JPH03290156A - Production of dry pellet for fish culture - Google Patents

Abstract

PURPOSE:To obtain dry pellets for fish culture with a high content of fats and oils and hardly any disintegration without separation of an oil by blending a raw material with polyoxyethylene glycerol ester of a fatty acid, etc., in a specific proportion and granulating the resultant blend in an extruder. CONSTITUTION:Dry pellets for fish culture, obtained by adding one or more of polyoxyethylene glycerol esters of fatty acids or further sucrose esters, (polyoxyethylene) sorbitan esters and (poly)glycerol esters of fatty acids and lecithin in an amount of 0.1-10wt.% based on fats and oils in a raw material thereto and granulating the resultant mixture in a single or twin-screw extruder and having 10-50% content of the fats and oils.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a method for producing dry pellets as fish feed.

[Conventional technology]

Conventional saltwater fish such as yellowtail, sea bream, salmon, flounder, and striped horse mackerel, carp, trout, sweetfish, eel, yamame, tilavia,
Fish feed for freshwater fish such as catfish, and crustaceans such as prawns and prawns, includes raw bait such as sardines, horse mackerel, and mackerel, moist pellets made by granulating a mixture of raw bait and matshu, or fish meal, gluten, and starch. There are dry pellets granulated using an extruder.

[Problem to be solved by the invention]

Live bait has the disadvantage of becoming a source of pollution for fishing grounds if it is minced and cast, and moist pellets are an excellent feed, but they require large-scale equipment such as freezing facilities and granulators because they are granulated after mixing raw bait and matshu. There is a problem that manufacturing is complicated. As fish feed, it is known that the addition of oil needles is effective in increasing fish weight and improving feed efficiency, so dry pellets with a high oil content are desired, but conventional dry pellets for fish farming In order to ensure strength or prevent oil separation, the oil content was kept low. Therefore, it is necessary to increase the fat and oil content by some method when casting bait. In order to add oil and fat, methods such as making dry pellets porous and soaking them in oil or spraying oil before casting are used, but these methods are time-consuming and cause the dry pellets to turn into powder. There are disadvantages such as oil separating and floating on the water surface when bait is cast. In addition, dry pellets with a high oil and fat content that are currently being proposed for yellowtail are generally expanded and granulated using an extruder using a large amount of starch to ensure a high oil and fat content. If the amount is further increased, the starch will not expand sufficiently and the temperature of the extruder barrel will have to be raised even higher, which may lead to the destruction of nutrients. In addition, when the oil content is increased, the oil exhibits the effect of impurities and reduces strength, and the oil and fat content migrates in the pellets, eventually causing oil separation on the pellet surface.

[Means to solve the problem]

This invention was made by focusing on such conventional problems, and as a result of intensive research on the method of manufacturing dry pellets for fish farming, the inventor found that the oil content can be adjusted using a single or double screw extruder. When producing dry pellets for fish farming containing 10 to 50% (wt%), polyoxyethylene glycerin fatty acid ester alone, polyoxyethylene glycerin fatty acid ester and sucrose fatty acid ester, polyoxyethylene sorbitan fatty acid ester, sorbitan fatty acid ester By adding at least one selected from ester, (poly)glycerin fatty acid ester, and lecithin to the fat and oil in an amount of 0.1 to 10% (wt%), dry pellets for fish farming with a high fat and oil content can be obtained. The present invention was achieved by discovering that it can be manufactured. (Requirements constituting the means) The target fish species of the dry pellets for fish farming of the present invention are saltwater fish such as yellowtail, sea bream, salmon, flounder, and striped horse mackerel; carp;
Examples include freshwater fish such as trout, sweetfish, eel, yamame, tilabia, and catfish, and crustaceans such as prawns and prawns. Raw materials for pellets include fish meal, meat meal, skim milk powder, proteins such as krill meal and squid meal, oil cake, grains, starch, and plant materials such as gluten meal, and vitamin B1.
．． B2. B6. B12. Vitamins such as C, minerals such as phosphorus, calcium, potassium, and sodium, oils and fats such as cod liver oil, pollock cod liver oil, sardine oil, beef tallow, pig intestine, soybean oil, cottonseed oil, and their hydrogenated oils. These raw materials can be mixed arbitrarily depending on the target fish species, body length, and season, but in general, crude protein of 40~
Contains 50% starch, 10-25% starch, and several % vitamins and minerals. The polyoxyethylene glycerin fatty acid ester used in the present invention is obtained by adding ethylene oxide to the glycerin fatty acid ester. The glycerin fatty acid ester that is the starting material is a monoester of glycerin and fatty acid, and fatty acids include those having 8 to 22 carbon atoms, but preferably 12 to 22 carbon atoms.
18 is good. These may be saturated or unsaturated. The number of moles of ethylene oxide added may range from 1 to 100, preferably from 5 to 30. The fatty acid constituting the sucrose fatty acid ester used in the present invention includes those having 8 to 22 carbon atoms, preferably those having 12 to 18 carbon atoms. These may be saturated or unsaturated. The polyoxyethylene sorbitan fatty acid ester used in the present invention is obtained by adding ethylene oxide to a sorbitan fatty acid ester. Polyols include not only sorbitan but also sorbitol dehydrated products such as sorbite. Examples of the fatty acid include those having 8 to 22 carbon atoms, preferably those having 12 to 18 carbon atoms. These may be saturated or unsaturated. The degree of esterification of sorbitan and fatty acid is 1 to 4. The number of moles of ethylene oxide added may range from 1 to 100, but preferably from 5 to 30. The sorbitan fatty acid ester used in the present invention can be the polyoxysorbitan fatty acid ester before addition of ethylene oxide. The (poly)glycerin fatty acid ester used in the present invention is an ester of a fatty acid and glycerin or polyglycerin, and a derivative thereof. For example, glycerin fatty acid ester, glycerin acetate fatty acid ester, glycerin lactic acid fatty acid ester, glycerin citric acid fatty acid ester,
Glycerin succinic acid fatty acid ester, glycerin diacetyl tartaric acid fatty acid ester, glycerin acetic acid ester,
Polyglycerol fatty acid esters and polyglycerol condensed lysyl phosphates can be used. Examples of fatty acids include those having 8 to 22 carbon atoms and condensed lysyl ic acid. Lecithin used in the present invention is a phospholipid obtained from soybeans, egg yolks, etc., and is a mixture of phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, etc. Furthermore, highly purified lecithin, enzymatically decomposed lecithin, and modified lecithin obtained by fractionating these can also be used. In the present invention, polyoxyethylene glycerin fatty acid ester alone, polyoxyethylene glycerin fatty acid ester and sucrose fatty acid ester, polyoxyethylene sorbicun fatty acid ester, sorbitan fatty acid ester,
At least one or more selected from (poly)glycerin fatty acid ester and lecithin are used in combination, but the amount added is 0 to the oil needle contained in the pellet.
．． It is 1 to 10% (wt%). If the amount added is less than 0.1%, oil separation cannot be prevented or strength cannot be increased, and if it exceeds 10%, it is economically disadvantageous. Methods for adding the above-mentioned components include methods such as mixing with raw material powder, dissolving or dispersing in water or oil, but are not particularly limited. The oil content is preferably 10 to 50 ffi% in the dry pellets; if it is less than 10% by weight, the oil or fat component is too small and has little utility value; if it exceeds 50% by weight, the oil or fat component will increase and nutrients such as protein will decrease. , it is not effective enough as feed.

[Function] The dry pellets produced by the present invention have a high oil and fat content, so they have high aquaculture efficiency, and they hardly separate from oil during storage.
When bait is cast, oil does not float on the water surface and the pellets are made into hard pellets that will not disintegrate.

【Example】

1-7 and Comparison 1-2 Dry pellets were manufactured using the recipe shown in Table 1.2 and the following method. Parts in the table are based on weight. Extruder: Alphalyzer α-70 type twin-screw extruder (manufactured by Suehiro Iron Works) Barrel temperature = 130°C Screw rotation speed: 12 Orpm The raw powder was supplied to the extruder using a screw feeder. Water was supplied to the barrel by a metering pump. Liquid oil was supplied to the barrel with a metering pump. The solid capacity was used by mixing it with the raw material powder. The polyoxyethylene glycerin fatty acid ester used in the examples was used after being dissolved or dispersed in water. Sucrose fatty acid ester is mixed with raw material powder, polyoxysorbicun fatty acid ester and sorbitan fatty acid ester are dissolved in water, and (poly)glycerin fatty acid ester is mixed with raw material powder in the case of powder, and liquid or paste is added. In the case of such a substance, it was dissolved in water and supplied. Thereafter, the pellets granulated with an extruder were dried and used as test samples. Next, the pellets manufactured above were evaluated using the following evaluation items.
The results are shown in Table 3. Granulation property: Evaluation of pellets by visual and tactile sensation Oil separation rate: Pellets were sandwiched between two filter papers, and a load 20 times the weight of the pellets (by weight) was placed on top of the pellets. It was left at 30°C for 24 hours. Determine the weight of the oil adsorbed on the filter paper,
The oil separation rate was calculated by calculating the oil separation amount per 1 g of oil and fat added during pellet production. Oil separation during bait casting: Pellets were thrown into artificial seawater and observed whether oil floated on the water surface. Strength: The breaking strength was measured using a rheometer manufactured by Fudo Kogyo Co., Ltd. and a wedge-embossed rod as an adapter. From Table 3, polyoxyethylene glycerin fatty acid ester alone, polyoxyethylene glycerin fatty acid ester and sucrose fatty acid ester, polyoxyethylene sorbitan fatty acid ester, sorbitan fatty acid ester,
It can be seen that dry pellets with a low oil separation rate and sufficient strength can be obtained by using at least one of (poly)glycerin fatty acid ester and lecithin together. (Left below) JP-A-3 290156 (5) 2 Comparison 13

【Effect of the invention】

Since the dry pellet according to the present invention has a high fat and oil content,
There is no need to absorb oil and fat before casting, there is almost no oil separation during storage or during feeding, and the product is hard and less likely to disintegrate. It is also possible to speed up or slow down the settling speed of the dry pellet.

Claims (1)

[Scope of Claims] 1. In the case of producing dry pellets for fish farming with an oil content of 10 to 50% (wt%) using a single-screw or twin-screw extruder, (a) polyoxyethylene glycerin fatty acid ester or (b) polyoxyethylene glycerin fatty acid ester, and at least one or more selected from sucrose fatty acid ester, polyoxyethylene sorbitan fatty acid ester, sorbitan fatty acid ester, (poly)glycerin fatty acid ester, and lecithin to fats and oils. A method for producing dry pellets for fish farming, characterized by adding 0.1 to 10% (wt%) of 2. Dry pellets for fish farming produced by the production method according to claim 1.