Food for sea bass juveniles in the pre-fattening stage

Abstract

The invention relates to a food for sea bass juveniles in the pre-fattening stage that is based on waste from the aquaculture industry. The food comprises at least one aquaculture waste meal selected from the group consisting of crustacean meals and / or oyster viscera meal in a proportion of 7 to 30% w / w; fish meal; starch; and vitamins, minerals and / or nutrients. The invention further comprises a method for producing a food for sea bass juveniles in the pre-fattening stage that is based on waste from the aquaculture industry.

Description

[0001] Feed for juvenile sea bass in the pre-fattening stage based on waste from the aquaculture industry and a method

[0002] FIELD OF INVENTION

[0003]

[0001] The present invention is located in the field of aquaculture and waste recovery, particularly, the invention is related to a feed for juvenile croaker in the pre-fattening stage based on waste from the aquaculture industry and a method for its preparation.

[0004] BACKGROUND OF THE INVENTION

[0005]

[0002] The Food and Agriculture Organization of the United Nations has projected that by 2050 a population of 9.1 billion people will need to be fed, which will require an increase in global food production of around 70%. Therefore, making seafood and aquaculture production more efficient is key to meeting this goal, especially considering that these products have unique properties in terms of the benefits they provide to human health.

[0006]

[0003] On the other hand, among seafood products, there is a constant increase in demand for sea bass, because it is a product sought after by consumers. Therefore, there is a need to optimize the production of this species, for example, through the development of new food compositions that allow for a better quality product. Thus, it is desirable, for example, for farmed sea bass to have a larger fillet, since it is the meat most desired by consumers, as well as to reduce mortality.

[0007]

[0004] However, the development of new food compositions presents a number of challenges.

[0008]

[0005] First, not all fish species have the same dietary requirements. On the contrary, each species has very specific requirements. Therefore, a person skilled in the art cannot assume that a dietary composition that works for one species will also work for another.

[0009]

[0006] Second, the same species has different nutritional requirements depending on its stage of development. For example, a juvenile croaker in the pre-fattening stage does not have the same requirements as an adult croaker. Therefore, a person skilled in the art cannot assume that a feed composition that works in one stage of development will also be optimal for another stage of development.

[0007] Third, there are a number of additional aspects that can have a substantial impact on feed performance. For example, an optimal feed must be palatable to croakers, it must have an optimal level of buoyancy and resistance for the species' consumption rate, among others.

[0010]

[0008] Fourth, in order to optimize a feed composition, it is desirable to reduce production costs, for example, by identifying technical alternatives that allow the replacement of fishmeal, which is currently the main component on the basis of which fish feed compositions are formulated and which has a high cost. Therefore, it is desirable to have alternative feed sources, for example, to replace fishmeal, either totally or partially.

[0011]

[0009] Finally, and although there are a number of additional challenges, it is important that the food compositions to be used are as environmentally friendly as possible.

[0012]

[0010] In view of the above, there is a need for new specific feed compositions for sea bass at each stage of their development, which allow optimizing their performance and replacing (at least partially) fishmeal with alternative sources. In this context, the inventors focused on the development of optimal feed compositions for juvenile sea bass in the pre-fattening stage, attempting to reduce the amount of fishmeal in them.

[0013]

[0011] In this regard, although there are state-of-the-art food compositions for corvinas, there is still a significant optimization gap.

[0014]

[0012] For example, patent CN1 10839783 describes a feed composition for saffron croaker. Although it seeks to formulate a specialized feed for a type of croaker, it is composed of feeds such as soy, corn, and wheat flour, which is negative, since it is known that the vast majority of plant components contribute to digestive deterioration and the production of waste, which contaminates the body of water where the fish are found and in turn decreases their reproduction rate. Furthermore, it is not focused on the pre-fattening stage, the most important stage of croaker growth. On the other hand, it does not include elements of aquaculture waste, so it is not optimal.

[0015]

[0013] In this context, the inventors developed new optimal feed compositions for juvenile sea bass in the pre-fattening stage, partially replacing fishmeal with oyster meal, crustacean meal, and a mixture thereof, corresponding to waste from the aquaculture industry. The inventors also developed a special method for producing said compositions.

[0016]

[0014] Thus, in general terms, the aforementioned compositions surprisingly made it possible to obtain an optimal diet, even improving certain aspects of traditional diets based on foods formulated essentially with fishmeal. Furthermore, mortality was reduced and larger fillets were obtained. Finally, a fundamental advantage is that waste from the aquaculture industry was revalued, promoting a circular economy.

[0017] BRIEF DESCRIPTION OF THE INVENTION

[0018]

[0015] The present invention is located in the field of aquaculture and waste recovery.

[0019]

[0016] In particular, the invention comprises a feed for juvenile croaker in the pre-fattening stage based on waste from the aquaculture industry, comprising:

[0020] - At least one aquaculture waste meal selected from the group consisting of crustacean meals and / or oyster viscera meal, in a proportion of 7 to 30% w / w;

[0021] - Fish meal;

[0022] - Starch; and

[0023] - Vitamins, minerals and / or nutrients.

[0024]

[0017] It further comprises a method for its manufacture comprising at least the following steps: a. Dosing step comprising dosing: i. an aquaculture waste meal selected from the group consisting of crustacean meals and / or oyster viscera meal;

[0025] i. fishmeal; ill. starch; iv. vitamins, minerals and / or nutrients; v. and other ingredients; b. Extrusion stage, comprising: i. Entering the elements into the extruder hopper;

[0026] i. Mix the ingredients; iii. Inject water into the mixture; iv. Apply pressure to the mixture; v. Gradually heat the mixture; vi. Cut the cooked mixture, obtaining a moist pellet; vii. Dry the moist pellet to obtain a dry pellet; and viii. Cool the dry pellet, obtaining the sea bass feed.

[0027]

[0018] The food of the present invention has a number of advantages.

[0028]

[0019] First, it was specifically optimized for juvenile sea bass in the pre-fattening stage. The inventors were able to confirm that it provides the ideal nutrients based on the requirements of the aforementioned species at this stage of development.

[0029]

[0020] Secondly, the inventors were able to confirm through tests that the food of the present application has medium buoyancy conditions, which is optimal for feeding this species, which was key due to the swimming behavior of the croakers and because the position of the food in the water column is essential for a certain species (in this case the croakers) to consume or not a given food.

[0030]

[0021] Thirdly, the inventors also determined that the food of the present invention had attractive organoleptic characteristics for the corvinas in the pre-fattening state, so they were particularly encouraged to ingest it.

[0031]

[0022] Fourthly, the feed composition of the present application constitutes an alternative for the reuse and revaluation of waste from the aquaculture industry, in particular, oyster and crustacean viscera. More particularly, the feeds of the present invention comprise a partial replacement of fishmeal with flours from said wastes, which also allows reducing the cost of the feed.

[0032]

[0023] These and other advantages will be clearer in the figures and the detailed description of the invention.

[0033] DESCRIPTION OF THE FIGURES

[0034]

[0024] Figure No. 1 corresponds to a graph that shows the fillet yield of juvenile corvina specimens in the pre-fattening stage subjected to DIET 1 (Crustacean Meal), DIET 2 (Oyster Meal), DIET 3 (Mixed Meal) and control (control diet of commercial origin), after 90 days.

[0035]

[0025] Figure No. 2 corresponds to a graph that shows the survival of juvenile corvina in the pre-fattening stage subjected to DIET 1 (Crustacean Meal), DIET 2 (Oyster Meal), DIET 3 (Mixed Meal) and control (control diet of commercial origin), after 90 days.

[0036]

[0026] Figure No. 3 corresponds to a reference image of the extrudates generated by means of the food production method.

[0037]

[0027] Figure No. 4 corresponds to the assembly system of the ponds for testing food in juvenile corvinas.

[0038]

[0028] Figure No. 5 corresponds to the layout of the ponds for each treatment where each color indicates one of the diets to be tested in triplicate.

[0039] DETAILED DESCRIPTION OF THE INVENTION

[0040]

[0029] The present invention relates to aquaculture and waste recovery. Specifically, the invention relates to a feed for juvenile sea bass in the pre-fattening stage based on waste from the aquaculture industry, and a method for preparing said feed.

[0041]

[0030] Various preferred embodiments of the invention, as well as preferred implementation modalities, will be detailed below. However, unless otherwise indicated, the various specific configurations, such as certain steps, raw materials and other aspects of the invention, which constitute the respective preferred embodiments, are to be construed only as illustrative and not as limiting the scope of the present technology, unless otherwise indicated.

[0042]

[0031] In particular, the invention comprises a feed for juvenile croaker in the pre-fattening stage based on waste from the aquaculture industry comprising:

[0043] - At least one aquaculture waste meal selected from the group consisting of crustacean meals and / or oyster viscera meal, in a proportion of 7 to 30% w / w;

[0044] - Fish meal;

[0045] - Starch; and

[0046] - Vitamins, minerals and / or nutrients.

[0047]

[0032] As described in the brief description of the invention, the food of the present application has a series of advantages, which make it particularly surprising compared to other available alternatives.

[0048]

[0033] In addition to the above, the selected aquaculture waste flours, namely crustacean and / or oyster viscera flour in the concentration of 7 to 30% w / w allowed to formulate an alternative feed to the existing ones, replacing part of the fish meal but, at the same time, providing the necessary nutrients for the correct development of the fish. An aspect that contributes to the surprising effect of the feed of the present application is that the inventors were able to identify and select aquaculture waste whose flours presented high quality macronutrients, promoting adequate growth of croakers in cultures.

[0049]

[0034] In one embodiment of the present invention, the aquaculture waste meal is oyster viscera meal in a proportion of 10 to 25% w / w. Preferably, the percentage of oyster viscera meal is 22% w / w.

[0050]

[0035] In one embodiment of the present invention, the percentage of fishmeal is 45% w / w to 55% w / w, preferably 53% w / w.

[0051]

[0036] In one embodiment of the present invention, the percentage of starch is 10% w / w to 25% w / w, preferably 21.97% w / w.

[0052]

[0037] In one embodiment of the present invention, the percentage of vitamins is 1% w / w to 3% w / w, preferably 2% w / w.

[0053]

[0038] In one embodiment of the present invention, the percentage of minerals is 1% w / w to 3% w / w, preferably 1% w / w.

[0054]

[0039] In one embodiment of the present invention, the percentage of choline is 0.01% w / w.

[0055]

[0040] In one embodiment of the present invention, the percentage of vitamin C is 0.01% w / w.

[0056]

[0041] In one embodiment of the present invention, the percentage of tocopherol is 0.01% w / w.

[0057]

[0042] In one embodiment of the present invention, the feed further comprises fish oil. This is advantageous because fish oil is a natural source of omega-3 fatty acids such as EPA and DHA, which promote the growth of sea bass and also increase their survival.

[0058]

[0043] In a preferred embodiment of the present invention, the food comprises the following elements:

[0059] - At least one aquaculture waste meal selected from the group consisting of crustacean meals and / or oyster viscera meal, in a proportion of 7 to 30% w / w;

[0060] - Fish meal 45 to 55% w / w;

[0061] - Starch 10 to 25% w / w; and

[0062] - Vitamins, minerals and / or nutrients from 2 to 6.1% w / w.

[0063]

[0044] Three even more preferred formulations are included in the following table, which will be referred to as DIET 1, DIET 2 and DIET 3:

[0064] Table 1: Preferred foods

[0065]

[0045] DIET 1 is the optimized feed in terms of replacing fish meal exclusively with crustacean meal. DIET 2 is the optimized feed in terms of replacing fish meal exclusively with oyster viscera meal. DIET 3 is the optimized feed in terms of replacing fish meal exclusively with oyster viscera meal.

[0066]

[0046] The feeds thus formulated, namely DIET 1, DIET 2 and DIET 3, exhibited optimal buoyancy, i.e., a medium buoyancy that allowed the feed to remain suspended at the depth at which the croakers feed, without settling to the bottom or floating to the surface. This was one of the main challenges faced by the inventors.

[0067]

[0047] Likewise, DIET 1, DIET 2 and DIET 3 have the advantage of increasing the percentage of proteins present in the sea bass fed with them, compared to a traditional diet. As explained in Example No. 7.

[0068]

[0048] Another advantage of DIET 1, DIET 2 and DIET 3 is that they increase the percentage of fatty acids present in the corvinas fed with them, compared to a traditional diet.

[0069]

[0049] Likewise, and in line with what was previously explained, DIET 1, DIET 2 and DIET 3, presented organoleptic characteristics that were particularly attractive to the corvinas in the pre-fattening state, which is why they were particularly encouraged to ingest it.

[0070]

[0050] The inventors also determined that DIET 1, DIET 2 and DIET 3 (as well as other alternatives of this invention) present a combination of components that allows for adequate feeding of the corvinas, providing macronutrients such as proteins, lipids and carbohydrates, as well as micronutrients such as vitamins and minerals.

[0071]

[0051] Now, among all the food compositions of the present invention, the inventors determined that DIET 2 is even more preferred than DIET 1 and DIET 3, especially for the following reasons:

[0072]

[0052] DIET 2 was the one that allowed obtaining the same fillet weight yield, as observed in Figure 1.

[0073]

[0053] Furthermore, it was particularly surprising to the inventors that not all feeds allowed to obtain levels close to the control (which was desirable). For example, DIET 1 allowed the development of substantially smaller fillets.

[0074]

[0054] On the other hand, the inventors determined that DIET 2 allowed to increase the survival of the specimens fed with it, as shown in Figure No. 2.

[0075]

[0055] In one embodiment of the invention, the feed is an extrudate. Even more particularly, an extrudate having a diameter of approximately 5.5 mm (i.e., plus or minus 20%). The inventors determined that said diameter was relevant, especially in combination with the formulations of DIET 1, DIET 2 and DIET 3, to ensure ideal buoyancy. Furthermore, said diameter is optimal given the size and behavior of juvenile croaker.

[0076]

[0056] In another embodiment of the invention, it comprises a method for producing a feed for juvenile sea bass in the pre-fattening stage based on waste from the aquaculture industry comprising at least the following steps: a. Dosing step comprising dosing: i. an aquaculture waste meal selected from the group consisting of crustacean meals and / or oyster viscera meal;

[0077] i. fishmeal; ill. starch; iv. vitamins, minerals and / or nutrients; v. and other ingredients; b. Extrusion stage, comprising: i. Entering the elements into the extruder hopper;

[0078] i. Mix the ingredients; iii. Inject water into the mixture; iv. Apply pressure to the mixture; v. Gradually heat the mixture; vi. Cut the cooked mixture, obtaining a moist pellet; vii. Dry the moist extrudate to obtain a dry pellet; and viii. Cool the dry pellet, obtaining the sea bass feed.

[0079]

[0057] The method presents a series of advantages that are detailed below. For example, the method allows the production of an extrudate, which entails advantages from both the nutritional and environmental perspectives. Thus, it allows the feed utilization rate to be improved, this being because the extrusion process is capable of breaking the 1,4-glycosidic bond of the starch, producing low molecular weight products that are easier to digest.

[0080]

[0058] On the other hand, the extrusion process is ideal for the production of food for juvenile croakers because it allows for an increase in the reproduction density of the croakers. This occurs because the extrusion reduces the residual bait and excrement discharged into the body of water, which allows for an increase in the aquaculture density per unit of water mass.

[0081]

[0059] Extruded food also reduces environmental pollution. This is because extruded foods are more stable in water than other foods, since the extrusion process gelatinizes the starch and organizes the proteins in the extrudate, making the food more adherent and reducing nutrient loss due to precipitation. In this way, the dual effect of avoiding the presence of residues in the water and, furthermore, preventing the food from losing its nutritional properties is achieved.

[0082]

[0060] As for the specific aspects of the method, it stands out in that it can be carried out in different extrusion equipment, such as single-screw or twin-screw, among others. However, in a preferred embodiment, it is carried out in a twin-screw extruder.

[0083]

[0061] The production method by means of extrusion allows for the generation of different sizes of extrudate. In a preferred embodiment, the extrudate has a diameter of approximately 5.5 mm (i.e., plus or minus 20%).

[0084]

[0062] With respect to sub-stage iii) of stage b), in a preferred embodiment, the water is incorporated in a percentage of approximately 80% v / v (i.e., plus or minus 10%) and at room temperature. The inventors determined that this was the optimal percentage.

[0085]

[0063] The pressure applied to the mixture is relevant since, if working with high pressure, the product will lose part of its water through vaporization upon exiting the equipment, resulting in a product with low water activity, therefore, more durable. On the contrary, if working with low pressure, the product exiting the die will have high moisture content and high density. In one embodiment of the invention, in sub-step iv) 15 Bar of pressure is applied, which is considered a relatively low pressure, allowing the product obtained to have an optimal density to obtain medium floatability.

[0086]

[0064] In one embodiment of the invention, sub-step v) of step b) consists of gradually applying temperature to the mixture, in such a way that the temperature is gradually increased. For example, in one embodiment of the invention, the temperature is increased as the mixture passes through each of the barrels (or sections of the barrel) of the extruder.

[0087]

[0065] Thus, in a preferred embodiment of the present method, sub-step v) of step b) comprises:

[0088] - Pass the mixture through a first barrel which is at a temperature of 42 to 44°C;

[0089] - Pass the mixture through a second barrel that is at a temperature of 69 to 70°C;

[0090] - Pass the mixture through a third barrel that is at a temperature of 86 to 88°C;

[0091] - Pass the mixture through a quarter barrel that is at a temperature of 99 to 100°C;

[0092] - Pass the mixture through a fifth barrel that is at a temperature of 99 to 100°C; and

[0093] - Pass the mixture through a sixth barrel that is at a temperature of 95 to 100°C.

[0094]

[0066] On the other hand, the method is specifically optimized for the preparation of DIET 1, DIET 2 and DIET 3.

[0095] The following table includes the specific conditions for each of the diets mentioned.

[0096] Table 2: Preferred foods

[0097]

[0067] The fluctuation of temperatures provides excellent physical and chemical characteristics to the extrudate, including the compaction or adherence necessary to avoid accelerated precipitation of the extrudate.

[0098]

[0068] In sub-stage vii) of stage b), the extrudate produced by the extruder is dried. This can be done in an oven, solar dryer, tray dryer, or by spray drying, among others. In one embodiment of the invention, the drying is carried out in an oven at 75°C for 1 h.

[0099] EXAMPLES

[0100]

[0069] The invention will be better understood by means of the following examples, which are merely illustrative and do not limit the scope of the invention. Various changes and modifications to the described embodiments would be obvious to those skilled in the art, and such changes may be made without departing from the spirit of the invention and the scope of the appended claims.

[0101] Example No. 1: Biochemical composition of aquaculture waste meals.

[0102]

[0070] The inventors began their research by selecting aquaculture waste meals. They considered that, to obtain a feed for juvenile croaker in the pre-fattening stage, the meals to be used must meet the necessary nutritional requirements. Therefore, the inventors performed a proximate analysis of the meals, using the following analytical methodologies:

[0103] - Humidity was determined by drying the samples in a convection oven, to constant weight, at a temperature of 95 °C;

[0104] - The ashes were quantified after combustion of the samples in a muffle furnace at 500°C;

[0105] - Crude protein levels were determined using the Kjeldahl digestion method and the amino acid profile was defined by liquid chromatography;

[0106] - Total lipids were determined using the Soxhlet method and their profile defined using gas chromatography;

[0107] - nitrogen-free extracts (NFE) were calculated by subtracting the sum of all fractions from 100; and

[0108] - The fatty acid profile was defined using gas chromatography and the amino acid profile was defined using liquid chromatography.

[0109]

[0071] All samples were analyzed in triplicate and expressed as a percentage on a dry basis.

[0110]

[0072] First, the proximate analysis of the flours was obtained, as shown in Table 3.

[0111] Table 3: Proximate analysis of aquaculture waste meals

[0112]

[0073] In the preceding table, ELN corresponds to the nitrogen-free extract.

[0113]

[0074] Secondly, the amino acid profile of the obtained flours was obtained, as shown in Table 4.

[0114] Table 4: Amino acid profile of flours obtained from aquaculture waste

[0115]

[0075] And thirdly, the fatty acid profile of the obtained flours was obtained, as shown in Table 5.

[0116] Table 5: Fatty acid profile of flours obtained from aquaculture waste

[0117]

[0076] These values ​​obtained were the starting point for the formulation of the feed in order to create a feed that meets the nutritional requirements of juvenile corvinas in the pre-fattening stage.

[0118] Example No. 2: Feed formulation.

[0119]

[0077] Subsequently, the inventors decided to develop formulations in which the fish meal was partially replaced by crustacean meal, with oyster viscera meal and with a mixture of crustacean and oyster viscera meals.

[0120]

[0078] To this end, they gradually modified a plurality of compositions by trial, error, and observation of their composition and behavior in liquid media, until arriving at 3 formulations: a. A composition in which the fish meal was partially replaced by crustacean meal (called DIET 1); b. A composition in which the fish meal was partially replaced by oyster viscera meal (called DIET 2); and c. A composition in which the fish meal was partially replaced by a mixture of crustacean meals and oyster viscera meals (called DIET 3).

[0121] Table 6: Composition of food compositions.

[0122]

[0079] Each of the feed compositions was formulated as an extrudate. The concentrations of each element were defined to ensure that the resulting extrudate was sufficiently resistant to the environmental conditions under which the feed is administered. Thus, depending on the type of aquaculture waste meal used, the inventors had to define a different quantity to ensure these purposes.

[0123]

[0080] Likewise, the aforementioned concentrations were also designed so that they would remain suspended in the water, at an optimal depth for consumption.

[0124] Example No. 3: Extrusion process.

[0125]

[0081] Together with the definition of the ideal formulations based on each replacement flour (crustacean and / or oyster viscera flour), the production method for each of them was optimized.

[0126]

[0082] In particular, the inventors faced the challenge that, in order to achieve the optimal physical composition, the parameters and conditions of the production method had to be adjusted. For example, the process used for DIET 1 was not optimal for DIET 2 and DIET 3, and vice versa.

[0127]

[0083] The final production methods were as follows:

[0128]

[0084] For all diets, a dosing step (a) was first carried out which comprised dosing the following:

[0129] (i) aquaculture waste meal selected from the group consisting of crustacean meals and / or oyster viscera meal, respectively, as appropriate for the manufacture of DIET 1, DIET 2 and DIET 3;

[0130] (i) fishmeal;

[0131] (iii) starch;

[0132] (iv) vitamins, minerals and / or nutrients;

[0133] (v) other ingredients;

[0134]

[0085] Each of these elements was dosed in the proportion indicated in Table 4 above.

[0135]

[0086] An extrusion stage was then carried out which comprised the following steps:

[0136] (i) The elements were entered into the hopper of an extruder, specifically, consisting of a twin-screw extruder;

[0137] (i) The elements were mixed;

[0138] (iii) Water was injected into the mixture in a proportion of 80% v / v and at room temperature;

[0139] (iv) Pressure was applied to the mixture;

[0140] (v) Temperature was gradually applied to the mixture. Specifically, a different, higher temperature was applied to each of the barrels or (barrel sections) of the extruder;

[0141] (vi) The cooked mixture was cut or chopped into a moist pellet so that the final product had a diameter of approximately 5.5 mm;

[0142] (vii) The wet extrudates or pellets were dried to obtain dry extrudates or pellets; and

[0143] (viii) The extruded or dry pellet was cooled, obtaining the feed for corvinas.

[0087] The conditions of the steps (iv) and (v) indicated above were specifically optimized for each of the compositions, in the terms detailed in the following table:

[0144] Table 7: Parameters of the extrusion process for food production.

[0145]

[0088] Figure No. 3 shows the resulting products.

[0146]

[0089] Under these conditions, medium-buoyant extrudates were obtained. This was optimal because the corvinas fed at the mid-water level, so this condition allows for maximum utilization of the feed and also prevents fouling of the bottom of the water body.

[0147] Example No. 4: Preparation of corvinas for food analysis.

[0148]

[0090] The formulations were evaluated by means of tests. For this purpose, 12 ponds of 1.3 m² were conditioned. 3 for open-flow culture of juveniles in a laboratory with an open-flow system. Once the ponds were installed, the hydraulic and drainage systems were prepared, as shown in Figure 4.

[0149]

[0091] 1,200 juvenile pre-fattening croakers were used and separated into the 12 ponds, so that each pond had 100 specimens.

[0150]

[0092] The volume of water was adjusted to reach a density of 35 kg / m 3 .

[0151]

[0093] The corvinas were conditioned with a commercial control diet.

[0152]

[0094] After this period, comparative tests were carried out by feeding 4 groups of corvinas with different food compositions, namely, DIET 1, DIET 2, DIET 3 and a control diet.

[0153]

[0095] The fish were maintained in seawater at a temperature of 15°C, with an environmental photoperiod of approximately 11 h of light and 13 h of darkness, 7 mg of C / mL and pH 7.7, with each pond being monitored daily. These parameters allowed the environmental and culture conditions of the croakers to be replicated.

[0154]

[0096] The treatments were carried out in triplicate, organizing the ponds in such a way that the treatments remain separated, as shown in Figure No. 5.

[0155]

[0097] The specimens were kept in the ponds and fed with the aforementioned formulations to be evaluated for a period of 90 days.

[0156]

[0098] Once the system was established, feeding analyses were carried out on the corvinas.

[0157] Example No. 5: Food consumed by juvenile sea bass subjected to the formulated feeds.

[0158]

[0099] The inventors tested the different formulated foods (DIET 1, DIET 2 and DIET 3) and the control diet on the croakers present in the ponds and carried out a series of measurements, among which one of the most relevant was the measurement regarding the fillet performance of the fed specimens.

[0159]

[0100] As can be seen in Figure 1, the inventors were able to verify that, after 90 days of testing, DIET 2 surprisingly presented the same fillet yield, namely, percentage of fillet with respect to total weight, as those fed with the control feed. This yield was slightly higher than that of DIET 3.

[0160]

[0101] It is worth highlighting that DIET 1 presented a fillet yield 36% lower than that of DIET 2, which also allowed us to verify that the product used to replace the fishmeal was not irrelevant, in order to achieve an alternative to traditional foods.

[0161] Example No. 6: Calculation of the survival rate of corvinas.

[0162]

[0102] The inventors tested the different formulated foods (DIET 1, DIET 2 and DIET 3) and the control diet on the corvinas present in the ponds and carried out a series of measurements, including survival.

[0163]

[0103] As can be seen in Figure 2, the inventors were able to verify that, after 90 days of testing, the diets that showed the lowest mortality were DIET 1 and DIET 2, surprisingly surpassing the survival rate of the control diet. In fact, while in the case of DIET 1 and DIET 2, 100% of the specimens survived, in the case of the control diet, 90% survived.

[0164] Example No. 7: Protein calculation in fed corvinas.

[0165]

[0104] Continuing with the analyses derived from feeding the fish with the 4 food compositions (DIET 1, DIET 2, DIET 3 and control diet), the inventors performed a proximate chemical analysis to determine the protein values. As can be seen in the following table, after 90 days, the fish fed with DIET 1, DIET 2 and DIET 3 presented a higher protein value than those fed with the control diet.

[0166] Table 8: Parameters of the extrusion process for food production.

Claims

CLAIMS SHEET 1. A feed for juvenile sea bass in the pre-fattening stage based on waste from the aquaculture industry, CHARACTERIZED because it includes: - At least one aquaculture waste meal selected from the group consisting of crustacean meals and / or oyster viscera meal, in a proportion of 7 to 30% w / w; - Fish meal; - Starch; and - Vitamins, minerals and / or nutrients.

2. The food according to claim 1, CHARACTERIZED in that the aquaculture waste meal is oyster viscera meal in a proportion of 10 to 25% w / w.

3. The food according to claim 2, CHARACTERIZED in that the percentage of oyster viscera flour is 22% w / w.

4. The food according to claim 1, CHARACTERIZED in that the percentage of fishmeal is 45% w / w or 55% w / w, preferably 53% w / w.

5. The food according to claim 1, CHARACTERIZED in that the percentage of starch is 10% w / w to 25% w / w, preferably 21.97% w / w.

6. The food according to claim 1, CHARACTERIZED in that the percentage of vitamins is 1% w / w to 3% w / w, preferably 2% w / w.

7. The food according to claim 1, CHARACTERIZED in that the percentage of minerals is 1% w / w to 3% w / w, preferably 1% w / w.

8. The food according to claim 1, CHARACTERIZED in that within the nutrients, the percentage of choline is 0.01% w / w.

9. The food according to claim 1, CHARACTERIZED in that within the vitamins, the percentage of vitamin C is 0.01% w / w.

10. The food according to claim 1, CHARACTERIZED in that within the vitamins, the percentage of tocopherol is 0.01% w / w.

11. The food according to claim 1, CHARACTERIZED in that it also comprises fish oil.

12. The food according to claim 3, CHARACTERIZED in that it also comprises: - Fish meal in a proportion of 53% w / w; - Starch in a proportion of 21.97% w / w; - Vitamin C in a proportion of 0.01% w / w; - Tocopherol in a proportion of 0.01% w / w; - Other vitamins in a proportion of 2% w / w; - Minerals in a proportion of 1% w / w; - Choline at a ratio of 0.01% w / w 13. The food according to claim 1, CHARACTERIZED in that the food is an extrudate.

14. The food according to claim 13, CHARACTERIZED in that the diameter of the extruded material is in a range of 5 to 6 mm.

15. A method for producing a feed for juvenile croaker in the pre-fattening stage based on waste from the aquaculture industry, CHARACTERIZED in that it comprises at least: a. Dosing stage comprising dosing: i. an aquaculture waste meal selected from the group consisting of crustacean meal and / or oyster viscera meal; i. fishmeal; ill. starch; iv. vitamins, minerals and / or nutrients; v. and other ingredients; In the proportions indicated in claims 1 to 14. b. Extrusion step, comprising: i. Entering the elements into the hopper of an extruder; i. Mix the ingredients; iii. Inject water into the mixture; iv. Apply pressure to the mixture; v. Gradually apply heat to the mixture; vi. Cut the cooked mixture, obtaining a moist extrudate; vii. Dry the moist pellet to obtain a dry extrudate; and viii. Cool the dry extrudate, obtaining the sea bass feed.

16. The method according to claim 15, CHARACTERIZED in that the extrusion step is carried out in a twin-screw extruder.

17. The method according to claim 15, CHARACTERIZED in that in sub-stage iii) of stage b) the water is at room temperature.

18. The method according to claim 15, CHARACTERIZED in that in sub-stage iii) of stage b) the water is incorporated in a percentage of 80% v / v.

19. The method according to claim 15, CHARACTERIZED in that in sub-stage iv) of stage b) 15 Bar of pressure are applied.

20. The method according to claim 15, CHARACTERIZED in that sub-step v) of step b) comprises: - Pass the mixture through a first barrel which is at a temperature of 42 to 44°C; - Pass the mixture through a second barrel that is at a temperature of 69 to 70°C; - Pass the mixture through a third barrel that is at a temperature of 86 to 88°C; - Pass the mixture through a quarter barrel that is at a temperature of 99 to 100°C; - Pass the mixture through a fifth barrel that is at a temperature of 99 to 100°C; - Pass the mixture through a sixth barrel which is at a temperature of 95 to 100°C; 21. The method according to claim 15, CHARACTERIZED in that in sub-stage viii) of stage b) the drying is carried out at 75°C, for 1 h, in an oven.

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