WO2012062015A1 - Method for manufacturing packaging material capable of sensing food freshness - Google Patents

Abstract

Disclosed is a method for manufacturing packaging material capable of sensing food freshness. The method comprises the following steps: A) according to different foods, selecting different gas color-sensitive materials capable of changing color when gas emits after food goes bad, B) selecting food-grade plastic wrap or acid-free paper as food packaging base material, C) dissolving the selected gas color-sensitive materials respectively into corresponding organic solvents to obtain 0.1-0.5mol/L solutions, D) adding 5mol/L stabilizer into each of the solutions, E) coating the obtained different solutions on the food packaging base material by ink-jetting to form a lattice array of the selected gas color-sensitive materials, or coating one of the obtained solutions on the food packaging base material to form a line of spots of the selected gas color-sensitive material, then drying to obtain a common or specific type of packaging material respectively. The obtained packaging material has freshness preserving function, and can sense food freshness and quality. The above-mentioned packaging material can be used in package of medicines, cosmetics, and chemical anti-counterfeit products as well.

Description

 Method for manufacturing packaging material capable of sensing food freshness Technical field

The invention relates to a food packaging material, in particular to a method for manufacturing a packaging material capable of sensing the freshness and quality of the food.

Background technique

Most of the current food packaging materials are based on their shape, color and function. The function is mainly to improve the breathability of packaging materials by adding rare metals to the materials and through special processes such as nanometers and silicon windows. And the shelf life. However, the quality of packaged foods, especially fresh foods, and whether they have deteriorated must be obtained through a series of physical and chemical analysis methods. At present, there is no packaging material that can sense the freshness of food, so that consumers or quality inspectors can know the freshness of the food at a glance.

The volatile gases (VOCs) of foods are mainly small organic molecules such as esters, aldehydes, alcohols, ketones, aromatic hydrocarbons, and organic acids. During the deterioration of food, VOCs will change significantly, and microorganisms will also produce stagnant gases such as acids, alcohols, ammonia and amines. The quality and freshness of the food can be known from the gas emitted from the food. However, the current volatile gas detection of food is mainly gas chromatography and sensory evaluation, both of which are time consuming and laborious, and require professional personnel to complete.

In 2000, Kenneth S. of the University of Illinois at Urbana-Champaign. Professor Suslick discovered that some chemicals, such as metalloporphyrins and pH indicators, undergo color changes when they encounter odor molecules. These chemicals are called gas color sensitive materials, so these gas color sensitive materials can be used as sensors to detect odors. The sensor is called a color sensitive gas sensor. The color-sensitive gas sensor has molecular recognition properties, can distinguish similar chemicals, even isomers with very similar chemical properties, and is not sensitive to the temperature and humidity of the environment.

technical problem

In order to overcome the deficiencies of the prior art, the present invention proposes a method for manufacturing a novel packaging material, which combines a gas color sensitive material with a conventional food packaging material, so that the prepared packaging material can directly sense the freshness and quality of the food.

Technical solution

The technical scheme of the present invention sequentially adopts the following steps: firstly, different gas color sensitive materials whose color is changed according to the odor of the food spoiled are selected for different kinds of foods; and then the food grade insurance film or acid-free paper is selected as the food grade. Food packaging base material; finally, different gas color sensitive materials are separately dissolved in the corresponding organic solvent to form different gas color sensitive material solutions with a concentration of 0.1-0.5 mol/L, and then added in different gas color sensitive material solutions. The stabilizer and stabilizer have a concentration of 5 mol/L, and then the different products are uniformly coated into a group of gases at a point interval by ink jet at intervals of L=10-15 cm at the center of the food packaging base material. An array of color-sensitive materials, each gas color-sensitive material has a diameter of 1-5 mm, and the array of gas color-sensitive materials is dried to form a uniform packaging material for various foods; or a product obtained In the center of the food packaging base material, every distance L=10-15cm is sprayed by dots in a dot-like manner and uniformly coated with a gas-sensitive material having a diameter of 1-5 mm. Color sensitive material is formed a dot, each of the drying gas sensitive color dots of material that is formulated for a specific type of food packaging material.

Beneficial effect

The packaging material prepared by the invention not only has the fresh-keeping function of the ordinary packaging material, but also can sense the freshness and quality of the packaged food, and can also be used for packaging of medicine, cosmetics and chemical anti-counterfeiting, and has broad application prospects.

DRAWINGS

The present invention will be further described in detail below with reference to the accompanying drawings and two embodiments:

1 is a schematic view of a unified packaging material in the first embodiment; the food packaging base material is a cling film;

2 is a schematic view of a specific type of packaging material in the first embodiment; the food packaging base material is a cling film;

Figure 3 is a diagram showing the freshness and storage period of eggs at room temperature in the color of the gas color sensitive material of the uniform wrap film;

Figure 4 is a diagram showing the color of the gas color sensitive material of the special type cling film indicating the freshness and storage period of the fish at normal temperature;

Figure 5 is a color display diagram of gas color sensitive materials of two commonly used perfumes in the market;

In the figure: 1. plastic wrap; 2. gas color sensitive material points.

Embodiments of the invention

Example 1

There are four main types of foods in daily life, namely, egg milk, meat, fish, and fruits and vegetables, each emitting a different smell. There are two types of cling film for these foods, one is a special type of plastic wrap, which is specially designed for the preservation of a certain type of food. Therefore, the special type cling film is divided into egg wrap plastic wrap, meat wrap film, Fish wrap and fruit and vegetable cling film. The other is a uniform type of plastic wrap that can be used for new types of food preservation. Among them, the odor component of egg milk spoilage is mainly hydrogen sulfide, so gas color sensitive materials with obvious changes in color of reaction with hydrogen sulfide, such as iron porphyrin, tin porphyrin, methylene blue, Nile red, fluorescent yellow, etc., are selected. Gas color-sensitive materials for egg-and-milk new plastic wrap; the odor component of meat spoilage is mainly ammonia odor, and the odor component of fish spoil is mainly amine odor, and the shovel with color reaction with ammonia and amine is selected. Porphyrin, zinc porphyrin, tin porphyrin, cobalt porphyrin, silver porphyrin and pH indicator as gas color sensitive materials for new plastic wrap of meat and fish; the odor component of fruit and vegetable spoilage is mainly methyl mercaptan. Cobalt porphyrin, protoporphyrin, copper porphyrin and pH indicator are used as gas color sensitive materials for new plastic wraps for fruits and vegetables. The gas color sensitive material of the uniform cling film contains each of the gas color sensitive materials mentioned above.

Food grade safety films such as polyethylene, polyvinyl chloride and polyvinylidene chloride are used as food packaging base materials. Each of the selected gas color sensitive materials is separately dissolved in a corresponding organic solvent, and dissolved in a concentration of 0.1 to 0.5 mol/L according to the gas color sensitive material to form different gas color sensitive material solutions. The present invention is directed to different gas color sensitive materials, and different organic solvents are selected, for example, chlorotoluene is selected as a solvent for the porphyrin compound, and alcohol is selected as a solvent for the hydrophobic acid-base indicator. Stabilizers are added to different gas color sensitive material solutions. The concentration of stabilizers in different gas color sensitive materials solutions is 5 mol/L, and the stabilizer can be dibutyl phthalate.

As shown in Fig. 1, different products obtained above, that is, different gas color sensitive material solutions to which stabilizers are added, are separately and uniformly applied to the wrap film 1 by means of spot spraying to form a group of gas color sensitive materials. Arrange the array. In the center of the wrap film, a set of such gas color sensitive material arrays are sprayed at intervals of L=10-15 cm. The diameter of each gas color sensitive material point 2 in the array is 1-5 mm, and then quickly hot air will be used. Each gas color sensitive material dot 2 in each group of gas color sensitive material dot arrays is dried to obtain a uniform type of plastic wrap for various food packagings.

As shown in Fig. 2, the production of the special type cling film is relatively simple, and only one of the gas color sensitive materials having a significant color change of the food odor is selected to be dissolved in the organic solvent at a concentration of 0.1 to 0.5 mol/L. Further, a stabilizer having a concentration of 5 mol/L is further added, and the obtained product is uniformly applied to the wrap film 1 by a dot spray method, and sprayed on the center of the wrap film 1 at a distance of L=10-15 cm. The gas color sensitive material point 2 with a diameter of 1-5 mm, all the gas color sensitive material points 2 form a row, and then quickly heat the gas color sensitive material point 2 in the column with hot air to obtain a desired one. A special type of plastic wrap for a type of food.

The uniform wrap film prepared as described above is packaged at room temperature, as shown in Fig. 3. Fig. 3(a) shows the color of a set of gas color sensitive materials on the wrap film for packaging fresh eggs, Fig. 3 (Fig. 3 b) is the color of the gas color sensitive material on the wrap film that has been preserved for 10 days; Figure 3 (C) is the color of the gas color sensitive material on the cling film preserved for 15 days. It can be seen that the color of the gas color sensitive material dot in the middle row of the wrap film has been changed in FIG. 3(b) for 10 days, and the lowest venting color sensitive material on the wrap film is preserved for 15 days. The color of the point has also changed. Therefore, the freshness and quality of the packaged eggs can be determined by the color change of the gas color sensitive material on the wrap film.

The special type plastic wrap prepared by the above method is packaged at room temperature, as shown in Fig. 4: Fig. 4(a) shows that the color of the gas color sensitive material on the fresh fish wrap film just wrapped is yellow, Figure 4 ( b) It is shown that the color of the gas color sensitive material on the wrap film becomes grass yellow after 4 hours; FIG. 4(C) shows that the gas color sensitive material on the wrap film turns blue after one day. Thereby, the freshness and quality of the food can be determined by the change in color of the gas color sensitive material on the wrap film.

Example 2

The selection of the gas color sensitive material was consistent with the method of Example 1, using acid-free paper as the food packaging base material. The manufacturing method was the same as in the method of Example 1, except that the gas color sensitive material was sprayed onto the acid-free paper by means of spot spraying instead of the cling film.

The unified packaging materials produced in Example 1 and Example 2 can be used as anti-counterfeiting packaging materials for cosmetics, and Figure 5 is the color of gas color-sensitive materials for two commonly used perfumes in the market. Figure 5 (a) is a gas color sensitive material on an acid-free paper and Lancome (LANCOME) The unique color of the sensory hypnotic perfume, Figure 5 (b) is the acid-free paper color sensitive material and Bosch (HUGO BOSS) The unique color of Yoko Ms. It can be seen that each perfume has its own unique fragrance, and these fragrances and the gas color sensitive material on the packaging material will produce their unique color. Therefore, the packaging material produced by the invention can be used for anti-counterfeiting packaging of cosmetics. For the same reason, anti-counterfeiting packaging materials for medicines, chemicals and other products can also be used.

Claims (2)

 A method for manufacturing a packaging material capable of sensing freshness of food, characterized in that the following steps are sequentially employed:  A. For different kinds of foods, different gas color sensitive materials having a color change of the odor of the food spoiled are selected; B. Use food grade insurance film or acid-free paper as the base material for food packaging; C. Dissolving different gas color sensitive materials in respective organic solvents to form different gas color sensitive material solutions having a concentration of 0.1 to 0.5 mol/L; D, adding a stabilizer to different gas color sensitive material solutions, the concentration of the stabilizer is 5mol / L; E. The different products obtained are uniformly coated in a dot-like interval at a distance of L=10-15 cm in the center of the food packaging base material by a jetting method, respectively, to form a set of gas color sensitive material dot arrays, each gas color sensitive material. The diameter of the dots is 1-5mm, and the array of gas color sensitive materials is dried to form a uniform packaging material for various foods; or a certain product is used at the same distance in the center of the food packaging base material. The inkjet method uniformly coats a gas color sensitive material point with the same diameter at a point interval, and all the gas color sensitive material dots form a row, and drying each gas color sensitive material point is made for a certain type of food. Specialized packaging materials. A method of producing a packaging material capable of sensing food freshness according to claim 1, wherein said stabilizer is dibutyl phthalate.

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