TECHNICAL HELD

This invention relates to an oxygen absorbing composition. BACKGROUND OF THE INVENTION

In packaging technology, especially the food packaging, it requires oxygen absorber to eliminate the remaining oxygen in the packaging after seal, including oxygen permeating into the packaging. The oxygen absorber reacts with oxygen to reduce oxygen amount This prevents oxidation reaction which is a major cause of product deterioration such as color, odors, or flavors changes. Also, this prevents product quality degradation due to microorganisms such as fungi or bacteria which are required oxygen in proliferation.

Currently, one of preferred oxygen absorber is an iron powder composition in sachet and placed in the packaging or incorporated in the polymer for producing packaging such as plastic bottle, pouch. The oxygen absorber having iron powder cannot be used in conjunction with certain types of packaging, i.e., the ones passed through metal detector. In addition, the oxygen absorber having iron powder only absorbs oxygen causing the packaging to collapse. This results in product’s damage, undesired packaging appearance and products when placed on display.

Therefore, the oxygen absorber with no metal composition has been developed to enable it to pass through the metal detector and reduce problems and limitations arising from the one having iron powder mentioned above. Some examples of commercial oxygen absorber having organic substance are the oxygen absorber having ascorbic acid as a core component, the oxygen absorber having enzymes as. a core component, etc.

The foregoing commercial oxygen absorber, especially the one having ascorbic acid which is sensitive to light, requires special design or improved oxygen absorber production. This leads to some drawbacks such as higher production costs, special storage and transportation required due to light sensitive, etc.

Some prior arts on oxygen absorber having natural phenolic compounds ( no metal composition) are as follows.

Korean patent publication no. KR 2015046677 A discloses oxygen scavenging composition having polyphenol-based compound and potassium carbonate, wherein the preferred polyphenol compound is gallic acid and 2, 3, 4-trihydroxybenzoic acid. Youn Suk Lee, et. al. from Yonsei University, Republic of Korea, published in 2016, discloses an oxygen removal system having natural phenol compound, including pyrogallol and sodium carbonate at a weight ratio of pyrogallol to sodium carbonate in a range of 1-5:1.

However, the composition and oxygen removal systems disclosed in both prior arts above use gallic acid and pyrogallol, which is an extract from plant complexes, to cleave to a single purified substance before use. This results in manufacturing complexity and high production costs.

SUMMARY OF THE INVENTION

An objective of this invention is to provide an oxygen absorbing composition having organic components that can address problems and limitations from previous oxygen absorbing compositions as mentioned above.

Another objective of this invention is to provide an oxygen absorbing composition having natural extracts capable of absorbing oxygen effectively and inhibiting microbial growth, where the production process can be carried out easily, not complicated, and low production costs.

This invention relates to an oxygen absorbing composition comprising

(a) an extract comprising a substance selected from a group consisting of galloyl ester, hexahydroxydiphenyl ester, derivatives thereof, and a combination thereof; and

(b) a carbonic acid salt, wherein a weight ratio of (a) the extract to (b) the carbonic acid salt is in a range of 0.5-

3:1.

In addition, the oxygen absorbing composition of this invention further comprises (c) sodium chloride, wherein a weight ratio of (a) the extract to (b) the carbonic acid salt to (c) sodium chloride is in a range of 0.5-3 : 1 : 1.

In another aspect, this invention relates to an oxygen absorbing product comprising the oxygen absorbing composition according to this invention.

The oxygen absorbing composition and product according to this invention can address problems arising from the use of oxygen absorbing composition and product having metal compounds such as iron powder. The packaging with the oxygen absorbing product has no issues once passing through the metal detector, and packaging collapse since the oxygen removal system of the oxygen absorbing composition according to this invention generating carbon dioxide in the packaging - preserving the inside product’s shape (i.e., no deformation).

In addition, the oxygen absorbing composition and product of this invention can absorb oxygen effectively and inhibit microbial growth within the packaging as well. This is because the reaction system of the oxygen scavenging composition within the packaging along with the release of carbon dioxide. Therefore, it can inhibit microbial growth requiring oxygen in respiration - extending the product’s shelf-life in the packaging.

The oxygen absorbing composition and product according to this invention can be easily prepared, not complicated, and low production cost. This is because it uses natural extract comprising galloyl ester, hexahydroxydiphenyi ester, derivatives thereof, or a combination thereof without any additional steps to isolate complex substances in natural extracts to a single chemical structure before use.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a graph showing oxygen absorption level of the composition according to this invention as a function of storage time at 33%, 75% and 99% RH.

Figure 2 is a graph showing oxygen absorption level of the composition according to this invention having 5-7% and 15% moisture content as a function of storage time at 33%, 75% and 99% RH.

Figure 3 is a graph showing oxygen absorption level of the composition according to this invention with different moisture content, with and without sodium chloride as a function of storage time, where (3A) at 33% RH, (3B) at 75% RH, and (3C) at 99% RH.

Figure 4 is a graph showing oxygen absorption level of the composition according to this invention with different moisture content, with sodium chloride as a function of storage time, where (4A) at 33% RH, (4B) at 75% RH, and (4C) at 99% RH.

Figure 5 is a graph showing oxygen absorption level of the composition according to this invention with extracts obtained from various sources as a function of storage time at 33%, 75% and 99% RH.

Figure 6 is a graph showing oxygen absorption level of the composition according to this invention, which is packed and non-packed in sachet as a function of storage time at 75% RH.

Figure 7 is a graph showing oxygen absorption level of the composition according to this invention, which is packed in a pack made of various materials as a function of storage time where (7A) at 75% RH, and (7B) at 99% RH.

Figure 8 is a graph showing oxygen concentration in headspace over bread which is packed in the packaging with and without the oxygen absorbing product according to this invention as a function of storage time at 25°C, 65% RH. Figure 9 is a graph showing carbon dioxide concentration in headspace over bread which is packed in the packaging with and without the oxygen absorbing product according to this invention as a function of storage time at 25°C, 65% RH.

Figure 10 is a graph showing total plate count (TPC) of bread which is packed in the packaging with and without the oxygen absorbing product according to tins invention as a function of storage time at 25°C, 65% RH.

Figure 11 is a graph showing yeast and mold count (Y/M) of bread which is packed in the packaging with and without the oxygen absorbing product according to this invention as a function of storage time at 25°C, 65% RH.

Figure 12 is a graph showing oxygen absorption level of the oxygen absorbing product according to this invention and a commercial oxygen absorbing product as a function of storage time at 99% RH.

DETAILED DESCRIPTION

Unless otherwise specified, any aspects listed herein include application to other aspects of this invention.

Unless otherwise specified, the technical and scientific terms used herein will become apparent to those of ordinary skill in the art from reading of the following detailed description and the appended claims.

Throughout the present specification and the accompanying claims, the words “ consist of’, "comprise", “have” and "include" and variations such as "comprises", "comprising", "consists of', "consisting of', “has”, “having”, "includes", and "including" are to be interpreted inclusively. That is, these words are intended to convey the possible inclusion of other elements or integers not specifically recited, where the context allows.

Any tools, devices, equipment, methods, materials, or chemicals mentioned herein are intended to indicate tools, devices, equipment, methods, materials, or chemicals used by those skilled in the art unless specified otherwise.

A first aspect of this invention relates to an oxygen absorbing composition comprising: (a) an extract comprising a substance selected from the group consisting of galloyl ester, hexahydroxydiphenyl ester, derivatives thereof, and a combination thereof; and

(b) a carbonic acid salt, wherein a weight ratio of (a) the extract to (b) the carbonic acid salt is in a range of 0.5-

3:1. Preferably, the oxygen absorbing composition has a weight ratio of (a) the extract to (b) the carbonic acid salt (b) at 2: 1.

Preferably, the extract according to this invention is a plant extract with a compound in a group of galloyl ester or its derivatives, or hexahydroxydiphenyl ester or its derivative where the compound has glucose bonding as binder in the structure and bonding with the natural process.

Examples of substances in the group of galloyl ester and hexahydroxydiphenyl ester according to this invention are tannic acid (known as gallotannin) , pentagalloyl glucose, pedunculagin, vescalagin, oenothein B, cocciferin D2, condensed tannin polymer, ellagitannin, C-glucosidically catechin), (-)-epigallocatechin gallate (3), hexahydroxydiphenic acid, ellagic acid, gallic acid, etc., which have the following structure examples.

For example, the extract may be a natural extract selected from a group consisting of grape seed, tea leave, mangosteen peel, gallnut, sweet chestnut, sumac, quebracho, witch hazel, eucalyptus bark, oak bark, acacia bark, mimosa bark, pine bark, softwood lignin, hardwood lignin, and a combination thereof. More preferably, the extract is from sweet chestnut, gallnut, or a combination thereof.

The carbonic acid salt used in this invention is selected from a group consisting of potassium carbonate, sodium carbonate, lithium carbonate, magnesium carbonate, and a combination thereof, preferably potassium carbonate.

According to this invention, when using the oxygen absorbing composition in a closed system with moisture, the carbonic acid salt, water, and a compound in a group of galloyl ester, hexahydroxydiphenyl ester, or the derivatives thereof in the extract, all components will react together as an oxygen removal system. This oxygen removal system is due to a mechanism of the reaction, which the carbonic acid salt (such as K ₂ CO ₃ ) reacts with water in the composition then generate carbon dioxide and hydroxide compounds (such as KOH), and a reaction which the compound in the group of galloyl ester or hexahydroxydiphenyl ester, or the derivatives thereof in the extract reacts with oxygen to eliminate oxygen.

With the above oxygen removal mechanism, the oxygen absorbing composition according to this invention can reduce oxygen concentration in the packaging’ s headspace. Hence, it can prolong the product’ s deterioration in the packaging caused by oxidation reaction. In addition, carbon dioxide generated in the system due to the carbonic acid salt reacts with water preventing the packaging’s collapse and inhibiting aerobic microbial growth. Hence, it prolongs the product’s deterioration due to microorganisms and extend the shelf life of the packaging.

In a preferred embodiment, the oxygen absorbing composition further comprises (c) sodium chloride which acts as a retardant to delay the oxygen absorbing reaction. Hence, it’ s possible to extend oxygen removal time in the system.

According to the preferred embodiment of this invention, the oxygen absorbing composition has a weight ratio of (a) the extract to (b) the carbonic acid salt to (c) sodium chloride in a range of 0.5-3:l:l, preferably 2:1:1.

The oxygen absorbing composition of this invention may have a moisture content in a range of 5-20%, more preferably 10-20%, and the most preferably 15-18%. The moisture of oxygen absorbing composition can be adjusted to comply with use considering various variables such as a moisture of the packed product, relative humidity (RH) in the packaging, quantity and type of substance mixed as the oxygen absorbing composition, etc.

The oxygen absorbing composition can be used in various applications depending on features or forms of the packaging and packed product. For example, the oxygen absorbing composition can be produced as an oxygen absorbing product with oxygen absorbing composition according to this invention, and a pack for packing the oxygen absorbing composition inside. The preferred oxygen absorbing product is, for example, a sachet placed in the packaging.

The pack of the oxygen absorbing product can be made from any materials usable in this oxygen absorption technology. For example, the pack may be made from material selected from a group consisting of polymer fiber, laminated paper, laminated non- woven fabric, mono- layer polymer film, multi-layer polymer film, laminated film, or a combination thereof.

Preferably, the polymer fiber is a high-density polyethylene, the laminated paper is a paper where one side laminated with perforated polyethylene terephthalate and the other side laminated with perforated polyethylene, and the laminated non- woven fabric is polypropylene or polyethylene terephthalate non- woven fabric where one side laminated with perforated polyethylene terephthalate and the other side laminated with perforated polyethylene.

More preferably, the pack is made of high- density polyethylene or paper where one side laminated with perforated polyethylene terephthalate and the other side laminated with perforated polyethylene.

The oxygen absorbing product according to this invention is suitable for absorbing oxygen in a closed system at room temperature, 33-99% RH. The oxygen absorbing composition and product of this invention is applicable to the packaging containing various products, which needs to control moisture and inhibit the microbial growth. For example, the oxygen absorbing composition and product of this invention is especially suitable for use with various types of food packaging such as dried food, bakery, cake, bread, pasta, meat, processing meat product (e.g. ham, sausage), processed fresh fruit, cheese, etc. Preferably, the oxygen absorbing composition and product suits with food products having fat since it is likely to react with oxygen (i.e. , oxidation reaction) easily causing food to turning rancid.

The following will describe an exemplary embodiment of this invention in more details by referring to the examples, test results and attached figures. However, these illustrated examples are not intended to limit the scope of this invention.

The oxygen absorption efficiency test of the oxygen absorbing composition was conducted by placing the composition’ s examples in the " closed" simulation device, which was made from sealed container equipped with PTFE / Silicone septa barrier at the lid of the container and drilled a channel for gas measurement. Within the closed system, a humidity sensor was installed and the condition within the container was adjusted to various %RH using magnesium chloride (MgCl ₂ ) at 33% RH, sodium chloride (NaCl) at 75% RH, and potassium sulfate (K ₂ SO ₄ ) at 99% RH. The oxygen and carbon dioxide concentrations in headspace within the closed system were measured with O ₂ /CO ₂ gas analyzer.

1. Oxygen absorbing composition

Samples of the oxygen absorbing composition for testing were prepared by mixing components as shown in Table 1 at room temperature before performing the oxygen absorption test.

Table 1 shows the composition’ s components, sources of the extract, weight ratio of the composition’s components, %moisture of the composition and % RH within the closed system. Table 1 1.1 Effect of relative humidity of the closed system on oxygen absorption The effect of relative humidity of the closed system on the oxygen absorption was studied by measuring oxygen absorption level of Samples 1-3 in Table 1 at 33%, 75%, and 99% RH, respectively. Next, the oxygen absorption level was plotted as a function of storage time. The results are as shown in Figure 1.

From the test results, Samples 1 -3 can absorb oxygen from the beginning once placed in the closed system (day 0). The oxygen absorption level is about 10 cc. Besides, it’s apparent that the oxygen absorption level of Samples 1-3 varies with the relative humidity. For example, the oxygen absorption level of Sample 3 at 99% RH is about 25 cc on the 2 ^nd day and increased to 70 cc maximum. While the oxygen absorption level of Sample 2 at 75% RH is 20 cc on the 3 ^rd day and increased to 60 cc maximum. No change of the oxygen absorption level, i.e:, 10 cc, for Sample 1 at 33% RH was observed from the beginning until 14 days. This indicates that the oxygen absorbing composition at high relative humidity provides faster and greater oxygen absorbing volume at low relative humidity.

1.2 Effect of moisture of the composition on oxygen absorption The effect of moisture content of the composition on the oxygen absorption was studied by measuring oxygen absorption level of Samples 1-6 in Table 1 at 5-7% moisture content (Samples 1-3) and 15% moisture content (Samples 4-6) at 33% RH (Samples 1 and 4), 75% RH (Samples 2 and 5), and 99% RH (Samples 3 and 6). Next, the oxygen absorption level was plotted against storage time as shown in Figure 2.

From the test results, it was found that increased moisture content significantly enhances the oxygen absorption efficiency in all relative humidity conditions. For example, at 33% RH, Sample 4 with greater 15% moisture content can absorb oxygen more than 40 cc on the 1 ^st day. No change of the oxygen absorption level for Sample 1 with 5-7% moisture content was observed even though the last 14 days. Sample 6 with 15% moisture content at 99% RH can absorb oxygen quickly and the most, and well retained the oxygen absorption level, i.e., slower decrease of oxygen absorption level over time. Hence, the moisture content of the composition can enhance greater oxygen absorbing rate.

1.3 Effect of sodium chloride on oxygen absorption

The effect of sodium chloride (NaCl) on the oxygen absorption was studied by measuring oxygen absorption level of Samples 1-6 in Table 1 without NaCl and Samples 7-18 in Table 1 with NaCl. Next, the oxygen absorption level was plotted as a function of storage time as shown in Figure 3 where Figure (3A) representing Samples 1, 4, 7 and 16 at 33% RH; Figure (3B) representing Samples 2, 5, 8 and 17 at 75% RH; and Figure (3C) representing Samples 3, 6, 9 and 18 at 99% RH.

From Figure (3 A), comparing the oxygen absorbing results at 33% RH between Samples

4 and 16 having the same 15% moisture content, Sample 16 with NaCl has the oxygen absorption level of 30 cc since starting the test, which is significantly greater than Sample 4 without NaCl. Sample 16 has a maximum oxygen absorption level of 50 cc after a day while Sample 4 can only absorb oxygen to a maximum of about 40 cc.

From Figure (3B), comparing the oxygen absorbing results at 75% RH between Samples

5 and 17 having the same 15% moisture content, Sample 17 with NaCl has a maximum oxygen absorption level of 50 cc since starting the test, which is significantly greater than Sample 5 without NaCl. Sample 17 has a maximum oxygen absorption level of 75 cc after two days while Sample 5 can only absorb oxygen to a maximum of about 60 cc and an oxygen absorption rate declines clearly faster than Sample 17.

From Figure (3C), comparing the oxygen absorbing results at 99% RH between Samples

6 and 18 having the same 15% moisture content, Sample 18 with NaCl has a maximum oxygen absorption level of 40 cc since starting the test, which is significantly greater than Sample 6 without NaCl. Sample 18 has a maximum oxygen absorption level of 60 cc after a day, but declines later due to saturation of excess moisture in the system (i. e. , a moisture content of the absorbing composition at 99% RH). This leads to rapid reaction affecting long-term absorbing efficiency. Sample 6 gradually absorbs more oxygen from the 1 ^st day to the 3 ^rd day, then remains constant, and starts to drop after 8 ^th day.

Therefore, adding sodium chloride into the composition, especially in the Samples with high moisture content, increases the oxygen absorption efficiency, accelerates the oxygen absorbing rate from the beginning, and maintains oxygen absorbing rate stability as clearly seen in the results of Samples 17 (Figure 3B) and 18 (Figure 3C). Both Samples can absorb oxygen in large quantities since starting the test, moreover; the oxygen absorption rate of both Samples is quite stable compared to other Samples. However, adding sodium chloride into the composition with low moisture content does not enhance oxygen absorption efficiency, and probably reduce oxygen absorption efficiency. Similar result was observed as adding sodium chloride into the composition with high moisture content at high relative humidity condition. Further study is required for combining sodium chloride together with the moisture content of the composition at various relative humidity conditions. 1.4 Effect of sodium chloride, moisture content of the composition and relative humidity conditions on oxygen absorption

From the above study, it’s found that either adding sodium chloride or increasing moisture content in the composition improves the oxygen absorption efficiency of the composition. Further study on effect of moisture content of the composition and the relative humidity condition on the oxygen absorption of the composition with sodium chloride was conducted using Samples 7-21 in Table 1. They all have the same component, but different moisture content and relative humidity. The oxygen absorption level was plotted as a function of storage time as shown in Figure 4 where Figure (4A) representing Samples 7, 10, 13, 16, and 19 at 33% RH; Figure (4B) representing Samples 8, 11, 14, 17, and 20 at 75% RH; and Figure (4C) representing Samples 9, 12, 15, 18, and 21 at 99% RH.

From the results in Figure (4A), at 33% RH, the oxygen absorption efficiency of the composition varied with increased moisture content. Sample 19 with 17.5% moisture content can absorb 40 cc oxygen since starting the test and increases to 60 cc after a day. Samples 13 and 16 with 12.5% and 15% moisture content, respectively can absorb 20 cc oxygen since starting the test and increases to 40 cc after a day. While Samples 7 and 10 with 5-7% and 10% moisture content, respectively can absorb oxygen less than other Samples.

From the results in Figure (4B), at 75% RH, Samples 11, 14, 17, and 20 with at least 10% moisture content can absorb more oxygen and faster than the one with low moisture content (e.g., Sample 8 with 5-7% moisture content). Moreover, it’s found that Sample 17 with 15% moisture content has better oxygen absorption efficiency than Sample 20 with 17.5% moisture content. Sample 17 can absorb 40 cc oxygen since starting the test and increases to a maximum of 80 cc, and retained stable absorbing rate for up to 14 days.

From the results in Figure (4C), at 99% RH, the oxygen absorption level varied with increased moisture as starting the test. Samples with higher moisture can absorb more oxygen as starting the test and absorb more during the 1 ^st - 3 ^rd day of the test, then slowly declines. It’ s observable that oxygen absorption of Sample 15 with 12.5% moisture content is more effective than Sample 18 with 15% moisture content

From the above test results, it can be concluded that sodium chloride addition together with moisture adjustment of the composition to suit the relative humidity in the use condition can greatly increase oxygen absorption efficiency. That is, if using the composition at 33% RH, it’ s desirable to add sodium chloride and the moisture content of the composition to 17.5%. If using the composition at 75% RH, it’s desirable to add sodium chloride and the moisture content of the composition to 15%. If using the composition at 99% RH, it’s desirable to add sodium chloride and the moisture content of the composition to greater than 5 - 7% , preferably 10% or more, to enhance high amount of absorbed oxygen and maintain oxygen absorption efficiency for longer.

1.5 Effect of the source of extract on oxygen absorption

The effect of the source of extract on oxygen absorption was studied using Samples 16- 30 in Table 1 including various extracted sources, which were sweet chestnuts (Samples 16, 17, and 18), gallnut (Samples 22, 23, and 24), eucalyptus bark (Samples 25, 26, and 27) and softwood lignin (Samples 28, 29, and 30). Graphs of oxygen absorption level as a function of time at 33%, 75%, and 99% RH are shown in Figure 5.

From the test results, all samples exhibit similar oxygen absorbing behavior, i.e., all of them can absorb a maximum oxygen at 75 % RH and a minimum oxygen at 33 % RH. Furthermore, at the same relative humidity, the oxygen absorption efficiency of the samples having sweet chestnuts, gallnut, eucalyptus bark, and softwood lignin reduces, respectively.

2. Oxygen absorbing product

Samples 31-57 were prepared as oxygen absorbing products using the oxygen absorbing compositions according to the invention. The oxygen absorbing test was conducted with different weight ratio of the composition’s component, moisture of composition (%), total composition weight, % RH in closed system as presented in Table 2 below.

Each sample in Table 2 was packed in sachet made from various materials, including 100% density polyethylene fiber (commercial available as Tyvek®) (Samples 31-40), dustproof paper where one side laminated with perforated polyethylene terephthalate and the other side laminated with perforated polyethylene (Samples 41-48) and waterproof paper where one side laminated with perforated polyethylene terephthalate and the other side laminated with perforated polyethylene (Samples 49-57) at 75% and 99% RH.

Table 2

2.1 Use and results of the pack

The oxygen absorption efficiency of composition not packed in sachet (Samples 14, 17, and 20 in Table 1 ) and the ones packed in sachet made from 100% density polyethylene fiber (Samples 31, 33, and 35 in Table 2) were studied. The oxygen absorbing level was measured and then plotted as a function of the storage time at 75% RH as shown in Figure 6.

With the same moisture content, the composition packed in sachet absorbs less oxygen, for example, with 15% moisture content, Sample 17 not packed in sachet can absorb maximum oxygen close to 80 cc where Sample 33 packed in sachet can absorb maximum oxygen at about 50 cc. It’ s also observable that the composition with greater moisture content should be used to enhance oxygen absorption efficiency of the composition in sachet This can be seen from Sample 35 (having greater moisture content) has the best absorption results compared to Samples 33 and 31, respectively.

2.2 Effect of material' s type of pack and the composition’ s amount on the oxygen absorption

The effect of material’s type of the pack on the oxygen absorption efficiency was studied. Three types of materials with 15% and 17.5% moisture content, including 100% density polyethylene fiber (Samples 31, 33, 35, 37, and 39), dustproof paper where one side laminated with perforated polyethylene terephthalate and the other side laminated with perforated polyethylene (Samples 41, 43, 45, and 47), and waterproof paper where one side laminated with perforated polyethylene terephthalate and the other side laminated with perforated polyethylene (Samples 50, 52, 54, and 56), were used. The oxygen absorbing level was measured and then plotted as a function of the storage time as shown in Figure 7 where Figures (7A) and (7B) show the test results at 75% and 99% RH, respectively.

From Figure (7 A) , at 75 % RH, those samples have similar oxygen absorbing behavior, i.e., the oxygen absorption efficiency increases when moisture increases.

With the same moisture content, the samples packed in the sachet made from dustproof paper mentioned above has better oxygen absorption efficiency than the one packed in the sachet made from 100% density polyethylene fiber, the one packed in the sachet made from the waterproof paper mentioned above, respectively. As seen from a comparison among Samples 35, 43, and 52, where Samples 35, 43 and 52 has the oxygen absorbing level of 60, 70, and 55 cc, respectively. Also, the oxygen absorption efficiency increases with total composition weight increases. As seen from a comparison among Samples 33, 37, and 39, where Samples 33, 37, and 39 have the maximum oxygen absorbing amount of 33, 50, and 75 cc, respectively.

From Figure (7B), at 99% RH, the oxygen absorbing level varies with increasing packed composition’s amount in the sachet. In addition, the test results exhibit different oxygen absorbing behavior as sachet made from different material’ s type and with different moisture content, i. e. , with 17.5% moisture content, the sample packed in the sachet made from the dustproof paper has better oxygen absorption efficiency than the one packed in the sachet made from the waterproof paper, and the one packed in 100% density polyethylene fiber, respectively. As seen from a comparison among Samples 36, 44, and 53, where Samples 36, 44 and 53 have the oxygen absorption level at 40.5, 80, and 70 cc, respectively. However, with 15% moisture content, the sample in the sachet made from 100% density polyethylene fiber can absorb greater amount of oxygen.

2.3 Using oxygen absorbing products

The oxygen absorbing product having composition according to the invention, which is packed in a sachet were placed in a heat- sealed polypropylene packaging having 230 g bread where the oxygen absorbing composition comprising extracts from sweet chestnuts, carbonic acid salt, and sodium chloride with a weight ratio of 2: 1 : 1 and having 15% moisture content. Whilst the other bread packaging contains no oxygen absorbing products according to this invention.

The foregoing bread packaging was stored at 25°C, 65 %RH. The O ₂ /CO ₂ gas analyzer was used to measure O ₂ and CO ₂ amount in headspace of the packaging. Next, % oxygen and % . carbon dioxide as a function of storage time were plotted as shown in Figures 8 and 9 , respectively.

From the results in Figures 8 and 9, the packaging with the oxygen absorbing product of this invention has significantly decreased oxygen (ref. Figure 8) and increased carbon dioxide (ref. Figure 9) compared to the one without the oxygen absorbing product.

In addition, the bread was tested for a total plate count (TPC) and a yeast and mold count (Y/M). Next, the TPC and Y/M as a function of storage time were plotted as shown in Figures 10 and 11, respectively.

From the test results, it was found that oxygen absorbing product according to this invention can inhibit and delay the microbial growth, and also retain stable number of microorganisms in the range of 3 to 7 days (ref. Figure 10) and can delay the growth of yeast and mold in the sample significantly over the past 5 to 7 days (ref. Figure 11) compared to the one without the oxygon absorbing product.

2.4 Comparing oxygen absorption efficiency between the oxygen absorbing products of this invention and commercially available oxygen absorbing products

Samples 40, 44, and 53 in Table 2 were used since they provided the best oxygen absorption efficiency. The commercially available oxygen absorbing products were comparative samples Cl, C2 and C3 having oxygen absorbing actives as shown in Table 3. The test was conducted at 99% RH. The oxygen absorbing level was measured and plotted as a function of storage time as shown in Figure 12.

Table 3

From Figure 12, Samples 40, 44, and 53 can absorb oxygen better than the Comparative samples C1-C3.

The oxygen absorbing composition and product disclosed and claimed in this invention is intended to cover the embodiments of the invention from the action, practice, modification or change of any factors without significantly different experiments from this invention. It will be clear to those skilled in the art that the present invention was described above with reference to a few preferred embodiments. The invention, however, is by no means limited to these embodiments. Equivalent and/or alternative embodiments and modifications, which may or may not be apparent to the average skilled person, are conceivable. Such modifications and embodiments may very well fall within the scope of protection applied for as defined in the appended claims.