Edible film as well as preparation method and application thereof

Abstract

The invention discloses an edible film as well as a preparation method and application thereof. The edible film sequentially comprises a first protective layer, one or more than two content layers and a second protective layer from outside to inside. The edible film provided by the invention can ensure uniform addition of trace components, reduces loss of heat-labile effective components, avoids reaction among the components, and has good barrier property; the problems that at present, trace components of food seasoning cannot be evenly added, heat-resistant components are prone to loss, the components are prone to reacting, the barrier property of packaging materials is poor, and the production process is complex are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of food packaging materials, and particularly relates to an edible film and a preparation method thereof. Background Art

[0002] With the increasing demand of consumers for healthy diets, there are higher requirements for the nutrition and taste of instant noodles. To meet these needs, manufacturers have started to add various trace components, such as vitamins, minerals, etc., to instant noodles to enhance their nutritional value and taste. In the field of food packaging technology, polymer materials are widely used in the packaging of various foods, including the packaging of instant noodles. These polymer materials can provide good barrier properties to prevent the loss of components in the food, and at the same time can also provide certain protection for the food.

[0003] The existing methods for adding various trace components to convenience foods mainly involve adding the trace components to the seasoning packets of convenience foods. These trace components are usually added in the form of powders or liquids, and convenience foods such as instant noodles. First, since the addition amount of the trace components is very small, it is difficult to ensure the uniform addition of these components during the industrial mass production process. If the addition of the trace components is not uniform, it will result in inconsistent nutrient contents in each portion of the convenience food, thus affecting the health of consumers. Second, the manufacturing process of convenience foods includes thermal processing processes, such as steaming and drying in instant noodles. These thermal processing processes may cause the loss of some heat-sensitive active ingredients. In addition, some manufacturers have also tried to directly add trace components to the polymer material packaging, hoping that these components can be slowly released into the food through the packaging material, but various problems still exist.

[0004] For example, Patent CN1137013A discloses a seasoning packaging bag made of a starch film that is soluble in water but insoluble in oil, which is used for packaging the seasonings and dehydrated vegetables of instant foods. However, this patent only provides simple film-coated edibility and does not have a packaging protection function. Patent CN105358453A discloses that at least a part of the inner surface of a capsule is coated with a water-dispersible coating containing the functional component. Appropriately, the functional component includes flavonoids, such as cocoa polyphenol extract. Appropriately, the coating contains the functional component and a film-forming polymer. The coating is preferably located downstream of the beverage preparation components inside the capsule. However, this patent simply solves the dispersion of the functional component in the beverage and avoids the adsorption or reaction of the functional component with the beverage components and the filter material, without considering the influence of the thermal processing process on heat-sensitive components and the effects of various complex functional nutrients.

[0005] Therefore, it is an urgent problem to be solved to develop an edible film that can ensure uniform addition of trace components, reduce the loss of heat-sensitive components, avoid reactions between components, improve the barrier properties of packaging materials, and has a simple production process. Summary of the Invention

[0006] To solve the above technical problems, the present invention provides an edible film, its preparation method and application, which solve the problems that trace components of current food seasonings cannot be uniformly added, heat-sensitive components are easily lost, reactions are likely to occur between components, the barrier properties of packaging materials are poor, and the production process is complex.

[0007] An edible film provided by the present invention includes, from outside to inside in sequence, a first protective layer, one or more than two content layers, and a second protective layer;

[0008] The components of the first protective layer or the second protective layer include:

[0009] 70 to 75 parts by weight of gelatin masterbatch, 0.3 to 0.9 parts by weight of hybrid material, 10 to 15 parts by weight of plasticizer, and 10 to 15 parts by weight of water;

[0010] The components of the content layer include:

[0011] 70 to 75 parts by weight of gelatin masterbatch, 0.3 to 0.9 parts by weight of hybrid material, 10 to 15 parts by weight of plasticizer, and 10 to 15 parts by weight of water.

[0012] Optionally, the components of the content layer further include trace components, and the trace components are added according to requirements.

[0013] Optionally, the number of the content layers is 7.

[0014] Optionally, the trace components are one or more of vitamins, minerals, DHA algal oil, probiotics, antioxidants.

[0015] Optionally, the hybrid material is one or more of montmorillonite, diatomite, silica.

[0016] Optionally, the plasticizer is one or more of polyol esters and epoxides.

[0017] Optionally, the polyol ester is one or more of ditrimethylolpropane tetraester, glycol benzoate, glyceryl triacetate; the epoxide is one or more of epoxidized soybean oil, linseed oil.

[0018] The present invention also provides a preparation method of an edible film for preparing the above-mentioned edible film, including:

[0019] Premix and hydrate the components of the first protective layer, the content layer, and the second protective layer respectively. After mixing, heat and melt the mixture in a conical blender, and rotate and extrude it to the die head of a multi-layer co-extrusion casting and stretching machine by a twin-screw extruder. After multi-layer extrusion and cooling by a cooling roll, it is delivered by a transfer roll and wound up to obtain a multi-layer edible film.

[0020] Optionally, the preparation method includes: premixing and hydrating the components of the first protective layer, the content layer, and the second protective layer respectively in a conical blender. After mixing evenly, heat and melt the mixture in a twin-screw extruder. The temperature in the heating zone of the twin-screw extruder is controlled in sections. The temperature at the feeding port is controlled at 80 °C, the temperature in the middle section is controlled at 90 °C to 100 °C, the screw speed is set at 140 rpm, and the temperature at the discharging port is controlled at 90 °C. Cooling is carried out to quickly solidify the extruded material, and then it is rotated and extruded to the die head of a multi-layer co-extrusion casting and stretching machine by a twin-screw extruder. The temperatures in the heating zones of different sheet extruders are set at 80 °C, 90 °C, and 95 °C, and the temperatures in the merging zone and the sealing head zone are set at 105 °C. After multi-layer extrusion and cooling by a cooling roll, it is delivered by a transfer roll and wound up to obtain a multi-layer edible film. By adjusting the rotation speeds of the cooling roll and the transfer roll between 5 - 7 revolutions per minute, the total thickness of the film is controlled at 200 ± 30 μm.

[0021] The present invention also provides an application of the edible film in a food packaging bag, and the edible film is the above-mentioned edible film or is prepared by the preparation method of the above-mentioned edible film.

[0022] Optionally, the food is instant noodles.

[0023] Optionally, the food packaging bag is a seasoning packaging bag.

[0024] The edible film, its preparation method, and application provided by the embodiments of the present invention have the following advantages compared with the prior art:

[0025] The edible film provided by the embodiment of the present invention sequentially includes a first protective layer, one or more than two content layers, and a second protective layer from outside to inside. Among them, the components of the first protective layer or the second protective layer include 70 to 75 parts by weight of gelatin masterbatch, 0.3 to 0.9 parts by weight of hybrid material, 10 to 15 parts by weight of plasticizer, and 10 to 15 parts by weight of water; the components of the content layer include 70 to 75 parts by weight of gelatin masterbatch, 0.3 to 0.9 parts by weight of hybrid material, 10 - 15 parts by weight of plasticizer, and 10 to 15 parts by weight of water. The edible film provided by the present invention can ensure the uniform addition of trace components, reduce the loss of heat-sensitive active ingredients, avoid the reaction between components, and has good barrier properties.

[0026] In addition, an embodiment of the present invention further provides a method for preparing an edible film, which is realized by a co - extrusion method, with a simple production process, high production efficiency, and low production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic structural diagram of a multi - layer co - extrusion casting and stretching machine in an embodiment of the present invention.

[0028] REFERENCE NUMERALS:

[0029] 1 - multi - layer co - extrusion casting and stretching machine;

[0030] 101a, 101b, 101c - conical mixers; 102a, 102b, 102c - twin - screw extruders; 103 - cooling roller; 104 - transfer roller; 105 - first protective layer; 106 - first content layer; 107 - second protective layer. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] As described in the background art, the existing methods for adding various trace components to instant noodles mainly involve adding trace components to the seasoning packets of instant noodles, and these trace components are usually added in the form of powders or liquids. First, since the addition amount of trace components is very small, it is difficult to ensure the uniform addition of these components during industrial mass production. If the addition of trace components is not uniform, it will lead to inconsistent nutrient content in each portion of instant noodles, thus affecting the health of consumers. Second, the production process of instant noodles includes thermal processing processes such as steaming and drying. These thermal processing processes may cause the loss of some heat - sensitive active ingredients. In addition, some manufacturers have also tried to directly add trace components to the packaging of polymer materials in the hope that these components can be slowly released into the food through the packaging material, but there are still various problems. Therefore, it is an urgent problem to develop an edible film that can ensure the uniform addition of trace components, reduce the loss of heat - sensitive components, avoid reactions between components, improve the barrier performance of packaging materials, and has a simple production process.

[0032] To solve the above technical problems, the edible film provided by the embodiments of the present invention sequentially includes a first protective layer, one or more than two content layers, and a second protective layer from outside to inside. The components of the first protective layer or the second protective layer include 70 to 75 parts by weight of gelatin masterbatch, 0.3 to 0.9 parts by weight of hybrid material, 10 to 15 parts by weight of plasticizer, and 10 to 15 parts by weight of water; the components of the content layer include 70 to 75 parts by weight of gelatin masterbatch, 0.3 to 0.9 parts by weight of hybrid material, 10 to 15 parts by weight of plasticizer, and 10 to 15 parts by weight of water. The edible film provided by the present invention can ensure the uniform addition of trace components, reduce the loss of heat-sensitive active ingredients, avoid the reaction between components, and has good barrier properties.

[0033] In addition, the embodiments of the present invention also provide a preparation method of an edible film. This preparation method is realized by co-extrusion blending, with a simple production process, high production efficiency, and low production cost.

[0034] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be described in detail below with reference to the drawings and specific embodiments.

[0035] The raw materials, samples, reagents, equipment, etc. used in the embodiments of the present invention are all commercially available products that can be purchased in the market unless otherwise specified.

[0036] An edible film provided by the embodiments of the present invention, the edible film sequentially includes a first protective layer, one or more than two content layers, and a second protective layer from outside to inside; the components of the first protective layer or the second protective layer include: 70 to 75 parts by weight of gelatin masterbatch, 0.3 to 0.9 parts by weight of hybrid material, 10 to 15 parts by weight of plasticizer, and 10 to 15 parts by weight of water; the components of the content layer include: 70 to 75 parts by weight of gelatin masterbatch, 0.3 to 0.9 parts by weight of hybrid material, 10 to 15 parts by weight of plasticizer, and 10 to 15 parts by weight of water.

[0037] In some embodiments, the components of the content layer further include trace components, and the trace components are added according to requirements. In some embodiments, the trace components are one or more of vitamins, minerals, DHA algal oil, probiotics, antioxidants.

[0038] In some embodiments, the number of content layers can be 7.

[0039] In some embodiments, the hybrid material is one or more of montmorillonite, diatomite, and silica.

[0040] In some embodiments, the plasticizer is one or more of polyol esters and epoxides.

[0041] In some embodiments, the polyol ester is any one or more of dipentaerythritol ester, glycol benzoate, and glyceryl triacetate; the epoxide is one or more of epoxidized soybean oil and linseed oil.

[0042] Please refer to Figure 1 , Figure 1 which is the process flow chart of the edible film in the embodiment of the present invention.

[0043] As described below, the present invention provides a method for preparing an edible film for preparing the edible film as described above, including: premixing and hydrating the components of the first protective layer, the content layer, and the second protective layer respectively, heating and melting and mixing them in a twin-screw extruder, rotating and pushing them out by the twin-screw extruder to the die head of a multi-layer co-extrusion casting machine, cooling them through a cooling roll after multi-layer extrusion, and delivering and winding them up by a transfer roll to obtain a multi-layer edible film. The preparation method is realized by a co-mixing extrusion method, with a simple production process, high production efficiency, and low production cost. It should be noted that the equipment for preparing the edible film in the embodiment of the present invention is a multi-layer co-extrusion casting and stretching machine, model FEPU-30-250, and this multi-layer co-extrusion casting and stretching machine includes a conical mixer, a twin-screw extruder, a cooling roll, and a transfer roll. Figure 1 which is the structural schematic diagram of the multi-layer co-extrusion casting and stretching machine in the embodiment of the present invention. As Figure 1 shown, the multi-layer co-extrusion casting and stretching machine 1 includes conical mixers 101a, 101b, 101c, twin-screw extruders 102a, 102b, 102c, a cooling roll 103, and a transfer roll 104, wherein the conical mixers 101a, 101b, 101c are connected to the twin-screw extruders 102a, 102b, 102c, and the materials stirred well by the conical mixers 101a, 101b, 101c are respectively conveyed to the corresponding twin-screw extruders 102a, 102b, 102c. The twin-screw extruders are sequentially connected to the cooling roll 103 and the transfer roll 104. After being extruded by the twin-screw extruders 102a, 102b, 102c, the materials are sequentially conveyed to the cooling roll 103 for cooling, and then conveyed to the product end through the transfer roll 104. Taking Figure 1 the three-layer edible film as an example, the multi-layer co-extrusion casting and stretching machine 1 can produce an edible film including a first protective layer 105, a first content layer 106, and a second protective layer 107 at one time. It should be noted that according to production needs, the multi-layer co-extrusion casting and stretching machine 1 can increase the number of conical mixers and twin-screw extruders corresponding to the number of content layers, and the maximum number of content layers can be 7 layers.

[0044] Further, please continue to refer toFigure 1 , in some embodiments, the preparation method includes: premixing and hydrating the components of the first protective layer, the content layer, and the second protective layer in conical mixers 101a, 101b, 101c respectively. After mixing evenly, melt and mix them in twin-screw extruders 102a, 102b, 102c. The temperature in the heating zones of twin-screw extruders 102a, 102b, 102c is controlled in sections (there are 6 temperature zones in the 102a area, and the temperature of each zone can be controlled independently). The temperature at the feeding port is controlled to 80°C, the temperature in the middle section is controlled to 90°C to 100°C, the screw speed is set to 140 rpm, the temperature at the discharging port is controlled to 90°C, and cooling is carried out to quickly solidify the extruded material. Then, it is rotated and pushed out by the twin-screw extruder to the die head of the multi-layer co-extrusion casting and stretching machine 1. The heating zones of different sheet extruders are set to 80°C, 90°C, and 95°C, the temperature in the merging zone and the sealing head zone (the position of the cooling roll 103) is set to 105°C. After multi-layer extrusion and cooling by the cooling roll, it is delivered by the transfer roll and the winding is completed to obtain a multi-layer edible film. By adjusting the rotation speed of the cooling roll 103 and the transfer roll 104 between 5 - 7 revolutions per minute, the total thickness of the edible film is controlled within 200 ± 30 μm.

[0045] The present invention also provides an application of the edible film in a food packaging bag, and the edible film is the above-mentioned edible film or is prepared by the preparation method of the above-mentioned edible film.

[0046] Optionally, in some embodiments, the food is instant noodles.

[0047] Optionally, in some embodiments, the food packaging bag is a seasoning packaging bag.

[0048] Example 1

[0049] The purpose of this Example 1 is to prepare an edible film including a first protective layer, a first content layer, and a second protective layer.

[0050] 1. Formula

[0051] The components of the first protective layer and the second protective layer are:

[0052] Gelatin 725 g, silicon dioxide 9 g, epoxidized soybean oil 110 g, water 110 g.

[0053] The components of the first content layer are:

[0054] Gelatin 725 g, silicon dioxide 9 g, epoxidized soybean oil 110 g, water 110 g, trace components: calcium carbonate 34 g, ferrous fumarate 9 g, zinc oxide 0.28 g.

[0055] 2. Equipment

[0056] Multi-layer co-extrusion casting and stretching machine, model FEPU-30-250. This multi-layer co-extrusion casting and stretching machine includes a conical mixer, a twin-screw extruder, a cooling roll, and a transfer roll. The specific structure is as Figure 1 shown.

[0057] 3. Preparation method

[0058] Respectively premix and hydrate the components of the first protective layer, the first content layer, and the second protective layer in a conical mixer. After mixing evenly, melt and mix them in a twin-screw extruder. The temperature in the heating zone of the twin-screw extruder is controlled in sections. The temperature at the feed inlet is controlled to 80 °C, the temperature in the middle section is controlled to 90 °C to 100 °C, the screw speed is set to 140 rpm, the temperature at the discharge port is controlled to 90 °C, and cooling is carried out to quickly solidify the extruded material. Then, it is rotated and pushed out by the twin-screw extruder to the die head of the multi-layer co-extrusion casting and stretching machine. The heating zones of different sheet extruders are set to 80 °C, 90 °C, and 95 °C, and the temperatures in the merging zone and the sealing head zone are set to 105 °C. After multi-layer extrusion, it is cooled by a cooling roll and then delivered by a transfer roll to complete winding, obtaining a multi-layer edible film. By adjusting the rotation speeds of the cooling roll and the transfer roll, within 5 - 7 revolutions per minute, the thickness of the film is controlled within 200 ± 30 μm.

[0059] Example 2

[0060] The purpose of this Example 2 is to prepare an edible film including a first protective layer, a first content layer, and a second protective layer.

[0061] 1. Formulation

[0062] The components of the first protective layer and the third protective layer are:

[0063] Gelatin 1500 g, silicon dioxide 9 g, epoxy soybean oil 220 g, water 220 g.

[0064] The components of the second content layer are:

[0065] Gelatin 1500 g, silicon dioxide 9 g, epoxy soybean oil 220 g, water 220 g, nutrient premix (including thiamine hydrochloride VB1, riboflavin VB2, pyridoxine hydrochloride VB6, edible corn starch) 20 g. The target values of VB1, VB2, and VB6 in the nutrient premix are all 7 g / kg.

[0066] 2. Equipment

[0067] Same as Example 1, which will not be elaborated here.

[0068] 3. Preparation method

[0069] Same as Example 1, which will not be elaborated here.

[0070] Example 3

[0071] The objective of Example 3 is to prepare an edible film including a first protective layer, a first content layer, and a second protective layer.

[0072] 1. Formulation

[0073] The components of the first protective layer and the second protective layer are as follows:

[0074] 1500 g of gelatin, 9 g of silicon dioxide, 220 g of epoxidized soybean oil, 220 g of water.

[0075] The components of the first content layer are as follows:

[0076] 1500 g of gelatin, 9 g of silicon dioxide, 220 g of epoxidized soybean oil, 220 g of water, 200 mg of vitamin E.

[0077] 2. Equipment

[0078] Same as Example 1, which will not be elaborated here.

[0079] 3. Preparation method

[0080] Same as Example 1, which will not be elaborated here.

[0081] Effect Example 1

[0082] The following specific effect examples are used to illustrate the advantages of the edible film of the present invention in adding trace minerals during the mass production of instant noodles.

[0083] 1. Conventional addition method of minerals in instant noodle seasoning packets

[0084] The production of instant noodles has a high degree of automation. An automatic weighing and batching system is used for powder production and packaging. The program is set to feed 320 kg of maltodextrin, 160 kg of compound seasoning powder, 80 kg of spices, 240 kg of edible salt, 6 kg of calcium carbonate, 100 g of ferrous fumarate, and 50 g of zinc oxide for mixing. When mixing, the motor speed is 1050 r / min (rated speed 1500 r / min). After mixing, it is packaged into 15 g / bag. Samples are taken at 10 points before, during, and after packaging, and 10 bags are sampled at each point and mixed for mineral detection. The test methods can refer to: GB 5009.92 National Food Safety Standard - Determination of Calcium in Foods; GB 5009.14 National Food Safety Standard - Determination of Zinc in Foods; GB 5009.90 National Food Safety Standard - Determination of Iron in Foods; The determination results are shown in Table 1.

[0085] Table 1 Sampling mineral detection results of the conventional addition method of minerals in instant noodle seasoning packets

[0086]

[0087] 2. The convenient food ingredient packet adopts the mineral addition method of the present invention

[0088] (1) Formula

[0089] The components of the content layer are the same as those in Example 1, and the specific components are as follows:

[0090] Gelatin 725g, silicon dioxide 9g, epoxy oil 110g, water 110g, trace minerals are: calcium carbonate 34g, ferrous fumarate 9g, zinc oxide 0.28g.

[0091] (2) Preparation method

[0092] To test the uniformity, only the content layer was prepared to explore whether its distribution is uniform.

[0093] The components of the content layer were premixed and hydrated in a conical blender. After being mixed evenly, they were melted and mixed in a twin-screw extruder. The temperature of the heating zone of the extruder was controlled in sections. The temperature at the feed inlet was controlled to 80°C to prevent the material from melting and blocking the feed inlet. The temperature in the middle section was controlled at 90°C to 100°C, the screw speed was set at 140 rpm, and the temperature at the take-up port was controlled at 90°C. External cooling (air cooling, water cooling) was combined to achieve rapid solidification of the extruded material. After cooling and solidification, it was sent into a casting machine, and the heating zone of the sheet extruder was set at 80°C. By adjusting the rotation speed of the cooling roll and the transfer roll between 5 - 7 revolutions per minute, the thickness of the film was controlled at 100 ± 30 μm. After making the edible powder coating, it was 3.3 g per portion. 10 samples were taken from different positions of the finished packaging material to detect the mineral content. The test methods can be referred to: GB 5009.92 National Food Safety Standard - Determination of Calcium in Foods; GB 5009.14 National Food Safety Standard - Determination of Zinc in Foods; GB 5009.90 National Food Safety Standard - Determination of Iron in Foods; The test results are shown in Table 2.

[0094] Table 2 Sampling Mineral Detection Results of the Convenient Food Ingredient Packet Adopting the Mineral Addition Method of the Present Invention

[0095]

[0096] It can be seen from the results of Table 1 and Table 2 that when trace minerals are directly added to the powdery seasonings, through actual sampling and detection, it is found that the content in the seasoning packet fluctuates greatly, especially the relative standard deviation of minerals such as iron and zinc is large and unacceptable. Since all materials are automatically added during the mass production process, it is impossible to add them in the form of premixing and equal gradients. However, in the present invention, trace minerals are added to each seasoning packet in the form of an edible film, which can achieve the uniformity of the addition of trace mineral elements.

[0097] Effect Example 2

[0098] The advantages of adding vitamins to the edible film of the present invention in the flour product will be described below through specific effect examples.

[0099] 1. Conventional methods of adding vitamins to flour products

[0100] Weigh 950 g of wheat flour, 350 g of water, and 20 g of a nutrient premix (including thiamine hydrochloride VB1, riboflavin VB2, pyridoxine hydrochloride VB6, and edible corn starch). The target values of VB1, VB2, and VB6 in the nutrient premix are all 7 g / kg. The nutrient premix is first dissolved in water, and then the water rich in nutrient fortification is mixed with the wheat flour in a dough mixer to obtain dough. The dough is successively subjected to proofing, compounding, rolling, and cutting to make raw noodles with a length of 30 cm, a thickness of 1.2 mm, and a width of 1.5 mm. The raw noodles are cooked at a water boiling temperature of 98°C to 100°C for 2 minutes to obtain α - modified noodles. The α - modified noodles are washed and cooled in clean water at a temperature of 20°C for 30 s. The washed noodles are placed in a drying box and dehydrated by hot - air drying. At least two drying processes are carried out. The first hot - air drying: the wind speed is 60 m / s, the temperature is 110°C, and the time is 10 min; the second hot - air drying: the wind speed is 5 m / s, the temperature is 80°C, and the time is 50 min. Non - fried instant noodles are thus obtained, with each noodle cake weighing 85 g. Before, during, and after the completion of the drying process, 3 samples are taken at each of 3 points for testing, and the retention rate is obtained by comparing with the theoretical addition amount. The retention rate is the vitamin content in the instant noodle cake after processing divided by the theoretical value of the vitamin content.

[0101] In the blank control experiment plan, the nutrient premix is not added, and the rest is the same as the above content.

[0102] The detection method of vitamins is determined according to the national standard method. Specifically, it can be referred to: GB 5009.84 - 2016 National Food Safety Standard - Determination of Vitamin B1 in Foods; GB 5009.85 - 2016 National Food Safety Standard - Determination of Vitamin B2 in Foods; GB 5009.154 - 2023 National Food Safety Standard - Determination of Vitamin B6 in Foods. The test results are shown in Table 3. It should be noted that the quantitative limits of VB1, VB2, and VB6 are 1 mg / kg, 0.2 mg / kg, and 0.4 mg / kg respectively. Values lower than this cannot be detected.

[0103] Table 3 Sampling vitamin detection results of the conventional method of adding vitamins to flour products

[0104]

[0105] Table 3 description: Wheat flour itself also contains some vitamins. Therefore, the vitamins in the wheat flour of the above formula were also detected. The test results showed that vitamin B1 was not detected in the wheat flour of the formula, the content of vitamin B2 was 0.60 mg / kg, and the content of vitamin B6 was 1.1 mg / kg.

[0106] In addition, there were 9 groups in the blank control group, all of which were additionally added with vitamins. The test results showed that vitamins B1, B2, and B6 were not detected in the 9 instant noodle samples of the blank control.

[0107] The theoretical value refers to the sum of the content of the externally added vitamins and the background value of the wheat flour. The moisture content of the instant noodles is 10.02%, and the moisture content of the wheat flour is 13%. The theoretical content of vitamins in the noodle cake = the content of the added vitamins / (the dry weight of the wheat flour + the moisture content of the noodle cake).

[0108] 2. The vitamin addition method of the present invention is adopted in the noodle body

[0109] (1) Formula (the formula of Example 2)

[0110] The components of the first content layer are:

[0111] 1500 g of gelatin, 9 g of silicon dioxide, 220 g of epoxy oil, 220 g of water, 20 g of nutrient premix (including thiamine hydrochloride VB1, riboflavin VB2, pyridoxine hydrochloride VB6, edible corn starch). The target values of VB1, VB2, and VB6 in the nutrient premix are all 7 g / kg.

[0112] The components of the first protective layer and the second protective layer are: 1500 g of gelatin, 9 g of silicon dioxide, 220 g of epoxy oil, 220 g of water.

[0113] (2) Preparation method

[0114] The components of the first content layer, the first protective layer, and the second protective layer are pre-mixed and hydrated separately in a conical mixer. After being evenly mixed, they are melted and mixed in a twin-screw extruder. The temperature of the heating zones of the extruder is controlled in sections. The temperature at the feed inlet is controlled to 80 °C to prevent the material from melting and blocking the feed inlet. The temperature in the middle section is controlled at 90 °C - 100 °C, the screw speed is set at 140 rpm, and the temperature at the take-up port is controlled at 90 °C. External cooling (air cooling, water cooling) is combined to achieve rapid curing of the extruded material. After cooling and curing, it is placed in a multi-layer co-extrusion casting machine. The temperatures of the heating zones of different sheet extruders are set at 80 °C, 90 °C, and 95 °C, and the temperatures in the merging zone and the sealing head zone are set at 105 °C. By adjusting the rotational speeds of the cooling roll and the transfer roll between 5 - 7 revolutions per minute, the thickness of the film is controlled at 200 ± 30 μm. After making the edible powder coating, it is 3.3 g per portion. 10 samples are taken from different positions of the finished packaging material to detect the mineral content. The test methods can be referred to: GB 5009.84-2016 National Food Safety Standard - Determination of Vitamin B1 in Foods; GB 5009.85-2016 National Food Safety Standard - Determination of Vitamin B2 in Foods; GB 5009.154-2023 National Food Safety Standard - Determination of Vitamin B6 in Foods; The test results are shown in Table 4.

[0115] Table 4 Vitamin Detection Results of Sampling with the Vitamin Addition Method of the Present Invention in the Tetrahedron

[0116]

[0117] It can be seen from the results of Table 3 and Table 4 that in the conventional vitamin addition method in the tetrahedron, heat-sensitive trace raw materials such as vitamins are easily lost under the hot processing conditions of the noodle cake. From the experimental data, about 90% of the added vitamin B1 is lost, only about 10% remains, about 84% of vitamin B2 is lost, only 15.73% remains, and about 80% of vitamin B6 is lost, only about 20.57% remains. However, by adding through the edible film of the present invention, the retention rate is greatly improved.

[0118] Effect Example 3

[0119] The following specific effect examples are used to illustrate the advantages of the edible film of the present invention in adding antioxidants to the fried noodle cake.

[0120] 1. Conventional Method of Adding Antioxidants to Fried Noodle Cake

[0121] (1) Noodle Cake Formula

[0122] 950 g of wheat flour, 350 g of water, and 26.5 g of other auxiliary materials. The other auxiliary materials are composed of 20 g of salt, 2.5 g of thickener, and 4 g of acidity regulator. It should be noted that the thickener is composed of guar gum, xanthan gum, and sodium alginate, and the weight ratio of guar gum:xanthan gum:sodium alginate is 5:4:1; the acidity regulator is composed of sodium carbonate, potassium carbonate, and phosphate, and the weight ratio of sodium carbonate:potassium carbonate:phosphate is 1:1.2:1.8.

[0123] (2)Method for preparing noodle cake

[0124] Weigh the raw materials according to the formula, and mix the raw materials in a dough mixer to obtain a dough; let the dough go through proofing, compounding, rolling, and cutting into raw noodles with a length of 30 cm, a thickness of 1.2 mm, and a width of 1.5 mm; place the raw noodles in a steamer at a temperature of 100 °C, a steam box pressure of 9 kPa, and a saturated steam flow rate of 800 kg / h, and steam for 3 min for α - gelatinization to obtain α - gelatinized noodles; place the α - gelatinized noodles in a frying box for gradient frying. The frying temperature of the first gradient is 110 °C - 125 °C, and the frying time is 35 s; the frying temperature of the second gradient is 125 °C - 135 °C, and the frying time is 40 s; the frying temperature of the third gradient is 135 °C - 152 °C, and the frying time is 35 s. Then the fried instant noodles are obtained, and the fried noodle cake is 85 g per portion.

[0125] The frying oil is palm oil. The conventional addition method of antioxidant in the fried noodle cake is to add 200 mg / Kg of vitamin E to the frying oil. Using the conventional addition method, the amount of antioxidant needed to add to one noodle cake = 85 * 20% * 200 / 1000 = 3.4 mg, where the oil content of the noodle cake is 20%.

[0126] 2. The antioxidant in the fried noodle cake adopts the addition method of the present invention

[0127] (1)Multi - layer material coating formula (formula of Example 3)

[0128] The components of the second content layer are:

[0129] 1500 g of gelatin, 9 g of silicon dioxide, 220 g of epoxy oil, 220 g of water, and 200 mg of vitamin E.

[0130] The components of the first protective layer and the second protective layer are both: 1500 g of gelatin, 9 g of silicon dioxide, 220 g of epoxy oil, and 220 g of water.

[0131] (2)Method for preparing multi - layer material coating

[0132] The content layer and the protective layer are pre-mixed and hydrated in a conical mixer respectively. After being evenly mixed, they are melted and mixed in a twin-screw extruder. The temperature of the heating zones of the extruder is controlled in sections. The temperature at the feed inlet is controlled to 80 °C to prevent the material from melting and blocking the feed inlet. The temperature in the middle section is controlled to be 90 °C to 100 °C, the screw speed is set to 140 rpm, and the temperature at the material receiving port is controlled to 90 °C. External cooling (air cooling, water cooling) is combined to achieve rapid curing of the extruded material. After cooling and curing, it is put into a multi-layer co-extrusion casting machine. The temperatures of the heating zones of different sheet extruders are set to 80 °C, 90 °C, and 95 °C, and the temperatures of the merging zone and the head zone are set to 105 °C. By adjusting the rotation speeds of the cooling roller and the transfer roller, which are between 5 - 7 revolutions per minute, the thickness of the film is controlled to be 200 ± 30 μm. After making the edible powder coating, it is 3.3 g per portion.

[0133] The frying oil is palm oil. The way of adding antioxidants in the present invention is to add 100 mg / Kg of vitamin E to the frying oil and add about 100 mg / Kg of vitamin E to the packaging material.

[0134] Using the adding method of the present invention, the content of antioxidants in a piece of noodle cake = 85 * 20% * 100 / 1000 + 3.3 * 100 / 1000 = 2.03 mg, where the oil content of the noodle cake is 20%.

[0135] After frying, the instant noodles are subjected to an accelerated storage experiment at 37 °C and 80% humidity. Samples are taken every week to detect the AV acid value and the POV peroxide value. The detection method can refer to the national food safety standard for instant noodles GB 17400, which will not be elaborated here. The results are shown in Table 5 and Table 6.

[0136] Table 5 Detection results of the AV acid value during the storage period after the antioxidant is added conventionally and by the method of the present invention (unit: acid value (calculated on the fat basis): (KOH) / (mg / g))

[0137]

[0138] Table 6 Detection results of the POV peroxide value during the storage period after the antioxidant is added conventionally and by the method of the present invention (unit: peroxide value (calculated on the fat basis): (g / 100g))

[0139]

[0140] As can be seen from the results in Table 5 and Table 6, when the antioxidant dosage in the frying oil is reduced and the antioxidant dosage in the coating is increased, the overall antioxidant dosage decreases by about 40% (the coating weight of the edible material is 3.3 g / portion), and there is a slight advantage in the antioxidant effect. The hot processing process of the coating is relatively short compared to the frying oil. The relatively short-time high-temperature treatment can provide certain antioxidant protection for the antioxidant. In addition, the coating directly contacts the food after packaging, and the antioxidant will have a slow release effect, achieving a long-term antioxidant effect.

[0141] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be subject to the scope defined by the claims.

Claims

1. An edible film, characterized in that: The edible film comprises, from the outside to the inside, a first protective layer, one or two content layers, and a second protective layer; The components of the first protective layer or the second protective layer include: 70 to 75 parts by weight of gelatin masterbatch, 0.3 to 0.9 parts by weight of hybrid material, 10 to 15 parts by weight of plasticizer, and 10 to 15 parts by weight of water; The components of the content layer include: 70 to 75 parts by weight of gelatin masterbatch, 0.3 to 0.9 parts by weight of hybrid material, 10 to 15 parts by weight of plasticizer, and 10 to 15 parts by weight of water.

2. The edible film according to claim 1, characterized in that The components of the content layer also include trace ingredients, which are added as needed.

3. The edible film according to claim 1, characterized in that The number of the content layers is 7.

4. The edible film according to claim 2, characterized in that The trace ingredients are one or more of vitamins, minerals, DHA algae oil, probiotics, and antioxidants.

5. The edible film according to claim 1, characterized in that The hybrid material is one or more of montmorillonite, diatomaceous earth and silicon dioxide.

6. The edible film according to claim 1, characterized in that The plasticizer is one or more of polyol ester and epoxy compound.

7. The edible film according to claim 6, characterized in that The polyol ester is one or more of dipentaerythritol ester, glycol benzoate, and glycerol triacetate; the epoxy compound is one or more of epoxidized soybean oil and linseed oil.

8. A method for preparing an edible film, characterized in that: For preparing the edible film according to any one of claims 1 to 7, comprising: The components of the first protective layer, the content layer and the second protective layer are premixed and hydrated respectively, and after mixing, they are heated, melted and mixed in a twin-screw extruder, and are rotated and pushed out by the twin-screw extruder to the film head of the multi-layer co-extrusion cast stretching machine. After the multi-layer extrusion is cooled by a cooling roller, it is delivered and rolled up by a transfer roller to obtain a multi-layer edible film.

9. The method for preparing an edible film according to claim 8, characterized in that: The preparation method comprises: The components of the first protective layer, the content layer and the second protective layer are premixed and hydrated in a conical mixer respectively, and after being evenly mixed, they are heated, melted and mixed in a twin-screw extruder. The temperature of the heating zone of the twin-screw extruder is temperature-controlled in sections, the feed port is controlled at 80°C, the middle section temperature is controlled at 90°C to 100°C, the screw speed is set to 140rpm, the receiving port temperature is controlled to 90°C, and the extruded material is cooled to solidify quickly, and then the twin-screw extruder is rotated and pushed out to the film head of the multi-layer co-extrusion cast stretching machine. The temperatures of the heating zones of different sheet extruders are set to 80°C, 90°C and 95°C, and the temperatures of the merging zone and the head sealing zone are set to 105°C. After the multi-layer extrusion is cooled by a cooling roller, it is delivered and rolled up by a transfer roller to obtain a multi-layer edible film. The total thickness of the edible film is controlled to be 200±30μm by adjusting the speeds of the cooling roller and the transfer roller between 5-7 rpm.

10. An application of an edible film in a food packaging bag, characterized in that: The edible film is the edible film according to any one of claims 1 to 7 or is prepared by the method for preparing an edible film according to claim 8 or 9.

11. Use of the edible film in a food packaging bag according to claim 10, characterized in that: The food is instant noodles.

12. Use of the edible film in a food packaging bag according to claim 10, characterized in that: The food packaging bag is a seasoning packaging bag.

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