Method for preparing food-grade glassine paper from edible fungus liquid fermentation hyphae and food-grade glassine paper

Abstract

The invention discloses a method for preparing food-grade glassine paper from edible fungus liquid fermentation hyphae and the food-grade glassine paper, and relates to a method for preparing the glassine paper from natural biological materials, the preparation method of the food-grade glassine paper comprises the following steps: step 1, preparing edible fungus liquid fermentation hypha backing paper; step 2, preparing edible fungus liquid fermentation mycelium surface paper; step 3, preparing the food-grade glassine paper; the food-grade glassine paper is prepared from the edible fungus liquid fermentation hyphae, can replace a traditional papermaking method with wood as a main raw material, does not need to add plastic and chemical coating agents, has the advantages of being environmentally friendly, low in carbon and degradable, is food-grade oil-proof, moisture-proof and semitransparent glass paper, and can be widely applied to the field of papermaking. The method has wide application prospects in the fields of food, medicine, express labels and the like.

Description

Technical Field

[0001] The invention relates to a method for preparing glassine paper by utilizing natural biological materials, and in particular to a method for preparing food-grade glassine paper by fermenting mycelium of edible fungi in liquid form and the food-grade glassine paper. Background Art

[0002] Glassine paper, also known as translucent cellophane, is a high-density wood pulp paper that has been specially treated with sizing and silicone oil coating. It has excellent oil and moisture resistance and good transparency. It is mainly used in release paper, high-speed automatic labeling paper, special tape and double-sided tape substrate in the food and pharmaceutical fields.

[0003] In recent years, my country's demand for specialty papers such as glassine paper has continued to increase. Labels made of glassine paper are widely used in retail consumer goods, durable consumer goods, logistics, anti-counterfeiting and other fields. However, the large-scale use of labels will lead to serious consumption of natural resources. As we all know, paper production uses wood as the main raw material. With the reduction of the number of virgin forests in the world, forest resources such as wood will become important strategic materials and have great significance for national security.

[0004] In addition, the waste generated after the use of label stickers has also become a difficult problem in today's environmental governance. In China, label stickers made of plastic-coated laminated paper are widely used due to their price advantage. Plastic-coated laminated paper contains plastic film, synthetic glue and other ingredients. These ingredients are difficult to degrade in the natural environment and accumulate over time, eventually hindering the air permeability and water permeability of the soil, and even polluting groundwater. At the same time, the recycling of label stickers is also very difficult. It is necessary to separate different materials such as surface materials, glue and base paper. The whole process is complicated and costly, and the recycling efficiency is extremely low. Therefore, it is imperative to use natural biomaterials instead of wood and develop low-cost, environmentally friendly, degradable, and widely used food-grade glassine paper.

[0005] In nature, fungi, as decomposers, maintain ecological balance together with eukaryotic organisms such as plants and animals. Among fungi, there are about 2,000 species of edible fungi known to humans. Mycelium is the main body of edible fungi. Unlike fruiting bodies that grow on the ground, mycelium grows underground and is composed of long filamentous substances. In recent years, edible fungi have been widely used in food, medicine and industrial materials for their rich nutrition, significant efficacy and superior performance. However, the yield of wild edible fungi is small and difficult to obtain. The artificial cultivation cycle of edible fungi is very long. For example, the artificial cultivation cycle of Ganoderma lucidum, a precious edible fungus in my country, exceeds 6 months, which not only increases the cultivation cost of edible fungi, but also limits its application as an industrial material. As a perfect substitute for edible fungi, mycelium not only contains almost the same nutritional value as edible fungi, but also has good strength and toughness, and shows good application potential in the manufacture of various industrial products. Compared with fruiting bodies, the cultivation cycle of mycelium is short, generally only about 10 days, which greatly reduces its production cost and broadens its application prospects as an industrial material. The excellent material properties of mycelium are used to prepare glassine paper, which greatly reduces the paper industry's consumption of forests. Summary of the invention

[0006] The present invention provides a method for preparing food-grade glassine paper by using liquid fermentation mycelium of edible fungi and the food-grade glassine paper, so as to solve the problems of excessive consumption of forest resources in the process of manufacturing glassine paper, and difficulty in controlling environmental pollution and recycling caused by waste after use of glassine paper.

[0007] According to one aspect of the present invention, a method for preparing food-grade glassine paper from edible fungus liquid fermentation mycelium is provided, the method comprising the following steps: Step 1: Preparation of edible fungus liquid fermentation mycelium base paper; Using edible fungus liquid fermentation mycelia and sodium hydroxide solution, preparing alkali-treated edible fungus liquid fermentation mycelia, placing the alkali-treated edible fungus liquid fermentation mycelia in a steamer for steaming, placing the steamed alkali-treated edible fungus liquid fermentation mycelia in pure water to obtain edible fungus liquid fermentation mycelia water dispersion, homogenizing the edible fungus liquid fermentation mycelia water dispersion to obtain mycelia suspension, centrifuging the mycelia suspension and retaining the precipitate, vacuum filtering the precipitate to obtain mycelia filter cake, placing the filter cake in a mold, and drying it to obtain edible fungus liquid fermentation mycelia base paper; Step 2: Preparation of edible fungus liquid fermentation mycelium facial tissue; Step 2.1: Preparation of antioxidant food gum; Waxy corn starch and purified water are prepared into starch solution, and catechin is added to obtain antioxidant food glue; Step 2.2: coating; Applying antioxidant food glue on both sides of the edible fungus liquid fermentation mycelium base paper to obtain the edible fungus liquid fermentation mycelium face paper; Step 3: Preparation of food grade glassine paper; Step 3.1: Preparation of Pickering nanoemulsion from edible fungus liquid fermentation mycelium; The edible fungus liquid fermentation mycelium and purified water are used to prepare edible fungus liquid fermentation mycelium powder, and the edible fungus liquid fermentation mycelium Pickering nanoemulsion is obtained by emulsification treatment; Step 3.2: coating; Edible fungus liquid fermentation mycelium Pickering nanoemulsion is coated on both sides of edible fungus liquid fermentation mycelium facial paper to obtain food-grade glassine paper.

[0008] Preferably, in step 1, the specific operation method of using edible fungi liquid fermentation mycelium and sodium hydroxide solution to prepare alkali-treated edible fungi liquid fermentation mycelium is: take edible fungi liquid fermentation mycelium, add sodium hydroxide solution with a mass concentration of 0.001%, so that the ratio of the mass of edible fungi liquid fermentation mycelium to the volume of sodium hydroxide solution with a mass concentration of 0.001% is: 10g / ml, and after stirring evenly, alkali-treated edible fungi liquid fermentation mycelium is obtained; the steaming method is: spreading the alkali-treated edible fungi liquid fermentation mycelium in a mold, placing it in a 100°C steamer, and steaming for 10 to 30 minutes.

[0009] Preferably, in step 1, the specific method of placing the steamed alkali-treated edible fungi liquid fermentation mycelium in pure water to obtain an edible fungi liquid fermentation mycelium aqueous dispersion is: take the steamed alkali-treated edible fungi liquid fermentation mycelium, rinse it with pure water 2-3 times and then place it in pure water to obtain an edible fungi liquid fermentation mycelium aqueous dispersion with a mass concentration of 20-60g / 100mL.

[0010] Preferably, in step 1, it is characterized in that the edible fungus liquid fermentation mycelium aqueous dispersion is homogenized to obtain a mycelium suspension by the following specific method: homogenizing the edible fungus liquid fermentation mycelium aqueous dispersion with a high-speed homogenizer for 10 to 30 minutes at 8500 to 10000 r / min to obtain a mycelium suspension A, placing the mycelium suspension A on a temperature-controlled magnetic stirrer, and dripping citric acid solution thereto to make the concentration of citric acid in the mycelium suspension A reach 0.1 to 0.5 g / 100 mL, and reacting for 10 to 40 minutes at a temperature of 100 to 150° C. and a rotation speed of 200 to 400 r / min to obtain a mycelium suspension B, then stopping heating, and magnetically stirring the mycelium suspension B at a rotation speed of 200 to 400 r / min until it is cooled to room temperature to obtain a mycelium suspension C.

[0011] Preferably, the specific method of centrifuging the mycelium suspension and retaining the precipitate is: placing the mycelium suspension C in a centrifuge, centrifuging at 4000-5500r / min for 10-20min, recovering the supernatant, retaining the precipitate, the precipitate is: mycelium precipitate A, rinsing the mycelium precipitate A with pure water and placing it in a centrifuge for centrifugation, repeating the above steps 2-3 times, retaining the precipitate, and the precipitate is: mycelium precipitate B; the specific method of vacuum filtering the precipitate to obtain the mycelium filter cake is: placing the mycelium precipitate B in a vacuum filter, maintaining the vacuum degree at -0.09 to -0.06MPa, filtering for 15 to 30min, and obtaining the mycelium filter cake.

[0012] Preferably, in step 1, the filter cake is placed in a rectangular mold and dried to obtain the edible fungus liquid fermentation mycelium base paper in a specific method as follows: the mycelium filter cake is placed in a rectangular mold with a width of 10 cm and a length of 15 cm, and the surface of the mycelium filter cake is smoothed with a spatula to make the thickness of the mycelium filter cake in the rectangular mold uniform, and the density of the mycelium filter cake in the rectangular mold is 0.6 to 1.6 g / cm 3 ; Place the mycelium filter cake at room temperature for 10 to 12 hours, dry it naturally, and obtain the edible fungus liquid fermentation mycelium base paper.

[0013] Preferably, after step 1, the method further comprises: screening the edible fungus liquid fermentation mycelium base paper to be free of wrinkles, holes and spots by visual observation; screening the edible fungus liquid fermentation mycelium base paper to be free of wrinkles, holes and spots by actual measurement; screening the edible fungus liquid fermentation mycelium base paper to be free of wrinkles, holes and spots by actual measurement; screening the edible fungus liquid fermentation mycelium base paper to be free of wrinkles, holes and spots by visual observation ... 3 ; Through the paper tear strength tester, the lateral tear degree of the edible fungus liquid fermentation mycelium base paper screened is not less than 180mN; through the constant speed stretching method, the longitudinal tensile strength of the edible fungus liquid fermentation mycelium base paper screened is not less than 3kN / m, and the transverse tensile strength is not less than 1.3kN / m; through the hot and cold cycle environmental temperature test method, the edible fungus liquid fermentation mycelium base paper screened does not deform within the temperature range of -20 to 60℃.

[0014] Preferably, in step 2, the specific method for preparing the antioxidant food gum is: waxy corn starch is prepared into a suspension with a mass concentration of 3 to 5 g / 100 mL with pure water, placed in a boiling water bath and heated for 45 to 95 min, heating is stopped, and the temperature is reduced to 85 to 95° C. to obtain a starch solution, catechins are added to the starch solution to make the mass concentration of catechins in the starch solution reach 0.3 to 0.6 g / 100 mL, a uniform speed mixer is used to stir for 10 to 30 min at 200 to 600 r / min, and then cooled to room temperature to obtain the antioxidant food gum.

[0015] Preferably, in step 2, the specific method for preparing the edible fungus liquid fermentation mycelium facial paper is: on both sides of the edible fungus liquid fermentation mycelium base paper, antioxidant food glue is evenly coated with a coating machine, and the single-sided coating thickness is 20 to 50 μm, and then placed in a forced air drying oven at 40 to 60° C., dried for 10 to 30 minutes, to obtain the edible fungus liquid fermentation mycelium facial paper.

[0016] Preferably, after step 2, the method further comprises: screening the edible fungus liquid fermented mycelium facial paper for having no bubbles and defects on the surface through surface observation; screening the edible fungus liquid fermented mycelium facial paper for having an oxidative free radical scavenging rate exceeding 90% through antioxidant test; screening the edible fungus liquid fermented mycelium facial paper for having a transparency of not less than 47% through a reflectance photometer; and using a contact angle measuring instrument to screen the edible fungus liquid fermented mycelium facial paper for having a water phase contact angle range of 70 to 90°.

[0017] Preferably, the specific method for preparing the edible fungus liquid fermentation mycelium Pickering nanoemulsion in step 3 is: the specific method for preparing the edible fungus liquid fermentation mycelium Pickering nanoemulsion is: taking edible fungus liquid fermentation mycelium and dispersing it in pure water to obtain an aqueous dispersion of edible fungus liquid fermentation mycelium with a mass concentration of 40%, and placing it in a planetary ball mill, setting the speed to 300-600r / min, and grinding it for 2-4h, placing the ground edible fungus liquid fermentation mycelium aqueous dispersion in a vacuum freeze dryer, and drying it at -70°C The method comprises the following steps: drying the mixture for 4 to 12 hours to obtain edible fungus liquid fermentation mycelium powder; taking purified water, adding the edible fungus liquid fermentation mycelium powder and beeswax in succession to obtain a mixed solution, wherein the mass concentration of the edible fungus liquid fermentation mycelium powder in purified water is 0.5 to 1.5 g / 100 mL, and the volume ratio of beeswax to purified water is 2:3 to 3:2; using a high-speed emulsifier, at 45 to 75° C., the mixed solution is emulsified at 20,000 to 30,000 r / min for 2 to 6 minutes to form edible fungus liquid fermentation mycelium Pickering nanoemulsion.

[0018] Preferably, in step 3, the specific method for preparing the food-grade glassine paper is: using a coating machine, evenly coating edible fungus liquid fermentation mycelium Pickering nanoemulsion on both sides of the edible fungus liquid fermentation mycelium facial paper, and the coating thickness is 10 to 30 μm; placing the edible fungus liquid fermentation mycelium facial paper coated with edible fungus liquid fermentation mycelium Pickering nanoemulsion in a blast drying oven, and drying it at 35 to 55° C. for 10 to 30 minutes to obtain food-grade glassine paper.

[0019] Preferably, after step 3, the method further comprises: screening the transparency of food-grade glassine paper to be not less than 42% by a reflectance photometer; screening the smoothness of food-grade glassine paper to be not less than 1000s by a smoothness tester; screening the roughness of food-grade glassine paper to be not more than 1.8 μm by a roughness meter; screening the water phase contact angle of food-grade glassine paper to be not less than 80° and the oil phase contact angle to be not less than 45° by a contact angle measuring instrument; screening the oil absorption of food-grade glassine paper to be not more than 1 g / m 2 ; Through the constant speed stretching method, the longitudinal tensile strength of the food-grade glassine paper is screened to be not less than 3.6kN / m, and the transverse tensile strength is not less than 1.8kN / m; through the gloss tester, the gloss of the food-grade glassine paper is screened to be not less than 40GU at a measuring angle of 75°; through the printer test, the text, barcode and other information printed on the food-grade glassine paper are screened to be clear and can be accurately read by the scanning equipment; using the colorimeter, the color deviation of the font printed on the food-grade glassine paper is screened to be no more than 5.

[0020] According to another aspect of the present invention, a food-grade glassine paper is provided.

[0021] The beneficial effects of the present invention are as follows: the present invention provides a method for preparing food-grade glassine paper by using edible fungus liquid fermentation mycelium, which will replace the traditional method of using wood, plastic film, chemical coating and chemical glue as main raw materials, without cutting down forests and without relying on logs; the method uses food-grade raw materials, does not add any chemical raw materials such as bleaching agents and fluorescent agents, is non-toxic to the human body, is environmentally friendly, and the prepared food-grade glassine paper has good transparency, smoothness, oil resistance and tensile strength, etc., is suitable for use as express logistics labels, product labels, anti-counterfeiting labels and food and medicine packaging paper, and has great application potential in many fields such as commercial retail, logistics and warehousing. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a specific implementation flow chart of the present invention; Figure 2 This is the morphology of mycelium from liquid fermentation of Ganoderma lucidum; Figure 3 This is a molecular structure diagram of citric acid cross-linked Ganoderma lucidum liquid fermentation mycelium; Figure 4 This is a microscopic structure diagram of the mycelium filter cake of Ganoderma lucidum liquid fermentation; Figure 5 This is a microscopic picture of the mycelium of Ganoderma lucidum liquid fermentation after grinding; Figure 6This is the apparent diagram of antioxidant food gum, where A: the content of EGCG in antioxidant food gum is 0; B: the content of EGCG in antioxidant food gum is about 5%; C: the content of EGCG in antioxidant food gum is about 10%; D: the content of EGCG in antioxidant food gum is about 15%; E: the content of EGCG in antioxidant food gum is about 20%; Figure 7 It is the Pickering nanoemulsion form of edible fungus liquid fermentation mycelium; Figure 8 Schematic diagram of food-grade glassine paper, wherein A is: flat food-grade glassine paper; B is: stacked food-grade glassine paper. DETAILED DESCRIPTION

[0023] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the present application. Obviously, the described embodiments are only embodiments of a part of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work should fall within the scope of protection of the present application. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0024] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0025] In addition, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, for example, a process, method, product, or apparatus comprising a series of steps or elements is not necessarily limited to those steps or elements explicitly listed, but may include other steps or elements not explicitly listed or inherent to such process, method, product, or apparatus.

[0026] Embodiment 1 of the present invention: See also Figure 1-Figure 8 shown.

[0027] The edible fungus liquid fermentation mycelium is mycelium obtained by using edible fungi. The edible fungi in the present invention include Agaricus bisporus and Matsutake of Agaricus family, Lentinula edodes and Flammulina of Tricholomataceae, Schizophyllum family Schizophyllum, Pleurotus eryngii and Pleurotus eryngii of Pleurotus family, Auriculariales Auriculariales Auriculariaceae Black Fungus, Tremellales Tremellaceae Tremella, Polyporaceae Polyporaceae Bologna and Hericium erinaceus, Coriolus family Mori linteus, Ganoderma lucidum of Ganoderma family, Pseudomonas spp. of Trichoderma family, Agrocybe spp. of Agrocybe spp. of Agrocybe spp. of Agrocybe spp. of Agrocybe spp. of Agrocybe spp. of Agrocybe spp. of Morchella family, Morchella spp. of Morchella spp., etc. Now, taking the edible fungus Ganoderma lucidum as an example, the application of Ganoderma lucidum liquid fermentation mycelium in the preparation process of food-grade glassine paper is explained.

[0028] Step 1: Preparation of edible fungus liquid fermentation mycelium base paper; Lingzhi liquid fermented mycelium is white and paste-like. Figure 2 As shown; 150g of Ganoderma lucidum liquid fermentation mycelium was taken, 15mL of sodium hydroxide solution with a mass concentration of 0.001% was added, and the mixture was stirred evenly to obtain alkali-treated Ganoderma lucidum liquid fermentation mycelium, the alkali-treated Ganoderma lucidum liquid fermentation mycelium was spread in a rectangular flat-bottomed porcelain dish, placed in a 100°C steamer, and steamed for 20min, 120g of the steamed alkali-treated Ganoderma lucidum liquid fermentation mycelium was taken from the rectangular flat-bottomed porcelain dish, rinsed with pure water 2-3 times, and placed in 300mL of pure water to obtain a Ganoderma lucidum liquid fermentation mycelium water dispersion, so that its mass concentration reached 40g / 100mL, and a high-speed homogenizer was used to homogenize the Ganoderma lucidum liquid fermentation mycelium water dispersion at 9000r / min for 20min to obtain a mycelium suspension A; the mycelium suspension A was placed on a temperature-controlled magnetic stirrer, 15mL of citric acid solution was dripped into the mycelium suspension A, and the mycelium was stirred for 20min. The concentration of citric acid in suspension A reaches 0.3 g / 100 mL, and the reaction is carried out for 30 minutes at a temperature of 120° C. and a rotation speed of 300 r / min to obtain a mycelial suspension B, then the heating is stopped, and the mycelial suspension B is magnetically stirred at a rotation speed of 300 r / min until it is cooled to room temperature to obtain a mycelial suspension C; after the reaction is completed, the mycelial suspension C is placed in a centrifuge, centrifuged at 5000 r / min for 15 minutes, the supernatant is recovered, and the precipitate is retained, and the precipitate is: mycelial precipitate A; the mycelial precipitate A is rinsed with pure water and placed in a centrifuge for centrifugation, the above steps are repeated 2-3 times, and the precipitate is retained, and the precipitate is: mycelial precipitate B; the mycelial precipitate B is placed in a vacuum filter, the vacuum degree is maintained at -0.07 MPa, and the filtration is performed for 20 minutes to obtain a mycelial filter cake, and the microscopic structure of the mycelial filter cake is as shown Figure 4 As shown in the figure, the mycelium filter cake is placed in a rectangular flat bottom porcelain dish with a width of 10 cm and a length of 15 cm. The surface of the mycelium filter cake is smoothed with a spatula to make the thickness of the mycelium filter cake in the rectangular flat bottom porcelain dish uniform. The density of the mycelium filter cake in the rectangular flat bottom porcelain dish is 1.0 g / cm 3The mycelium filter cake was placed at room temperature for 12 hours and dried naturally to obtain the edible fungus liquid fermentation mycelium base paper. The molecular structure of citric acid cross-linked Ganoderma lucidum liquid fermentation mycelium is shown in the figure Figure 3 As shown; Through visual observation, the edible fungus liquid fermentation mycelium base paper is screened to have no wrinkles, holes and spots; through actual measurement method, the thickness deviation of the edible fungus liquid fermentation mycelium base paper is screened to be no more than ±6% and the tightness is no less than 0.7g / cm 3 ; Through the paper tear strength tester, the lateral tear degree of the edible fungus liquid fermentation mycelium base paper screened is not less than 180mN; through the constant speed stretching method, the longitudinal tensile strength of the edible fungus liquid fermentation mycelium base paper screened is not less than 3kN / m, and the transverse tensile strength is not less than 1.3kN / m; through the hot and cold cycle environmental temperature test method, the edible fungus liquid fermentation mycelium base paper screened does not deform within the temperature range of -20 to 60℃.

[0029] All raw materials used in the present invention are food grade.

[0030] Edible fungi refer to edible mushrooms, including mycelium, fruiting body and spores. The edible fungi in the present invention include Agaricus bisporus and Matsutake of Agaricales, Lentinula edodes and Flammulina of Tricholomataceae, Schizophyllum of Schizophyllum of Pleurotus eryngii, Auriculariales, Auriculariales, Auriculariales, Tremellaceae, Tremella, Polyporaceae, Bologna and Hericium erinaceus, Coriolus foetida of Coriolus, Ganoderma lucidum of Ganodermaceae, Pseudomonas spp. of Trichodermaceae, Agrocybe spp. of ...

[0031] The above embodiments are preferred implementation modes of the present invention, but are not limited to the above embodiments. They are applicable to edible fungi such as shiitake mushrooms, straw mushrooms, button mushrooms, black fungus, white fungus, hericium erinaceus, bamboo fungus, matsutake, trichoderma, red mushroom, ganoderma lucidum, cordyceps, truffle, white mushroom and boletus. Any changes, replacements, combinations, etc. made without departing from the principles of the present invention are included in the protection scope of the present invention.

[0032] The edible fungi and edible fungi liquid fermentation mycelium used in the present invention are both available to the public through conventional channels, and are not limited to a specific edible fungi liquid fermentation mycelium.

[0033] The citric acid used in the present invention is a green and non-toxic food-grade raw material, which can be used as a cross-linking agent to cross-link the treated edible fungus liquid fermentation mycelium, which helps the edible fungus liquid fermentation mycelium to form a network structure. During the natural drying of the mycelium filter cake, the edible fungus liquid fermentation mycelium network becomes denser. After the edible fungus liquid fermentation mycelium base paper is made, it helps to improve the tightness, tear resistance and tensile strength of the paper.

[0034] Step 2: Preparation of edible fungus liquid fermentation mycelium facial tissue; Step 2.1: Preparation of antioxidant food gum; 12 g of waxy corn starch was prepared into a suspension with a mass concentration of 4 g / 100 mL with 300 mL of pure water, and the suspension was placed in a boiling water bath and heated for 70 min. The heating was stopped and the temperature dropped to 90° C. to obtain a starch solution. 1.2 g of catechins was added to the starch solution to make the mass concentration of catechins in the starch solution reach 0.4 g / 100 mL. The suspension was stirred for 20 min at 400 r / min using a constant speed mixer, and then cooled to room temperature to obtain an antioxidant food glue. The waxy corn starch used in the present invention is a type of glucose-based polymer, with a branched starch content of more than 95%, different molecular weights, a degree of polymerization between 600-6000, and a side chain degree of polymerization between 20-25; starch granules are composed of radially arranged straight-chain starch and branched starch molecules, with an alternating structure of crystalline and amorphous regions; waxy corn starch granules are composed of highly branched molecules arranged radially. Compared with ordinary varieties of starch, the crystalline regions of waxy corn starch granules are loosely arranged, making it easier for heat, moisture, etc. to enter the interior of the microcrystal bundles, reducing the binding force of interchain oxygen bonds and changing the structure of the starch crystalline regions. After wet heat treatment, the starch granules will swell and rupture, starch molecules will flow out, starch gelatinization reaction will occur, and the viscosity of the system will increase; Catechin is epigallocatechin gallate, which is: Figure 6 After adding the natural antioxidant catechin, since catechin also contains a large number of hydroxyl groups, it can form hydrogen bonds with the hydroxyl groups of waxy starch molecules, play a bridging role in the waxy starch molecules, and promote the starch molecules to form a network structure, which further increases the viscosity of the system. After the temperature drops to room temperature, a food glue with antioxidant function is formed; Step 2.2: coating; The two sides of the edible fungus liquid fermentation mycelium base paper obtained in step 1 are evenly coated with the antioxidant food glue obtained in step 2.1 by a coating machine, and the single-side coating thickness is 40 μm, and then placed in a blast drying oven at 50° C. for 20 minutes to obtain the edible fungus liquid fermentation mycelium face paper; Through surface observation, the edible fungus liquid fermentation mycelium facial paper was screened to have no bubbles and defects on the surface; through antioxidant test, the edible fungus liquid fermentation mycelium facial paper was screened to have an oxidative free radical scavenging rate of more than 90%; through reflection photometer, the transparency of the edible fungus liquid fermentation mycelium facial paper was screened to be not less than 47%; using contact angle measuring instrument, the water phase contact angle of the edible fungus liquid fermentation mycelium facial paper was screened to be in the range of 70-90°; The present invention can fill the tiny pores on the surface of the edible fungus liquid fermentation mycelium base paper by evenly coating the antioxidant food glue on the edible fungus liquid fermentation mycelium base paper, improve the smoothness of the edible fungus liquid fermentation mycelium base paper, and give the edible fungus liquid fermentation mycelium base paper good hydrophobicity, thereby enhancing the antioxidant and antibacterial properties of the edible fungus liquid fermentation mycelium base paper, making it suitable as paper for food and medicine.

[0035] Step 3: Preparation of food grade glassine paper; Step 3.1: Preparation of Pickering nanoemulsion from edible fungus liquid fermentation mycelium; 120 g of Ganoderma lucidum liquid fermentation mycelium was dispersed in 300 ml of pure water to obtain a water dispersion of Ganoderma lucidum liquid fermentation mycelium with a mass concentration of 40%, and the water dispersion was placed in a planetary ball mill with a speed of 400 r / min for grinding for 3 h. After grinding, the microstructure of the Ganoderma lucidum liquid fermentation mycelium in the water dispersion of Ganoderma lucidum liquid fermentation mycelium was as follows: Figure 5 As shown; the ground water dispersion of Ganoderma lucidum liquid fermentation mycelium is placed in a vacuum freeze dryer and dried at -70°C for 8 hours to obtain Ganoderma lucidum liquid fermentation mycelium powder; 120mL of pure water is taken, 6g of Ganoderma lucidum liquid fermentation mycelium powder and 80mL of beeswax are added successively, so that the mass concentration of Ganoderma lucidum liquid fermentation mycelium powder in pure water is 0.5g / 100mL, and the volume ratio of beeswax to pure water is 2:3; the mixed solution is emulsified at 60°C using a high-speed emulsifier, and the emulsification is carried out at 25000r / min for 4 minutes to form edible fungus liquid fermentation mycelium Pickering nanoemulsion; In the preparation of food-grade glassine paper, edible fungus liquid fermentation mycelium powder is used as Pickering emulsifier, and after emulsification treatment, edible fungus liquid fermentation mycelium Pickering nanoemulsion with beeswax as dispersed phase is formed, which is evenly coated on edible fungus liquid fermentation mycelium facial paper, which helps to improve the glossiness of the facial paper and enhance the oil resistance of the facial paper; Step 3.2: coating; Using a coating machine, evenly coating the edible fungus liquid fermentation mycelium Pickering nanoemulsion on both sides of the edible fungus liquid fermentation mycelium facial paper obtained in step 2.2, with a coating thickness of 20 μm; placing the edible fungus liquid fermentation mycelium facial paper coated with the edible fungus liquid fermentation mycelium Pickering nanoemulsion in a blast drying oven, and drying it at 45° C. for 20 minutes to obtain food-grade glassine paper; The transparency of food-grade glassine paper screened by reflectance photometer is not less than 42%; the smoothness of food-grade glassine paper screened by smoothness tester is not less than 1000s; the roughness of food-grade glassine paper screened by roughness meter is not more than 1.8μm; the water contact angle of food-grade glassine paper screened by contact angle meter is not less than 80° and the oil contact angle is not less than 45°; the oil absorption test method is used to screen the oil absorption of food-grade glassine paper not more than 1g / m 2 ; Through the constant speed stretching method, the longitudinal tensile strength of the screened food-grade glassine paper is not less than 3.6kN / m, and the transverse tensile strength is not less than 1.8kN / m; through the gloss tester, the gloss of the screened food-grade glassine paper is not less than 40GU at a measuring angle of 75°; through the printer test, the text, barcode and other information printed on the screened food-grade glassine paper are clearly legible and can be accurately read by the scanning equipment; using the colorimeter, the color deviation of the font printed on the surface of the food-grade glassine paper is screened to be no more than 5.

[0036] Embodiment 2 of the present invention: The main difference from Example 1 is that when preparing the edible fungus liquid fermentation mycelium Pickering nanoemulsion, the Ganoderma lucidum liquid fermentation mycelium powder is dispersed in pure water at a concentration of 1 g / 100 mL, and the other operating steps are the same as those in Example 1.

[0037] Embodiment 3 of the present invention: The main difference from Example 1 is that when preparing the edible fungus liquid fermentation mycelium Pickering nanoemulsion, the Ganoderma lucidum liquid fermentation mycelium powder is dispersed in pure water at a concentration of 1.5 g / 100 mL, and the other operating steps are the same as those in Example 1.

[0038] Comparative Example 1: The main difference from Example 1 is that when preparing the edible fungus liquid fermentation mycelium Pickering nanoemulsion, no Ganoderma lucidum liquid fermentation mycelium powder is added, and the other operating steps are the same as those in Example 1.

[0039] The edible fungus liquid fermentation mycelium Pickering nanoemulsion prepared by Examples 1-3 and Comparative Example 1 is as follows Figure 7 As shown, Figure 7 From left to right in the figure are: Comparative Example 1: no Ganoderma lucidum liquid fermentation mycelium powder was added; Example 1: Ganoderma lucidum liquid fermentation mycelium powder was dispersed in pure water at a concentration of 0.5 g / 100 mL; Example 2: Ganoderma lucidum liquid fermentation mycelium powder was dispersed in pure water at a concentration of 1 g / 100 mL; Example 3: Ganoderma lucidum liquid fermentation mycelium powder was dispersed in pure water at a concentration of 1.5 g / 100 mL.

[0040] The parameters of the food grade glassine paper prepared in Examples 1-3 and Comparative Example 1 are shown in Table 1.

[0041] Paper transparency (%) Smoothness (s) Roughness(μm) Water contact angle (°) Oil phase contact angle (°) <![CDATA[Oil absorbency (g / m 2 )]]> Longitudinal tensile strength (kN / m) Transverse tensile strength (kN / m) Glossiness (GU) Font color deviation Example 1 43 1100 1.6 82 50 0.8 3.6 1.8 41 3 Example 2 42 1080 1.6 83 48 0.7 3.9 2.1 41 3 Example 3 40 1050 1.7 84 45 0.5 4.2 2.3 40 4 Comparative Example 1 40 900 1.9 76 35 1.4 2.8 1.4 37 6

[0042] Table 1 Various parameters of food grade glassine paper prepared from Examples 1-3 and Comparative Example 1.

[0043] Experimental Example 1: The only difference from Example 1 is that when preparing the antioxidant food gel: catechins are not added to the starch solution, so the catechin content in the antioxidant food gel is 0, and the other operating steps are the same.

[0044] Experimental Example 2: The only difference from Example 1 is that when preparing the antioxidant food gum: catechin is added to the starch solution so that the mass concentration of catechin in the starch solution reaches 0.2 g / 100 mL. Therefore, the catechin content in the antioxidant food gum is about 5%. The other operating steps are the same.

[0045] Experimental Example 3: The only difference from Example 1 is that when preparing the antioxidant food gum: catechin is added to the starch solution so that the mass concentration of catechin in the starch solution reaches 0.4 g / 100 mL. Therefore, the catechin content in the antioxidant food gum is about 10%. The other operating steps are the same.

[0046] Experimental Example 4: The only difference from Example 1 is that when preparing the antioxidant food gum: catechins are added to the starch solution so that the mass concentration of catechins in the starch solution reaches 0.6 g / 100 mL. Therefore, the catechin content in the antioxidant food gum is about 15%, and the other operating steps are the same.

[0047] Experimental Example 5: The only difference from Example 1 is that when preparing the antioxidant food gum: catechins are added to the starch solution so that the mass concentration of catechins in the starch solution reaches 0.8 g / 100 mL. Therefore, the catechin content in the antioxidant food gum is about 20%, and the other operating steps are the same.

[0048] The parameters of the food grade glassine paper prepared in Experimental Examples 1-5 are shown in Table 2.

[0049] Table 2 Various parameters of food grade glassine paper prepared in Experimental Examples 1-5.

[0050] Paper transparency (%) Smoothness(s) Roughness(μm) Water contact angle (°) Oil phase contact angle (°) <![CDATA[Oil absorbency (g / m 2) > Longitudinal tensile strength (kN / m) Transverse tensile strength (kN / m) Glossiness (GU) Font color deviation Experimental Example 1 40 850 2.0 60 35 1.5 2.7 1.3 36 6 Experimental Example 2 41 980 1.8 73 40 1.0 3.3 1.5 38 5 Experimental Example 3 42 1090 1.6 80 45 0.7 3.9 2.1 41 3 Experimental Example 4 42 1050 1.7 83 48 0.6 4.0 2.4 41 3 Experimental Example 5 41 990 1.8 78 42 0.9 3.7 1.9 39 4

[0051] Experimental Example 6 Preparation method of Ganoderma lucidum liquid fermentation mycelium: (1) Select the strain: Select high-quality, highly active, and genetically stable Ganoderma lucidum strains, such as Ganoderma lucidum, Ganoderma rubrum, etc. (the Ganoderma lucidum strain used in the present invention is Ganoderma lucidum), and prepare for liquid fermentation; (2) Preparation of slant culture medium and bacterial activation: Slant culture medium formula: 200 g potatoes (peeled, cut into pieces, boiled), 20 g glucose, 20 g agar, 1000 mL water; Mix the ingredients evenly, place in an autoclave, and sterilize at 121°C for 1 h. Then, wait for the culture medium to cool to about 42°C, pour it into a glass test tube under sterile conditions, cool it to room temperature, and prepare a slant culture medium. Inoculate the Ganoderma lucidum strain into the slant culture medium, and culture it at 28°C for 7 days. White Ganoderma lucidum hyphae can be seen sprouting and growing; (3) Preparation of seed culture medium and bacterial culture: Seed culture medium formula: 25 g glucose, 15 g peptone, 7 g yeast extract, 2 g potassium dihydrogen phosphate, 1 g magnesium sulfate, 1000 mL water; Mix the ingredients evenly, pour into a 300 mL Erlenmeyer flask, and place in an autoclave at 121°C for 1 hour. Then, wait for the culture medium to cool to room temperature, and under sterile conditions, use an inoculation spatula to pick 4 mycelium blocks with a diameter of 0.5 cm from the slant culture medium and place them in the Erlenmeyer flask containing the seed culture medium; The inoculated triangular flask was placed on a shaker and cultured at 28°C and 200 r / min for 7 days to allow the mycelium to fully grow and multiply to form a Ganoderma lucidum liquid fermentation mycelium suspension;

[0052] (4) Obtaining Ganoderma lucidum liquid fermentation mycelium by centrifugation: The Ganoderma lucidum liquid fermentation mycelium suspension was transferred to a centrifuge tube and centrifuged at 4000 r / min for 20 min to allow the Ganoderma lucidum liquid fermentation mycelium to settle at the bottom of the centrifuge tube, and the supernatant was recovered. The precipitated Ganoderma lucidum liquid fermentation mycelium was rinsed with ultrapure water for 3 times to obtain pure Ganoderma lucidum liquid fermentation mycelium.

[0053] After the above steps, food grade glassine paper prepared from liquid fermented mycelium of Ganoderma lucidum can be obtained. Figure 8 shown.

[0054] The steps in the method of the embodiment of the present invention can be adjusted in order, combined and deleted according to actual needs. In the scheme of the present invention, the description of each embodiment has its own emphasis. For the part that is not described or recorded in detail in a certain embodiment, refer to the relevant description of other embodiments. The various technical features of the technical solution of the present invention can be combined arbitrarily. In order to make the description concise, all possible combinations of the various technical features in the embodiment are not described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of the present invention.

[0055] The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A method for preparing food-grade glassine paper from edible fungus liquid fermentation mycelium, characterized in that: The method comprises the following steps: Step 1: using edible fungus liquid fermentation mycelium and sodium hydroxide solution to prepare alkali-treated edible fungus liquid fermentation mycelium, placing the alkali-treated edible fungus liquid fermentation mycelium in a steamer for steaming, placing the steamed alkali-treated edible fungus liquid fermentation mycelium in pure water to obtain edible fungus liquid fermentation mycelium water dispersion, homogenizing the edible fungus liquid fermentation mycelium water dispersion to obtain mycelium suspension, centrifuging the mycelium suspension and retaining the precipitate, vacuum filtering the precipitate to obtain mycelium filter cake, placing the filter cake in a mold, and drying it to obtain edible fungus liquid fermentation mycelium base paper; Step 2: waxy corn starch and purified water are prepared into starch liquid, and catechins are added to obtain antioxidant food glue; the antioxidant food glue is applied on both sides of the edible fungus liquid fermentation mycelium base paper to obtain the edible fungus liquid fermentation mycelium face paper; Step 3: Take edible fungus liquid fermentation mycelium and pure water to prepare edible fungus liquid fermentation mycelium powder, and obtain edible fungus liquid fermentation mycelium Pickering nanoemulsion by emulsification treatment; apply edible fungus liquid fermentation mycelium Pickering nanoemulsion on both sides of edible fungus liquid fermentation mycelium facial paper to obtain food-grade glassine paper.

2. The method for preparing food-grade glassine paper from edible fungus liquid fermentation mycelium according to claim 1, characterized in that: The specific operation method of using edible fungus liquid fermentation mycelium and sodium hydroxide solution to prepare alkali-treated edible fungus liquid fermentation mycelium is as follows: taking edible fungus liquid fermentation mycelium, adding sodium hydroxide solution with a mass concentration of 0.001%, so that the ratio of the mass of edible fungus liquid fermentation mycelium to the volume of sodium hydroxide solution with a mass concentration of 0.001% is: 10g / ml, and after stirring evenly, alkali-treated edible fungus liquid fermentation mycelium is obtained; the steaming method is as follows: spreading the alkali-treated edible fungus liquid fermentation mycelium in a mold, placing it in a 100°C steamer, and steaming it for 10 to 30 minutes.

3. The method for preparing food-grade glassine paper from edible fungus liquid fermentation mycelium according to claim 2, characterized in that: The specific method of placing the steamed alkali-treated edible fungus liquid fermentation mycelium in pure water to obtain the edible fungus liquid fermentation mycelium aqueous dispersion is: taking the steamed alkali-treated edible fungus liquid fermentation mycelium, rinsing it with pure water 2-3 times and then placing it in pure water to obtain the edible fungus liquid fermentation mycelium aqueous dispersion with a mass concentration of 20-60g / 100mL.

4. The method for preparing food-grade glassine paper from edible fungus liquid fermentation mycelium as claimed in claim 3, characterized in that: The specific method for homogenizing the edible fungus liquid fermentation mycelium water dispersion to obtain the mycelium suspension is as follows: homogenizing the edible fungus liquid fermentation mycelium water dispersion with a high-speed homogenizer for 10 to 30 minutes at 8500 to 10000 r / min to obtain mycelium suspension A, placing the mycelium suspension A on a temperature-controlled magnetic stirrer, dripping citric acid solution thereto to make the concentration of citric acid in the mycelium suspension A reach 0.1 to 0.5 g / 100 mL, reacting for 10 to 40 minutes at a temperature of 100 to 150° C. and a rotation speed of 200 to 400 r / min to obtain mycelium suspension B, then stopping heating, and magnetically stirring the mycelium suspension B at a rotation speed of 200 to 400 r / min until it is cooled to room temperature to obtain mycelium suspension C.

5. The method for preparing food-grade glassine paper from edible fungus liquid fermentation mycelium according to claim 4, characterized in that: The specific method of centrifuging the mycelium suspension and retaining the precipitate is: placing the mycelium suspension C in a centrifuge, centrifuging at 4000-5500 r / min for 10-20 minutes, recovering the supernatant, retaining the precipitate, and the precipitate is: mycelium precipitate A; rinsing the mycelium precipitate A with pure water and placing it in a centrifuge for centrifugation, repeating the above steps 2-3 times, retaining the precipitate, and the precipitate is: mycelium precipitate B; the specific method of vacuum filtering the precipitate to obtain the mycelium filter cake is: placing the mycelium precipitate B in a vacuum filter, maintaining the vacuum degree at -0.09-0.06MPa, filtering for 15-30 minutes, and obtaining the mycelium filter cake.

6. The method for preparing food-grade glassine paper from edible fungus liquid fermentation mycelium as claimed in claim 5, characterized in that: The specific method of placing the filter cake in a rectangular mold and drying it to obtain the edible fungus liquid fermentation mycelium base paper is as follows: placing the mycelium filter cake in a rectangular mold with a width of 10 cm and a length of 15 cm, using a spatula to smooth the surface of the mycelium filter cake so that the thickness of the mycelium filter cake in the rectangular mold is uniform, and the density of the mycelium filter cake in the rectangular mold is 0.6-1.6 g / cm3; placing the mycelium filter cake at room temperature for 10-12 hours, and drying it naturally to obtain the edible fungus liquid fermentation mycelium base paper.

7. The method for preparing food-grade glassine paper from edible fungus liquid fermentation mycelium as claimed in claim 6, characterized in that: The specific method for preparing the antioxidant food glue is as follows: waxy corn starch is prepared into a suspension with a mass concentration of 3-5 g / 100 mL with purified water, placed in a boiling water bath and heated for 45-95 min, heating is stopped, and the temperature is reduced to 85-95° C. to obtain a starch solution, catechin is added to the starch solution to make the mass concentration of catechin in the starch solution reach 0.3-0.6 g / 100 mL, a uniform speed mixer is used to stir for 10-30 min at 200-600 r / min, and then cooled to room temperature to obtain the antioxidant food glue.

8. The method for preparing food-grade glassine paper from edible fungus liquid fermentation mycelium according to claim 7, characterized in that: The specific method for preparing the edible fungus liquid fermentation mycelium facial paper is as follows: using a coating machine to evenly coat the two sides of the edible fungus liquid fermentation mycelium base paper with antioxidant food glue, with a single-side coating thickness of 20 to 50 μm, and then placing it in a blast drying oven at 40 to 60° C. for 10 to 30 minutes to obtain the edible fungus liquid fermentation mycelium facial paper.

9. The method for preparing food-grade glassine paper from edible fungus liquid fermentation mycelium according to claim 8, characterized in that: The specific method for preparing the edible fungus liquid fermentation mycelium Pickering nanoemulsion is as follows: taking edible fungus liquid fermentation mycelium and dispersing it in pure water to obtain an aqueous dispersion of edible fungus liquid fermentation mycelium with a mass concentration of 40%, placing it in a planetary ball mill, setting the rotation speed to 300-600r / min, and grinding it for 2-4h, placing the ground edible fungus liquid fermentation mycelium aqueous dispersion in a vacuum freeze dryer, and drying it at -70°C for 4-12h to obtain the edible fungus liquid fermentation mycelium aqueous dispersion. Fermented mycelium powder; taking purified water, successively adding edible fungus liquid fermented mycelium powder and beeswax to obtain a mixed solution, wherein the mass concentration of the edible fungus liquid fermented mycelium powder in purified water is 0.5-1.5 g / 100 mL, and the volume ratio of beeswax to purified water is 2:3-3:2; using a high-speed emulsifier, at 45-75° C., the mixed solution is emulsified at 20000-30000 r / min for 2-6 min to form edible fungus liquid fermented mycelium Pickering nanoemulsion.

10. The method for preparing food-grade glassine paper from edible fungus liquid fermentation mycelium according to claim 9, characterized in that: The specific method for preparing the food-grade glassine paper is as follows: using a coating machine, uniformly coating edible fungus liquid fermentation mycelium Pickering nanoemulsion on both sides of the edible fungus liquid fermentation mycelium facial paper, with a coating thickness of 10 to 30 μm; placing the edible fungus liquid fermentation mycelium facial paper coated with edible fungus liquid fermentation mycelium Pickering nanoemulsion in a blast drying oven, and performing drying treatment at 35 to 55° C. for 10 to 30 minutes to obtain the food-grade glassine paper.

11. The method for preparing food-grade glassine paper from edible fungus liquid fermentation mycelium according to claim 10, characterized in that: The edible fungus liquid fermentation mycelium base paper is screened to have no wrinkles, holes and spots; through the actual measurement method, the thickness deviation of the edible fungus liquid fermentation mycelium base paper is screened to be no more than ±6%, and the tightness is no less than 0.7g / cm3; through the paper tear strength tester, the edible fungus liquid fermentation mycelium base paper is screened to have a transverse tear strength of no less than 180mN; through the constant speed stretching method, the longitudinal tensile strength of the edible fungus liquid fermentation mycelium base paper is screened to be no less than 3kN / m, and the transverse tensile strength is no less than 1.3kN / m; through the hot and cold cycle environmental temperature test method, the edible fungus liquid fermentation mycelium base paper is screened to be free from deformation within the temperature range of -20 to 60°C.

12. The method for preparing food-grade glassine paper from edible fungus liquid fermentation mycelium according to claim 11, characterized in that: The edible fungus liquid fermented mycelium facial paper screened has no bubbles and defects on its surface; through antioxidant test, the edible fungus liquid fermented mycelium facial paper screened has an oxidative free radical scavenging rate of more than 90%; through reflectance photometer, the edible fungus liquid fermented mycelium facial paper screened has a transparency of not less than 47%; using a contact angle measuring instrument, the water phase contact angle range of the edible fungus liquid fermented mycelium facial paper screened is 70 to 90°.

13. The method for preparing food-grade glassine paper from edible fungus liquid fermentation mycelium according to claim 12, characterized in that: The transparency of the food-grade glassine paper is screened to be not less than 42% by a reflectance photometer; the smoothness of the food-grade glassine paper is screened to be not less than 1000s by a smoothness tester; the roughness of the food-grade glassine paper is screened to be not more than 1.8μm by a roughness meter; the water phase contact angle of the food-grade glassine paper is screened to be not less than 80° and the oil phase contact angle is not less than 45° by a contact angle measuring instrument; the oil absorption determination method is used to screen the oil absorption of the food-grade glassine paper to be not more than 1g / m2; the constant speed pull is used to screen the food-grade glassine paper to be not more than 1g / m2 By using the stretching method, the longitudinal tensile strength of the food-grade glassine paper is screened to be not less than 3.6 kN / m, and the transverse tensile strength is not less than 1.8 kN / m. By using the gloss tester, the gloss of the food-grade glassine paper is screened to be not less than 40 GU at a measuring angle of 75°. By using the printer test, the text, barcode and other information printed on the food-grade glassine paper are screened to be clear and can be accurately read by the scanning device. By using the colorimeter, the color deviation of the font printed on the surface of the food-grade glassine paper is screened to be no more than 5.

14. A food-grade glassine paper prepared from edible fungus liquid fermentation mycelium, characterized in that: The food-grade glassine paper is prepared by the method for preparing food-grade glassine paper from edible fungus liquid fermentation mycelium as described in any one of claims 1 to 13.

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