JPH0427903B2 - - Google Patents

Description

[Detailed description of the invention]

"Industrial Application Field" The present invention relates to a novel oxygen absorber for roasted coffee. For more details, please refer to the inside of roasted coffee packaging.
O ₂ and CO ₂ continuously generated from roasted coffee
Regarding the oxygen scavenger, which has the ability to efficiently remove various gases, it absorbs the aroma of roasted coffee in the package by blending metal chelate resin, and also denatures and
The purpose is to maintain the quality of roasted coffee without decomposing and impairing the aroma or generating off-flavors, and to prevent containers or packaging bags from swelling or bursting due to generated _CO2 . ``Prior art'' Regarding oxygen absorbers for coffee, JP-A-56-
Publication No. 130222, ``From granular material (A) in which granular alkaline earth metal hydroxide is impregnated with water or humidity control liquid and its surface is coated with a fine filler, iron powder (B), and electrolyte (C). ``Oxygen scavenger consisting of granular alkaline earth metal hydroxide (A), iron powder (B), electrolyte (C) and granular water-containing substance (D)'', published in JP-A-56-130223. ``Oxygen scavenger'', JP-A-56-133027, ``Composed of poorly water-soluble granular material (A) impregnated with an alkaline aqueous solution and whose surface is coated with a fine filler, iron powder (B) and electrolyte (C) ``Oxygen scavenger'' and JP-A-59-
Publication No. 210844 states, "Granular slaked lime with a particle size of 0.5 to 3 mm is impregnated with water or a humidity conditioning solution in which an inorganic compound or an organic compound is dissolved in water, and the moisture content is adjusted to 1 to 35%. A composition consisting of granules (A), iron powder (B), and electrolyte (C) whose surface has been coated with 1 to 10% of filler is then laminated with a plastic film on one side of oil-repellent paper. Air temperature 5000~10000 seconds/100ml of air
(JIS P8117) and moisture permeability 17g/ ^m2・24hrs (JIS
Z0208) A method for preserving coffee, which comprises storing roasted coffee in a substantially air-impermeable bag or container together with an oxygen absorber encapsulated in the following packaging material and sealed: ' has been disclosed. ``Problems to be Solved by the Invention'' The inventions disclosed in the above-mentioned publications all have iron powder and an electrolyte such as salt as the basic composition of the oxygen scavenger, and are made by distributing an alkaline substance to this. It's on. Oxygen scavengers whose basic composition is an electrolyte such as iron powder and salt do not have a sufficiently satisfactory oxygen scavenging effect, and there are problems in that it is difficult to adjust the oxygen scavenging rate, _etc. It had a fatal flaw that greatly hindered its effectiveness. for example,
Using a commercially available oxygen absorber whose basic composition is iron powder and salt or an oxygen absorber prepared in a laboratory, approximately
It has been found that if approximately 5% CO ₂ is injected into a packaging bag that is set to have 0% O ₂ in 48 hours, 5 to 10% O ₂ will remain after being left for about 48 hours. Therefore, an oxygen scavenger whose basic composition is an electrolyte such as iron powder and salt and an alkaline substance is used.
When used in roasted coffee, which has an extremely low moisture content and generates a large amount of CO ₂ , the deoxidizing reaction will not proceed sufficiently until most of the generated CO ₂ has been removed. The water in the water-containing substances contained in the coffee is transferred to the roasted coffee, and no deoxidation reaction takes place. CO ₂ is generated over a long period of time, and if O ₂ is not sufficiently removed during this period, it will not be of any use as an oxygen scavenger.
Even if you can devise a way to prevent water from being stolen by roasted coffee, there is no point in doing so. "Means for Solving the Problems" The present inventor has disclosed the invention of "Oxygen scavenger made of metal chelate resin and iron powder" in Japanese Patent Application No. 61-87763 (see Japanese Patent Application Laid-open No. 62-244443). The application was filed as The oxygen scavenger of this invention is an epoch-making product that has a stronger oxygen scavenging effect in a smaller amount than oxygen scavengers whose basic composition is an electrolyte such as iron powder and common salt. The present inventor conducted further research based on this invention and found that the oxygen scavenging effect of an oxygen scavenger whose basic composition is metal chelate resin and iron powder is not inhibited at all by the coexistence of _CO2 , and that metal chelate Because the resin has high hygroscopicity, the alkaline substances and
They discovered that it is possible to sustain the deoxidizing reaction by strongly absorbing a small amount of water vapor produced by the reaction with CO ₂ or by the heat of the reaction, and completed the present invention. That is, the present invention includes "an oxygen absorber for roasted coffee comprising a metal chelate resin, iron powder, and an alkaline substance". First, the substances used in the present invention will be explained. A metal chelate resin is a resin that has an aldoxime group, an aminophosphoric acid group, a dithiocarbamate group, a pyridine, or a primary, secondary, or tertiary amine and has a chelate binding ability (hereinafter referred to as a chelate resin), and Pb ^{2 +} , Cd ²⁺ , and metal ions other than Cr ³⁺ are chelated. Examples of chelate resins include the following. A combination of a basic anion exchange resin and a chelating agent. Examples of basic anion exchange resins include: Manufactured by Rohm and Haas Company Registered trademark Amberlite IRA-45 or IRA-
68 (hereinafter simply referred to as IRA-45 or IRA-68)
Manufactured by Dow Chemical Company ●Registered trademark Dowex MSA-2 (hereinafter simply referred to as
(referred to as MSA-2) Manufactured by Muromachi Chemical Industry Co., Ltd. Registered trademark Muromatsuku A-7 (hereinafter simply referred to as A-
Examples of chelating agents include: ●Disodium salt of ethylenediaminetetraacetic acid (hereinafter referred to as EDTA-2Na) ●Trans-cyclohexanediaminetetraacetic acid ●Diaminepropanoltetraacetic acid ●Triethylenetetraminehexaacetic acid ●Ethylenediaminediolhydroxyphenylacetic acid Basic anion exchange as above A chelate resin can be easily obtained by bringing a resin and an aqueous solution of a chelating agent into contact with each other by a conventional method. The amount of the chelating agent to be used varies depending on the ion exchange ability of the exchange resin and the molecular weight of the chelating agent, but it is preferable to combine the chelating agent so that the exchange resin is saturated.
Generally, about 0.3 to 5 parts by weight of the chelating agent is required for 100 parts by weight of the exchange resin (dry weight), but since the solubility of the chelating agent in water is low, add an appropriate amount of water so that the amount dissolved is the above amount. For example, a saturated solution or M/10 to M/
It may be used at a concentration of about 100. The formation reaction of the chelate resin is thought to be an ionic bond between the primary, secondary, or tertiary amine of the basic anion exchange resin and the carboxyl group of the chelating agent. Commercially available chelate resins include, for example, the registered trademark Sumikylate CR-2 or Q-10R (hereinafter simply referred to as CR-2 or Q-10R) manufactured by Sumitomo Chemical Industries, Ltd. A basic anion exchange resin containing Cu ²⁺ ,
When it can be directly chelated with metal ions such as Fe ²⁺ , Fe ³⁺ , Ni ²⁺ , or Co ²⁺ . In other words, basic anion exchange resins can literally bond with anions, but the basic anion exchange resins listed above are Cu ²⁺
It has stable bonding strength with cations such as and Fe ³⁺ . Note that the object of the present invention cannot be achieved with an acidic cation exchange resin in which metal ions are ionically bonded. A metal chelate resin can be obtained by chelate bonding the above chelate resin and metal ion. The metal ions used in the present invention include K ⁺ , Na ⁺ ,
Mg ²⁺ , Ca ²⁺ , Al ³⁺ , Mn ²⁺ , Fe ²⁺ , Fe ³⁺ , Co ²⁺ ,
Ni ²⁺ , Cu ⁺ , Zn ²⁺ , Nb ⁵⁺ , Ag ⁺ , Sn ²⁺ , Sb ³⁺ ,
Most metal ions that can form a chelate bond can be used, such as Au ³⁺ , Hg ²⁺ , Bi ³⁺ , Pt ⁴⁺ , etc. (However, if Pb ²⁺ , Cd ²⁺ , Cr ³⁺ is used, , the purpose of the present invention could not be achieved). These metal ion supply substances include KCl, Na ₂ SO ₄ , MgSO ₄ ,
CaCl ₂ , AlCl ₃ , MnCl ₂ , FeSO ₄ , Fe ₂ (SO ₄ ) ₃ ,
_CoCl2 , _NiCl2 , CuCl, _CuSO4 , _ZnCl2 , _NbCl5 ,
_AgNO3 , _Ag2SO4 , _SnSO4 , _SbCl3 , _{HAuCl4 ,}
Examples include water-soluble metal salts such as HgCl ₂ , BiCl ₃ and H ₂ PtCl ₆ . A metal chelate resin can be easily obtained by contacting the aqueous solution of the above metal ion supply substance with a chelate resin. The amount of metal ion supply substance used varies depending on the type and ion binding ability of the chelate resin, but generally the amount of the chelate resin (on a dry basis)
About 1 to 50 parts by weight per 100 parts by weight is good, and
The concentration of the aqueous solution is preferably about 0.01 to 10%. In addition, when metal ions are in excess, it is desirable to remove the excess metal ions by washing with water. The metal chelate resin can be used in any of granular, crushed, or powdered forms, but in general, the finer the resin, the higher the deoxidation reaction rate, so the particle size of the resin is preferably 20. A mesh of at least 100 meshes, more preferably 100 to 250 meshes is used. Metal chelate resin with a moisture content in the range of 0 to 70% can be used, but if the moisture content is high, it will immediately start a deoxidizing reaction when mixed with iron powder, so the environment of the process should not be contaminated with _N2 , etc. Considering that the process must be carried out under an anaerobic gas flow, it is more desirable that the water content is about 20% or less. The iron powder used in the present invention is preferably electrolyzed iron powder, reduced iron powder, etc., but it goes without saying that not only these iron powders but also any powder whose main component is iron powder can be used. . The particle size of the iron powder is preferably 60 mesh or more, more preferably 150 mesh or more.
~250 mesh is used. The above metal chelate resin and iron powder are mixed into 1 part by weight (in terms of dry matter) of the former, 0.5 to 600 parts by weight of the latter,
Preferably 4 to 200 parts by weight, more preferably 10
The basic composition of the oxygen scavenger is obtained by mixing in a proportion of ~100 parts by weight. However, even when used for roasted coffee, this alone cannot remove CO ₂ or O ₂ at all, and the following alkaline substance must be added. The alkaline substances used in the present invention are, for example,
Ca(OH) ₂ , CaO, Mg(OH) ₂ , Ba(OH) ₂ , BaO
Alkaline earth metal hydroxides or oxides such as NaOH, KOH and soda lime, _CO2
Examples include those that exhibit absorbency. Among these
It is most desirable because Ca(OH) ₂ reacts with CO ₂ to generate water vapor, there is no leakage from the breathable bag, it is less irritating and is a food additive standard product, and it is cost effective. . These alkaline substances can be used in any form such as granules or powder, but in terms of CO ₂ absorption efficiency and convenience of handling, those with a mesh size of 60 to 250 mesh are preferably used, and preferably 100 to 200 mesh. . The amount of alkaline substance used is stoichiometrically determined in response to CO ₂ generated from roasted coffee. The amount of _CO2 generated varies greatly depending on the type of coffee, degree of roasting, degree of grinding, and storage time in the air after roasting, but in general, 1 part by weight of a mixture of metal chelate resin and iron powder. 1~
By using more than 20 parts by weight, preferably about 2 to 10 parts by weight, the two purposes of deoxidation and decarboxylation are achieved. Even if the alkaline substance is placed directly in the mixture of metal chelate resin and iron powder, the alkaline substance will not be added to the basic anion exchange resin unless the chelate resin is a basic anion exchange resin with a chelating agent bonded to it. (If a product with a chelating agent bound to it comes into direct contact with an alkaline substance, the bonded part of the chelating agent will break and there is a strong tendency to lose its oxygen scavenging effect).However, even in this case, the object of the present invention is achieved. If the resin is in direct contact with an alkaline substance for a long period of time, it will tend to gradually reduce its oxygen scavenging effectiveness, for example, after 2 to 3 weeks. Therefore, if long-term stability is desired in the oxygen scavenger of the present invention, it is preferable to seal the mixture of metal chelate resin and iron powder and the alkaline substance in an air-permeable bag in a state where they are separated. Isolation and enclosure methods include using a breathable bag partitioned with a breathable membrane, or sealing one or both of them in a breathable bag and then sealing them in a larger breathable bag. Another method is to impregnate zeolite or the like with an alkaline substance and coat the surface of the granules. Among these methods, the method of sealing a mixture of metal chelate resin and iron powder in a breathable bag and sealing this and an alkaline substance in a larger breathable bag is the most effective in terms of O ₂ and CO ₂ removal efficiency. According to this configuration,
A mixture of metal chelate resin and iron powder is stable unless water vapor is present in the environment, and alkaline substances are stable and do not generate heat or water vapor unless CO ₂ coexists in the environment. Therefore, the manufacturing environment for oxygen absorbers should be
It does not need to be kept under anaerobic conditions with N ₂ etc., and when used for roasted coffee, it is quite stable even when left in the air, giving rise to the advantage of being very easy to handle. Through the above steps, the oxygen absorber for roasted coffee of the present invention is completed. That is, with this configuration, first
When CO ₂ is absorbed by an alkaline substance and soda lime is used as the alkaline substance, the metal chelate resin absorbs a small amount of the water vapor _generated by the reaction or the water vapor generated by the heat of the reaction. , the deoxygenation reaction immediately proceeds in parallel with the decarboxylation reaction. In the present invention, when an alkaline substance that does not generate water vapor upon reaction with CO ₂ is used, when a deoxygenation reaction that does not trigger a reaction with CO ₂ , or when a more effective deoxygenation and decarboxylation reaction is desired. It is preferable to coexist a known water-containing substance with the composition of the present invention. Examples of known water-containing substances include calcium metasilicate, calcium carbonate, activated carbon, talc, bentonite, etc., which contain water to the extent that filling properties are not lost. These water-containing substances can be made to coexist with either or both of the mixture of metal chelate resin and iron powder, and the alkaline substance. As the reaction progresses, it becomes necessary to maintain the production environment under anaerobic conditions, and it also causes inconvenience in handling for users. Therefore, it is most desirable that the water-containing substance coexists with the alkaline substance. In this case, an aqueous solution containing an alkaline substance dissolved in the water-containing substance may be absorbed before use. "Effects of the Invention" As explained above, the oxygen absorber for roasted coffee according to the present invention absorbs two types of gases, O ₂ and CO ₂ , extremely effectively and almost simultaneously, and It is possible to maintain the quality of the product and prevent the container or bag from swelling or bursting due to CO ₂ . In addition, by adopting a structure in which a mixture of metal chelate resin and iron powder and an alkaline substance or a water-containing substance coexist with it are sealed in a breathable bag in a separated state, the stability of its efficacy and the manufacturing process and This provides convenience during use. A detailed explanation will be given below using experimental examples. "Experiment 1 (Examples 1-2)" When using commercially available chelate resins Two types of commercially available chelate resins (CR-2, Q-10R)
100 ml of 1% Fe ₂ (SO ₄ ) ₃ aqueous solution was added to the mixture and stirred to complete the reaction. After washing with water several times, the resin was dried with ventilation at about 50° C. overnight and pulverized to obtain 100 to 200 meshes of metal chelate resin (reddish brown color with substantially 0% water content). A mixture of 0.025 g of these metal chelate resins and 1 g of reduced iron powder and 3 g of soda lime (20 to 30 mesh) were sealed in a breathable bag to obtain two types of oxygen scavengers according to the present invention. The oxygen scavenger efficacy test was conducted as follows. Put 100g of medium-ground roasted coffee and an oxygen absorber into a vinylidene chloride-coated polypropylene bag (hereinafter referred to as a KOP bag), and make sure the air content in the bag is approximately
It was sealed to a volume of 350ml. these packaging bags
It was stored at 20°C, and the O ₂ and CO ₂ concentrations inside the bag were measured over time. O ₂ concentration is measured using Toregi Zirconia oxygen meter LC700T.
Depending on the type, the CO ₂ concentration can be measured using a Kitagawa type detection tube (Kitagawa Sangyo K.
(for K and _CO2 ), respectively. In this case, if roasted coffee is stored without removing CO ₂ , the bag will swell to the point of bursting after 5 days. In the following oxygen scavenger efficacy tests, O ₂ and CO ₂
was measured using the method described above. The results of the above tests are shown in Table 1.

[Table] According to Table 1, the oxygen scavenger according to the present invention is O ₂ and
Both CO ₂ gases could be efficiently absorbed and removed. "Experiment 2 (Examples 3 to 6)" Types and effects of resins Four types of basic anion exchange resins (IRA-45,
IRA-68, MSA-2 and A-7, the chlorine type was treated with sodium hydroxide to become the free form)
Add 100ml of M/100EDTA-2Na aqueous solution to 10g,
The reaction was terminated by stirring, and then washed with water several times to obtain four types of chelate resins. 100 ml of 1% Fe ₂ (SO ₄ ) ₃ aqueous solution was added to these chelate resins and stirred to complete the reaction. Next, after washing several times with water and drying with ventilation at approximately 40°C for several hours, the metal chelate resin (reddish brown color with a water content of 3 to 5
%) was obtained. 0.035g of these metal chelate resins and reduced iron powder
0.8 g of the mixture was sealed in a breathable bag. Separately Ca
A fine powder mixture of 5 g of (OH) ₂ and 3 g of CaSiO ₃ with a moisture content of 60% was prepared, and a large breathable bag was prepared along with a breathable bag filled with each metal chelate resin and iron powder obtained above. to obtain four types of oxygen absorbers for roasted coffee according to the present invention. 100 roasted coffee (grains) using the oxygen absorber obtained above
Put it in a KOP bag with g, and make sure that the air content in the bag is almost
The volume was sealed to 350 ml and stored at room temperature to test the effectiveness of the oxygen scavenger. As a result of the above tests, as shown in Table 2, the oxygen scavenger of the present invention was found to be highly effective.

[Table] As a reference experiment, instead of the mixture of metal chelate resin and iron powder used in the previous experiment, a commercially available oxygen scavenger (one whose basic composition is iron powder and salt) was used.
500 ml) or a mixture of 2 g of iron powder and 1 g of common salt, and the other conditions were the same as in the previous experiment. The CO ₂ content was the same as in the previous example, but
The O ₂ content was 5 to 10%, making it unsuitable as an oxygen absorber for roasted coffee. "Experiment 3 (Examples 7 to 8)" When using a basic anion exchange resin to which no chelating agent was bound For 10 g of basic anion exchange resin IRA-45,
100 ml of 1% Fe ₂ (SO ₄ ) ₃ or 1% CuSO ₄ aqueous solution was added and stirred to complete the reaction (the color tone of the resin was
The yellow color before the reaction changed to reddish brown or blue, respectively). Next, after washing with water several times, the mixture was dried with ventilation at about 50° C. overnight and pulverized to obtain 100 to 200 meshes of metal chelate resin. A mixture of 0.2 g of these metal chelate resins and 0.5 g of electrolytic iron was sealed in a breathable bag. Separately Ca(OH) ₂ 4g and NaOH0.05
A finely powdered mixture of g is sealed in an air permeable bag, and the air permeable bag containing the metal chelate resin and iron powder obtained above is placed in a larger air permeable bag. Two types of oxygen absorbers for roasted coffee were obtained. Put the oxygen absorber obtained above in a KOP bag together with 100 g of well-ground roasted coffee, seal it so that the air content in the bag is approximately 350 ml, and store it at room temperature to test the effectiveness of the oxygen absorber. I did it. As a result of the above tests, as shown in Table 3, the oxygen scavenger of the present invention was found to be highly effective.

[Table] “Experiment 4 (Examples 9 to 29) Effect of type of metal ion Basic anion exchange resin IRA-45 M/kg per kg
10 EDTA-2Na aqueous solution was added and stirred to complete the reaction, and then washed with water several times to obtain a chelate resin. For 10 g of this chelate resin, 100 ml of 1% metal salt aqueous solution (KCl, Na ₂ SO ₄ , MgSO ₄ ,
CaCl ₂ , AlCl ₃ , MnCl ₂ , FeSO ₄ , Fe ₂ (SO ₄ ) ₃ ,
_CoCl2 , _NiCl2 , CuCl, _CaSO4 , _ZnCl2 , _NbCl5 ,
_AgNO3 , _SnSO4 , _SbCl3 , _HAuCl4 , _HgCl2 ,
BiCl ₃ and H ₂ PtCl ₆ (however, in the case of HAuCl ₄ and H ₂ PtCl ₆ , use 1000 ppm standard solutions each),
The reaction was terminated by stirring. After washing with water several times,
They were dried with ventilation at about 60° C. and pulverized to obtain 150 or more meshes of metal chelate resin (water content substantially in the range of 0 to 7%). A mixture of 0.025 g of these metal chelate resins and 0.8 g of reduced iron powder was sealed in a breathable bag. Separately, a mixture of 4 g of Ca(OH) ₂ powder and 4.5 g of activated carbon with a water content of 30% was prepared and sealed in a large breathable bag along with the metal chelate resin and iron powder obtained above. Thus, 21 types of oxygen absorbers for roasted coffee according to the present invention were obtained. The oxygen absorber obtained above was placed in a KOP bag along with 100g of coarsely ground roasted coffee, sealed so that the air content in the bag was approximately 350ml, and stored at 10℃ to test the effectiveness of the oxygen absorber. I did this. The results are shown in Table 4.

[Table] Table 4 shows that a wide range of metal ions can be used. However, the metal ion is Pb ²⁺ ,
In the case of Cd ²⁺ and Cr ³⁺ , no oxygen scavenging efficacy was observed at all. "Experiment 5 (Examples 30 to 37)" Effect of usage ratio of metal chelate resin and iron powder Basic anion exchange resin IRA-45, EDTA-
A metal chelate resin powder was obtained in the same manner as in Experiment 4 using 2Na and Fe ₂ (SO ₄ ) ₃ . A mixture of 0.3 to 0.0025 g of this powder and 0.2 to 1.5 g of reduced iron powder was sealed in a breathable bag. Separately Ca(OH) ₂ 10g
A mixture of 2 g of CaSiO ₃ with a moisture content of 50% is prepared, and the mixture is sealed in a large breathable bag together with the metal chelate resin obtained above and the iron powder sealed therein, thereby deoxidizing the oxygen according to the present invention. Eight types of agents were obtained. Put the oxygen absorber obtained above in a KOP bag together with 100 g of medium-ground roasted coffee, seal it so that the air content in the bag is approximately 350 ml, and store it at 25℃ to remove the oxygen absorber. An efficacy test was conducted. The results are shown in Table 5. According to Table 5, metal chelate resin (dry matter g)
When the combination of iron powder and iron powder is in the range of 0.3 to 0.010:0.2 to 1.0, there is virtually no difference in oxygen scavenging efficacy, and 0.005:1.2
The following shows a tendency for its effectiveness to gradually decrease,
0.0025: It was found that less than 1.5 is not practical. Note that the decarboxylation efficacy was good in all cases.

[Table] "Experiment 6 (Examples 38 to 46)" Effect of ratio of alkaline substance used 500 ml of 0.2% FeCl ₃ aqueous solution was added to 25 g of chelate resin CR-2 and stirred for 30 minutes to complete the reaction.
Then, after washing with water several times, it was dried with ventilation at about 50° C. overnight, and pulverized to obtain an Fe chelate resin with a particle size of 150 mesh or more. Fe chelate resin 0.02g and reduced iron powder 0.98g
The mixture was sealed in a breathable bag. Separately, Ca
0.1 to 20 g of an alkaline substance obtained by mixing 99% (OH) ₂ and 1% NaOH in fine powder form, along with a breathable bag containing the Fe chelate resin and iron powder obtained above,
Nine types of oxygen absorbers for roasted coffee according to the present invention were obtained by sealing them in large air-permeable bags. 100 roasted coffee (grains) using the oxygen absorber obtained above
Put it in a KOP bag with g, and the air content in the bag is about 350.
ml

[Table] Table 6 shows the results of testing the effectiveness of the oxygen absorber by storing it in a sealed container at room temperature. As shown in Table 6, when the amount of alkaline substance used was 1 g or more per 100 g of roasted coffee, both the oxygen scavenger and the oxygen scavenging effect were good. However, if further stored for 7 days, the CO ₂ of alkaline substances of 1.5 g or less will gradually increase, and 0.5
If the bag weighs less than 1 g, the bag becomes quite swollen. Therefore, the amount of alkaline substance used is 1.5g.
The use of the following is limited to cases where a considerable amount of CO ₂ is released after grinding roasted coffee, or when vacuum packaging is performed. Furthermore, if the amount of alkaline substance used is small, the deoxidizing reaction will be insufficient, so the coexistence of a water-containing substance is essential. There is generally little significance in using more than 20g of alkaline substances. As mentioned above, the oxygen scavenger of the present invention is completed by blending metal chelate resin, and not only can O ₂ and CO ₂ of roasted coffee be efficiently removed, but also the metal chelate resin The aroma of roasted coffee in the package can be absorbed or denatured and decomposed to maintain its quality without producing any strange odor, while also preventing the container or packaging bag from swelling or bursting. This eliminates the post-roasting CO ₂ dissipation process, which greatly contributes to preventing aroma components from escaping and reducing costs.

Claims (1)

[Claims] 1. An oxygen absorber for roasted coffee comprising a metal chelate resin, iron powder, and an alkaline substance. 2. The oxygen absorber for roasted coffee according to claim 1, wherein the mixture of metal chelate resin and iron powder and the alkaline substance are sealed in a breathable bag in a separated state. 3. The metal chelate resin is a basic anion exchange resin or a basic anion exchange resin with a chelating agent bound to a metal ion other than Pb ²⁺ , Cd ²⁺ and Cr ³⁺ The oxygen absorber for roasted coffee according to claim 1 or 2. 4. The oxygen absorber for roasted coffee according to claim 1, 2, or 3, in which an alkaline substance and a water-containing substance coexist. 5 0.6 to 100 parts by weight of iron powder per 1 part by weight of metal chelate resin (dry basis), and 1 part by weight of alkaline substance per 1 part by weight of the mixture of metal chelate resin and iron powder.
~20 parts by weight Claims 1 and 2
The oxygen absorber for roasted coffee according to item 1, 3 or 4.