Feed for aquatic organisms with stable, soft and elastic texture

Abstract

Extruded complete feed for aquatic organisms, said complete feed comprising: - at least one non-hydrolyzed protein source; - at least one fat source; - fibers inherent in at least one raw material; - optionally present at least one carbohydrate-containing source; - vitamin additive; - mineral additive; - water; - a binder comprising at least partially an edible starch-containing tuber-derived thickener; - a hydrolyzed vegetable protein source; and - a plasticizer, and the complete feed has a moisture content of from about 12.5% to about 25% (w / w) of the complete feed. A method for preparing such feed is also disclosed.

Description

[0001] introduction

[0002] The present invention relates to a soft and elastic feed. The present invention relates to a feed for aquatic organisms. The feed with a stable, soft and elastic texture can be fish feed, shrimp feed or octopus feed. Specifically, the present invention relates to a fish feed, and more specifically, the present invention relates to a tuna (Thunnus spp.) fish feed. The feed remains soft and elastic after storage. The tuna can be captured tuna raised to market size or farmed tuna raised in closed boxes / nets from hatching to harvesting. Tuna (especially Pacific bluefin tuna (T.orientalis) and southern bluefin tuna (T.maccoyii)) are very popular in the Japanese market and are well-rewarded catches.

[0003] Background and Problem Description

[0004] The feed for aquaculture purposes available on the market today is prepared by so-called cooking extrusion. Before the thermoplastic extrusion process, most of the ingredients are mixed in the form of dry blends. Some ingredients (especially liquid ingredients) can be added in the pre-conditioner step before the extrusion step or can be added to the barrel of the extruder. Too much fat in the initial mixture or too much fat added in liquid form is unfavorable to the extrusion process due to its lubrication. Fat (i.e. edible oil) is added in a separate oil coating step after the extrusion process. The oil coating step can be carried out in a container under negative pressure.

[0005] The extrudate is soft and elastic right out of the extruder. After drying, coating, cooling and bagging, the pellets harden during storage and reach their final hardness. After storage and transportation to the fish farm, such feeds are relatively hard and brittle. It is important that the pellets remain intact. Broken pellets will produce "broken" feed as well as powder. Small pellets are not eaten by fish and are a loss.

[0006] It has been found that some wild caught fish grown in captivity will accept extruded hard feeds after a weaning period. However, some species of wild caught fish (such as tuna) do not seem to accept extruded feeds. Such fish are reared with "game" fish, such as herring, sardines, mackerel, etc., or with soft feeds, such as feed pellets freshly made from ground fish. Such rearing is laborious, involves a more complex logistical feed chain, and the utilization (feed conversion rate) is not optimal.

[0007] It has also been found that tuna fish reared from eggs in hatcheries and then kept in tanks and nets do not accept hard feed extruded, but prefer soft feed.

[0008] Accordingly, there is a need for a feed, in particular a fish feed, which is prepared by extrusion cooking and which is softer and more elastic than known extruded feeds. Importantly, the feed pellets retain their softness and elasticity during storage.

[0009] Another limiting condition for the required feed is that the feed ingredients must be "complete", i.e. it must meet all the nutritional requirements regarding proteins / amino acids, energy, fatty acids, minerals and vitamins, since only one type of feed is supplied to the aquatic organisms over a continuous period of time.

[0010] EP2412248 describes a soft and elastic feed suitable for tuna, which consists of an inner layer and an outer layer with different compositions. The inner layer mainly contains fish meal and is covered by a starch-based thermally induced gel (referred to as the outer layer). Such a double-layer feed is difficult to prepare.

[0011] The object of the present invention is to correct or reduce at least one disadvantage of the prior art, or at least to provide a useful alternative to the prior art.

[0012] This object is achieved by the features detailed in the following description and in the appended claims. Summary of the Invention

[0014] The present invention relates to a thermoplastic extruded compound feed for aquatic organisms, which is complete for the nutritional requirements of the specified aquatic organisms. Some feeds for aquatic organisms are complete after thermoplastic extrusion. Some feeds for aquatic organisms require a higher fat content than can be obtained by thermoplastic extrusion, and thus fat is added in a separate coating step after the extrusion step. Such feeds are complete after the fat coating step. This complete feed is soft and elastic after storage.

[0015] The inventors have found that the combination of a starch-containing tuber-derived thickener, a hydrolyzed vegetable protein source and a plasticizer is important for achieving the target properties. Comparative studies excluding the hydrolyzed vegetable protein source or the plasticizer component have shown that the feed pellets are not soft and elastic enough and that cracks are easily formed inside the pellets under a small compression pressure. This results in broken pellets and powder formation during storage and transportation of the feed.

[0016] These ingredients are more particularly disclosed in the dependent claims.

[0017] The present invention is defined by independent patent claims. The dependent claims define advantageous embodiments of the present invention.

[0018] Feed

[0019] In a first aspect, the present invention particularly relates to an extruded complete formulated feed for aquatic organisms, in particular an extruded complete formulated fish feed, the formulated complete feed comprising:

[0020] - at least one non-hydrolyzed protein source;

[0021] - at least one fat source;

[0022] - fiber;

[0023] - vitamin additive;

[0024] - mineral additive;

[0025] - water;

[0026] - a binder at least partially comprising an edible starch-containing tuber-derived thickener;

[0027] - a hydrolyzed plant protein source; and

[0028] - a plasticizer,

[0029] - and the formulated complete feed comprises a moisture content of about 12.5% to about 25% (w / w) of the complete feed.

[0030] In a suitable embodiment, the feed for aquatic organisms described herein is fish feed.

[0031] As used herein, the weight percentages of the feed components described herein may be relative to the weight of the complete feed described herein.

[0032] The extruded complete formulated feed described herein may comprise at least one carbohydrate-containing source.

[0033] The fiber in the feed may be inherent in the raw materials and may be derived from a non-hydrolyzed protein source, a fat source, a carbohydrate-containing source, a binder or a hydrolyzed plant protein source, or may be added as a separate fiber outside the listed raw materials.

[0034] The feed may comprise about 5% to about 9% (w / w) of an edible starch-containing tuber-derived thickener of the complete feed. The feed may comprise about 6% to about 8% (w / w), or about 7% (w / w), or about 8% (w / w) of the edible starch-containing tuber-derived thickener. The edible starch-containing tuber-derived thickener may comprise or consist essentially of pregelatinized potato starch, natural potato starch or tapioca starch or any combination thereof.

[0035] The hydrolyzed vegetable protein may be a hydrolyzed vegetable protein with a degree of hydrolysis of about 3% to about 25%. The feed may comprise about 5% to about 15% (w / w) of the hydrolyzed vegetable protein of the complete feed. The feed may comprise about 6% to about 15% (w / w) of the hydrolyzed vegetable protein of the complete feed. The feed may comprise about 7% to about 12.5% (w / w) of the hydrolyzed vegetable protein of the complete feed. The feed may comprise about 5% to about 10% (w / w) of the hydrolyzed vegetable protein of the complete feed. The hydrolyzed vegetable protein may include hydrolyzed wheat gluten.

[0036] The feed may comprise about 1.5% to about 5% (w / w) of a plasticizer of the complete feed. The feed may comprise about 1.5% to about 4% (w / w) of a plasticizer of the complete feed. The feed may comprise about 1.5% to about 3.5% (w / w) of a plasticizer of the complete feed. The feed may comprise about 2% to about 5% (w / w) of a plasticizer of the complete feed. The feed may comprise about 2% to about 4% (w / w) of a plasticizer of the complete feed. The feed may comprise about 2% to about 3.5% (w / w) of a plasticizer of the complete feed. The plasticizer may include glycerol, sorbitol, invert sugar, glucose powder, or fish gelatin, or any combination thereof.

[0037] The feed may have a moisture content of about 12.5% to about 25% (w / w) of the complete feed, such as about 14% to about 20% (w / w), and even more preferably about 15% (w / w) to about 17% (w / w).

[0038] The feed may have a crude protein content of about 30% to about 65% (w / w) of the complete feed, such as about 35% to about 60% (w / w), or about 40% to about 60% (w / w). Those skilled in the art know which non-hydrolyzed protein sources can be used to prepare the feed described herein. Non-limiting examples include, but are not limited to, wheat protein (such as wheat gluten), soy protein, and the like.

[0039] The feed may have a crude fat content of about 5% to about 40% (w / w) of the complete feed, such as about 10% to about 37% (w / w), or about 15% to about 35% (w / w). The weight ratio of crude fat:crude protein may be about 15:60 to about 35:40. Those skilled in the art know which fat sources are suitable for use in the present application. They include, but are not limited to, fish oil, fish meal, krill meal, squid meal, seaweed oil, seaweed meal, vegetable oil, and any combination thereof.

[0040] The feed may have less than 1000g mm -1The hardness, i.e., the breaking strength, is measured by radial compression using a texture-analyser equipped with a 50 kg load cell and a 5 mm diameter spherical stainless-steel cylinder, reaching a trigger force of 10 g, at a pre-test speed of 2 mm s -1 and a constant test speed of 2 mm s -1 to compress the horizontally placed feed pellets to a force of 35 g. The post-test speed is set to 10 mm s -1 , the break sensitivity is set to 10 g, and the strength-time graph is recorded by a computer. The feed may have a hardness of less than 900 g mm -1 The feed may have a hardness of less than 800 g mm -1 The feed may have a hardness of less than 700 g mm -1 The feed may have a hardness of less than 600 g mm -1 The feed may have a hardness of less than 550 g mm -1 The feed may directly have a hardness of less than 1100 g mm after preparation -1 The feed may directly have a hardness of less than 1000 g mm after preparation -1 The hardness can be determined by radially compressing the feed using a suitable texture-analyser equipped with a load cell and a 5 mm diameter spherical cylinder as the probe. Once a trigger force of 10 g is reached, the probe can move at a pre-test speed of 2 mm s -1 and a constant test speed of 2 mm s -1 to compress the sample to a force of 35 g. The post-test speed can be set to 10 mm s -1 , and meanwhile the break sensitivity can be set to 10 g. Alternatively, the hardness can be determined by radially compressing the feed using a suitable texture-analyser equipped with a load cell and a 25 mm diameter spherical cylinder as the probe. Once a trigger force of 5 g is reached, the probe can move at a pre-test speed of 2 mm s -1 and a constant test speed of 2 mm s -1 to compress the sample to 40% compression, set the post-test speed to 10 mm s -1 , record the force-strain graph by a computer, and calculate the gradient = force (g) / strain (%) at the first peak of the force.

[0041] After storage at 25 °C and 75% RH (relative humidity) for one month, the feed may have a hardness of less than 1000 g mm -1 e.g., a hardness of less than 900 g mm-1 , for example, with a hardness of less than 300 g / mm -1 . After storage at 25 °C and 75% RH for three months, the feed may have a hardness of less than 1000 g / mm -1 , for example, with a hardness of less than 900 g / mm -1 , for example, with a hardness of less than 850 g / mm -1 . After storage at 25 °C and 75% RH for six months, the feed may have a hardness of less than 1000 g / mm -1 , for example, with a hardness of less than 950 g / mm -1 , for example, with a hardness of less than 900 g / mm -1 .

[0042] The feed may be homogeneous or substantially homogeneous. In a suitable embodiment, substantially all of the ingredients that make up the feed and provide the compositions described herein have been mixed together and processed together. In one embodiment, substantially all of the ingredients that make up the feed and provide the compositions described herein, except for the fat source, have been mixed together and processed together, and then the fat source may be incorporated into the feed by vacuum coating to obtain a substantially homogeneous feed.

[0043] In one embodiment, the feed described herein has no or substantially no distinct layers.

[0044] The feed described herein can be obtained by the methods described herein.

[0045] Method for preparing the feed of the present invention

[0046] In a second aspect, the present invention provides a method for preparing the feed described herein, which comprises the following steps:

[0047] i) Providing the following:

[0048] - At least one non-hydrolyzed protein source;

[0049] - At least one fat source;

[0050] - Fiber;

[0051] - Vitamin additive;

[0052] - Mineral additive;

[0053] - Water;

[0054] - A binder that at least partially comprises an edible starch-containing tuber-derived thickener;

[0055] - Hydrolyzed vegetable protein source; and

[0056] - Plasticizer,

[0057] ii) Mix at least the at least one non-hydrolyzed protein source, fiber, vitamin additive, mineral additive, binder comprising at least in part an edible starch-containing tuber-derived thickener, hydrolyzed vegetable protein source, and optionally at least one fat source, plasticizer, and water;

[0058] iii) Optionally, feed the mixture of step ii) into a pre-conditioner;

[0059] iv) Optionally, add a plasticizer and / or at least one fat source to the pre-conditioner;

[0060] v) Optionally, add steam and / or water to the pre-conditioner;

[0061] vi) Feed the (optionally pre-conditioned) mixture into a cooking extruder;

[0062] vii) Optionally, add a plasticizer and / or at least one fat source to the cooking extruder;

[0063] viii) Optionally, add water and / or steam to the mixture of step vii);

[0064] ix) Prepare an extrudate and optionally cut the extrudate into feed pellets; and

[0065] x) Optionally, add at least one fat source to the extrudate and / or feed pellets by negative pressure coating.

[0066] In the method described herein, all of the ingredients provided in step i) can be mixed together in step ii). Alternatively, during pre-conditioning (steps iii)-v)) and / or cooking extrusion (steps vi)-ix)), water can be added in the form of steam or water. If the plasticizer is a liquid (such as glycerol), the plasticizer can be added during mixing (step ii)), or can be added during pre-conditioning or cooking extrusion. It will be apparent to those skilled in the art that the plasticizer can also be added in two or three parts during two or more of mixing, pre-conditioning, and / or cooking extrusion. At least one fat source used in feeds for aquatic organisms is typically a liquid. Similar to the plasticizer, the at least one fat source can be added during mixing (step ii)), or can be added during pre-conditioning or cooking extrusion. It will be apparent to those skilled in the art that the at least one fat source can also be added in two or three parts during two or more of mixing, pre-conditioning, and / or cooking extrusion.

[0067] Alternatively, a feed and / or an extrudate containing all ingredients except at least one fat source can be prepared by thermoplastic extrusion, and then at least one fat source can be incorporated using coating (also known as "vacuum coating") under negative pressure conditions. As is well known to those skilled in the art, coating under negative pressure conditions enables at least one fat source to be incorporated substantially uniformly into the feed for aquatic organisms, thereby obtaining a feed for aquatic organisms. The feed can have a homogeneous or substantially homogeneous composition.

[0068] The thermoplastic extruder can be operated at a relatively low temperature (such as at 60 - 140 °C, for example 70 - 130 °C, or 80 - 120 °C, or 90 - 110 °C).

[0069] If a preconditioner is used, it can also be operated at a relatively low temperature (such as at 60 - 140 °C, for example 70 - 130 °C, or 80 - 120 °C, or 90 - 110 °C).

[0070] Those skilled in the art will appreciate that the amount of added water and / or steam may be sufficient to achieve a moisture content of about 12.5% to about 25% (w / w) of the complete feed.

[0071] In one embodiment, the mixing step ii) is carried out until the mixture is uniform or substantially uniform.

[0072] The resulting feed pellets are homogeneous or substantially homogeneous feed pellets.

[0073] On the other hand, the present invention particularly relates to a method for preparing the above-mentioned compound complete fish feed, wherein the method comprises the following steps:

[0074] i) Providing the following:

[0075] - a non-hydrolyzed protein source;

[0076] - an optional carbohydrate-containing source;

[0077] - a vitamin additive;

[0078] - a mineral additive;

[0079] - an edible starch-containing tuber-derived thickener; and

[0080] - a hydrolyzed plant protein source;

[0081] ii) Mixing the materials provided in step i);

[0082] iii) Feeding the mixture of step ii) into a preconditioner;

[0083] iv) Optionally, adding a plasticizer to the preconditioner;

[0084] v) Add steam to the pre-conditioner to a temperature of about 60 - 100 °C and optionally add water to the pre-conditioner;

[0085] vi) Feed the heated material from the pre-conditioner into the barrel of a thermoplastic extruder;

[0086] vii) Optionally, add a plasticizer to the barrel of the thermoplastic extruder;

[0087] viii) Optionally, add moisture to the mixture of step vii) in the barrel of the extruder;

[0088] ix) Hold the mixture in the barrel of the extruder at a temperature of about 70–120 °C;

[0089] x) Prepare a cut porous extrudate having an oil absorption capacity of at least 10% (w / w); then

[0090] xi) Add a fat source to the cut porous extrudate in a coating device operating under negative pressure.

[0091] The thermoplastic extruder may be provided with a die plate having through holes to minimize the diameter of the extrudate to at least 3 mm after puffing the extrudate.

[0092] Method of use

[0093] The present invention teaches a method of raising aquatic organisms, the method comprising the step of administering or feeding the feed described herein to the aquatic organisms.

[0094] The present invention also teaches a method of improving the weight gain and / or average daily weight gain and / or specific growth rate of aquatic organisms, the method comprising the step of administering or feeding the feed described herein to the aquatic organisms.

[0095] The present invention also teaches a method of improving the FCR (feed conversion ratio) of aquatic organisms, the method comprising the step of administering or feeding the feed described herein to the aquatic organisms.

[0096] In one embodiment, the aquatic organisms are selected from finfish and crustaceans.

[0097] In one embodiment, the aquatic organisms are selected from tuna, groupers, salmonids, perches, tilapia, cleaner fish, cod, flatfish (such as Japanese flounder, sole, turbot, halibut, and Greenland halibut), catfish, pike and pickerel, carps, sea breams (such as red sea bream), shrimps, prawns, crabs, lobsters, and crayfish. In a preferred embodiment, the aquatic organism is tuna.

[0098] Relative to feeding aquatic organisms with forage fish (also known as "prey fish" or "bait fish", which are small pelagic fish that are preyed upon by larger predators as food), and / or relative to feeding aquatic organisms with an aquatic organism feed based on ground forage fish (such feed is referred to as a wet or semi - wet feed), it can be considered that the weight gain and / or average daily gain and / or specific growth rate of the aquatic organisms are improved.

[0099] Similarly, relative to feeding aquatic organisms with forage fish and / or feeding aquatic organisms with a wet or semi - wet feed based on ground forage fish, it can be considered that the FCR of the aquatic organisms is improved.

[0100] Definitions

[0101] The present invention is described by terms having the following meanings:

[0102] "Extrusion" or "thermoplastic extrusion" refers to the extrusion process through a single - screw extruder or a twin - screw extruder. In addition to referring to extrusion under conditions above 100 °C in the extruder barrel, extrusion or thermoplastic extrusion further refers hereinafter to the extrusion process under hot conditions in the extruder barrel (single - screw extruder barrel or twin - screw extruder barrel). Hot conditions mean that at least one region of the extruder barrel is maintained at 70 °C or higher than 70 °C. Extruded feed refers to feed prepared by the extrusion process.

[0103] "Compound feed" refers to feed containing one or more protein sources, such protein sources being for example (but not limited to) marine - organism proteins (such as fish meal and krill meal), plant proteins (such as soybean meal, rapeseed meal, wheat gluten, corn gluten, lupin meal, pea meal, sunflower seed meal, and rice meal), and slaughterhouse wastes (such as blood meal, bone meal, feather meal, and chicken meal). By mixing different protein sources (each protein source having its own amino - acid profile), the desired amino - acid profile in the feed can be achieved within certain limits, and the feed is adapted to the fish for which it is intended.

[0104] Compound feed also contains oils (such as fish oil and / or vegetable oils (such as rapeseed oil and soybean oil)) as an energy source. Compound feed also contains binders, usually in the form of starch - rich raw materials, such as wheat or wheat flour, potato flour, rice, rice flour, pea flour, legumes, or cassava flour, to give the feed the required strength and form stability.

[0105] Compound feed also contains minerals and vitamins necessary to ensure good growth and good health of aquatic organisms such as fish. The feed can further contain other additives such as pigments to achieve certain effects.

[0106] Thus, a formulated feed is a compound feed in which the relative amounts between proteins, fats, carbohydrates, vitamins, minerals, and any other additives are calculated based on the age or life stage of aquatic organisms such as fish, to best meet the nutritional requirements of aquatic organisms such as fish. Usually, only one type of feed is used for feeding, and each portion of the feed is nutritionally sufficient.

[0107] The dried formulated feed refers to an extruded feed.

[0108] Examples of preferred embodiments are described below, and the analysis results are shown in the accompanying drawings, where:

[0109] Figure 1 Shows a texture comparison between a standard Atlantic salmon feed with a diameter of 9 mm and the 8.5 mm soft and elastic feed of the present invention, x-axis: strain (%), y-axis: force (g);

[0110] Figure 2 In the same manner as Figure 1 Shows a texture comparison between a standard turbot feed with a diameter of 17 mm and the 20 mm soft and elastic feed of the present invention;

[0111] Figure 3 Shows a comparison between several standard fish feeds (hard pellets) and the soft and elastic feed of the present invention, expressed as "gradient" (= force (g) / strain (%)), and the "gradient" (= force (g) / strain (%)) is a function of the particle size;

[0112] Figure 4 Shows a texture comparison between five different 8.5 mm diameter feeds of the present invention stored at 25 °C and 75% RH for up to six months;

[0113] Figure 5 Shows the results of a growth test conducted with juvenile bluefin tuna (T. orientalis), comparing feeding with raw feed fish and feeding with the feed of the present invention;

[0114] Figure 6A - Figure A of -B shows a sample of Feed 1 (according to the present invention); Figure B shows the feed pellets after being manually extruded four or five times;

[0115] Figure 7A - Figure A of -B shows a sample of Feed 2 (without wheat gluten hydrolysate); Figure B shows the feed pellets after being manually extruded four or five times; and

[0116] Figure 8A - Figure A of -B shows a sample of Feed 3 (without glycerol); Figure B shows the feed pellets after being manually extruded four or five times.

[0117] Feed texture analysis method #1

[0118] The fracture strength (hardness) was measured by radial compression using a texture analyzer (TA XT2, Model 1000R; SMS StableMicro Systems, Blackdown Rural Industries, Surrey, UK) equipped with a 50 kg load cell. Once a trigger force of 10 g was reached, the probe began to compress the sample. Using a 5 mm diameter spherical stainless steel cylinder (P / 5S, Stable Micro Systems), the cylinder was pressed against the horizontally placed pellets at a pre-test speed of 2 mm s -1 and a constant test speed of 2 mm s -1 to a force of 35 g for analysis. The post-test speed was set to 10 mm s -1 , and the rupture sensitivity was set to 10 g. The intensity-time graph was recorded by a computer and analyzed using Texture Exponent for Windows (version 6.1.7.0, Stable Micro Systems), and the fracture strength of ten pellets was recorded. The reported strength was the average of ten pellets.

[0119] Feed texture analysis method #2

[0120] The fracture strength (hardness) and elasticity were measured by radial compression using the same texture analyzer equipped with a 50 kg load cell as in method #1. Once a trigger force of 5 g was reached, the probe began to compress the sample. Using a 25 mm diameter spherical stainless steel cylinder (P / 25, Stable Micro Systems), the cylinder was pressed against the horizontally placed pellets at a pre-test speed of 2 mm s -1 and a constant test speed of 2 mm s -1 to a 40% compression for analysis. The post-test speed was set to 10 mm s -1 . The force-strain (%) graph was recorded by a computer, analyzed and reported as "gradient", i.e., gradient = force (g) / strain (%). The reported fracture strength was the average of ten pellets. Examples

[0121] As is well known to those skilled in the art, the standard compound dry pellets with diameters of 9 mm and 22 mm in the examples were prepared in a conventional manner by extrusion. After extrusion, the total moisture content was adjusted to about 7 - 8% by drying. As described below, soft and elastic fish feed pellets suitable for feeding tuna according to the present invention were prepared respectively.

[0122] The formulated fish feeds used in the examples met the theoretical nutritional requirements of the Atlantic bluefin tuna (T. thynnus). The formulations of tuna feeds with diameters of 8.5 mm, 25 mm, and 35 mm are given in Table 1A. The 8.5 mm tuna feed corresponds to a standard formulated dry pellet of 9 mm, and the 25 mm tuna feed corresponds to a standard formulated dry pellet of 22 mm, as these are equivalent feed sizes.

[0123] Preparation of a fish feed suitable for rearing tuna

[0124] The first fish feed with a diameter of 8.5 mm according to the present invention is prepared as follows: The dry ingredients are pre-mixed in a vertical mixer and ground in a Dinnissen 30 kW hammer mill (Dinnissen, Sevenum, The Netherlands) with a screen aperture size of 0.75 mm. These ingredients are then mixed in a Dinnissen horizontal ribbon mixer (500 LTR) for 7 minutes. The feed grind is conditioned in a differential diameter conditioner (DDC 2; Wenger Manufacturing, Sabetha, KS, USA) and extruded in a Wenger X-85 single screw extruder with a screw diameter of 85 mm. The ingredients are extruded as described above to produce extrudates with a diameter of 8.5 mm and a length of approximately 9 mm. The rotational speed of the cutter is adjusted according to the specified extrudate length.

[0125] The drying temperature is set at 25 °C, and the product is dried in a Wenger Series III horizontal 3-zones dryer for exactly 5 minutes. Typically, under these conditions, the product will only lose approximately 1% of its nominal weight in moisture, so the entire process can be considered a "no drying process". Subsequently, the obtained pellets are coated with oil in a Forberg 6-l vacuum coater (Forberg, Oslo, Norway). Considering the almost negligible moisture loss during the drying process and considering the moisture loss in the "flash off" at the extruder die and during the coating process, the total moisture addition during the extrusion process is calculated in such a way that the total moisture content in the finished product is 15%, i.e., the total amount of moisture added to the pre-conditioner and / or the extruder barrel. The actual moisture addition amounts are shown in Table 2.

[0126] The second type of fish feed according to the present invention with a diameter of 8.5 mm was prepared as described above, but was extruded in a Wenger TX-57 twin-screw extruder. The barrel diameter of the extruder was 57 mm and the length-to-diameter ratio was 17.5:1. The barrel of the extruder consisted of four head parts, each part having a jacket to allow steam heating (Parts 1-4) or water cooling (Parts 2-4). Temperature control of the second, third, and fourth parts was achieved by balancing the heating and cooling power inputs. The ingredients were extruded as described above to produce an extrudate with a diameter of approximately 8.5 mm and a length of approximately 9.5 mm. The rotational speed of the cutter was adjusted according to the specified extrudate length.

[0127] The obtained fish feed was dried to approximately 850 g kg dry matter in a Wenger Series III horizontal 3-zone dryer. -1 Dry matter.

[0128] Subsequently, the first type of 8.5 mm fish feed and the second type of 8.5 mm fish feed obtained were coated with fish oil in a Forberg 60-l vacuum coater.

[0129] The 25 mm diameter fish feed according to the present invention was prepared on a commercial extruder (Wenger, X-175 single-screw extruder). This fish feed was prepared using the same operations as described for the preparation of the 8.5 mm diameter fish feed. The process parameters are shown in Table 2.

[0130] Table 1A Fish feed formula of the present invention

[0131]

[0132] Table 1B Composition of some fish feeds of the present invention analyzed by NIR

[0133]

[0134] * Glycerol, carbohydrates, fiber

[0135] Table 2 Extruder process parameters

[0136]

[0137] * The temperature of the material inside the extruder barrel was at least 20 K higher than the extruder barrel.

[0138] Table 3 Drying parameters

[0139]

[0140] Texture analysis

[0141] The generally recognized threshold for a soft extruded product is a force of 1000 g / mm. The determination is made using the curve shape of Feed Texture Analysis Method #1 in combination with Feed Texture Analysis Method #2, as Figure 1 and 2 shown. If the force is less than 1000 g / mm, the product is soft.

[0142] In some cases, using Feed Texture Analysis Method #1, standard feed pellets may be below the 1000 g / mm threshold, depending on, for example, the feed ingredients used, but will remain unchanged as Figure 1 and 2 shown even when compared to the curve shape of Feed Texture Analysis Method #2.

[0143] As Figure 3 shown, the results of texture analysis can be presented in different forms. Each pair of "Force (g)" and "Strain (%)" values at the first peak of the force is given as "Gradient" (= Force / Strain). The "Gradient" is shown as a function of the particle size, and a "Gradient" is plotted for each measured fish feed pellet. If there is no first peak of the force, see, for example, Figure 1 for soft and elastic fish feed, then the pair of values is the end point of the graph, i.e., 40% compression has been reached without particle breakage.

[0144] Example 1

[0145] Prepare the first 8.5 mm diameter fish feed according to the present invention as described in Tables 2 and 3 and according to the formulation shown in Table 1A. The actual contents of the main ingredients are shown in Table 1B. Compare this 8.5 mm feed with a standard (i.e., commercial) 9 mm diameter Atlantic salmon fish feed.

[0146] Analyze the texture of the feed as described in Feed Texture Analysis Methods #1 and #2. Figure 1 Shows the results of Feed Texture Analysis Method #2.

[0147] Figure 1 The curve shape of the salmon feed shown is typical of a standard hard and brittle extruded feed pellet. The maximum force value representing the hardness or the first break point of the feed pellet occurs relatively early, i.e., the penetration distance of the probe is short, resulting in a steep peak. After the first break, the force does not immediately become zero because the feed pellet still shows some resistance as it steadily breaks down into smaller particles.

[0148] On the other hand, the soft and elastic fish feed pellets according to the present invention show a completely different curve shape. This is typical for soft and elastic samples. The long probe compression of the feed pellets without breaking them or reaching the first peak indicates that the feed pellets are not broken. This shows the elasticity of the pellets. A short puncture distance before the first peak indicates that the feed pellets are brittle, while a long puncture distance before rupture indicates that the feed pellets are more elastic. In addition, compared with the Atlantic salmon feed pellets, the maximum breaking force of the elastic fish feed pellets is significantly lower.

[0149] The hardness value of the first 8.5 mm elastic fish feed measured by feed texture analysis method #1 is 516 g mm -1 . The hardness of the 9 mm Atlantic salmon feed (i.e., comparable size) is 3778 g mm -1 .

[0150] According to the commercial guidelines established by the applicant, the elastic fish feed shows standard quality criteria, such as sinking speed, oil absorption capacity, and durability (data not shown).

[0151] Example 2

[0152] As described in Tables 2 and 3 and prepared according to the formulation shown in Table 1A, fish feeds with a diameter of 25 mm according to the present invention are prepared. The actual contents of the main ingredients are shown in Table 1B. The 25 mm diameter feed is compared with a standard (i.e., commercial) 22 mm diameter turbot fish feed.

[0153] As described in feed texture analysis methods #1 and #2, the texture of the feed is analyzed. Figure 2 The results of feed texture analysis method #2 are shown.

[0154] The standard turbot feed did not show resistance or showed very little resistance before the first rupture (i.e., the maximum force value), so the force immediately dropped to zero, resulting in a steep peak.

[0155] The hardness value of the 22 mm standard turbot feed is 3874 g mm -1 , while the hardness of the 25 mm tuna feed according to the present invention is 416 g mm -1 .

[0156] According to the commercial guidelines established by the applicant, the elastic fish feed shows standard quality criteria, such as sinking speed, oil absorption capacity, and durability (data not shown).

[0157] Comparison Figure 1 and Figure 2 of the curves shows that increasing the feed pellet size from 8 - 9 mm to about 20 mm does not change the texture of the feed pellets according to the present invention.

[0158] As Figure 3 shown, the particles of the present invention follow a linear distribution as a function of particle size in the "particle size" - "gradient" plot. This distribution may follow the formula: gradient = 33.5 x (particle size) - 235. In contrast, the hard particles of the prior art may follow the formula: gradient = 202 x (particle size) – 1364.

[0159] Example 3

[0160] Five different feeds with a diameter of 8.5 mm according to the present invention were prepared as described in Tables 2 and 3 and according to the formulation shown in Table 4. The aim was to evaluate the shelf life of the feeds. Different amounts of calcium propionate were added as preservatives to the formulation. During the entire storage period, the feeds were stored at a temperature of 25 °C and 75% RH (relative humidity).

[0161] Table 4 Formulation of the fish feed of Example 3

[0162]

[0163] Sampling was carried out after 1 month, 3 months and 6 months of storage. The microbial characteristics (i.e., moulds, aerobic bacteria, anaerobic bacteria and Clostridium perfringens) and hardness of the samples were analysed. The hardness results are shown in Figure 4 this

[0164] Generally, the microbial results showed that the product could be stored for six months without the addition of a mould inhibitor (results not shown). In addition, after six months of storage, the texture of all the products prepared in this test was acceptable.

[0165] Some hardening was observed between the 1-month and 3-month samples. After that, the hardness remained stable between 3 and 6 months of storage. All the samples remained soft and elastic during storage, and all the samples showed a hardness of less than 1000 g mm after six months of storage -1 .

[0166] Example 4

[0167] A pilot-scale fish feed with a diameter of 35 mm according to the present invention was prepared as described in Tables 2 and 3 and according to the formulation shown in Table 1A. The actual contents of the main components are shown in Table 1B.

[0168] The measured hardness of the product was 443 g mm -1 . In addition, the standard quality criteria of this feed met the applicant's commercial guidelines (data not shown).

[0169] Example 5

[0170] The 35 mm tuna feed according to the present invention is prepared in the same manner as described for the 8.5 mm tuna feed. To compare and examine the influence of the process scale, an additional 35 mm tuna feed was prepared using a second single-screw extruder (X-175, Wenger Manufacturing, screw diameter 175 mm).

[0171] The 35 mm diameter fish feed was prepared according to the formulations described in Tables 2 and 3 and shown in Table 1A.

[0172] The feed was soft and elastic. In addition, the standard quality criteria for this feed met the applicant's commercial guidelines (data not shown).

[0173] Example 6

[0174] In 2017, juvenile bluefin tuna (T. orientalis) weighing approximately 6 kg were caught by purse seine and transferred to four seawater cages in a commercial fishery near Wakayama (W. Japan). Approximately 850 fish were placed in each cage and fed raw feed fish consisting mainly of Japanese sardine (Sardinops melanostictus), Japanese jack mackerel (Trachurus japonicas), Japanese mackerel (Scomber japonicas) and / or Australian bonito (S. australasicus) until clearly satiated. During the one-month period prior to the start of the growth trial, the fish in two cages were gradually acclimated to eating the SOFT EP food of the present invention. The growth trial compared SOFT EP with raw feed fish and started on December 11, 2017. The trial lasted for 4 months until April 10, 2018. The ambient water temperature decreased from 19 °C at the start of the trial to 14 - 15 °C in February - March and then rose again to 17 °C at the end of the trial. The fish were fed until clearly satiated, and the progress of body size / growth was tracked monthly using an AQ1 camera system. The survival rate during the trial was high (>99%) and was independent of the food. The fish fed SOFT EP grew significantly better (an increase of approximately 30% compared to the initial body weight), compared to the fish fed raw feed fish (an increase of approximately 5%) (Figure 6). Especially during the period of decreasing water temperature and low water temperature, SOFT EP supported better growth compared to raw feed fish. Calculating the feed conversion ratio (FCR) in terms of the dry matter (kg) of feed used per kg weight gain of the fish, the feed conversion ratio (FCR) of SOFT EP (3.5 and 6.0) was also better compared to that of the fish fed raw feed fish (5.3 and 11.2).

[0175] Example 7

[0176] The following three diets were prepared by thermoplastic extrusion into pellets with a diameter of 20 mm and their elasticity and burst strength were evaluated. Diet 1 contained both wheat gluten hydrolysate and glycerol, whereas diet 2 did not contain wheat gluten hydrolysate and diet 3 did not contain glycerol.

[0177]

[0178] The particles of food 1 had a smooth surface and a shiny appearance. The particles were soft and elastic ( Figure 6A ), can be easily squeezed four to five times without breaking ( Figure 6B ).

[0179] In contrast, the particles of food 2 and 3 had torn edges, rough cut surfaces, and prominent protrusions and grooves (see Figure 7A and 8A ). These particles are not elastic. After one squeeze, these particles crack / break. After four or five squeezes, they break very obviously and start to disperse (see Figure 7B and 8B ).

[0180] Therefore, to obtain the soft and elastic particles described herein, both a vegetable protein hydrolysate and a plasticizer are required.

[0181] It should be noted that the above embodiments illustrate rather than limit the present invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference symbols in brackets should not be interpreted as limiting the claims. The use of the verb "comprise" / "include" and its variations does not exclude the presence of elements or steps other than those stated in the claims. The article "a" or "an" before an element does not exclude the presence of a plurality of such elements.

[0182] The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0183] The present invention may also be described by the following numbered items.

[0184] 1. An extruded complete feed for aquatic organisms, wherein the complete feed comprises:

[0185] - at least one non-hydrolyzed protein source;

[0186] - at least one fat source;

[0187] -fiber;

[0188] - Vitamin supplements;

[0189] - Mineral additives;

[0190] - Water;

[0191] - An adhesive comprising at least partially an edible starch-containing tuber-derived thickener;

[0192] - A hydrolyzed vegetable protein source; and

[0193] - A plasticizer,

[0194] and the compound complete feed contains a moisture content of about 12.5% to about 25% (w / w) of the complete feed.

[0195] 2. The feed according to item 1, wherein the feed contains about 5% to about 9% (w / w) of an edible starch-containing tuber-derived thickener of the complete feed.

[0196] 3. The feed according to item 2, wherein the edible starch-containing tuber-derived thickener comprises pregelatinized potato starch.

[0197] 4. The feed according to item 2, wherein the edible starch-containing tuber-derived thickener comprises natural potato starch.

[0198] 5. The feed according to item 2, wherein the edible starch-containing tuber-derived thickener comprises tapioca starch.

[0199] 6. The feed according to any one of the preceding items, wherein the hydrolyzed vegetable protein is a hydrolyzed vegetable protein with a degree of hydrolysis of about 3% to about 25%.

[0200] 7. The feed according to any one of the preceding items, wherein the feed contains about 5% to about 15% (w / w) of a hydrolyzed vegetable protein of the complete feed.

[0201] 8. The feed according to any one of the preceding items, wherein the hydrolyzed vegetable protein includes hydrolyzed wheat gluten.

[0202] 9. The feed according to any one of the preceding items, wherein the feed contains about 1.5% to about 5% (w / w) of a plasticizer of the complete feed.

[0203] 10. The feed according to item 9, wherein the plasticizer includes glycerol.

[0204] 11. The feed according to any one of the preceding items, wherein the feed contains a moisture content of about 14% to about 20% (w / w) of the complete feed.

[0205] 12. The feed according to any one of the preceding items, wherein the crude protein content comprised in the feed is about 40% to about 60% (w / w) of the complete feed.

[0206] 13. The feed according to any one of the preceding items, wherein the crude fat content comprised in the feed is about 15% to about 35% (w / w) of the complete feed.

[0207] 14. The feed according to item 12 or 13, wherein the ratio of crude fat:crude protein is about 15:60 to about 35:40.

[0208] 15. The feed according to any one of the preceding items, wherein the feed has a hardness of less than 1000 g mm -1 which is measured by radial compression using a texture analyzer equipped with a 50 kg load cell and a 5 mm diameter spherical cylinder, reaching a trigger force of 10 g, with a pre-test speed of 2 mm s -1 and a constant test speed of 2 mm s -1 to compress the horizontally placed feed pellets to a force of 35 g, setting the post-test speed to 10 mm s -1 , setting the fracture sensitivity to 10 g, and recording the intensity-time graph with a computer.

[0209] 16. The feed according to any one of items 1 to 14, wherein the feed has a hardness of less than 1000 g mm -1 which is measured by radial compression using a texture analyzer equipped with a 50 kg load cell and a 25 mm diameter spherical cylinder, reaching a trigger force of 5 g, with a pre-test speed of 2 mm s -1 and a constant test speed of 2 mm s -1 to compress the horizontally placed feed pellets to a 40% compression, setting the post-test speed to 10 mm s -1 , recording the force-strain graph with a computer, and calculating the gradient = force (g) / strain (%) at the first peak of the force.

[0210] 17. A method for preparing a feed for aquatic organisms according to any one of the preceding items, comprising the following steps:

[0211] i) providing the following:

[0212] - at least one non-hydrolyzed protein source;

[0213] - at least one fat source;

[0214] - fiber;

[0215] - vitamin additive;

[0216] - Mineral additives;

[0217] - Water;

[0218] - A binder that at least partially comprises an edible starch-containing tuber-derived thickener;

[0219] - A source of hydrolyzed vegetable protein; and

[0220] - A plasticizer,

[0221] ii) Mix at least the at least one non-hydrolyzed protein source, fiber, vitamin additive, mineral additive, a binder that at least partially comprises an edible starch-containing tuber-derived thickener, a source of hydrolyzed vegetable protein, and optionally the at least one fat source, plasticizer, and water that are present;

[0222] iii) Optionally, feed the mixture from step ii) into a pre-conditioner;

[0223] iv) Optionally, add the plasticizer and / or the at least one fat source to the pre-conditioner;

[0224] v) Optionally, add steam and / or water to the pre-conditioner;

[0225] vi) Feed the optionally pre-conditioned mixture into a thermoplastic extruder;

[0226] vii) Optionally, add the plasticizer and / or the at least one fat source to the thermoplastic extruder;

[0227] viii) Optionally, add water and / or steam to the mixture from step vii);

[0228] ix) Prepare an extrudate and optionally cut the extrudate into feed pellets; and

[0229] x) Optionally, add the at least one fat source to the feed pellets by negative pressure coating.

[0230] 18. A method for preparing a compound complete feed according to any one of the preceding items, wherein the method comprises the following steps:

[0231] i) Provide the:

[0232] - Non-hydrolyzed protein source;

[0233] - Optionally present source of carbohydrates;

[0234] - Vitamin additive;

[0235] - Mineral additive;

[0236] - An edible starch-containing tuber-derived thickener; and

[0237] - A hydrolyzed vegetable protein source;

[0238] ii) Mix the materials provided in step i);

[0239] iii) Feed the mixture of step ii) into a pre-conditioner;

[0240] iv) Optionally, add the plasticizer to the pre-conditioner;

[0241] v) Add steam to the pre-conditioner and optionally add water to the pre-conditioner;

[0242] vi) Feed the heated material from the pre-conditioner into a thermoplastic extruder;

[0243] vii) Optionally, add the plasticizer to the thermoplastic extruder;

[0244] viii) Optionally, add moisture to the mixture of step vii) in the extruder;

[0245] ix) Prepare an extrudate with an oil absorption capacity of at least 10% (w / w); and

[0246] x) Add the fat source to the extrudate in a coating device operating under negative pressure.

[0247] 19. The method according to item 18, wherein the thermoplastic extruder is provided with a die plate having through holes to minimize the diameter of the extrudate to at least 3 mm after puffing the extrudate.

[0248] 20. A method for raising aquatic organisms, the method comprising the step of applying to the aquatic organisms a feed according to any one of items 1-16.

[0249] 21. A method for improving the weight gain and / or average daily weight gain and / or growth rate of aquatic organisms, the method comprising the step of applying to the aquatic organisms a feed according to any one of items 1-16.

[0250] 22. A method for improving the feed conversion ratio (FCR) of aquatic organisms, the method comprising the step of applying to the aquatic organisms a feed according to any one of items 1-16.

[0251] 23. The method according to any one of items 19-21, wherein the aquatic organisms are selected from fish and crustaceans, and the fish include finfish.

[0252] 24. The method according to any one of items 19-22, wherein the aquatic organism is selected from tuna, salmonids, perches, tilapia, cleaner fish, cod, such as flatfish including flounder, sole, turbot, Greenland halibut and halibut, catfish, pike and pickerel, cyprinids, such as porgies including sea bream, shrimp, prawns, crabs, lobsters and crayfish.

[0253] 25. The method according to any one of items 19-23, wherein the aquatic organism is tuna.

Claims

1. An extruded complete feed for aquatic organisms, wherein the complete feed comprises: - at least one non-hydrolyzed protein source; - at least one fat source; - fiber; - a vitamin additive; - a mineral additive; - water; - a binder that at least partially comprises an edible starch-containing tuber-derived thickener; - a hydrolyzed plant protein source; and - a plasticizer, and the complete feed has a moisture content of about 12.5% to about 25% (w / w) of the complete feed.

2. The feed according to claim 1, wherein the feed comprises about 5% to about 9% (w / w) of the complete feed of an edible starch-containing tuber-derived thickener.

3. The feed according to claim 1 or 2, wherein the hydrolyzed plant protein is a hydrolyzed plant protein having a degree of hydrolysis of about 3% to about 25%.

4. The feed according to claim 1 or 2, wherein the feed comprises about 5% to about 15% (w / w) of the complete feed of a hydrolyzed plant protein.

5. The feed according to claim 1 or 2, wherein the hydrolyzed plant protein comprises hydrolyzed wheat gluten.

6. The feed according to claim 1 or 2, wherein the feed comprises about 1.5% to about 5% (w / w) of the complete feed of a plasticizer.

7. The feed according to claim 6, wherein the plasticizer comprises glycerol.

8. The feed according to claim 1 or 2, wherein the feed has a moisture content of about 14% to about 20% (w / w) of the complete feed.

9. The feed according to claim 1 or 2, wherein the feed has a crude protein content of about 40% to about 60% (w / w) of the complete feed.

10. The feed according to claim 1 or 2, wherein the feed has a crude fat content of about 15% to about 35% (w / w) of the complete feed.

11. The feed according to claim 1 or 2, wherein the feed has a hardness of less than 1000 gmm -1 and the hardness is measured by radial compression using a texture analyzer equipped with a 50 kg load cell and a 5 mm diameter spherical cylinder, reaching a trigger force of 10 g, at a pre-test speed of 2 mm s -1 and a constant test speed of 2 mm s -1 to compress the horizontally placed feed pellets to a force of 35 g, setting the post-test speed to 10 mm s -1 , setting the fracture sensitivity to 10 g, and recording the intensity-time graph with a computer.

12. The feed according to claim 1 or 2, wherein the feed has a hardness of less than 1000 gmm -1 , and the hardness is measured by radial compression using a texture analyzer equipped with a 50 kg load cell and a 25 mm diameter spherical cylinder, reaching a trigger force of 5 g, at a pre-test speed of 2 mm s -1 and a constant test speed of 2 mm s -1 to compress the horizontally placed feed pellets to 40% compression, setting the post-test speed to 10 mm s -1 , recording the force-strain diagram with a computer, and calculating the gradient = force (g) / strain (%) at the first peak of the force.

13. A method for preparing a feed for aquatic organisms according to any one of claims 1-12, comprising the following steps: i) Providing the: - at least one non-hydrolyzed protein source; - at least one fat source; - fiber; - a vitamin additive; - a mineral additive; - water; - a binder that at least partially comprises an edible starch-containing tuber-derived thickener; - a hydrolyzed plant protein source; and - a plasticizer, ii) Mixing at least the at least one non-hydrolyzed protein source, fiber, vitamin additive, mineral additive, binder that at least partially comprises an edible starch-containing tuber-derived thickener, hydrolyzed plant protein source, and optionally the at least one fat source, plasticizer, and water; iii) Optionally, feeding the mixture of step ii) into a preconditioner; iv) Optionally, adding the plasticizer and / or the at least one fat source to the preconditioner; v) Optionally, adding steam and / or water to the preconditioner; vi) Feeding the optionally preconditioned mixture into a thermoplastic extruder; vii) Optionally, adding the plasticizer and / or the at least one fat source to the thermoplastic extruder; viii) Optionally, water and / or steam is added to the mixture of step vii); ix) An extrudate is prepared and optionally the extrudate is cut into feed pellets; and x) Optionally, the at least one fat source is added to the feed pellets by negative pressure coating.

14. The method according to claim 13, wherein the oil absorption capacity of the extrudate prepared in step ix) is at least 10% (w / w).

15. A method for raising aquatic organisms, the method comprising the step of administering to the aquatic organisms a feed according to any one of claims 1-12.

16. The method according to claim 15, wherein the aquatic organisms are selected from tuna, salmonids, perches, tilapia, cleaner fish, cod, flatfish, catfish, pike, carps, sea breams, shrimps, and crabs.

17. The method according to claim 15, wherein the aquatic organisms are selected from flounder, sole, turbot, Greenland halibut, halibut, young pike, sea bream, prawn, lobster, and crayfish.

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