WO2004056985A2

WO2004056985A2 - Production of crude krill enzyme solution, the crude enzyme solution and freeze-dried product thereof and feeds using the same

Info

Publication number: WO2004056985A2
Application number: PCT/JP2003/016167
Authority: WO
Inventors: Tetsu Mori; Kazuhiro Yoshikawa; Yoshio Matsuda
Original assignee: Nippon Suisan Kaisha, Ltd.
Priority date: 2002-12-19
Filing date: 2003-12-17
Publication date: 2004-07-08
Also published as: WO2004056985A3

Abstract

It is intended to provide a crude krill enzyme solution from which impurities inhibiting the enzyme activity have been removed as far as possible and organic impurities causing putrefaction have been removed as far as possible, and, therefore, which can be distributed at a reduced cost while sustaining the desired enzyme activity. The aimed crude krill enzyme solution can be obtained by a production process characterized by comprising pressing fresh krill and thus separating them into the body fluid containing much enzymes and solid matters containing much nutrients such as proteins.

Description

Description Manufacturing method of krill crude enzyme solution, its crude enzyme solution and its frozen product, and feed technology using them

The present invention relates to a method for producing a crude krill enzyme solution, a crude enzyme solution produced by the method, and a feed utilizing the crude enzyme solution. More specifically, a crude krill enzyme solution containing an active enzyme of krill, which can be used as an enzyme preparation for pharmaceuticals and foods, a modifier for food, a fish attractant for leisure, a feeding promoter for cultured fish, etc. And a feed containing the crude enzyme solution. Background art

Krill is caught and used around the world, but the largest catch is Antarctic krill. There is a high demand for fresh products of Antarctic krill as fishing baits. There are also processed food products such as peeled meat, but their production is not high, and the main processing method is meal production, and most of them are for feed.

Krill has a strong enzyme activity, and blackening and auto-digestion progress rapidly after catching, which is a factor that limits the use of krill. On the other hand, the use of this potent enzyme activity has also been advanced, for example, in US Pat. Using digestive enzymes prepared from Further, Patent Document 2 describes that an enzyme preparation prepared from the order Krillida is used for a pharmaceutical composition that promotes digestion of food. Further, Patent Document 3 describes a plaque removing agent containing an enzyme isolated from Antarctic krill. All of these conventional krill enzymes utilize frozen koki after fishing. The first step was to thaw, hydrolyze and homogenize the amy, and then purified the enzyme by various methods.

On the other hand, Patent Document 4 discloses that as a method for purifying a krill enzyme, pressed krill and the like are autolyzed to facilitate separation and extraction. However, it is a problem that squeezed and self-digested by this method has a high moisture content and lacks preservability.

It goes without saying that enzymatically active ingredients must be of high purity in order to maximize their effectiveness. In other words, proteins and their hydrolysates such as water-soluble low-molecular-weight and muscle proteins other than the enzyme active ingredient are unnecessary. Rather, some of them act as enzyme inhibitors, but removal of them is usually very large. Requires great effort.

In a method of extracting and purifying the desired krill enzyme from a homogenate in which all the components of krill, such as meat pieces, shells, and lipids forming emulsion, are made from frozen krill, the purity of the starting material is low. The low value has been a problem in terms of potency and preparation cost for the use of Okinawa enzymes. In addition, the process of preparing the homogenate requires water, so that the homogenate generally becomes bulky and causes an increase in transportation cost and storage cost. Not only is it not possible to obtain a sufficient value, but also the organic matter contained as impurities is liable to rot because its pH is close to neutral, so it is essential to distribute it in a frozen state, which is also a transportation cost This contributed to the increase in storage costs. These costs are particularly important in Antarctic krill, which are caught in the Antarctic Ocean far from the consuming area.

The main raw material for fish farming feed is fish meal, but under the circumstances where the supply of fish meal is decreasing and prices are rising, vegetable protein, especially defatted soybean meal, etc. is used as an alternative protein to fish meal. Attempts have been made to use them. However, the amino acids required for fish and shellfish are different from the constituent amino acids of plant proteins, digestive enzyme inhibitory active factors are contained in addition to plant proteins, and indigestible carbohydrates of plants inhibit digestion and absorption. For some reasons, there were limits to their use (see Non-Patent Document 1).

Patent Document 1 JP-A-5-2626665

Patent Literature 2 Japanese Translation of International Publication No. 6 1-50

Patent Document 3 JP-A-2000-3 5 1 734

Patent Document 4 Japanese Patent Publication No. 2-5504446

Non Patent Literature 1 V i y a k a r n e t a \. N i p p o n S u i s a n Ga kk a i s h i ^ 5 8, 1 9 9 1-2000 (1 9 9 2)

The present inventors have found that by partially decomposing indigestible carbohydrates contained in a plant used as a raw material of a fish farm feed with an enzyme in advance, the feed efficiency of a feed made from plant protein is improved. Application has been filed (Japanese Patent Application No. 200 2—2 3 2 501, not disclosed). Although krill enzymes have been found to be suitable as this enzyme, they required a source of krill enzymes that satisfy the degree of purification and price suitable for use as feed material.

Impurities that inhibit enzyme activity are eliminated as much as possible, organic impurities that cause spoilage are eliminated as much as possible, and production and distribution costs are suppressed, and krill preparations that maintain the desired enzyme activity are obtained. Accordingly, the present inventors have conducted intensive studies, and as a result, have found a method for producing a krill body fluid that has a small amount of impurities such as muscle proteins and hydrolysates thereof, has a low risk of spoilage, and maintains a desirable enzyme activity. Developed and completed the present invention.

In the present invention, fresh krill is squeezed to obtain krill body fluid, and further concentrated at low temperature A method for producing a crude krill enzyme solution and a crude krill enzyme solution produced by this method are summarized. The low-temperature concentration is preferably carried out at a temperature lower than the temperature at which the target enzyme is deactivated, and a solid content of 30% or more is preferable.

Further, the present invention provides a frozen krill crude enzyme solution obtained by squeezing fresh krill and concentrating at a low temperature. After pressing, it is preferable to concentrate at a low temperature below the temperature at which the enzyme is deactivated, and it is preferable that the solid content is 30% or more. Further, the present invention provides an animal feed containing a raw material treated with a krill crude enzyme solution obtained by squeezing fresh krill and concentrating at a low temperature. The gist is an animal feed containing plant protein raw material treated with a crude krill enzyme solution obtained by squeezing fresh krill and concentrating at low temperature. Preferably, the gist of the present invention is an animal feed containing a krill crude enzyme solution obtained by squeezing fresh krill and concentrating at a low temperature to partially decompose the indigestible saccharide of a vegetable protein material.

That is, the present invention relates to a method for producing and utilizing a krill crude enzyme solution in which the content of an extra enzyme inhibitory factor is small and the depletion or deterioration of the enzyme activity due to oxidation and freezing is suppressed, that is, a krill body fluid and a concentrate thereof. . BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described specifically.

The present invention squeezes fresh krill and separates it into a body fluid rich in enzymes and a solid content rich in nutrients such as proteins. Concentrate below. In this step, a volume reduction effect due to concentration can also be expected, which facilitates distribution of the krill pressed liquid concentrate of the present invention.

On the other hand, the solid content generated in the pressing step of the present invention can be used as a meal raw material as in the past. Also, lipids are extracted from the pressed solids by centrifugation or other methods. In addition, it is possible to extract the active ingredients such as polyunsaturated fatty acids, antioxidant dyes, and phospholipids, etc., and commercialize them as chemical products and health foods.

The raw krill used in the present invention is preferably fresh. Frozen products conventionally used for the preparation of enzymes from krill, for example, require a certain amount of time for freezing on a fishing boat, so that some self-digestion has progressed. This is because autolysis starts immediately from the part where thawing has been completed, such as on the surface of the fish, and enzyme activity inhibitors such as peptides are generated. Even those that are not frozen after harvest, those with low freshness are due to the incorporation of auto-digestion products and autoxidized components into body fluids. Therefore, it is preferable to squeeze immediately after catching.

Since the salt content is excessive, it is desirable to remove as much as possible by a known method. This can be achieved by transporting the raw materials on a net conveyor or washing with fresh water. For squeezing to obtain the krill body fluid of the present invention, a known method used for solid-liquid separation can be used. Specifically, it can be selected from sandwiching with a mesh from two directions, pushing into a mesh from one direction such as a screw press, filling a filter cloth, and the like. Since krill has no skeleton and its outer shell is very soft, the force required for squeezing is small. Although the results differ depending on the timing of the raw krill and the method of pressing, usually about 1 to 50% of the weight of the raw krill is obtained as a pressed liquid.

The solids produced here can be prepared almost in the same manner as normal meal by treating it with the usual method for producing meal from caught krill. In normal meal production, the enzyme is deactivated during the ripening step, and then a substantial portion of the water-soluble components are removed during the solid-liquid separation step. This is because all and a significant portion of the water-soluble components usually do not naturally remain in meal products. Known methods can be used for the concentration of the krill body fluid of the present invention, but concentration at a low temperature is effective for suppressing the inactivation of the enzyme and the oxidation and denaturation of the active ingredient. Specifically, the temperature is preferably 55 ° C or less when protease is considered as the enzyme, and 40 ° C or less when carbohydrate degrading enzyme is considered. Concentrations in this temperature range can be selected according to the purpose, such as concentration under reduced pressure, membrane concentration, drying with cold air, and removal of water by an adsorbent.

In the crude krill enzyme solution of the present invention, the pH is hardly changed from that before the concentration, the salt concentration is about 2.5 to 5.0, and the enzyme activity immediately after the compression is maintained even after the concentration.

The krill body fluid concentrate of the present invention retains its enzymatic activity due to its production method and can be used as an enzyme preparation for medicine and food, a modifier for food, feed and the like. In particular, when used for feeding, additional effects can be expected because they contain pigments such as astaxanthin and food attractants in addition to enzymes.

In the present invention, as the vegetable protein raw material, any vegetable protein raw material used as a substitute for animal protein raw material for animal feed raw material can be used. The main examples include soybean, defatted soybean meal, corn gluten meal, raw bran, processed bran, wheat, rapeseed oil cake, cottonseed oil cake, potato protein and the like.

The animal feed material of the present invention is preferably prepared by adding the krill crude enzyme solution of the present invention or the concentrated krill crude enzyme solution to a plant protein material containing an indigestible saccharide at 20 to 60 ° C. Is aged at 30 to 50 ° C for 1 to 48 hours, preferably 2 to 6 hours, and then heated at 80 ° C or more, preferably at 85 ° C for 10 minutes or more. It is obtained by sterilizing and drying. During ripening, stirring treatment is performed, but it is also possible to add fresh water so that stirring is difficult and ripening is not insufficient.

The indigestible carbohydrate-degrading activity of the krill squeezed liquid was determined by thin layer mouth chromatography. Its activity can be easily confirmed. The degradation activity of the indigestible saccharide is measured as described below. That is, the solid content of the krill crude enzyme solution is separated and removed, and oligosaccharides such as bituminose or maltohexaose are added to a final concentration of 1%, and the mixture is stirred at 40 ° C for 2 hours. Thereafter, the supernatant obtained by centrifuging at 300 rpm, 10 minutes at 4 ° C. was spotted on a silica gel thin layer plate, butanol: propanol: water (1: 3: 2). Then, develop the color using orcinol sulfuric acid solution. At this time, spots of oligosaccharides such as cellobiose and maltohexaose are completely eliminated, and only those spots of monosaccharides considered to be / 3-dalcoses and α-glucose are limited to those having an activity of appearing. You.

As the krill used in the present invention, Nankoku krill which has abundant resources and high enzymatic activity is preferable, but other krills having the same activity can be used.

The animal feed material in the present invention is a feed material used for livestock, poultry farming, and fish farming, and is a feed material used as a protein supplement source. The feed of the present invention is particularly suitable for fish farming and crustacean farming. Examples of fish culture and crustaceans include fish to be cultured, such as red sea bream, salmon, hamachi, trevally, trout, flounder, eel and shrimp.

The animal feed of the present invention can be produced by processing and shaping the animal feed raw material of the present invention and other feed raw materials together. The animal feed material of the present invention can be provided in powdered form by heating and drying after okiami treatment, and can be easily used as a feed material of various types, particularly as a substitute for animal protein. Can be. In the case of fish farming, it can be used as a substitute for fishmeal. Example

Hereinafter, examples of the present invention will be described, but the present invention is not limited thereto.

Example 1: Production of krill body fluid and its properties

Nankiyotakiami was caught by a trawler (February 2002) and transported on a net conveyor to remove excess seawater attached to the fish. Using an umbrella-type press (Asahi Press F-50-S-3 type), the fish was sandwiched between both sides of the fish body with a wire mesh, and the liquid was discharged as a krill body fluid to the outside of the wire mesh and collected (yield from 2 kg of krill). 389 g) ₀

Table 1 shows the component data of the obtained krill body fluid.

Example 2: Krill body fluid concentration test and physicochemical analysis

389 g (water content: 81.8%) of the krill body fluid obtained in Example 1 was placed in a 2 L volumetric flask, and concentrated under reduced pressure by a rotary evaporator. At this time, the flask was heated in a water bath kept at 30 ° C, and the water pressure was reduced using an ice-cooled water pump. At each stage of concentration, sampling was carried out appropriately to obtain concentrated solutions having different water contents. Table 2 shows the physicochemical analysis data for these.

Table 2

Water salt concentration

H

(%) (%)

Before concentration 82 6. 7 2. 1

Concentrate 1 81 6.7.2.2.

Concentrate 2 77 6.7 2.5

Concentrate 3 72 6.7 3.1

Concentrate 4 63 6.7 4.0

Concentrate 5 56 6.6 4.6 Example 3: Protease activity of krill body fluid

Protease activity of each concentrated solution obtained in Example 2 was estimated using azocasein degradation as an index. The data in Table 3 was obtained from the absorbance at 44 Onm. This table shows the increase in absorbance at 44 nm when the concentrated solution was reacted with azocasein at a final concentration of 1% at 37 ° C for 60 minutes. In this table, “enzyme activity of the concentrated solution” indicates the enzyme activity of the concentrated solution itself, and “concentration correction value” is a correction value obtained by converting the enzyme activity to the solid content in the concentrated solution.

Table 3

From Table 2, it can be seen that the concentration changes the salt concentration of the concentrated solution, but the pH does not change much under the concentration conditions of this example. In addition, `` Concentration correction value J in Table 3 is considered to represent the relative value of the specific activity of the enzyme, but this does not change much during the enrichment process, and the salt concentration does not affect the protease activity. Example 4 Glycolytic Enzyme Activity of Krill Body Fluid

For each of the concentrates obtained in Example 2, the carbohydrate-degrading activity was estimated using the degradation of p-ditophenyl phenyldarcoside as an index. This is to estimate the intensity of the enzyme activity by quantifying p-nitrophenone anion generated when the enzyme in the concentrated solution acts on the substrate to release glucose, from the absorbance. 420 nm when a decomposition reaction was performed for 5 minutes at 37 and H 6.0 using 5 mM substrate Table 4 shows the increase in absorbance at. In this table, “absorbance” represents the increase in absorbance for each concentrated solution, and “concentration correction value” is a correction value obtained by converting the value of “absorbance” to the solid content in the concentrated solution.

Table 4

The `` concentration correction value '' in Table 4 is considered to indicate the relative value of the specific activity of the enzyme, but this does not change much during the enrichment process, and changes in salt concentration do not affect carbohydrate degradation activity It is shown that. Example 5: Conservation of enzyme activity of krill body fluid

24.7 kg (82% water content) of the krill body fluid obtained in Example 1 was placed in a 100 L vacuum vessel and concentrated under reduced pressure while stirring at a liquid temperature of 25 ° C to obtain a concentrate having a solid content of 37%. Got. This was dispensed into plastic containers by 80 to 10 Om1 and sealed, and stored at 20 ° C, 5 ° C, 25 ° C, and 40 ° C for 1 to 5 months. Tables 5 to 7 show the protease activity, saccharolytic enzyme activity, and general viable cell count per sample lg of each stock solution, respectively. The notation of the enzyme activity value is the same as the enzyme activity of the concentrated solution shown in Example 3 for the protease activity and the absorbance shown in Example 4 for the carbohydrate degrading enzyme activity. The protease activity and glycolytic enzyme activity before storage of this sample were 3.5 and 17.4, respectively. Table 5

Protease activity of krill body fluid concentrate

Table 6

Saccharolytic enzyme activity of krill body fluid concentrate

Table 7

General viable count of krill body fluid concentrate

According to these tables, the krill body fluid concentrate can be stored at a solid content of about 37% for 1 month at a temperature of 120 to 40 ° C, and for 5 months at a glycolytic enzyme activity of 5 It can be seen that the general viable cell count does not increase for 4 months below 5 ° C. Example 6: Production of feed from raw material treated with krill crude enzyme solution Squeezing krill with indigestible carbohydrate-decomposing activity to produce krill raw material

A 10% by weight squeezed liquid was prepared. 30 kg of defatted soybean meal was added to 25 kg of the squeezed liquid, heated and stirred at 40 ° C for 2 hours, maintained at 85 ° C for 10 minutes, and then cooled and freeze-dried. Decomposed defatted soybean meal was prepared.

The obtained decomposed defatted soybean oil cake is mixed in advance with a mixer together with a mixture of fishmeal, rice bran, vitamins and minerals, and water and oils are added using a twin-screw truss extruder. Molded into. Table 8 shows the composition.

Table 8

Example 7: Breeding test using krill-treated soybean supplemented feed

An 8-week rearing test was performed using red sea bream with an average body weight of 17.9 g. All test plots grew without problems, no mortality was observed, no fish disease occurred, and no parasites were parasitized. Table 9 shows the results of physical measurements at 4 weeks (middle) and 8 weeks (at the end of the study). Table 9

As can be seen from the results, the weight increase (growth) was better in the krill-treated soybean plot than in the other two plots. Furthermore, the feed efficiency was higher than that of the control group, suggesting the superiority of the feed supplemented with krill-treated soybeans. Example 8: Comparison of storability between squeezed liquid not autolyzed and autolyzed juice.

In this example, the crude enzyme solution having a solid content of 37% obtained in Example 5 is referred to as a body fluid concentrate. On the other hand, the krill harvested in February was crushed and kept at 50 ° C for 1 hour to promote autolysis, and further concentrated at 23 ° C under reduced pressure to reduce the solid content. A crude enzyme solution of 29% was obtained (referred to as autolysate). The body fluid concentrate and the autolysate were subjected to a storage test at 120 ° C for 25 weeks at 25 ° C. The protease activity and saccharolytic enzyme activity of each storage solution were examined, and the values before storage were set to 100% and shown in Tables 10 to 11. Table 12 shows the number of general viable bacteria per 1 g of the sample. The notation of the value of the enzyme activity is the same as the enzyme activity of the concentrated solution shown in Example 3 for the protease activity and the absorbance shown in Example 4 for the carbohydrate degrading enzyme activity. Table 10

Proteolytic enzyme activity of storage solution (%)

Saccharolytic enzyme activity of stock solution (%)

From Table 10, it can be seen that the activity of the proteolytic enzyme in the autolysate was significantly reduced during the storage period, whereas the activity of the body fluid concentrate was not reduced. Next, from Table 11, it can be seen that a decrease in the activity of the carbohydrate-degrading enzyme during storage of both is observed, but the degree of the decrease is more remarkable in the autolysate. Finally, from Table 12, it can be seen that the general viable cell count increased during storage at 25 ° C in both storage solutions. Example 9: Effect of adding free protein by treatment with krill crude enzyme solution

Defatted soybean meal and krill body fluid (obtained from krill caught in February 2002) Was mixed so that the solid content ratio was 5: 1. Protease inhibitor cocktail (Sigma, product number P 2714: 4- (2-aminoethyl) benzenesulfonylfluoride, aprotune, bestatin, EDTA, trans-epoxysuccinyl-L-leucylamide (4-Guanidino) butane and leptin) was added in an amount sufficient to stop the activity of krill protease, and the mixture was kept at 40 ° C for a certain period of time, and the centrifuged supernatant was collected. The fact that the protease activity was effectively suppressed by the protease inhibitor was confirmed by SDS-PAGE analysis of the supernatant from the fact that the swimming pattern did not change before and after the treatment at 40 ° C. Table 13 shows the soluble proteins per 1 mL of the supernatant measured by the Bradford method.

Table 13 Progress of krill treatment and soluble protein (g / mL)

When both components were kept alone, the amount of soluble protein hardly changed over time. Compared to the sum of these, the protein mass observed when mixed was greatly increased. In addition, the increase in the amount of soluble protein observed over time suggested that the action of the krill component promoted the solubilization of the insoluble protein in soybean meal. This is thought to mean that the utilization of soybean meal treated with krill body fluid as feed is enhanced. Reference Example 1: Effect of increasing soybean soluble protein by commercially available carbohydrate-degrading enzyme

5 g of defatted soybean meal is suspended in 45 mL of 5 OmM citrate buffer (pH 4.5), and a protease inhibitor cocktail (manufactured by Sigma, product number P2714) is suspended enough to stop the protease activity of krill. Was added. On the other hand, a 5% (w / v) solution of Cellulase Y—NC (Yakult Yakuhin Kogyo), Macerozyme A (Yakult Yakuhin Kogyo), or Piscozyme L (Nopozym) was added in 1 mL for 30 minutes. Table 14 shows the results of measuring the protein concentration of the centrifuged supernatant by the Pirett method after reacting for 3 hours.

Table 14 Saccharolytic enzyme treatment and soy soluble protein (mgZmL)

From this table, it can be seen that saccharolytic enzymes have the effect of increasing the soluble protein of soybean meal. Example 10: Effect of Crude Crude Enzyme Treatment on Sugar Reducing Terminal Increase

Using 2 g of defatted soybean meal, this was mixed with the krill body fluid so that the solid content ratio was 5: 1. This was kept at 40 ° C for 0, 1, and 16 hours, and then the enzymatic reaction was stopped by adding 5 times the amount of 2.4% hydrochloric acid containing 20% sodium sulfate. Using the filtrate, the reducing end of the sugar in the solution was quantified using a ferricyanide reagent. Glucose was used as a standard sample. The measured reducing end was converted to 1 g of defatted soybean meal, and the results shown in Table 15 were obtained.

Table 15 5 Krill treatment of defatted soybean meal and amount of reducing terminal (% Zg soybean meal)

From these results, it was confirmed that the krill treatment of the defatted soybean meal increased the number of sugar-reducing terminals, suggesting the progress of carbohydrate degradation. Example 11: Effect of Protease Inhibitor on Krill Body Fluid In this example, krill used as a raw material was collected in February and May 2002. According to the method shown in Example 1, about 400 g of krill body fluid was produced from each of these 2 kg. Egg white, soy milk, kinako, SBM (defatted soybean meal), or CGM (corn gluten meal) were used as protease inhibitors. To each krill body fluid, 0.4% of each protease inhibitor was added at a solid content ratio, and the protease activity and glycosidase activity were measured by the methods described in Examples 3 and 4. Table 16 and Table 17 show the residual activity when each inhibitor was added, where the activity when no inhibitor was added was 1. Table 16 Effect of protease inhibitors on krill protease activity

As is clear from this table, soy milk (raw soybean) and roasted soybean (roasted soybean) among egg white and soy products inhibited krill protease. On the other hand, SBM and CGM did not show protease inhibitory activity. Also, these tested inhibitors did not inhibit krill dalcosidase activity at all. In general, the magnitude of the kakiamipu oralase activity varies according to the fishing season, and is high in summer in Antarctica, and is expected to decrease significantly after autumn. In the results of this example, the protease activity was lower in May (winter) than in February (antarctic summer), when the protease activity was high. It can be seen that thease inhibitors function more effectively.

Industrial applicability

According to the present invention, a krill crude enzyme solution in which oxidization, denaturation, and alteration are suppressed and storage stability is improved can be produced. This is a simple and inexpensive production method as compared with known methods for preparing krill-derived enzymes. It is possible to provide a high-quality crude krill enzyme solution with less contamination of muscle proteins and hydrolysates thereof. This crude enzyme solution can be used effectively as a feed material other than the enzyme when it is used as a feed material, while the enzyme is concentrated when a highly pure enzyme is produced. Thus, a preferred intermediate material can be provided.

Claims

The scope of the claims

1. A method for producing a crude krill enzyme solution, comprising squeezing fresh krill to obtain a krill body fluid and concentrating it.

2. A crude krill enzyme solution produced by the method of claim 1.

3. The crude krill enzyme solution according to claim 2, which is obtained by squeezing and concentrating at a low temperature below the target enzyme inactivation temperature.

4. The crude krill enzyme solution according to claim 2 or 3, wherein the solid content is 30% or more.

5. A frozen product of the crude krill enzyme solution according to claim 2, 3 or 4.

6. An animal feed containing the raw material treated with the krill crude enzyme solution according to any one of claims 2, 3 and 4.

7. The animal feed according to claim 6, wherein the raw material to be treated with the krill crude enzyme solution is a vegetable protein raw material.

8. The animal feed according to claim 6, wherein the treatment with the krill crude enzyme solution is obtained by partially degrading the indigestible saccharide of the raw material with the krill crude enzyme solution.