Method and device for converting waste food into resource

Abstract

To provide means for converting edible waste into a resource simply on site.SOLUTION: There are provided a method and a device for converting a waste food into a resource. In converting the waste food into the resource such as feed for livestock etc., the waste food composed of a single component is prepared to which a required additive is then added followed by mixing. The resultant is then extruded into a polyvalent anion compound mixture tank which contains a polyvalent anion compound aqueous solution having an adjusted predetermined concentration range. In addition, the resultant passes through a curing liquid tank which contains a curing agent aqueous solution having an adjusted predetermined concentration range. The resultant passes through a filtration and water-washing tank and, as necessary, a drying step so as to be surface-coated.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method and an apparatus for recycling waste food, and more particularly to a method and an apparatus for recycling waste food that contains a large amount of moisture. [Background technology]

[0002] A typical example of recycling food waste is feed production. Conventionally, a known method for this type of production involves mixing solid and liquid waste food, fermenting it for a long period of time with fermenting bacteria, dehydrating it, sterilizing it, and drying it to produce feed (see, for example, Patent Document 1).

[0003] Also, a method has been proposed in which kitchen waste is crushed, dehydrated, sterilized and fermented, nutrients are added, blended, pelletized, and dried (for example, Patent Document 2).

[0004] Furthermore, a method is known for producing feed with a uniform composition by separating and preparing waste food as raw materials into multiple categories, blending predetermined ingredients into the raw material, and then subjecting the raw material to heat treatment, heat sterilization treatment, and degreasing treatment to set the moisture content and animal and plant content to a certain level or less (e.g., Patent Document 3).

[0005] In addition, although waste food containing water contains sufficient nutrients, it is currently being discarded wastefully because there is no economical way to recycle it. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2002-11432 A [Patent Document 2] JP 2003-34588 A [Patent Document 3] JP 2005-333863 Summary of the Invention [Problem to be solved by the invention]

[0007] However, in Patent Document 1, the fermentation and dehydration processes required to turn food waste into feed take a long time, and sterilization and drying are also required, which means that turning food waste into feed has disadvantages such as long installation and production times, which are a huge economic burden.

[0008] Furthermore, in Patent Document 2, various processes such as separation, crushing, dehydration, sterilization and fermentation, blending of nutrients, pelleting, drying, etc. are required, and furthermore, fermentation takes as long as three hours, and since the material is made through the blending and pelleting processes, there are issues such as a large economic burden in terms of equipment costs and labor costs, and a long production time.

[0009] Furthermore, in Patent Document 3, waste food mixed with a predetermined ingredient blend is supplied at the stages of collecting waste food and producing feed, and is then dried, heat sterilized, and degreased to produce feed.Although the feed ingredients are homogenized, there are many complicated steps involved in measuring and adding each ingredient, and there are many drawbacks in terms of production efficiency when collecting waste food.

[0010] As mentioned above, many attempts have been made to turn waste food into, for example, animal feed, but all of these require special processing steps such as fermentation, dehydration, addition of missing nutrients, and pelleting, which require a long time.

[0011] The present invention aims to provide an economical method and device for recycling food waste by incorporating a chemical method into the device. [Means for solving the problem]

[0012] The present inventors have conducted extensive research to solve the above problems and have arrived at the present invention, which relates to a method and apparatus for recycling waste food, which comprises waste food, a polyvalent anionic compound, a hardening agent, a thickener, fermentation bacteria and their feed, a coating reinforcement material, and related equipment. [Effects of the Invention]

[0013] The method and device for recycling waste food of the present invention have the following advantages: Because it is an economical recycling device incorporating chemical techniques, generated waste food can be recycled into feed, fertilizer, and other resources on the spot without being mixed with other waste food, eliminating the need for complicated processes such as analyzing nutrients and adding missing nutrients as in conventional technologies. In addition, the polyvalent anion compound and hardening agent of the present invention are approved as food additives, which means that they are safe for use as feed, for example. DETAILED DESCRIPTION OF THE INVENTION

[0014] The method and apparatus for recycling waste food of the present invention are composed of an extruder (hereinafter referred to as (1)) that has the function of mixing waste food and, if necessary, a thickener, a polyvalent anion compound mixing tank (hereinafter referred to as (2)) that has a filtering function and contains an aqueous solution of a polyvalent anion compound, a hardening tank (hereinafter referred to as (3)) that has a filtering function and contains an aqueous solution of a hardener and, if necessary, a coating reinforcement material, a water washing tank (hereinafter referred to as (4)) that has a filtering function and contains water, and, if necessary, a dryer (hereinafter referred to as (5)).

[0015] The above (1) includes a noodle making machine (for example, the home noodle maker HR2365 (manufactured by Philips)).

[0016] The above (2) can be a metal or resin container containing a mesh filter such as a wire mesh and an aqueous solution of a polyvalent anion compound, which will be described later.

[0017] The above (3) can be a metal or resin container containing a mesh filter such as a wire mesh and an aqueous solution of the hardener, which will be described later.

[0018] (4) can be a metal or plastic container filled with water.

[0019] The above (5) may be a normal electric dryer or sun dryer, and is not particularly limited.

[0020] Waste food is mixed with thickeners, fermentation bacteria and their feed in (1) as needed, extruded, and sent to (2). After being filtered through a wire mesh to remove unnecessary aqueous solutions of polyvalent anion compounds, it is cut into pellets in the liquid in (3), washed with water, filtered, and made into products in (4), or dried as needed and then made into products.

[0021] The waste food, polyvalent anionic compound, crosslinking agent, thickener, fermentation bacteria and their feed, and coating reinforcing material in the present invention will be described below.

[0022] In the present invention, the discarded food contains liquid, and specific examples thereof include tofu, milk, cake, soybean pulp, and alcohol-derived dregs (e.g., sake lees, beer lees, wine lees, etc.). In order to prevent spoilage of the feed produced from the discarded food, it is preferable to add a necessary amount of an antiseptic agent containing alcohol, such as sake lees or wine lees.

[0023] Examples of polyvalent anion compounds in the present invention include aqueous solutions of alginates (e.g., sodium alginate and potassium alginate) and aqueous dispersions of oxidized cellulose nanofibers, of which alginates are preferred, and of alginates, sodium alginate is particularly preferred.

[0024] The polyvalent anion compound is used in the form of an aqueous solution, the concentration of which (by weight) is usually 0.3 to 5%, preferably 0.5 to 3%.

[0025] Examples of crosslinking agents in the present invention include aqueous solutions of polyvalent inorganic salts (e.g., aluminum sulfate, magnesium chloride, calcium chloride, etc.) and hydroxy acids (e.g., gluconic acid, tartaric acid, succinic acid, citric acid, etc.). Among these crosslinking agents, aluminum sulfate and calcium chloride are preferred as polyvalent inorganic salts, and tartaric acid and citric acid are preferred as gluconic acids. Furthermore, calcium chloride and citric acid are more preferred.

[0026] The crosslinking agent is dissolved in water and used as a hardening liquid. The concentration (by weight) of the aqueous solution is usually 0.3% to 50%, preferably 0.4% to 20%. If necessary, the required amount of sugars (e.g., maltose, glucose, etc.), edible film, or paper powder may be added or dissolved as a coating reinforcing material.

[0027] The thickener of the present invention can be derived from starch (e.g., wheat flour, rice flour, etc.) or cellulose (e.g., KC Flock (Nippon Paper Industries, Ltd., etc.)). The thickener is used in the required amount when the waste food has a high moisture content and it is difficult to maintain its shape when left to stand.

[0028] The fermentation bacteria and their feed of the present invention will be described. As the fermentation bacteria, bacteria of the genus Bacteroides and lactic acid bacteria can be used, and as the feed for bacteria of the genus Bacteroides, sodium alginate can be used. [Example]

[0029] Examples of the present invention will be described below, but the present invention is not limited to these examples. [Example]

[0030] As the above (1), a home noodle maker HR2365 (Philips) was used, as the above (2), a 3-liter open stainless steel container containing 2 kg of 1 wt% sodium alginate aqueous solution was used, as the above (3), a 3-liter open stainless steel container containing 2 kg of 10 wt% calcium chloride or 20 wt% citric acid was used, and as the above (4), a 3-liter open stainless steel container containing 2 kg of water was used. As the above (2) and (3), wire meshes (2-1) and (3-1) with 1 mm spacing were provided. As the above (5), a constant temperature dryer SA312 (Masuda Rika Kogyo) was used. [Example]

[0031] 50 g of discarded commercially available soybean pulp and 50 g of commercially available wheat flour (flour soft wheat flour (Nissin Manufacturing Co., Ltd.)) were placed in (1) described in Example 1, extruded into the liquid in (2) described in Example 1, and cut into pellets. After that, the pellets were scooped up in (2-1), and excess liquid was shaken off. The pellets were transferred to (3) described in Example 1 containing 10 wt% calcium chloride and left for 15 minutes. Thereafter, the pellets were scooped up in (3-1), and excess liquid was shaken off. The contents were immersed in (4) and washed with water three times, and then dried in (5) at 80°C for 20 minutes to obtain a food resource. [Example]

[0032] The food resource was obtained in the same manner as in Example 2, except that 80 g of discarded wine lees was used as (1) above, 20 g of the wheat flour described in Example 1, and citric acid was used as (3). [Example]

[0033] The food resource was obtained in the same manner as in Example 2, except that 100 g of discarded sake lees was used in (1) above, calcium chloride was used in (3), and drying was performed in the sun. [Industrial Applicability]

[0034] The method and apparatus for recycling waste food of the present invention can recycle waste food that has conventionally been discarded at low cost, and is therefore extremely useful for utilizing it as a food resource, for example, as feed for livestock.

Claims

1. A method and device for recycling food waste, comprising a mixing and extrusion device for food waste and polyvalent anion compounds, a polyvalent anion compound mixing tank, a hardening liquid tank, a filtration and washing tank, and, if necessary, a drying process.

2. 2. The method and apparatus for recycling waste food according to claim 1, wherein the polyvalent anion compound is sodium alginate and the cross-linking agent is calcium chloride.

3. 3. The method and apparatus for recycling waste food according to claim 1, wherein the waste food is dregs derived from alcohol.

4. 4. The method and apparatus for recycling waste food according to any one of claims 1 to 3, wherein the recycled waste food is surface-coated waste food.

5. 5. The method and apparatus for recycling waste food according to any one of claims 1 to 4, wherein the waste food is recycled as feed.