WO2005002322A1

WO2005002322A1 - Method for cultivation of edible fungi by using garbage

Info

Publication number: WO2005002322A1
Application number: PCT/KR2004/001649
Authority: WO
Inventors: Kwang Rae Jeong; Dae Kyung Sung
Original assignee: Kwang Rae Jeong; Dae Kyung Sung
Priority date: 2003-07-04
Filing date: 2004-07-03
Publication date: 2005-01-13
Also published as: JP2007521002A; KR100431924B1

Abstract

This disclosed invention refers to the method of making the medium for cultivation of edible fungi, and also the method for cultivation of fungi utilizing the said medium. This method is characterized by adjusting pH to 5~7 by adding alkali during the water content control phase. This invention provides the benefit that food waste will be properly treated so that it will not damage the environment, and that the fungi farmer will benefit from additional income.

Description

METHOD FOR CULTIVATION OF EDIBLE FUNGI BY USING GARBAGE

Technical Field The present invention relates to a method of cultivating edible mushrooms using food waste.

Background Art Mushrooms are microorganisms that belong to the Basidiomycetes, and most of them except for those with toxicity are edible. Mushrooms are protein-rich foods having potential to replace meat in the future and thus have an effect of improving dietary life. Thus, mushrooms are expected to be a major product next to rice and other grains. Mushrooms were conventionally cultivated by forming holes in wood from, for example, hackberry, poplar, oak such as Quercus robur and other trees, and inoculating mushroom spawns in the holes (see Japanese Pat. Laid-open Publication Nos. 60-62918, 61-268109 and 62-186726). However, since this cultivation method in wood has disadvantages in that the wood is not reliably supplied, . and that a lot of manpower is required. To overcome these problems, mushroom cultivation has recently been achieved using sawdust as a substrate in bottles, boxes, bags, and the like (see Japanese Pat. Publication Nos. 46-40169, 48- 39540, 49-41076, 50-10222, 60-58017, 61-47122 and 62- 285730) . In addition, nation- or region-specific agricultural waste products have been used as media for mushroom cultivation. For example, sugar cane was used in India (see Sivaprakasam, K. and T.K. Kandaswamy, Waste materials for the cultivation of Pleurotus sajor-caju. Mushroom J. 101:178-179 (1981); Japanese Pat. Publication Nos. 47- 22768, 48-2179 and 61-21038) . Banana leaves were used in the Philippines (see Quimio, T.H., Physiological consideration of Auricularia spp. in tropical mushrooms; Biological nature and cultivation methods . Eds . S . T . Chang and T.H. Quimio. The Chinese University Press [1982] Hong Kong, pp. 397-408) .

Disclosure

Technical Problem Food waste includes surplus food that remains after food is ingested. In particular, food waste in Korea has a high content of water and salts. A portion of food waste is recycled in feedstuffs and compost due to its nutritional benefit, but most of it is buried in the ground. However, the current disposal of food waste has significant problems, as follows. In the case that food waste is buried in the ground, a large area of ground is required, and, with the passage of time, the soil and the underground water are contaminated by seepage from the buried food waste. Also, in the case that food waste is utilized as feed for animals, if food waste is derived from animals, it has the potential to negatively affect farm animals consuming the waste, for example, causing bovine spongiform encephalopathy. Further, in the case of being used for agricultural compost, food -waste is likely to increase salt concentration in the soil, thereby making continuous farming impossible. Thus, the use of food waste in mushroom cultivation may lead to effective disposal of food waste and economical mushroom cultivation. However, this strategy is also problematic because food waste contains a large quantity of water and useless impurities in addition to organic materials. This food waste is not suitable for mushroom growth. To cultivate edible mushrooms using food waste, many efforts have been made to overcome the above-mentioned problems. For example, Korean Pat. Registration No. 10- 0189644 (registered in January 18, 1999) discloses a method of disposing of food waste using edible mushrooms. The Korean patent states that a fiber source should be mixed with a food waste in an amount ranging from 1/2 to 2 times that of the volume of the food waste to reduce the water content of the food waste. However, this method is uneconomical because it requires a large amount of a fiber source. Also, this method has another disadvantage in that mushroom cultivation is uneconomical. Technical Solution It is therefore an object of the present invention to provide a method of cultivating edible mushrooms using a medium where the edible mushrooms grow well. In order to accomplish the above object, the present invention provides a method of cultivating edible mushrooms, comprising preparing a medium for cultivation of edible mushrooms by removing impurities from food waste, adding sawdust to the food waste to reduce water content of the food waste, and sterilizing and cooling the food waste; inoculating a mushroom spawn in the medium; and incubating the mushroom spawn. The water content control is achieved by adding a fiber source to the food waste in an amount of 0.04-0.07 parts by weight based on the dry weight of the food waste, adding sawdust to the food waste after 10-60 minutes in an amount of 0.30-0.35 parts by weight based on the dry weight of the food waste, and adding an alkali to the food waste to adjust the food waste to a pH of 5.0 to 7.0. The sterilization and cooling are achieved by sterilizing the food waste adjusted to a pH of 5.0 to 7.0 with the alkali and cooling the sterilized food waste to 18-20°C within 24 hours. The inoculation is achieved by inoculating the mushroom spawn in the medium maintained at 16-18°C after being cooled in an inoculation room. The incubation is achieved by incubating the mushroom spawn- inoculated medium in an incubation room at 19-21°C. Hereinafter, the present invention will be described in more detail. , Food waste used in the present invention is prepared by collecting surplus food remaining after being ingested in all places where humans inhabit regardless of form and type. Typically food waste is not suitable for the growth of mushrooms because it contains a lot of inorganic impurities. Thus, inorganic impurities inhibiting the growth of mushrooms are first removed from food waste. Food waste is then crushed into a suitable size, preferably ranging from a minimum of 1 mm to a¹ maximum of 10 cm. In this size range, mushroom mycelia have good access to food waste so that they easily use substrates. The crushed food waste typically contains 80-90% (w/w) or higher in Korea. Since this water content is not suitable for mushroom growth, the crushed food waste should be adjusted to have proper water content. To achieve economical growth of mushrooms, the water content of the medium ranges from 50-70% (w/w) , and preferably 60-65% (w/w) . However, water content control without pH adjustment may bring about uneconomical growth of mushrooms. Thus, the pH of food waste must be adjusted. Typically, collected food waste has a pH of 5.0 or lower, which is not suitable for mushroom growth. Thus, food waste should be adjusted to a pH of 5.0 to 7.0 for optimal growth of mushrooms. If a medium has a pH lower than 5.0, it is highly acidic so that mushroom growth therein is uneconomical. Also, if a medium has a pH greater than 7.0, it has low acidity, leading to uneconomical mushroom growth (see Test Example 1, below) . In this regard, in the present invention, food waste used as a medium for mushroom production are adjusted to an optimal pH of 5.0 to 7.0. In the present invention, an alkaline material is added to food waste to adjust the pH to 5.0 to 7.0. Preferred alkaline materials include calcium carbonate and lime. Also, the pH adjustment may be achieved by using commercially available products for agricultural, industrial or medical use and commercially available reagents containing positively charged ions. In addition, the crushed food waste is supplemented with a dried material to control its water content. _.In the present invention, a fiber source where mushrooms can grow is used as a water controller. Preferred fiber sources include dried by-products left after main products are harvested from annual or perennial plants, e.g., cotton, corn, sugar cane, rice, barley and bean, and dried agricultural by-products containing main products. The dried agricultural by-products, whether containing main products or not, are used singly or in combination of two or more. The fiber source is primarily used in an amount of 0.04-0.07 parts by weight based on the dry weight of the crushed food waste, thereby adjusting the water content to 65-75% (w/w). After the water content is adjusted as described above, sawdust is added to the crushed food waste in an amount of 0.30-0.35 parts by weight based on the' dry weight of the crushed food waste, thereby reducing the water content to 50-70% (w/w) . The sawdust is preferably that from deciduous broad- leaved trees, and more preferably that from evergreens. In the case of using sawdust from evergreens, evergreen sawdust is used after being fermented. The fiber source and the sawdust have different absorption rates for water. Thus, when the fiber source and the sawdust are simultaneously added to food waste, the residual water content is not constant, thereby causing problems upon sterilization. In this regard, the fiber source is added to food waste first to be allowed to sufficiently absorb water. After 10-60 minutes, the sawdust is additionally added. If the incubation time is shorter than 10 minutes, the water content is not controlled to be constant. If the incubation time exceeds 60 minutes, the fiber source absorbs excessive water, and this case is thus uneconomical . On the other hand, the dried material from annual or perennial plants and the sawdust, used to adjust the water content of the crushed food waste to a final 50-70% (w/w) in the present invention, are used in an amount listed in Table 1, below, per 1 kg of the crushed food waste.

TABLE 1

Using the medium having water content of 50-70% (w/w) and a pH of 5.0-7.0, prepared according to the present method, various mushrooms may be cultivated by methods commonly used in the art. Preferably, mushroom cultivation is carried out by the following methods . For mushroom cultivation, the medium with a water content and a pH value adjusted according to the method of the present invention is put into bottles or bags using a bottling or bagging machine commonly used in farming. After being put into bottles or bags, the medium is sterilized to provide optimal conditions for mushroom growth by methods commonly used in the art. Preferably, the medium sterilization is carried out after the bottles or bags containing the medium are put into a sterilizer by one of the following four methods . In a 'first method, the sterilizer is heated to 90- 99°C within one hour by using steam and maintained at the temperature for 3-6 hours. In a second method, the sterilizer is heated to 101- 110°C within one hour by using steam and maintained at the temperature for 3-6 hours. In a third method, the sterilizer is heated to 101- 110°C within one hour by using steam and maintained at the temperature for 1-2 hours, and is further heated to 121°C and maintained at the temperature for 1-2 hours. In a fourth method, the sterilizer is heated to 121°C by using steam and maintained at the temperature for 2-5 hours . The sterilized medium is cooled to an optimal temperature for inoculation of mushroom spawn, that is, 18-

20°C. The cooled medium is transferred to an inoculation room at 16-18°C and inoculated with a desired mushroom spawn (e.g., agaric, enoki, oyster and oak mushrooms). After mushroom spawn inoculation, the medium is transferred to an incubation room. The incubation room is preferably maintained at 19- 21°C under a humidity of less than 40%. The incubation period varies depending on the type of the inoculum. Preferably, the incubation is carried out for 25-35 days for agaric and enoki mushrooms, 30-45 days for oyster mushrooms, and 80-120 days for oak mushrooms.

Advantageous Effects As described hereinbefore, the present invention provides a method of cultivating edible mushrooms, which is capable of effectively disposing of surplus foods without environmental contamination. The present method also has excellent effects in increasing incomes of mushroom farmers, advancing environment-related industries and improving mushroom cultivation. A better understanding of the present invention may be obtained through the following examples which are set forth to illustrate, but are not to be construed as the limit of the present invention. It will be apparent to those skilled in the art that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Mode for Invention Hereinafter, the present invention will be described in detail according to the following Examples and Test Example .

EXAMPLES 1-3: Preparation of a medium for cultivation of edible mushrooms according to the present method

After impurities were removed from food waste collected at Yongin-si, Korea, the food waste was crushed into a size of 1 cm. To 1 kg (dry weight) of the crushed food waste, 0.07 kg (dry weight) of dried cotton plant byproducts remaining after cotton is harvested was added. After 40 minutes, 0.33 kg of poplar sawdust was added to the food waste. Then, calcium carbonate was added to the food waste mixed with the cotton by-products and the poplar sawdust to adjust the pH to 6 in Example 1, 5 in Example 2 and 7 in Example 3. Media for cultivation of edible mushrooms were prepared according to the procedure as described above.

EXAMPLE 4 : Cultivation of agaric mushroom using the media prepared in Examples 1 to 3

The media prepared in Examples 1 to 3 were individually put into bags using a generally used bagging machine. Then, the media were sterilized by heating in a sterilizer within one hour to 95°C by using steam and maintaining the temperature for at least four hours . The sterilized media were cooled to 18°C within 12 hours. Thereafter, 20 g of an agaric mushroom spawn was inoculated in the cooled media in an inoculation room at 18°C. After being inoculated, the mushroom spawn was incubated in an incubation room at 20°C under 35% humidity for 30 "days. Thereafter, the spawn was grown at 15°C under 85% humidity, a light intensity at which newspaper is readable and 1000 ppm C0₂ for 12 days according to a method commonly used for sprouting agaric mushroom.

EXAMPLE 5: Cultivation of enoki mushroom using the media prepared in Examples 1 to 3

The media prepared in Examples 1 to 3 were individually put into bags using a generally used bagging machine. Then, the media were sterilized by heating in a sterilizer to 95°C within one hour by using steam and maintaining the temperature for at least four hours. The sterilized media were cooled to 18°C within 12 hours. Thereafter, 20 g of an enoki mushroom spawn was inoculated in the cooled media in an inoculation room at 18°C. After being inoculated, the mushroom spawn was incubated in an incubation room at 20°C under 35% humidity for 30 days. Thereafter, the spawn was grown at 15°C under 85% humidity, a light intensity lower than that of Example 2 and 1000 ppm C0₂ for 12 days according to a method commonly used for sprouting enoki mushroom.

EXAMPLE 6: Cultivation of oyster mushroom using the media prepared in Examples 1 to 3

The media prepared in Examples 1 to 3 were individually put into bags using a generally used bagging machine. Then, the media were sterilized by heating in a sterilizer to 95°C within one hour by using steam and maintaining the temperature for at least four hours. The sterilized media were cooled to 18°C within 12 hours. Thereafter, 20 g of an oyster mushroom spawn was inoculated in the cooled media in an inoculation room at 18°C. After being inoculated, the mushroom spawn was incubated in an incubation room at 20°C under 35% humidity for 40 days. Thereafter, the spawn was grown at 15°C under

85% humidity, a light intensity at which newspaper is readable and 1000 ppm C0₂ for 12 days according to a method commonly used for sprouting oyster mushroom.

EXAMPLE 7 : Cultivation of oak mushroom using the media prepared in Examples 1 to 3 The media prepared in Examples 1 to 3 were individually put into bags using a generally used bagging machine. Then, the media were sterilized by heating in a sterilizer to 95°C within one hour by using steam and maintaining the temperature for at least four hours . The sterilized media were cooled to 18°C within 12 hours. Thereafter, 20 g of an oak mushroom spawn was inoculated in the cooled media in an inoculation room at

18°C. ^' After being inoculated, the mushroom spawn was incubated in an incubation room at 20°C under 35% humidity for 90 days. Thereafter, the spawn was grown at 15°C under 85% humidity, a light intensity at which newspaper is readable and 1000 ppm CO₂ for 12 days according to a method commonly used for sprouting oak mushroom.

TEST EXAMPLE 1: Amount of fruiting body formed by the procedure of Examples 2 to 5 according to pH

Production yields of mushrooms cultivated according to the procedure of Examples 4 to 7 according to the present invention were compared to those of mushrooms cultivated by the same procedure as in Examples 4 to 7 except that media have different pH values shown in Table 2, below, that is, pH 4.0 for Comparative Example 1 and pH 5.0 for Comparative Example 2. The results are given, in Table 2, below. The numerals listed in Table 2 represent the ratio of the weight of an inoculated spawn to the production yield of fruiting bodies . All tests were repeated ten times, and the results are expressed as the mean±S.E.

TABLE 2

Typically, mushroom cultivation is considered to be economic if fruiting body production is as many as five times for agaric and oyster mushrooms and ten times for oak and enoki mushrooms the mass of a spawn inoculated in a medium. As apparent in Table 2, in the present Examples using media of a pH of 5.0 to 7.0, fruiting bodies were found to be produced with economic yields.

Claims

1. A method of cultivating edible mushrooms, comprising: preparing a medium for cultivation of edible mushrooms by removing impurities from food waste, adding sawdust to the food waste to control water content of the food waste, and sterilizing and cooling the food waste; inoculating a mushroom spawn in the medium; and incubating the mushroom spawn, wherein the water content control is achieved by adding a fiber source to the food waste in an amount of 0.04-0.07 parts by weight based on dry weight of the food waste, adding sawdust to the food waste after 10-60 minutes in an amount of 0.30-0.35 parts by weight based on dry weight of the food waste, and adding an alkali to the food waste to adjust the food waste to a pH of 5.0 to 7.0; the sterilization and cooling are achieved by sterilizing the food waste adjusted to a pH of 5.0 to 7.0 with the alkali and cooling the sterilized food waste to 18-20°C within 24 hours; the inoculation is achieved by inoculating the mushroom spawn in the medium maintained at 16-18°C after being cooled in an inoculation room; and the incubation is achieved by incubating the mushroom spawn-inoculated medium in an incubation room at 19-21°C.

2. The method of cultivating an edible mushroom according to claim 1, wherein the edible mushrooms are selected from among agaric, enoki, oyster and oak mushrooms .