Sealed Package Comprising Parchment Paper and a Polysaccharide-Based Coating

Abstract

The present invention relates to a sealed package for food comprising i) a first parchment paper sealing and forming a volume for storage of food ii) a polysaccharide-based composition coated ii.a) on one side of said first parchment paper; or ii.b) on a biobased binder coating which is coated directly on one side of said first parchment paper wherein the polysaccharide-based composition is coated on the side of the package facing away from the formed volume. The invention also relates to a method of forming a sealed package and the use thereof.

Claims

1. A sealed package for food comprising: i) a first parchment paper sealing and forming a volume for storage of food; and ii) a polysaccharide-based composition coated ii.a) on one side of said first parchment paper; or ii.b) on a bio-based binder coating which is coated directly on one side of said first parchment paper, wherein the polysaccharide-based composition is coated on the side of the package facing away from the formed volume.

2. The package according to claim 1, wherein the first parchment paper has been pretreated by a sizing agent selected from a resin and/or a rosin.

3. The package according to claim 1, wherein the polysaccharide-based composition comprises hemicellulose, microfibrillar cellulose, nanofibrillar cellulose, or mixtures thereof.

4. The package according to claim 1, wherein the parchment paper is free from silicone-based and/or fluorine-based compounds.

5. The package according to claim 1, wherein the polysaccharide-based composition comprises microfibrillar and/or nanofibrillar cellulose.

6. The package according to claim 1, wherein the bio-based binder is coated directly on the first parchment paper and/or on the coating of the polysaccharide-based composition.

7. The package according to claim 1, wherein a second parchment paper coated with a bio-based binder is laminated to the first parchment paper on the side of the package closest to the formed volume, wherein the bio-based binder coating of the second parchment paper is disposed between the first and the second parchment papers.

8. The package according to claim 1, wherein the polysaccharide-based composition coating has a thickness ranging from 1 to 20 μm.

9. The package according to claim 1, wherein the bio-based binder coating comprises latex, wax, polylactic acid modified polyester, derivatives and/or mixtures thereof.

10. The package according to claim 1, wherein the package is an inner package enclosed by a polyethylene-based and/or bio-based extrudable polymer package forming an outer package.

11. The package according to claim 10, wherein the outer package is tightly sealed to the inner package according to claim 1.

12. The package according to claim 10, wherein a gap between the inner package and the outer package contains air or is vacuumized.

13. The package according to claim 1, wherein the bio-based binder coating comprises polylactic acid modified polyester.

14. The package according to claim 1, wherein the bio-based binder coating has a thickness ranging from 5 to 50 μm.

15. The package according to claim 1, wherein the polysaccharide-based composition does not comprise carboxymethyl cellulose, starch, and hydroxyethyl cellulose.

16. The package according to claim 1, wherein a second parchment paper is coated with a polysaccharide-based composition, and a bio-based binder is coated on the formed polysaccharide-based composition coating, wherein said second parchment paper being closest to the sealed volume is laminated to the first parchment paper, wherein the coating of the polysaccharide-based composition and the bio-based binder coating are disposed between the first and the second parchment papers.

17. A method of forming a sealed package, the method comprising: coating a first parchment paper on one side with a polysaccharide-based composition or a bio-based binder coating; folding the first parchment paper to form an enclosed volume; utilizing adhesive properties of the polysaccharide-based composition to seal edges of neighbouring folded sides of said at least first parchment paper to form the sealed package enclosing a volume for food.

18. A method of using a sealed package for food, the package having i) a first parchment paper sealing and forming a volume for storage of food and ii) a polysaccharide-based composition coated ii.a) on one side of said first parchment paper or ii.b) on a bio-based binder coating which is coated directly on one side of said first parchment paper, the method comprising: sealing, in the package, food having a water content lower than 20 wt % or at least 25 wt %.

19. (canceled)

20. The method of claim 18 wherein the food has a fat content in the range from 40 to 100 wt %.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0061] FIGS. 1-3 show embodiments of suitable patterns for forming the packages according to the invention by folding the paper by the indicated lines. FIGS. 4a-c show different embodiments of the composition of the packaging material.

DESCRIPTION OF THE DRAWINGS

[0062] FIG. 1 shows a parchment paper prepared according to the invention. A sealed package is prepared by folding the paper at the indicated markings. FIG. 2 shows in a similar way how a package may be produced by folding the paper. Also FIG. 3 shows a pattern for folding to form a package. The packages are sealed by adhering neighbouring edges of the parchment paper when folding it. Suitably, the edges are provided with flaps (not shown in the figures) which are adhered to each other, preferably by means of a polysaccharide, for example by applying the edges and/or flaps under heating to improve the adhesiveness and sealing of the formed package. In embodiments containing bio-based binders, the bio-based binder may equally be used as adhering material between the edges and/or flaps. Also, a bio-based glue may equally be used to adhere neighbouring edges and/or flaps.

[0063] FIG. 4a shows a schematic side of the package and the composition thereof according to one embodiment of the invention. Layer a) is a HDPE (High Density Polyethylene), especially HDPE produced from sugar cane, e.g. SGF 9490. This layer is suitably 0.1-1 mm.

[0064] Symbol b) in FIG. 4a represents an air gap and c) represents a polysaccharide coating such as Skalax® (based on hemicellulose which also may be combined with a bio-based binder).

[0065] Layer d) is a parchment paper such as Super Perga Opatique WS Parchment®.

[0066] Layer d) is exposed to the content of the package, e.g. solid or liquid food, and layer a) is exposed to the atmosphere surrounding the package.

[0067] A package composed of only parchment paper and polysaccharide-based composition, i.e. in absence of a polyethylene layer a) as illustrated in FIG. 4a, can be used for e.g. dry foods or fat foods, for example foods with a wet content lower than 20 wt % or lower than 10 wt %.

[0068] FIG. 4c corresponds to FIG. 4a but wherein the bio-based binder (layer e) is coated on the parchment paper on the side facing away from the enclosed volume. A polysaccharide-based coating c is disposed on the bio-based binder e (in FIG. 4c, layers e and c are indicated as a joint layer). b) represents an air gap or a vacuum. In FIG. 4b, a further parchment paper d) and a bio-based binder e) have been added to the structure shown in FIG. 4c. The further parchment paper is arranged to have contact with the food stored in the package. As can be noted in FIG. 4b, the additional bio-based binder (layer e) is disposed between the two parchment papers (layers d). Packages with a layer composition as illustrated in FIGS. 4b and 4c are suitable for wet and/or sour foods, e.g. foods with a water content above 20 wt %. As evident from the invention, the invention may also be implemented without the use of an outer package.

Example 1

[0069] A method (EN 1185-5, an accredited analysis) for overall migration from plastics into aqueous food simulants by cell (one-sided contact) was applied in which 2.25 dm.sup.2 of a sample was exposed to 100 ml of acetic acid (used as simulant). The measurement uncertainty for the determination of overall migration is ±2 mg/dm.sup.2.

[0070] Sample: Parchment paper+ High Density Polyethylene plastic (the parchment paper was placed closest to the food simulant).

[0071] Migration Simulant

[0072] 3% acetic acid was used as simulant. Report limit: 2 mg/dm.sup.2.

[0073] Test Conditions

[0074] 20 days, 40° C. (20 days according to the test corresponds to 1 year of exposure).

[0075] Results

[0076] Overall migration (in mg/dm.sup.2 sample) was 7.6 and 7.3 respectively (mean result 7.5). The overall migration limit is 10 mg/dm.sup.2 according to commission regulation (EU) No 10/2011. There were no visible particles in the food simulant after 20 days of migration.

[0077] Example 1 shows that the parchment paper without any coating in contact with acidic and/or wet foods (acetic acid being an established simulant in the test) is intact and have good properties as to migration.

Example 2

[0078] Grease proof parchment paper of 65 gram per square meter provided by Nordic Paper was used.

[0079] Skalax (hemicellulose-based polysaccharide) from Seelution was used as polysaccharide and BIM BA 85015 X was used as bio-based binder (latex-based SBR-latex).

[0080] The coatings were prepared by means of a bench rod coater, a drier with both hot air and IR heater. The parchment paper was coated using a laboratory bench rod coater. The sheet was dried in an oven at 180° C. for approximately 1.5 minutes. Before the surface properties were evaluated the sheets were climatized to 23° C. and 50% relative humidity (RH) for at least one hour.

[0081] Hydrophobicity of the surface was evaluated for 300 seconds using Cobb300 (ISO 535) method. For the evaluation of grease resistance, KIT (TAPPI T-559 pm-96) was used. A 1 dm.sup.2 piece of the coated parchment paper was weighed and compared to a non-coated paper to determine the weight of the coating per square meter.

[0082] The COBB300-test was used to determine the quantity of water that can be absorbed by the surface of paper or board in a given time. The samples were evaluated for 300 s with COBB300 (ISO 535) method. Duplicate tests were performed. Grease resistance was measured with KIT-test (TAPPI T-559 pm-96), and reported as a value between 0 to 12. The KIT test solution with highest number that does not penetrate the surface of the substrate is the noted grease resistance (KIT-number).

[0083] As Skalax and BIM BA 85015X according to the above were available as already prepared solutions, no further preparation was needed. The samples were coated according to the below in the indicated order by means of a Rod number 2 (color code: red). The following samples were prepared:

[0084] Sample 111: Skalax (polysaccharide) 5.5 g/m.sup.2 coated on parchment paper

[0085] Sample 112: Skalax 5.5 g/m.sup.2 coated on parchment paper; Bim BA 85015X (bio-based binder) 10.6 g/m.sup.2 coated on the Skalax

[0086] Sample 116: Bim BA 85015X (bio-based binder) 8.9 g/m.sup.2 coated on parchment paper; Skalax 5.3 g/m.sup.2 coated on the bio-based binder.

TABLE-US-00001 TABLE 1 Coating weight Cobb300 Sample (g/m.sup.2) (g/m.sup.2) KIT 111 5.2 76.6 12 112 16.1 87.4 12 116 14.2 62.6 12

[0087] The table shows samples 111, 112, and 116 according to the invention have good Cobb300 and KIT values.

Example 3—Oxygen Transmission Rate

[0088] To measure a packaging material's ability to prevent oxygen to pass through it, standard methods ASTM D3985 and ISO 15105-2 were used.

[0089] The OTR (oxygen transmission rate) is the steady state rate at which oxygen gas permeates through a film or laminate at specified temperature and relative humidity (Value % RH).

[0090] A Biodolomer® available from Gaia Biomaterials, being a granular modified polyester of polylactide and calcium carbonate as filler, was used as bio-based binder.

[0091] Samples

[0092] Sample 111 as above.

[0093] Sample 101: Finnfix® 10 Dry (a carboxymethyl cellulose) 20 g/m.sup.2 coated on the parchment paper on either side thereof. 8 g/m.sup.2 hydroxyethylcellulose from TCI Europe and 4.6 g Barrisurf LX® slurry (mineral), 43% solids, from Imerys was coated on the Finnfix on both sides of the parchment paper.

[0094] Sample 120: as 111 but in addition a Biodolomer® coated on the side of the first parchment paper facing the enclosed volume in an amount of 42 g/m.sup.2 which biodolomer also formed a coating on a second parchment paper laminated to the first parchment paper on the side thereof facing away from the enclosed volume. The packaging structure counted from the enclosed volume thus comprises the second parchment paper, Biodolomer® coating 42 g/m.sup.2, first parchment paper, Skalax coating 5.5 g/m.sup.2.

[0095] Sample 101 was prepared from a solution of FinnFix by adding 20 g of Finnfix 10 Dry to 180 g tap water during mixing. The mixture was heated to 50° C. and kept at that temperature. Once Finnfix was fully dissolved, parchment paper was coated using rod number 3 (color code: green). The reverse side of sample 101 was coated with rod number 1 (color code: yellow).

[0096] Subsequently a solution was prepared by mixing 184.6 g tap water with 8 g HEC and 4.6 Barrisurf LX slurry. The mixture was heated to 50° C. and kept at that temperature. Once a homogenous mixture was reached, coating using rod number 3 (color code: green) on the formed Finnfix coating was initiated.

[0097] The results from the oxygen transmission rate (OTR) show that sample 111 (invention) has very good OTR. The sample 101 (reference) is equal to polyethylene, i.e. regarded as not possible to use as OTR barrier. When looking into the results from the OTR measurement below 10 cc/m.sup.2 24 h, materials with those levels are regarded as true oxygen barriers. Sample 120 likewise show excellent results.

TABLE-US-00002 TABLE 2 OTR Sample 111 120 101 cc/m.sup.2 24 h 10 1 >2000

Example 4—Migration with Vegetable Oil Simulant

[0098] The migration tests were performed with iso-octane as simulant mimicking vegetable oil and conducted according to the following:

[0099] Contact area sample: 0.45 dm.sup.2

[0100] Volume iso-octane: 50 ml

[0101] The results of the screening after migration into iso-octane are displayed in table 3. The results are expressed in mg/kg foodstuff and/or mg/6 dm.sup.2, based on the conventional EU food contact ratio of 1 kg of food in contact with 6 dm.sup.2 of surface area. Calculations are made based on the starting volume of 50 ml simulant.

[0102] The LOQ for this analysis is 0.01 mg/kg (ppm) food, therefore components with a concentration lower than the LOQ are not reported in table 3.

TABLE-US-00003 TABLE 3 Sample 112 Sample 116 RT *(MIN) Component (mg/kg) (mg/kg) 25.1 Unbranched alkane 1 0.08 0.13 25.9 Unbranched alkane 2 0.07 0.16 26.67 Unbranched alkane 3 0.08 0.17 27.41 Unbranched alkane 4 0.06 0.15 28.17 Unbranched alkane 5 0.04 0.11 28.6 Unbranched alkane 6 — 0.03 29.02 Unbranched alkane 7 0.02 0.06 * RT: retention time in the chromatogram from the gas chromatography mass spectrometry analysis of the extracts.

[0103] Table 3 shows the retention time (RT) for unbranched alkanes (different species). As can be noted from table 3, the migration is clearly lower where alkanes originating from the bio-based binder coating has to pass both the Skalax coating and the parchment paper (sample 112) than when the bio-based binder coating is disposed directly on the parchment paper. Table 3 thus shows that the Skalax layer (the polysaccharide) contributes to reduced migration.

Example 5

[0104] A test method to observe the different laminates and their ability to remain intact after exposure to various foodstuffs has been performed. The test was designed as an accelerated test using Arrhenius equation and an elevated temperature whereby the acceleration factor is approximately 50 times. When looking into the different tables with time to failure (breakthrough), all time periods measured should be multiplied by 50 to arrive at corresponding time to failure at room temperature.

[0105] The design of the experiment procedure was with glass jar, cap and packaging material as described in the table below. The foodstuff was put on top of the packaging material and the backside of material was observed optically, i.e. visibility of spots at the backside was observed. The observation started after 5 minutes and was ended after 20 hours. No sample in the test was intact after 900 minutes. The temperature was set to 75° C. The foodstuffs were thus deposited on the surface corresponding to the formed volume according to the invention.

[0106] Meatball Test

[0107] The meatballs used were Swedish meat balls commercially available from Scan. Sample 103 was prepared as sample 101 but the coatings on the side of the parchment paper facing away (corresponding to the bottom side in this test) from the side at which the foodstuffs (meatballs etc.) were deposited was left uncoated. Sample 121 is a paper laminate with the following layers in the mentioned order seen from the inner side, i.e. the side on which the foodstuff was deposited corresponding to the inner surface of the formed volume of the package: second parchment paper (65 g/m.sup.2), Skalax (5.5 g/m.sup.2), Biodolomer (42 g/m.sup.2), parchment paper (65 g/m.sup.2), Skalax (5.5 g/m.sup.2). Sample 121 was also used in following graved salmon and pickled cucumber tests.

TABLE-US-00004 TABLE 4 Time (min) 101 103 111 112 116 121 30 X X X X X X 60 X X X X X X 90 X X X X 120 X X X X 180 X X X X 240 X X X X 900 X X: No breakthrough of water or fat

[0108] It can be noted from the results that samples 101 and 103 (references) have a breakthrough of moisture after 60 minutes, i.e. material failure. The samples 111, 112, and 116 according to the invention respectively showed breakthroughs after 240 minutes, i.e. material failure. As can be seen from table 4, sample 121 (according to the invention) showed excellent performance compared to all other samples. The differences of the different set of samples are significant. To be noticed is that this is an accelerated test with a factor of 50 and the differences between the samples according to the invention and the references 101 and 103 became quite large.

[0109] Graved Salmon Test

[0110] The salmon was a standard Swedish graved salmon. The salmon is put in a mixture of salt, sugar and oil for 3 days. The species fish is then dried with some paper and cut into pieces.

TABLE-US-00005 TABLE 5 Time (min) 101 103 111 112 116 121 30 X X X X X X 60 X X X X X X 90 X X X X 120 X X X X 180 X X X X 240 X X X X 900 X X: No breakthrough of water or fat

[0111] It can be noted from the results that samples 101 and 103 (references) have breakthroughs of moisture after 60 minutes, i.e. material failure. The samples 111, 112, and 116 according to the invention respectively showed breakthroughs after 240 minutes, i.e. material failure. As can be seen from table 5, sample 121 showed excellent performance compared to all other samples. The differences of the different samples are significant. To be noticed is that this is an accelerated test with a factor of 50 and the differences became quite large.

[0112] Cucumber in Acetic Acid Test

[0113] This test was performed with cucumber including equal amount of acetic acid by weight. The cucumber used was Felix® Attiksgurka (pickled cucumber).

TABLE-US-00006 TABLE 6 Time (min) 101 103 111 112 116 121 30 X X X X X X 60 X X X X X X 90 X X X X 120 X X X X 180 X X —.sup.1 X 240 X X X 900 X X: No breakthrough of water or fat .sup.1Sample 116 had some minor defects observed most probably influencing the results

[0114] It can be noted from the results that samples 101 and 103 (references) show breakthroughs of moisture after 60 minutes, i.e. material failure. The samples 111 and 112 according to the invention respectively showed breakthroughs after 240 minutes, i.e. material failure. The sample 116 (invention) was significantly better than samples 101 and 103 (references) but not as good as 111, 112 and 121 (invention). The observation is that samples 111 and 112 are to be regarded as significantly better than sample 116. As can be seen from table 6, sample 121 showed excellent performance compared to all other samples. To be noticed is that this is an accelerated test with a factor of 50 and the differences became quite large.