DE102008044814B4 - Process for obtaining legume protein and use thereof - Google Patents

Abstract

Aquatic animal feed containing fatty legume protein obtainable by a process comprising the steps of: (i) extracting fatty legume protein from ground legume raw material, excluding soybean, with water at a substantially neutral pH; (ii) isolating fatty legume protein from the aqueous solution by heat coagulation substantially at a pH between the isoelectric point and pH 7 at a temperature of 70 ° C to 120 ° C for a maximum of 60 seconds; (iii) optionally holding the coagulated legume protein solution used in step (ii) at a temperature of from 70 ° C to 100 ° C for one minute to 60 minutes; (iv) separating the coagulated fatty legume protein and optionally washing with water; (v) drying the coagulum; and (vi) optionally concentrating soluble legume protein contained in the solution obtained in step (iv).

Description

The present invention relates to a water animal feed.

Aquatic animal feed, especially fish feed, are known both on a plant and animal basis. Here are, for example, fish food based on fish meal and / or fish oil to call. In the production of aquatic animal food is always trying to find the optimal price / performance ratio. Therefore, often residual materials such as juice and pomace, waste such as slaughterhouse waste, waste from fisheries or fish processing, or other protein sources, such as fermentation residues or sometimes even sewage sludge, are used.

When animal protein sources are used for general animal feed, a type of cannibalism is often tolerated by feeding products from one's own species. By way of example, ground chicken feathers, which are added to chicken feed, may be mentioned here. Freshwater fish, sea fish and shellfish are fed according to the state of the art in fish farms with feed based on fish meal and fish oil.

Animal proteins intended as animal feed generally have two major disadvantages in feeding to animals, especially fish. Firstly, the risk of transmission of species-specific diseases is extremely high, which is met with a prophylactic addition of antibiotics in high doses, which is expensive and in turn leads to follow-up problems. Here are both the growing number of resistant bacterial strains mentioned as well as the unwanted consumption of remnants of these antibiotics in the ingestion of these fish by humans, where resistance or chronic symptoms are also to be feared.

On the other hand, studies show that marine resources for human consumption with high-quality protein and fat would be used more effectively if the marine fish processed into fishmeal and fish oil were instead used directly for human consumption. It is also known that for the production of animal meat mass, and thus animal protein, a multiple in weight feed, especially proteins, is needed, for example, about 4 kg of fish feed needed for the production of 1 kg fish weight.

In a time of increasingly scarce resources for feeding humanity, this is a serious drawback. In addition, stocks of wild fish suitable for processing into fishmeal and fish oil are slowly but steadily declining, while fish stocks in aqua farms are still increasing exponentially. This is also reflected in the price of fishmeal, which has more than doubled since 1995, and continues to rise.

In order to reduce the problems of increasingly expensive, available in ever smaller quantities of fish meal as the main ingredient for aquafarming, according to the prior art, a part of fishmeal is replaced by soybeans, in various forms, raw and untreated, as untreated soybean meal or flour, as a purified and isolated protein product. However, vegetable protein materials, such as soy, in particular, often have problems with contamination by genetically modified organisms that are not desired by the consumer. In addition, these vegetable protein sources often do not show a sufficient nutritional value or a wrong nutritional profile with a high content of anti-nutritive substances. The latter is especially true for untreated vegetable raw materials, such as meal, flour or processed flours, especially soy.

Representative of many anti-nutritive substances, the trypsin inhibitors (TI) of soy products are mentioned. The anti-nutritive substances must be inactivated expensive and expensive in the manufacturing process, which is done according to the prior art in soy products by hydrothermal treatment. Due to the nonspecific and extremely strong heat effect on the whole soybean (high temperature in connection with long residence time and damp heat, which causes a high heat transfer), in turn, the important protein for animal nutrition is excessively damaged, whereby the digestibility of the soy protein product is lowered, which leads to economic losses and increased environmental impact through eutrophication.

In order to further reduce the TI content in the soy product, which is still too high after that, processes for the production of soy protein concentrates or isolates are used. Although these soy products are no longer adversely antinutritional, they are so expensive that they do not play a role in aquafarming. Come in addition their low availability, as these high purity proteins make up only a fraction of the mass of the original raw material.

Other anti-nutritive substances are alkaloids, as they occur in the potato protein. Either the availability of vegetable raw materials are severely limited by the presence of these alkaloids by the plant proteins can be used only in feed for sufficiently large and / or immune species. Or the anti-nutritive alkaloids must be expensive and expensive removed in the manufacturing process or at least reduced their content in proteinaceous feed.

Other anti-nutritive substances are the phytic acids, which cause the complexation of alkaline earth metals that a shortage of minerals may occur. In addition, sugar, which contains galactose and thereby leads to flatulence and diarrhea in humans as well as in animals and marine animals, which has economic disadvantages as well as increased environmental impact, since the fish are stimulated to excessive excretion of nitrogen in the form of ammonia.

However, fibers, in particular the insoluble, fiber-borne fibers, are also anti-nutritional in animal feed, since they stimulate digestion and lead to economic losses as the proportion of animal matter produced decreases in proportion to the consumption of feed.

A further disadvantage of the protein-containing aquatic animal feeds known from the prior art is that their fat content is proportionately low, in order to be able to substitute not only the fish meal but also the fish oil which is absolutely necessary in the feed. According to the state of the art, the production of fishmeal is linked to the production of fish oil, and from 30 to 35 tonnes of wild fish it is possible to produce about 6 to 7 tonnes of fish meal and 1.1 to 1.2 tonnes of fish oil.

Although feedstuffs prepared with great technical effort reduce losses due to loss of feed before it is absorbed by the animals, the disadvantage is that the additional steps of packaging (such as, for example, crosslinking of the proteins) significantly increase the price of the feedstuffs prepared feed in the usual way. In addition, a pure formulation of the dosage form does not solve the problems of the incorrect nutritional profile and the levels of anti-nutritional substances.

From the DD 155 133 A1 For example, a process is known in which a neutralized field bean protein isolate and field bean meal are heated in aqueous dispersion at 95 ° C for 60 minutes. Subsequently, the product is vacuum-dried.

The object of the present invention is to provide a water animal feed which overcomes the disadvantages of the prior art in which the levels of anti-nutritive substances compared to soybean significantly reduced. In addition, the proteins obtained should have a usable for the fish fat content to replace fish meal and fish oil at least partially or completely.

• (i) Extrahieren von fetthaltigem Leguminosenprotein aus gemahlenem Leguminosenrohstoff, mit Ausnahme von Soja, mit Wasser bei einem im wesentlichen neutralen pH-Wert;
• (ii) Isolieren von fetthaltigem Leguminosenprotein aus der wässrigen Lösung mittels Hitzekoagulation im Wesentlichen bei einem pH-Wert zwischen dem isoelektrischen Punkt und pH 7 bei einer Temperatur von 70°C bis 120°C für eine Dauer von maximal 60 Sekunden;
• (iii) optional Halten der in Schritt (ii) eingesetzten Lösung mit koaguliertem Leguminosenprotein bei einer Temperatur von 70°C bis 100°C für eine Minute bis 60 Minuten;
• (iv) Abtrennen des koagulierten fetthaltigen Leguminosenproteins und optional Waschen mit Wasser;
• (v) Trocknen des Koagulats; und
• (vi) optional Aufkonzentrieren von in der in Schritt (iv) erhaltenen Lösung enthaltenem löslichen Leguminosenprotein.

The object is achieved by a water animal feed containing fatty legume protein obtainable by a process comprising the steps:

• (i) extracting fatty legume protein from ground legume raw material, excluding soy, with water at a substantially neutral pH;
• (ii) isolating fatty legume protein from the aqueous solution by heat coagulation substantially at a pH between the isoelectric point and pH 7 at a temperature of 70 ° C to 120 ° C for a maximum of 60 seconds;
• (iii) optionally holding the coagulated legume protein solution used in step (ii) at a temperature of from 70 ° C to 100 ° C for one minute to 60 minutes;
• (iv) separating the coagulated fatty legume protein and optionally washing with water;
• (v) drying the coagulum; and
• (vi) optionally concentrating soluble legume protein contained in the solution obtained in step (iv).

The extraction takes place at a substantially neutral pH, so as not to destroy the fat contained in the legume raw material by acid or alkaline hydrolysis and to keep the fat bound to the protein. For the heat coagulation temperatures and residence times are selected, so that a high yield is possible with a very low, that is gentle coagulation temperature possible. This is achieved by the coagulation temperature and residence time given above the protein gently isolated and at the same time deactivating antrinutritive substances, in particular trypsin inhibitors, as far as possible. By the optional washing with water, the separation of water-soluble antinutritier substances, such as sugars, alkaloids, phytic acid, etc., even further improved.

The extraction is preferably carried out in step (i) at a pH of 6 to 8, preferably 6.5 to 7.5.

It is further preferable that the heat coagulation in step (ii) is carried out at a pH which is at least 1 pH point higher than the isoelectric point, preferably at a pH of 4 to 7, more preferably 5 to 7 ,

The legume raw material is particularly preferably selected from pea, bean, lupine or mixtures thereof.

Also particularly preferably, the fat-containing legume protein has a fat content of 5 to 20% by weight, preferably 10 to 20% by weight, particularly preferably 15 to 20% by weight, based on the total weight of the legume protein.

It is also preferred that the legume protein be in liquid or powder form.

It is also proposed that the aquatic animal feed be in the form of pellets, flakes, powder, cooked dough, agglomerates, compacts or granules.

The aquatic animals are preferably fish, crustaceans or shellfish, preferably shrimp, shrimp, crabs, crabs, clams, salmon trout, trout spawning, trout, carp, sturgeon, koi or salmon.

More preferably, the aquatic animal feed contains other ingredients selected from the group consisting of fish meal, fish oil, soy products such as meal, flour, grits, blood meal, vitamins, minerals and medicines.

Surprisingly, it has been found according to the invention that a method for obtaining legume protein can provide a protein which can be used in or as aquatic animal feed and the complete or at least partial replacement of animal constituents, such as fish meal and fish oil, and / or other adverse animal and / or herbal ingredients such as soy products. The legume protein is produced so that the anti-nutritive substances have a minimal proportion, in particular trypsin inhibitors, soluble oligosaccharides (galactose-containing sugars), phytic acid, alkaloids and fibers. Furthermore, the fat content of the legume proteins produced is so high that an at least partial replacement of fish oil is possible.

Essential to the process is that the coagulation in step (ii) is carried out at a pH between the isoelectric point and the neutral point of pH 7. As a result, no extreme pH values are used, so that the quality of the fat content in the protein is spared. The optimum pH for heat coagulation can preferably be determined by preliminary experiments in order to determine an optimum between maximum fat protection (pH 7, lowest possible temperature) and a maximum yield (pH = isoelectric point, highest possible temperature).

Further, it is preferred that after coagulation a residence time of one minute to 60 minutes at a temperature between 70 ° C and 100 ° C (boiling temperature) is maintained, which serves to ripen the coagulated protein flakes so that as little protein as possible is lost in the concentration step , As a result, the consistency and stability of the flakes formed is improved, which simplifies separation, for example in a decanter.

The process can easily be integrated into a total reprocessing process of the raw material, in which the other valuable substances of the legumes, primarily starch, fibers, oil and proteins usable in foods, which are economically of at least the same meaning as the proteins obtained in the process, to be obtained.

Thus fat-containing legume proteins are purposefully isolated from their vegetable raw materials.

Also, the principle possible partial replacement of fish oil by additional dosage of vegetable oils, such as rapeseed oil, can be omitted when using the produced proteins. This is advantageous because the addition of vegetable oils would make the formula of aquatic animal feed even more complex.

The produced legume proteins offer the advantage that the raw materials have a lower content of trypsin inhibitors compared to soybeans. Furthermore, these legume proteins can be isolated with gentle methods, the proteins contain a high proportion of fat or oil, which is suitable for the fish, and furthermore they have a good nutritional profile.

In addition, it should be noted that these legume proteins can be provided cheaply by the high quality use of the other constituents of legume, ie starch, fibers, oil / fat.

When using peas and beans, the other high-quality ingredients are first and foremost the starches whose economic importance even exceeds that of the protein. Furthermore, the fibers of the legumes should be mentioned, whose insoluble fiber components in the food sector are healthy fiber. Soluble fibers offer valuable functional properties in food technology, in particular high binding of water and oil / fat.

The process may thus be a sub-process of the whole process of processing the vegetable legume raw material, isolating the value components starch, protein, oil and fibers.

It has also surprisingly been found that the milled raw materials not only leave the fat in its composition at suitable gentle process conditions and no decomposition into fatty acid and glycerol occurs, but that the oils and fats are enriched almost exclusively in the protein, so that these, both absolutely and relatively, are higher in fat than the original starting materials. It must therefore be technically not separated for the use of legume proteins as aquatic animal feed the natural socialization of the protein with oil or fat. Rather, the high fat content in the protein can be optimized procedurally, so that these legume proteins can be produced gently and inexpensively and their quality remains high.

With the produced legume protein it is therefore possible, within the framework of a balanced diet of aquatic animals, to at least partially replace the nutritionally suboptimal component soya and the suboptimal components fishmeal and fish oil economically, priced and under the aspects of the global food crisis.

Furthermore, as another important criterion, it is important to maintain the functional properties of the proteins in order to simplify the formula for the aquatic animal feed manufacturer and to make the formula cheaper.

So that the aquatic animal feed does not disintegrate immediately into its individual components in water, a binder must be added. A typical property of proteins is this binding ability. If the legume protein is gently coagulated, this binding capacity is at least partially preserved and can replace some or all of common binders such as starch or chicken egg albumin.

The content of trypsin inhibitors in the legume protein produced according to the invention is at most 100 ppm, preferably at most 50 ppm. The alkaloid content when using lupins amounts to a maximum of 800 ppm, preferably 400 ppm, otherwise a maximum of 150 ppm. The proteins produced according to the invention furthermore have a phytic acid content of less than 1% by weight, a sugar content of less than 1% by weight and a content of fibers likewise of less than 1% by weight.

Further advantages and features of the subject invention will now be apparent from the following detailed description by way of example.

Example 1: Lupine protein

100 kg lupins with 30.3 kg protein content, are ground to a flour with a particle size of <250 microns. The lupine flour is suspended in 500 liters of tap water and stirred for about 20 minutes. The self-adjusting pH is 6.7. Thereafter, the suspension is centrifuged, the supernatant poured off and stored. The centrifuged solid is resuspended in 300 L of water and an additional 20 minutes stirred without changing the pH. Thereafter, the suspension is also centrifuged and the two supernatants are combined. They contain the dissolved fatty lupine protein. The centrifuged solid consists essentially of the lupine fibers with residues of fat and protein. This pulp can be used as animal feed without further treatment.

The protein-containing aqueous matrix is then adjusted to pH 5.5 and heated to 80 ° C. The protein coagulates and precipitates. After centrifugation, the protein is resuspended in the same amount of water, stirred and then centrifuged. After drying, 25.9 kg lupine protein with 91.2% TS, 75.6% protein content in TS and 12.0% fat in TS. The yield is 85.5%.

Example 2:

100 kg peas with 25.6 kg protein content and 3.0% fat are ground to a flour with a grain size of <250 microns. The pea flour is suspended in 500 liters of tap water and stirred for about 20 minutes. The self-adjusting pH is 6.2. Thereafter, the suspension is centrifuged, the supernatant poured off and stored. The centrifuged solid is resuspended in 250 L of water and stirred for a further 20 minutes without changing the pH. Thereafter, the suspension is also centrifuged and the two supernatants are combined. They contain the dissolved fatty pea protein. The centrifuged solid consists of pea starch and pea fibers with remnants of protein. With the plants of a starch factory, the starch and fibers can be separated and purified to final products and dried in further process steps.

The proteinaceous solution is now adjusted to pH 5.2 and heated to 110 ° C for 20 seconds. The protein coagulates and precipitates and is kept suspended for 10 minutes at 90 ° C. After drying, 31.4 kg pea protein with 10.2% moisture, 74.4% protein content in TS and 9.6% fat in TS. The yield is 81.9%. 90.2% of pea fat is in the protein.

Example 3: Fat extraction from pea protein

5 g of fatty pea protein with a fat content of 9.6% are mixed in a Soxhlet apparatus with 100 ml of petroleum ether and extracted under reflux for 2 hours.

After removal of the solvent left as residue 0.454 g of fat. This means that 94.6% of the fat from the pea protein is not chemically bound, but merely adsorbed and surprisingly can be obtained by the method according to the invention together with the protein. Only 5.4% of the fat of the peas appear, e.g. B. in the form of lipoproteins, chemically bound to the protein.

Example 4: Water binding

10.0 g of bean protein are suspended in 90 mL of distilled water and stirred for 30 minutes. The suspension is then centrifuged for 10 minutes at 3,500 rpm (about 3,000 g). The supernatant is poured off carefully and the supernatant water removed with a disposable pipette. The weigher gives 51.4 g. The water binding capacity of the bean protein is 1: 4,14, d. H. 10 g of bean protein can bind 41.4 g of water. By this feature z. As cold water soluble starch be proportionately saved in the fish feed formulation.

Example 5: Nutrition facts

The following table shows the nutritional values of pea protein, soybean meal and fishmeal. It becomes clear that the important content of cysteine and lysine corresponds to that of fishmeal. Overall, the amino acid supply of pea protein is better than soy. Erbsenproein soybean meal fishmeal Energy content [MJ / kg] 15.6 14.8 18.5 Protein [%] 72.4 42.5 70.7 Fat [%] 8.9 1.4 9.0 Cysteine [%] 0.8 0.7 0.6 Threonine [%] 3.0 1.7 3.1 Lysine [%] 6.0 2.7 5.4

Example 6:

A typical fish food and nutrient composition may look like this: Ingredients [g / 100 g TS] Compared fish food without pea protein Fish food with 30% fish meal substitute with pea protein fishmeal 55.66 38.96 pea protein 0.00 14,88 fish oil 5.67 5.83 wheat starch 29,66 31.32 Vitamin Premix ¹ 2.00 2.00 Minalia premix ² 2.00 2.00 wheat gluten 2.00 2.00 carboxymethylcellulose 3.00 3.00 Nutrient composition [% TS] Crude protein, RP 42,25 42.13 Crude fat, RF 11.10 10.43 Raw ash, RA 12.87 10.48 Raw fiber, RF 0.33 0.41 NFE ³ 33.78 36.96 Gross energy ⁴ 20.46 20.73 P / E ⁵ 2.06 2.03 ¹ vitamin premix (IU or g / kg): retinol palmitate 500,000 IU; Thiamine 5; Riboflavin 5; Niacin 25; Folic acid 1; Pyrodoxin 5; Cyanocobalamin 5; Ascorbic acid 10; Cholecalciferol 50000 IU; α-tocopherol 2.5; Menadione 2; Inositol 25; Pantothenic acid 10; Choline chloride 100; Biotin 0.25
² mineral premix (g / kg) CaCO ₃ 336; KH ₂ PO ₄ 502; MgSO ₄ .7H ₂ O 162; NaCl 49.8; Fe (II) gluconate 10.9; MnSO ₄ .H ₂ O 3,12; ZnSO ₄ .7H ₂ O 4.67; CuSO ₄ .5H ₂ O 0.62; KI 0.16; CoCl ₂ .6H ₂ O 0.08; NH ₄ molybdate 0.06; Na ₂ SeO ₃ 0.02
³ NFE = Nitrogen-free Extractants = 100 - (RP + RF + RA + RF)
⁴ Calculated by: crude protein = 23.9 MJ / kg, crude fat = 39.8 MJ / kg, NFE = 17.6 MJ / kg
⁵ protein / energy ratio: g protein / MJ gross energy

Thus, the following results in the growth of z. B. Cichlids achieve: Compared fish food without pea protein Fish food with 30% fish meal substitute with pea protein Initial weight [g] 2.24 2.23 Final weight [g] 23.63 21.32 SWR ¹ % 4.21 4.03 FQ ² 0.90 0.98 PER ³ 2.62 2.43 ¹ Specific growth rate SWR; SWR = [(ln final weight [g] - ln initial weight [g]) / duration of experiment [d]] · 100
² feed quotient FQ; FQ = amount of feed [g] / increment [g]
³ protein efficiency ratio PER = increase [g] / protein intake [g]
⁴ obesity factor K = (body mass [g] / body length ³ [cm]) · 100

The specific growth rate shows that with a protein content of 30% from the pea isolate, there are no significant differences to the comparative feed with 100% fish meal.

At higher levels of pea protein (up to 60%), the growth performance is reduced independently of the further pea protein amount constant by max. 12%. Therefore, anti-nutritive ingredients such. As tannins, protease inhibitors or lectins that may not be inactivated or isolated in the protein isolation process of the peas, and a reduction in the palatability of the feed with increasing levels of vegetable protein carriers are excluded, otherwise the growth performance would decrease proportionally with higher pea protein levels.

The generally very high growth performance with extremely effective feed utilization (FQ = 0.9 - 1.06, PER = 2.25 - 2.62) proves the outstanding suitability of the pea protein isolate as a vegetable protein carrier in the crayfish diet.

Claims (8)

Aquatic animal feed containing fatty legume protein obtainable by a process comprising the steps: (i) extracting fatty legume protein from ground legume raw material, excluding soy, with water at a substantially neutral pH; (ii) isolating fatty legume protein from the aqueous solution by heat coagulation substantially at a pH between the isoelectric point and pH 7 at a temperature of 70 ° C to 120 ° C for a maximum of 60 seconds; (iii) optionally holding the coagulated legume protein solution used in step (ii) at a temperature of from 70 ° C to 100 ° C for one minute to 60 minutes; (iv) separating the coagulated fatty legume protein and optionally washing with water; (v) drying the coagulum; and (vi) optionally concentrating soluble legume protein contained in the solution obtained in step (iv). Aquatic animal feed according to claim 1, wherein the extraction in step (i) takes place at a pH of 6 to 8, preferably 6.5 to 7.5. The aquatic animal feed according to claim 1 or 2, wherein the heat coagulation in step (ii) is carried out at a pH which is at least 1 pH point higher than the isoelectric point, preferably at a pH of 4 to 7, more preferably 5 to 7. The aquatic animal feed according to any one of claims 1 to 3, wherein the legume raw material is selected from pea, bean, lupine or mixtures thereof. Aquatic animal feed according to one of the preceding claims, wherein the fatty legume protein has a fat content of 5 to 20 weight percent, preferably 10 to 20 weight percent, particularly preferably 15 to 20 weight percent, based on the total weight of the legume protein. Aquatic animal feed according to any one of the preceding claims, wherein the legume protein is in liquid or powder form. The aquatic animal feed according to claim 6, wherein the aquatic animal feed is in the form of pellets, flakes, powder, cooked dough, agglomerates, pellets or granules. The aquatic animal feed of any one of the preceding claims, wherein it contains other ingredients selected from the group consisting of fish meal, fish oil, soy products such as shot, flour, grits, blood meal, vitamins, minerals and medicines.