum quantity of 5.3%. The study's findings also affirmed that the model was vital in enhancing the crude protein content during fermentation. In conclusion, the model's results contribute valuable insights into fermentation processes, offering practical implications for enhancing protein content and digestibility in similar contexts.

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., En la actualidad, se han desarrollado numerosas metodologías para obtener el máximo aprovechamiento de proteínas del pescado, con la finalidad de satisfacer la demanda nutricional humana, este aprovechamiento se ha realizado tanto, a partir de pescado entero como de sus residuos o subproductos (hígado, cabeza, piel, gónadas, esqueleto y vísceras) los que representan hasta el 60% del pescado entero. Potencialmente el pescado entero y los subproductos pueden utilizarse como fuentes de aminoácidos esenciales, colágeno, gelatina, lípidos poliinsaturados y enzimas. Mediante el uso de la tecnología enzimática se han obtenido hidrolizados proteicos con amplio potencial para su aplicación como ingredientes en el desarrollo y producción de alimentos fortificados, debido a sus propiedades funcionales (antihipertensivos, antioxidantes, antimicrobianos e inmunomoduladores) los que pueden reducir los riesgos de cáncer, envejecimiento, diabetes y enfermedades cardiovasculares. Además, estos hidrolizados presentan importantes propiedades tecno-funcionales (formación de espuma, solubilidad, emulsificación, gelificación, retención de agua y aceite) que proveen características tecnológicas deseables para el procesamiento, almacenamiento y calidad del producto, así como para el comportamiento durante el procesamiento y almacenamiento. Esta revisión analiza los avances en la tecnología de obtención, identificación y producción de hidrolizados proteicos de pescado (FPH) por acción enzimática, con énfasis en residuos de pescado destacando la aplicación de los FPH en alimentos, el análisis de mercado y las regulaciones globales. Se recomienda continuar los estudios de optimización de producción enzimática de FPH a fin de lograr mejorar el sabor y su aplicación en la fortificación de alimentos de consumo masivo.

Six treatments were formulated to make silages with fish wastes, corn stubble, molasses, pineapple peel (PP) [15, 30 and 45%] and inoculum Lactobacillus sp. or Lactobacillus B2. The silages of each treatment were made in triplicate and incubated at 30 °C for 0, 2, 4, 7 and 14 days in order to evaluate the acidification under a 3 x 2 x 5 factorial design. The chemical composition and in vitro dry matter digestibility (IVDMD) were determined to the silages at end of fermentation. The highest acidification (p<0.05) was presented in the treatments with PP 15 and 30% and Lactobacillus B2 for 7 days. The highest dry matter content (39.3%) (p<0.05) was obtained with 15% of PP and the crude protein was from 26.5 to 31% without significant difference. The highest concentration of lipids (9.85%) was present in the treatments with PP 30 and 45% and Lactobacillus B2. Detergent fiber fractions decreased with increasing PP level and the highest IVDMD (82.9%) occurred in silages when using Lactobacillus B2, regardless of PP level. The silages obtained are an alternative in ruminant feeding, Se formularon seis tratamientos para elaborar ensilado biológico con desechos de pescado, rastrojo de maíz, melaza, cáscara de piña (CP) [15, 30 y 45%] e inóculo Lactobacillus sp. o Lactobacillus B2. Los ensilados de cada tratamiento se hicieron por triplicado y se incubaron a 30°C durante 0, 2, 4, 7 y 14 días con el propósito de evaluar la acidificación bajo un diseño factorial 3 x 2 x 5. A los ensilados se les determinó la composición química y la digestibilidad in vitro de la materia seca (DIVMS) al terminar la fermentación. La acidificación más alta (p<0.05) la presentaron los tratamientos con CP 15 y 30% y Lactobacillus B2 a los 7 días. Con 15% de CP se obtuvo el mayor contenido de materia seca (39.3%) (p<0.05) y la proteína cruda (26.5 a 31%, rango) fue igual (p>0.05). La concentración mayor de lípidos (9.85%) se presentó en los tratamientos con CP 30 y 45% y Lactobacillus B2. Las fracciones de fibra detergente disminuyeron al aumentar el nivel de CP y la DIVMS más alta (82.9%) se presentó en los ensilados al utilizar Lactobacillus B2, independientemente del nivel de CP (p<0.05). Los ensilados obtenidos son una alternativa para alimentación de rumiantes

Integrated Multi-Trophic Aquaculture (IMTA) systems have been designed to optimize nutrient and energy use, to decrease waste, and to diversify fish-farm production. Recently, the development of detritivorous aquaculture has been encouraged, as detrivores can consume organic particulate matter, reducing benthic eutrophication and the environmental footprint of aquaculture. To this end, the polychaete Hediste diversicolor is a promising species due to its broad feeding behaviour and its resistance in a wide range of environments. In this study, an existing Dynamic Energy Budget (DEB) model of H. diversicolor was used to predict the ragworm's metabolic processes in various environmental conditions and to estimate its bioremediation capacity in an aquaculture context. First, the scaled functional response (f) was calibrated in a 98-day growth experiment with two types of food (Fish faeces and Fish feed). Then, we further validated the model using data on the ammonia excretion and oxygen consumption of individuals fed with fish faeces at four different temperatures using the previously calibrated f. Overall, we found that the DEB model was able to correctly predict the experimental data (0.51

Integrated Multi-Trophic Aquaculture (IMTA) systems have been designed to optimize nutrient and energy use, to decrease waste, and to diversify fish-farm production. Recently, the development of detritivorous aquaculture has been encouraged, as detrivores can consume organic particulate matter, reducing benthic eutrophication and the environmental footprint of aquaculture. To this end, the polychaete Hediste diversicolor is a promising species due to its broad feeding behaviour and its resistance in a wide range of environments. In this study, an existing Dynamic Energy Budget (DEB) model of H. diversicolor was used to predict the ragworm's metabolic processes in various environmental conditions and to estimate its bioremediation capacity in an aquaculture context. First, the scaled functional response (f) was calibrated in a 98-day growth experiment with two types of food (Fish faeces and Fish feed). Then, we further validated the model using data on the ammonia excretion and oxygen consumption of individuals fed with fish faeces at four different temperatures using the previously calibrated f. Overall, we found that the DEB model was able to correctly predict the experimental data (0.51

Six treatments were formulated to make silages with fish wastes, corn stubble, molasses, pineapple peel (PP) [15, 30 and 45%] and inoculum Lactobacillus sp. or Lactobacillus B2. The silages of each treatment were made in triplicate and incubated at 30 °C for 0, 2, 4, 7 and 14 days in order to evaluate the acidification under a 3 x 2 x 5 factorial design. The chemical composition and in vitro dry matter digestibility (IVDMD) were determined to the silages at end of fermentation. The highest acidification (p<0.05) was presented in the treatments with PP 15 and 30% and Lactobacillus B2 for 7 days. The highest dry matter content (39.3%) (p<0.05) was obtained with 15% of PP and the crude protein was from 26.5 to 31% without significant difference. The highest concentration of lipids (9.85%) was present in the treatments with PP 30 and 45% and Lactobacillus B2. Detergent fiber fractions decreased with increasing PP level and the highest IVDMD (82.9%) occurred in silages when using Lactobacillus B2, regardless of PP level. The silages obtained are an alternative in ruminant feeding, Se formularon seis tratamientos para elaborar ensilado biológico con desechos de pescado, rastrojo de maíz, melaza, cáscara de piña (CP) [15, 30 y 45%] e inóculo Lactobacillus sp. o Lactobacillus B2. Los ensilados de cada tratamiento se hicieron por triplicado y se incubaron a 30°C durante 0, 2, 4, 7 y 14 días con el propósito de evaluar la acidificación bajo un diseño factorial 3 x 2 x 5. A los ensilados se les determinó la composición química y la digestibilidad in vitro de la materia seca (DIVMS) al terminar la fermentación. La acidificación más alta (p<0.05) la presentaron los tratamientos con CP 15 y 30% y Lactobacillus B2 a los 7 días. Con 15% de CP se obtuvo el mayor contenido de materia seca (39.3%) (p<0.05) y la proteína cruda (26.5 a 31%, rango) fue igual (p>0.05). La concentración mayor de lípidos (9.85%) se presentó en los tratamientos con CP 30 y 45% y Lactobacillus B2. Las fracciones de fibra detergente disminuyeron al aumentar el nivel de CP y la DIVMS más alta (82.9%) se presentó en los ensilados al utilizar Lactobacillus B2, independientemente del nivel de CP (p<0.05). Los ensilados obtenidos son una alternativa para alimentación de rumiantes

Six treatments were formulated to make silages with fish wastes, corn stubble, molasses, pineapple peel (PP) [15, 30 and 45%] and inoculum Lactobacillus sp. or Lactobacillus B2. The silages of each treatment were made in triplicate and incubated at 30 °C for 0, 2, 4, 7 and 14 days in order to evaluate the acidification under a 3 x 2 x 5 factorial design. The chemical composition and in vitro dry matter digestibility (IVDMD) were determined to the silages at end of fermentation. The highest acidification (p<0.05) was presented in the treatments with PP 15 and 30% and Lactobacillus B2 for 7 days. The highest dry matter content (39.3%) (p<0.05) was obtained with 15% of PP and the crude protein was from 26.5 to 31% without significant difference. The highest concentration of lipids (9.85%) was present in the treatments with PP 30 and 45% and Lactobacillus B2. Detergent fiber fractions decreased with increasing PP level and the highest IVDMD (82.9%) occurred in silages when using Lactobacillus B2, regardless of PP level. The silages obtained are an alternative in ruminant feeding, Se formularon seis tratamientos para elaborar ensilado biológico con desechos de pescado, rastrojo de maíz, melaza, cáscara de piña (CP) [15, 30 y 45%] e inóculo Lactobacillus sp. o Lactobacillus B2. Los ensilados de cada tratamiento se hicieron por triplicado y se incubaron a 30°C durante 0, 2, 4, 7 y 14 días con el propósito de evaluar la acidificación bajo un diseño factorial 3 x 2 x 5. A los ensilados se les determinó la composición química y la digestibilidad in vitro de la materia seca (DIVMS) al terminar la fermentación. La acidificación más alta (p<0.05) la presentaron los tratamientos con CP 15 y 30% y Lactobacillus B2 a los 7 días. Con 15% de CP se obtuvo el mayor contenido de materia seca (39.3%) (p<0.05) y la proteína cruda (26.5 a 31%, rango) fue igual (p>0.05). La concentración mayor de lípidos (9.85%) se presentó en los tratamientos con CP 30 y 45% y Lactobacillus B2. Las fracciones de fibra detergente disminuyeron al aumentar el nivel de CP y la DIVMS más alta (82.9%) se presentó en los ensilados al utilizar Lactobacillus B2, independientemente del nivel de CP (p<0.05). Los ensilados obtenidos son una alternativa para alimentación de rumiantes

Abstract In Chile, the Artisanal Fishing Port of the city of Coquimbo is used as the main landing point for the region. One of the main activities is the evisceration and cleaning of fish, which results in the generation of a large volume of waste. This waste is stored during the day in plastic containers with colanders, located in the backyard of the Port. Because it is not covered, the waste is exposed to solar radiation, accelerating its decomposition and therefore generating bad odors and attracting flies. Although the waste is used for the production of fish flour, it is also thrown into the sea, because it is not constantly removed from the port. In the present work, two waste management proposals are presented: the elaboration of compost and the design of a process for the adequate collection, segregation, transport, treatment and final disposal of the waste., En Chile, el Puerto Pesquero Artesanal de la ciudad de Coquimbo es usado como el principal centro de desembarque de la región. Una de las principales actividades que se realiza es el eviscerado y limpieza de pescados, cuyo resultado es la generación de un gran volumen de residuos. Estos son almacenados durante el día en contenedores plásticos con escurridores, ubicados en el patio del Puerto. Debido a que no están bajo una cubierta, estos están expuestos a la radiación solar, por tanto su descomposición se acelera, favoreciendo la generación de malos olores y atrayendo moscas por el escurrimiento de sangre. Dichos residuos son utilizados para la fabricación de harina de pescado, pero cuando estos no son retirados sistemáticamente, se dispone que sean arrojados al mar. En el presente trabajo se plantean dos propuestas de manejo para los residuos: la elaboración de compost y el diseño de un proceso para la adecuada recolección, segregación, transporte, tratamiento y disposición final de los mismos. .

Abstract In Chile, the Artisanal Fishing Port of the city of Coquimbo is used as the main landing point for the region. One of the main activities is the evisceration and cleaning of fish, which results in the generation of a large volume of waste. This waste is stored during the day in plastic containers with colanders, located in the backyard of the Port. Because it is not covered, the waste is exposed to solar radiation, accelerating its decomposition and therefore generating bad odors and attracting flies. Although the waste is used for the production of fish flour, it is also thrown into the sea, because it is not constantly removed from the port. In the present work, two waste management proposals are presented: the elaboration of compost and the design of a process for the adequate collection, segregation, transport, treatment and final disposal of the waste., En Chile, el Puerto Pesquero Artesanal de la ciudad de Coquimbo es usado como el principal centro de desembarque de la región. Una de las principales actividades que se realiza es el eviscerado y limpieza de pescados, cuyo resultado es la generación de un gran volumen de residuos. Estos son almacenados durante el día en contenedores plásticos con escurridores, ubicados en el patio del Puerto. Debido a que no están bajo una cubierta, estos están expuestos a la radiación solar, por tanto su descomposición se acelera, favoreciendo la generación de malos olores y atrayendo moscas por el escurrimiento de sangre. Dichos residuos son utilizados para la fabricación de harina de pescado, pero cuando estos no son retirados sistemáticamente, se dispone que sean arrojados al mar. En el presente trabajo se plantean dos propuestas de manejo para los residuos: la elaboración de compost y el diseño de un proceso para la adecuada recolección, segregación, transporte, tratamiento y disposición final de los mismos. .

Abstract In Chile, the Artisanal Fishing Port of the city of Coquimbo is used as the main landing point for the region. One of the main activities is the evisceration and cleaning of fish, which results in the generation of a large volume of waste. This waste is stored during the day in plastic containers with colanders, located in the backyard of the Port. Because it is not covered, the waste is exposed to solar radiation, accelerating its decomposition and therefore generating bad odors and attracting flies. Although the waste is used for the production of fish flour, it is also thrown into the sea, because it is not constantly removed from the port. In the present work, two waste management proposals are presented: the elaboration of compost and the design of a process for the adequate collection, segregation, transport, treatment and final disposal of the waste., En Chile, el Puerto Pesquero Artesanal de la ciudad de Coquimbo es usado como el principal centro de desembarque de la región. Una de las principales actividades que se realiza es el eviscerado y limpieza de pescados, cuyo resultado es la generación de un gran volumen de residuos. Estos son almacenados durante el día en contenedores plásticos con escurridores, ubicados en el patio del Puerto. Debido a que no están bajo una cubierta, estos están expuestos a la radiación solar, por tanto su descomposición se acelera, favoreciendo la generación de malos olores y atrayendo moscas por el escurrimiento de sangre. Dichos residuos son utilizados para la fabricación de harina de pescado, pero cuando estos no son retirados sistemáticamente, se dispone que sean arrojados al mar. En el presente trabajo se plantean dos propuestas de manejo para los residuos: la elaboración de compost y el diseño de un proceso para la adecuada recolección, segregación, transporte, tratamiento y disposición final de los mismos. .

Abstract In Chile, the Artisanal Fishing Port of the city of Coquimbo is used as the main landing point for the region. One of the main activities is the evisceration and cleaning of fish, which results in the generation of a large volume of waste. This waste is stored during the day in plastic containers with colanders, located in the backyard of the Port. Because it is not covered, the waste is exposed to solar radiation, accelerating its decomposition and therefore generating bad odors and attracting flies. Although the waste is used for the production of fish flour, it is also thrown into the sea, because it is not constantly removed from the port. In the present work, two waste management proposals are presented: the elaboration of compost and the design of a process for the adequate collection, segregation, transport, treatment and final disposal of the waste., En Chile, el Puerto Pesquero Artesanal de la ciudad de Coquimbo es usado como el principal centro de desembarque de la región. Una de las principales actividades que se realiza es el eviscerado y limpieza de pescados, cuyo resultado es la generación de un gran volumen de residuos. Estos son almacenados durante el día en contenedores plásticos con escurridores, ubicados en el patio del Puerto. Debido a que no están bajo una cubierta, estos están expuestos a la radiación solar, por tanto su descomposición se acelera, favoreciendo la generación de malos olores y atrayendo moscas por el escurrimiento de sangre. Dichos residuos son utilizados para la fabricación de harina de pescado, pero cuando estos no son retirados sistemáticamente, se dispone que sean arrojados al mar. En el presente trabajo se plantean dos propuestas de manejo para los residuos: la elaboración de compost y el diseño de un proceso para la adecuada recolección, segregación, transporte, tratamiento y disposición final de los mismos. .

One of the present-days largest challenges are the increased climate change and the scarcity of nonrenewable resources. From both global, national and local levels comes exhortations concerning lowering energy use from fossil fuels and streamlining resources more efficiently. An important solution to attack this problem is to increase the use of biofuels that leave a lower carbon footprint and that is not threatened by scarcity (if consumed in a responsible way). Developing more advanced biofuels, biofuels that are made from residues or waste, could create multiple environmental advantages and make exploitation of resources more effective and sustainable. Åland, the self-governing island between Sweden and Finland, is a small economy with an essential fish industry. Every year this island, with less than 30 000 inhabitants, produce fish for more than 300 000 human’s consumption in their fish farms every year. With that production comes a lot of waste that currently is mostly sold to animal farms in mainland Finland. This thesis will investigate whether Åland have a better use for the waste residual from their fish farming. The intent is to compare the current applications for fish waste to a biogas scenario where the fish waste is used for anaerobic digestion to make biogas upgraded to vehicle gas. The first objective is to identify theoretical impacts from the biogas scenario on society’s utility in relation to status quo. Both internal and external effects are recognized. The second objective is to value this scenario using a Cost Benefit Analysis where the impacts are monetized and evaluated over time to find whether it is socio economically profitable to applicate biogas production of fish waste. The result showed a negative Net Present Value for biogas production from fish waste of EUR 2 552 853 over a studied 40-year period. In the sensitivity analysis, the robustness of this result was tested and showed that the result stayed below zero regardless of whether

This work was focused on the study of the bioactive potential of three fish protein hydrolysates, one of them prepared from industrial sardine by-products (heads and viscera) and the others from tuna by-products (heads, and muscle and viscera). These protein hydrolysates exhibited moderate ability to inhibit Angiotensin Converting Enzyme (IC50 between 0.24-1.16 mg dry weight/ml) and Prolyl Oligopeptidase (IC50 between 3.30-9.57 mg/ml), being those obtained from tuna by-products the most effective. Overall, ACE- and PO-inhibiting activities were enhanced by sequential nanofiltration through 3 and 1 kDa MWCO membranes (IC50 between 0.02-0.16 mg/ml (ACE) and 1.10-4.21 mg/ml (PO)). The inhibitory properties of the hydrolysates were greatly improved by in vitro gastric digestion, and were barely affected by further intestinal digestion. The digested tuna hydrolysates proved to be the best source of PO- and ACE- inhibiting molecules (mainly that from heads (IC50 = 0.16 mg/ml (ACE) and 1.04 mg/ml (PO)) and could be potential new ingredients in food with interest in the prevention or treatment of cardiovascular and neurological diseases.

Fish farming releases extensive amounts of particulate organic waste that can be exploited by bivalves in integrated culture. We tested if mussels Mytilus galloprovincialis cultured at two depths (1 and 6 m) in a raft, moored 170 m from a fish farm had greater growth than bivalves held 550 m from the fish cages. Mussel growth was monitored monthly, covering the second phase of the culture, from thinning-out to harvest (March to November 2011). We also studied if fish solid and dissolved nutrients increased the organic content of the seston and chlorophyll-a levels near the fish cages through weekly samples. Results showed no differences in seston, chlorophyll and physiochemical characteristics of the water among rafts. Maximum growth and Condition Index (CI) occurred during spring–summer (April–August), when mussels had access to greater food quality and quantity. Mussels cultivated close to the cages showed similar shell length, weight and CI compared with mussels distant from the fish farm. Average shell length, meat dry weight and CI at harvest were 76.31 mm, 2.51 g and 23%. Bivalves cultured distant from the fish cages displayed 26% higher biomass than the other raft at the end of the experiment. Differences in biomass were explained by the significantly higher recruitment of mussel seed observed at the raft distant from the fish cages from June to November. The lack of a significant enhancement in growth of the bivalves cultured next to finfish is discussed.

Cada vez es más común el uso de compost en la elaboración de sustratos de cultivo, pero uno de los inconvenientes más frecuentes que presentan este tipo de materiales para ser utilizados como sustrato es su elevada salinidad. Este problema puede ser tratado de distintas maneras. En este trabajo se evalúan dos de las técnicas disponibles: el lavado rápido (15 h) con agua previo al cultivo y el lavado gradual (60 días) mediante un riego con solución nutritiva (SN). Se comparan ambos métodos, tanto desde el punto de vista de la eficiencia como desde el punto de vista de la liberación de nutrientes, como técnica más adecuada para el manejo de la salinidad de un compost con alta C.E. (18,7 dS m-1 en extracto de saturación). En ambos ensayos se produjo un rápido e importante descenso de la C.E., y fue suficiente el aporte de 3 veces el volumen de su capacidad de contenedor (CC) para llegar a valores de C.E. en los lixiviados por debajo de 4 dS m-1. El riego con solución nutritiva produjo un lavado más eficiente, especialmente, en el caso de los iones más perjudiciales como son el sodio, los cloruros y los sulfatos. La liberación de iones mediante la lixiviación siguió patrones similares en ambos ensayos, excepto para los fosfatos, el calcio y el magnesio, The use of compost as substrate in soilless systems is increasing quickly, but its high salinity is one of the most common problems of these materials for this use. This problem can be easily treated in different ways. In this paper we evaluate two of these techniques: one is a quick washing (15 h) with tap water prior to cultivation, and the other consist in a gradual washing (60 days) by watering with nutrient solution (NS). The aim of this paper is to compare the two methods, in terms of effectiveness and assess the dynamics of nutrient release, as most appropriate technique for managing salinity of compost with high E.C. (18,7 dS m-1 in saturation extract). In both trials there was a rapid and significant decrease in E.C. Three times the volume of its container capacity (CC) was sufficient to reach values of E.C. in leachate below to 4 dS m-1. The leaching efficiency was higher in the case of watering with SN especially more harmful ions such as Na+, Cl- and SO4 2-. Ion release by leaching followed similar patterns in both cases except for phosphate, calcium and magnesium

Manufacturing processes in fish canning industries generate a considerable amount of solid waste that can be digested anaerobically. The aim of this research was to study the biochemical methane potential of different solid fish waste. For tuna, sardine and needle fish waste, around 0.47 g COD–CH4/g CODadded was obtained in batch experiments with 1%TS; whereas for mackerel waste, the methane production attained 0.59 g COD–CH4/g CODadded. The increase in the waste/inoculum ratio, from 1.1–1.3 to 2.8–3.3 g VSwaste/g VSinoculum, led to overload due to VFA and LCFA accumulation. Afterward, co-digestion assays of fish waste with gorse were undertaken but the biochemical methane potential did not improve.

Seafood processing by-products account for approx. 75% of the total weight of the catch, and 30% of the waste is in the form of bones, skins and fins, waste that is either discarded in the sea or is processed into animal feed of low added value. Nonetheless, this raw material has a potential as a food ingredient, since constitutes an important source of biologically active molecules possessing peculiar properties and promising practical applications. Enzymatic hydrolysis is one of the methods for recovery of valuable components from fish by-products. However, to our knowledge, there is no information in the literature about the effect of enzymatic proteolysis on the antigenicity of fish proteins, which is of interest for the use of the fish protein hydrolysed as a food ingredient. Allergies to seafood are estimated to affect 1 to 2 percent of the adult population. Parvalbumins are responsible for IgE-mediated reactions in fish, while Tropomyosins are major allergens in the shrimp and the squid. In the current study, heads of seabream (Sparus aurata), muscle and tunic of giant squid (Dosidicus gigas) were hydrolysed by Pepsine, Alcalase and Esperase. These hydrolysis were carried out at 37ºC for 5 h for pepsine and at 60ºC for 3 h for the other enzymes. The cleaved peptide bonds (5) and an ELISA test using pools of sera from patient allergic to hake, shrimp, and anisaki were determined to evaluate the residual antigenicity. The enzymatic treatments enhances the fish protein hydrolysis, and, very low immunoreactivity was detected in the hydrolysates by using hake and schrimp sera. In contrast, no activity was shown against anisaki sera by either untreated/treated samples. The results suggest that proteolysis of fish waste by either of these enzymes has the potential to produce hypoallergenic hydrolysates.

In marine harvesting, fish waste due to the discards of non-targeted species represent a risk for the sustainability of fisheries, a loss of potentially valuable living resources and a threat for the ecological equilibrium. The project FAROS aims to develop and implement an efficient, integral management network for discards, to reduce global impact of this established practice, while putting in value and optimising the use of the by-catch. The development of an on-ship automated system for discards evaluation and species biomass estimation is proposed in this contribution. The Biomass Estimation Optical System (BEOS) integrates machine vision technologies and optical information processing and feature extraction by means of nonlinear modeling based on artificial neural networks. A first functional prototype and a methodology for system implementation and operation are presented here.