CN102864689A - Wheat protein coating food wrap paper and preparation method thereof - Google Patents

Abstract

The invention relates to a wheat protein-coated food packaging paper and a preparation method thereof, belonging to the technical field of food packaging. The preparation method comprises the following steps: preparation of base paper, preparation of coating solution, and coating amount of 5-60g/m2. In the paint composition, the weight concentration of wheat protein is 20-50%, the weight concentration of sodium sulfite is 0.05-0.1%, and the volume concentration of acetic acid is 1-4%. The food packaging paper obtained in the present invention can not only be used for general food packaging, but also meet special requirements for oxygen permeability, carbon dioxide permeability, and prevention of permeation and loss of two aromatic components, 2-heptanone and 2-nonanone. food packaging.

Description

A kind of wheat protein coated food wrapping paper and its preparation method

technical field

The invention relates to a wheat protein-coated food packaging paper and a preparation method thereof, belonging to the technical field of food packaging.

Background technique

With the increasing awareness of green food and green food packaging, the research and development of safe and non-toxic packaging materials has become a topic of concern for the food industry and related industries.

Whether traditional food packaging materials are plastic, paper, paper-plastic composite paper, aluminum-plastic composite paper or other composite paper, the residues of some industrial raw materials in the production process after packaging food will pollute the food more or less. Especially in the printing process of packaging paper, a large amount of volatile organic solvents such as acetone and xylene are used, which will bring secondary pollution to food, causing serious hidden dangers in food safety, and bringing food recalls to enterprises. risk.

In the past 20 years, more and more people are devoted to the research of environmental protection products, and they look for natural polymers from agricultural products as raw materials. The film-forming properties of biomacromolecules such as proteins make them have great development potential in material applications.

Chinese patent application number 200910197507.X discloses a "composite of edible film and food wrapping paper", which uses modified starch film to compound the food contact layer in the food wrapping paper. However, paper lamination technology for edible packaging films is complex and expensive. Chinese patent application number 200910097730.7 discloses a "wheat protein/methyl cellulose composite edible film and its preparation method", which uses the ratio of methyl cellulose and protein to adjust the mechanical properties and moisture permeability of the film. Harmful additives. However, the mechanical strength of edible packaging film is limited, and it is easy to be infected with bacteria, which is not conducive to the outer packaging of food.

my country is a big wheat producing country, but there are very few studies on the deep processing and transformation of wheat, and the development and research on the industrial use of wheat protein is still in its infancy. Therefore, using my country's abundant wheat resources as raw materials, using the film-forming properties of wheat gluten to develop the field of wheat utilization will have great social and economic benefits for reducing white pollution and protecting the earth's environment. However, the mechanical strength of the protein film is insufficient, so the protein is used for the coating of paper. Both protein and paper are biodegradable and recyclable, which sets them apart from existing man-made fiber materials. Moreover, the contact between wheat protein coating and packaged food is not only beneficial to avoid harmful ingredients in the production process of traditional packaging materials, but also the wheat protein coating based on hydrophilic solvent can improve the freshness of packaged food and ensure the quality and safety of food sex.

Contents of the invention

The purpose of the present invention is to overcome the above disadvantages, to provide a safe and non-toxic natural polymer material wheat protein to coat the paper to produce food packaging paper and its preparation method, avoiding the harm of food contamination by traditional food packaging materials. The coated paper can be used for general food health and environmental protection packaging, and can also be used for special food packaging that needs to selectively permeate oxygen and carbon dioxide and prevent the permeation and loss of two aromatic components, 2-heptanone and 2-nonanone. The wrapping paper is recyclable, biodegradable and comes from a wide range of sources.

According to the technical scheme of the present invention, a wheat protein-coated food wrapping paper comprises a base paper made from pulp beating and a coating coated on the base paper;

The formula ratio in the coating is as follows in parts by weight: 20-50 parts of wheat protein, 0.05-0.1 parts of sodium sulfite to form an aqueous solution with a mass concentration of 0.05%-0.1%, and 1-4 parts of acetic acid to form an aqueous solution with a volume concentration of 1%~4% aqueous solution.

The preparation method of described wheat protein coated food packaging paper, the steps are as follows in parts by weight:

(1) Preparation of base paper: Take 100 parts of raw pulp pulp based on the weight of the absolute dry pulp, and perform beating. The degree of beating is 30~60°SR. After dehydration and drying at 95~110℃, the base paper is obtained;

(2) Preparation and coating of paint: Take 20~50 parts of wheat protein powder, pour it into a sealed bottle, add an aqueous solution with a mass concentration of 0.05%~0.1% prepared by 0.05~0.1 part of sodium sulfite, shake it to disperse it Open; let it stand for 20~40min, then slowly add an aqueous solution with a volume concentration of 1%~4% prepared by 1~4 parts of acetic acid under the condition of magnetic stirring, control the pH to 3~5, stir and mix well to get the coating ; Coating the obtained coating on the paper obtained in step (1) by plastic pressing; during plastic pressing, the feed speed is 1-6m/min, the temperature is 20-40°C, and the surface pressure is 100-150kg/cm ³ .

The pulp papermaking step in the step (1) is as follows: adding additives to the pulp after beating, mixing uniformly to obtain pulp, and dehydrating and forming by a paper machine to obtain a wet paper sheet. The pulp described in step (1) is wood pulp and/or non-wood plant fiber pulp. The additives described in the step (1) are: 1-4 parts of cationic starch as an enhancer and/or 1-4 parts of modified starch. The basis paper described in the step (1) has a basis weight of 100-110 g/m2.

The coating amount described in step (2) is 5 ~ 60 g/m2.

The invention has the following advantages: all raw materials used in the invention are safe and non-toxic products, and will not migrate into food and affect the flavor of food. Moreover, wheat protein coated paper has special properties such as selectively permeating oxygen and carbon dioxide, reducing water vapor transmission rate and preventing the permeation and loss of two aromatic components, 2-heptanone and 2-nonanone. These properties make the coated paper not only suitable for general food health and environmental protection packaging, but also meet the special requirements of some food packaging. For example, based on the selective permeability of oxygen and carbon dioxide, coated paper is very beneficial for packaging foods that release carbon dioxide during storage; The packaging of food with ingredients can effectively prevent the loss of flavor and ensure the original taste of food.

Detailed ways

In the examples, the cationic starch was purchased from National Starch Industry (Shanghai) Co., Ltd., and the modified starch was purchased from National Starch Industry (Shanghai) Co., Ltd.

Example 1

(1) Preparation of base paper: Select kraft softwood pulp as the original pulp, add 1.5% cationic starch (based on the weight of absolute dry pulp) to the pulp, and make paper. The base paper weight is 60 g/m2. Beating, the beating degree is 30~60°SR, and then the wet paper sheet is obtained through pulp papermaking, the wet paper sheet is pressed, dehydrated, and dried at 95~110°C to obtain the base paper;

(2) Preparation and coating of paint: Weigh 20 grams of wheat protein powder, pour it into a sealed bottle, add 100 mL of sodium sulfite solution with a weight concentration of 0.08%, shake it to disperse it; let it stand for 30 minutes, and then stir it under magnetic force Slowly add 100 mL of acetic acid solution with a volume concentration of 2% under the conditions, control the pH to 4, stir well to make the mixture evenly mixed, and set aside. The obtained coating is coated on the paper obtained in step (1) by plastic pressing; the feeding speed is 2 m/min, the temperature is 30°C, and the surface pressure is 100 kg/cm ³ during plastic pressing.

Coating weight is 30 g/m2.

The coated paper prepared in this embodiment has the following indicators after testing:

The whiteness is 88.1%; the opacity is 96.2%; the surface strength is 1.86m/s; the breaking length is 3.89km; the tearing degree is 252mN; the oxygen permeability is 9000×10 ^-18 mol m ^-1 s ^-1 Pa ^-1 , the permeability of carbon dioxide is 18000×10 ^-18 mol m ^-1 s ^-1 Pa ^-1 , the permeability of 2-nonanone is 12950×10 ^-15 kg mm ^-2 s ^-1 Pa ^-1 , 2- The transmittance of heptanone is 750×10 ^-15 kg mm ^-2 s ^-1 Pa ^-1 .

Example 2:

(1) Preparation of base paper: take 100 parts of kraft softwood pulp based on the dry pulp weight as raw pulp for beating, and the beating degree is 55°SR, and then pulp papermaking to obtain wet paper sheets, wet paper sheets Press, dehydrate, and dry at 110°C to obtain the base paper; the basis weight of the base paper is 105 g/m2.

(2) Weigh 30 grams of wheat protein powder, pour it into a sealed bottle, add 100 mL of sodium sulfite solution with a weight concentration of 0.1%, shake it to disperse it; let it stand for 40 minutes, and then slowly add the volume concentration of 100mL of 3% acetic acid solution, control the pH to 4, stir well to make the mixture evenly mixed, set aside. The obtained paint is coated on the paper obtained in step (1) by plastic pressing; the feeding speed is 6m/min, the temperature is 40°C, and the surface pressure is 150kg/cm ³ during plastic pressing.

The obtained coating is coated on the paper obtained in step (1) by plastic pressing; the feeding speed is 1m/min, the temperature is 20°C, and the surface pressure is 120kg/cm ³ during plastic pressing. The coating basis weight was 55 g/m2.

The coated paper prepared in this embodiment has the following indicators after testing:

The whiteness is 87.3%; the opacity is 98.1%; the surface strength is 1.92m/s; the breaking length is 3.95km; the tearing degree is 342mN; the oxygen permeability is 5300×10 ^-18 mol m ^-1 s ^-1 Pa ^-1 , the permeability of carbon dioxide is 10700×10 ^-18 mol m ^-1 s ^-1 Pa ^-1 , the permeability of 2-nonanone is 9000×10 ^-15 kg mm ^-2 s ^-1 Pa ^-1 , 2- The transmittance of heptanone is 350×10 ^-15 kg mm ^-2 s ^-1 Pa ^-1 .

Example 3:

(1) Preparation of base paper: take 100 parts of kraft softwood pulp based on absolute dry pulp weight, and perform beating with a beating degree of 60°SR, and then obtain wet paper through pulp papermaking, wet paper pressing, The base paper is obtained after dehydration and drying at 95°C; the basis weight of the base paper is 70 g/m2.

(2) Preparation and coating of paint: Weigh 25 grams of wheat protein powder, pour it into a sealed bottle, add 100 mL of sodium sulfite solution with a weight concentration of 0.09%, shake it to disperse it; let it stand for 30 minutes, and then stir it under magnetic force Slowly add 100 mL of acetic acid solution with a volume concentration of 2.5% under the conditions, control the pH to 4, stir well to make the mixture evenly mixed, and set aside. The obtained paint is coated on the paper obtained in step (1) by plastic pressing; the feeding speed is 5m/min, the temperature is 25°C, and the surface pressure is 150kg/cm ³ during plastic pressing. The coating amount was 30 g/m2.

The coated paper prepared in this embodiment has the following indicators after testing:

The whiteness is 86.2%; the opacity is 95.1%; the surface strength is 1.87m/s; the breaking length is 3.97km; the tearing degree is 265mN; the oxygen permeability is 7250×10 ^-18 mol m ^-1 s ^-1 Pa ^-1 , the permeability of carbon dioxide is 14600×10 ^-18 mol m ^-1 s ^-1 Pa ^-1 , the permeability of 2-nonanone is 10300×10 ^-15 kg mm ^-2 s ^-1 Pa ^-1 , 2- The transmittance of heptanone is 460×10 ^-15 kg mm ^-2 s ^-1 Pa ^-1 .

Claims (7)

1. aleuronat coat foods wrapping paper is characterized in that: comprise by the manufacture paper with pulp basic paper that forms and coat coating on the basic paper of pulp beating;

Formula rate is as follows by weight in the coating: 20 ~ 50 parts of aleuronats, the mass concentration that is configured to take 0.05 ~ 0.1 part of sodium sulfite aqueous solution as 0.05% ~ 0.1%, the volumetric concentration that is configured to take 1 ~ 4 part of acetic acid aqueous solution as 1% ~ 4%.

2. the preparation method of the described aleuronat coat foods of claim 1 wrapping paper is characterized in that step is as follows by weight:

(1) preparation of basic paper: get and count 100 parts paper pulp magma with oven dry stock weight, pull an oar, beating degree is 30 ~ 60 ° of SR, copies paper through paper pulp again and obtains the l Water Paper page or leaf, obtains basic paper after the squeezing of l Water Paper page or leaf, dehydration, 95 ~ 110 ℃ of oven dry;

(2) preparation of coating and coating: get 20 ~ 50 parts of aleuronat powder, pour in the air-tight bottle, the mass concentration that adding is configured to by 0.05 ~ 0.1 part of sodium sulfite is 0.05% ~ 0.1% the aqueous solution, and concussion makes it to scatter; Leave standstill 20 ~ 40min, then slowly add the volumetric concentration that is configured to take 1 ~ 4 part of acetic acid aqueous solution as 1% ~ 4% under the magnetic agitation condition, control pH is 3 ~ 5, obtains coating after fully mixing; Adopt the plastic compression method to coat on step (1) the gained paper gained coating; Charging rate is 1 ~ 6m/min during plastic compression, and temperature is 20 ~ 40 ℃, and surface pressure is 100 ~ 150kg/cm ³

3. the preparation method of aleuronat coat foods wrapping paper as claimed in claim 2, it is characterized in that: paper pulp described in the step (1) is copied the paper step and is: add additive in the slurries after making beating, obtain paper pulp after mixing, behind paper machine, dehydration forming, namely get the l Water Paper page or leaf.

4. the preparation method of aleuronat coat foods wrapping paper as claimed in claim 2, it is characterized in that: paper pulp described in the step (1) is wood pulp and/or non-wood plant fibre slurry.

5. the preparation method of aleuronat coat foods wrapping paper as claimed in claim 3, it is characterized in that: additive is described in the step (1): 1 ~ 4 part of reinforcing agent cationic starch and/or 1 ~ 4 portion of modified starch.

6. the preparation method of aleuronat coat foods wrapping paper as claimed in claim 2, it is characterized in that: coating weight is 5 ~ 60 g/m2 described in the step (2).

7. the preparation method of aleuronat coat foods wrapping paper as claimed in claim 2, it is characterized in that: basic paper described in the step (1) quantitatively is 100 ~ 110 g/m2.