JPS59213367A - Preparation of feather meal - Google Patents

Abstract

PURPOSE:To prepare a deodorized meal product at a lot fuel cost with low evolution of smell during drying process, by hydrolyzing feathers of birds under pressure and heating, removing a solution from them, drying them. CONSTITUTION:Feathers of birds which are raw as they are or compressed and dehydrated are hydrolyzed under pressure and heating with an acidic, alkali or neutras aqueous solution or pure water adjusted to 4-11pH. They are compressed and separated or centrifuged so that the solution is removed, and they are dried to give feather meal. A large amount of fuel is required by a conventional procedure because the raw material is directly dried to evaporate water, excess decomposition of protein is promoted during drying to evolve bad smell, and the prepared product has bad smell because excess decomposition product remains in it. The demerit is eliminated by separating the excess decomposition product obtained by the hydrolysis as a solution from the feathers, followed by drying them.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for obtaining high-protein feed from bird feathers (hereinafter referred to as feathers).

Conventionally, feathers are rendered using pressure and heat to hydrolyze them and then dried as is to be used as feed (feather meal).However, (1) The moisture content of the raw material is high at about 70%, and it is directly evaporated and dried. It takes a lot of fuel to do so.

(2) Excessive decomposition of proteins occurs during the drying process, producing a large amount of foul odor, which causes pollution problems for the processing plant and local residents, and requires a large amount of expense for deodorizing treatment.

(3) The produced feather meal has a low added value as a feed because it has a foul odor due to residual overlyzed protein.

There are other problems.

To explain the present invention in detail, raw feather raw materials or compressed and dehydrated feather raw materials are hydrolyzed by heating and pressurization by adding a pH-adjusted aqueous solution as is or by adding a pH-adjusted aqueous solution, and then deliquified by pressing or centrifugation. By separating and removing low-molecular water-soluble components such as non-protein nitrogen, aqueous solution, and protein free water generated during hydrolysis in the pre-drying process, fuel consumption can be reduced and odor generation during the drying process can be reduced. This method is characterized by reducing odor and making the product meal odorless.

Raw feathers are a useful protein source containing about 70% water and 30% protein, but their digestibility is low and it is difficult to use them as feed, so they can be converted into low-molecular protein decomposition products by hydrolysis. Improves digestibility. However, in reality, hydrolysis cannot be uniform, and it is difficult to adjust the degree of decomposition, and decomposition persists even during the drying process, and overlyzed products become volatile substances and generate bad odors. Among these decomposed products, low-molecular substances that have undergone decomposition become easily soluble in water or in a liquid state.

The present invention focuses on this point, and performs odor-free drying by separating such overlyzed products as a solution at the end of hydrolysis and removing this odor source in the next drying process. Moreover, the final product is a uniform protein decomposition product and a high value-added feather meal. Furthermore, protein-bound water is produced as free water during hydrolysis, and by removing this by squeezing, the fuel required for drying can be significantly reduced.

Feather contains about 10% cystine as a protein-constituting amino acid, and when heated for a long time in the presence of a large amount of water during the pressure hydrolysis and drying process, the constituent proteins of feather are converted into -5-8-bond sites. , and a large amount of low-molecular-weight malodorous compounds are produced due to further decomposition.

The malodorous substances generated include acrolein, methyl mercaptan, hydrogen sulfide, diethylamine, and ammonia.

In the present invention, the aqueous solution added before pressure-heating hydrolysis is used as a solvent and a neutralizing agent to elute and neutralize low-molecular water-soluble protein decomposition products produced during pressure-heating hydrolysis, thereby eliminating these odor-causing substances. The generation of odorous substances during the drying process is suppressed by removing the aqueous solution by squeezing or centrifugation in the pre-drying process, and the added aqueous solution acts as a heat medium during hydrolysis, resulting in a uniform Hydrolysis becomes possible, and odor generation during decomposition can also be reduced. Furthermore, it is possible to prevent the generation of unpleasant odors in the feather meal product.

Normally, feathers collected from broiler factories are processed for 1 to 3 days before they are processed, and autolysis of the feathers is progressing.Especially in the summer, the freshness of the feathers is significantly reduced, and the protein is already denatured before processing. Odors are being generated. In such cases, pre-squeezing is performed before treatment to remove the odor-causing liquid, and water is added before pressure hydrolysis, using water as a solvent during hydrolysis to extract low-molecular-weight water-soluble proteins that are odor sources. The decomposition products are eluted and then squeezed. In addition, due to differences in the progress of digestion due to differences in raw materials and freshness, the pH of the hydrolyzed water before hydrolysis is adjusted to between 4 and 11 using acid or alkali to improve the elution of water-soluble protein products and the Improves the absorption rate and suppresses odor generation during squeezing. In the case of fresh feather raw material obtained by boiling or the like and having sufficient moisture, water may not be added.

To explain in detail the embodiments of the present invention, in the case of fresh and clean feathers made from blanched feathers etc. generated from broiler factories, etc., we can use them as they are, and we can use feathers whose freshness has decreased and digestion has progressed. Washing with water is performed as a pretreatment, followed by compression dehydration using a screw press to remove decomposition products. Next, add 20 to 200% fresh water or an acid or alkaline solution with a pH of 4 to 11 to the raw material feather, depending on the type of raw material.
Added according to the difference in freshness, pressure 2-5 kg/cJa,
Steam decomposition is carried out at a temperature of 130 to 160°C for 10 minutes to 2 hours. Next, the mixture is compressed and separated using a screw press to remove the solution, and then dried by a conventional method to obtain feather meal.

Patent applicant name: Fumio Nishiyo Takashi Yamamoto Masufumi Taguchi

Claims (1)

[Claims] Feathers of birds are used as they are or are compressed and dehydrated, and after hydrolysis by pressure heating by adding an acid, alkaline or neutral aqueous solution or clean water whose pH is adjusted to between 4 and 11, A method for producing feather meal, which comprises performing compression separation or centrifugation, removing a solution, and then drying.