CN111349343A - Method for manufacturing easily degradable food preservative film with fish scale gelatin matrix - Google Patents

Abstract

The invention discloses an easily degradable food preservative film with a fish scale gelatin matrix, belonging to the technical field of aquatic product processing, wherein the preservative film comprises the following components in percentage by weight: 30-40% of freshwater fish scale gelatin, 1-5% of wheat starch, 0.01-0.05% of vitamin C, 0.05-0.1% of essential oil, 1-5% of 100u/ml saccharifying enzyme, 1-3% of 5% magnesium chloride solution and the balance of deionized water. The invention adopts fresh water fish scales to prepare fish scale gelatin through steps of water washing, alkali washing, acid washing, hot water extraction and the like, and the fish scale gelatin is used as a main raw material to prepare the easily degradable food preservative film with the fish scale gelatin matrix. By adding wheat soluble starch, 100u/ml saccharifying enzyme; and 5% magnesium chloride solution, the three kinds of degradation promoters are mixed to obtain the degradation promoter, the propagation of aspergillus oryzae in soil can be effectively promoted, and the degradation rate of aspergillus oryzae in soil on protein products can be accelerated, so that the preservative film which is extremely easy to degrade is obtained.

Description

A kind of preparation method of easily degradable food fresh-keeping film of fish scale gelatin matrix

technical field

The invention belongs to the technical field of aquatic product processing, and in particular relates to a preparation method of a fish scale gelatin-based easily degradable food fresh-keeping film.

Background technique

According to statistics, the global output of plastic products increased from 230 million tons in 2005 to 348 million tons in 2017, with an average annual growth rate of 3.51%. However, with the enhancement of global awareness of environmental protection, people pay more attention to the easily degradable food preservative film. The unique advantages have won a good reputation, especially in the fields of organic environmental protection food, aquaculture and other fields, which can avoid the harm caused by indigestion and degradation caused by accidental consumption of packaging.

It is processed into plastic-like materials from raw materials such as protein and starch, which are used to package food, so that it has good strength, elasticity and moisture resistance, and has a certain antibacterial and disinfection ability. It is called easily degradable food plastic wrap. However, the easily degradable food preservative film based on starch has many disadvantages, such as insufficient mechanical strength and poor water resistance. Therefore, protein-based easily degradable food wraps have received more and more attention.

Among proteins, gelatin is a good film-forming material. Studies have shown that the edible film prepared with fish gelatin has good air permeability and certain mechanical properties, and is used as a potential substitute for plastic films. in the study of food preservation. Moreover, due to the outbreak of infectious diseases such as mad cow disease and foot-and-mouth disease, the safety of common mammalian gelatin has been questioned by consumers to a certain extent. Religious believers also have food taboos on certain mammalian products. The use of fish scales to produce fish gelatin, which can be processed into easily degradable food preservative films, not only reduces environmental pollution, but also improves the high-value utilization value of fish scales. Therefore, in terms of technical effects, market requirements, environmental protection and economy, etc., the easily degradable food preservative film based on fish scale gelatin has broad development and application prospects.

SUMMARY OF THE INVENTION

In order to solve the above-mentioned technical problems, the present invention provides an easily degradable food preservative film based on fish scale gelatin. %, vitamin C 0.01%-0.05%, clove essential oil 0.05%-0.1%, 100u/ml saccharification enzyme 1%-5%, 5% magnesium chloride solution 1-3%, the rest is deionized water.

The degradable food fresh-keeping film of the fish scale gelatin matrix, the preparation method is composed of the following steps:

(1) adding freshwater fish scale gelatin in deionized water by the described weight percentage, dissolving at 50～60 ℃, cooling to room temperature after dissolving completely, obtaining fish scale gelatin solution;

(2) adding wheat starch, saccharifying enzyme, magnesium chloride and vitamin C to the fish scale gelatin solution according to the weight percentage, and dissolving at 25° C. to obtain a mixed solution;

(3) adding essential oil to the mixed solution by the weight percentage, ultrasonically dispersing for 15～20min, then homogenizing twice through a microjet homogenizer at 20～30MPa, and adjusting the pH to 4.0～6.0;

(4) Put the mixture into a water bath at 75～85℃ for 15～40min, and then place it in a high temperature steam oven at 110～120℃ to form a film by solution casting method.

Described freshwater fish scale gelatin is prepared by the following method:

1) Washing: Soak fresh freshwater fish scales in deionized water, drain, wash twice, shake well each time, drain and squeeze dry with nylon gauze for the last time;

2) Alkaline washing: fish scales are treated with edible alkali solution, shaken and left to soak for 1 hour, drained, and then soaked again with edible alkali solution;

3) Secondary water washing: 5 times of water washing, 4min each time, and drained. Squeeze dry with nylon gauze one last time;

4) Pickling: the fish scales are treated with citric acid solution, shaken and left to soak for 1 hour, drained, and then soaked again with citric acid solution;

5) Three times of water washing: 5 times of water washing, 4min each time, and drained. Squeeze dry with nylon gauze one last time;

6) Hot water extraction: fish scales were extracted with deionized water with a material-to-liquid ratio of 1:4 in a 65°C water bath for 3 hours, and then the gelatin solution was obtained by suction filtration;

7) Spray drying: spray drying to obtain a freshwater fish scale gelatin product.

Preferably, the freshwater fish scales are selected from one or a mixture of grass carp, herring and silver carp.

Preferably, the concentration of the edible alkali solution is 0.3 mol/L, and the concentration of the citric acid solution is 0.05 mol/L; ml, all raw materials are food grade.

The advantages of the present invention are:

1. The use of fish scales to produce fish gelatin, which is processed into easily degradable food plastic wrap, not only reduces environmental pollution, but also improves the high-value utilization value of fish scales.

2. By adding wheat soluble starch, 100u/ml saccharification enzyme; and 5% magnesium chloride solution, the above three are mixed to obtain a degradation accelerator, which can effectively promote the reproduction of Aspergillus oryzae in the soil, and the Aspergillus oryzae in the soil can accelerate the degradation rate of protein products , so as to obtain a highly degradable fresh-keeping film.

3. The film has high tensile strength and excellent toughness.

Detailed ways

Describe in detail below in conjunction with embodiment:

Example 1

Prepare freshwater fish scale gelatin, and described freshwater fish scale gelatin is prepared by the following method:

1) Washing: Soak fresh freshwater fish scales in deionized water, drain, wash twice, shake well each time, drain and squeeze dry with nylon gauze for the last time;

2) Alkaline washing: The fish scales are treated with an edible alkali solution, shaken and left to soak for 1 hour, and then drained. Repeat the soaking with the edible alkali solution again. The concentration of the edible alkali solution is 0.3mol/L, and the material-to-liquid ratio of fish scales/edible alkali solution is 1/5g/ml;

3) Secondary water washing: 5 times of water washing, 4min each time, and drained. Squeeze dry with nylon gauze one last time;

4) Pickling: The fish scales were treated with citric acid solution, shaken and soaked for 1 hour, then drained. Repeat soaking with citric acid solution again. The concentration of citric acid solution is 0.05mol/L; the material-to-liquid ratio of fish scale/citric acid solution is 1/5g/ml;

5) Three times of water washing: 5 times of water washing, 4min each time, and drained. Squeeze dry with nylon gauze one last time;

6) Hot water extraction: fish scales were extracted with deionized water with a material-to-liquid ratio of 1:4 in a 65°C water bath for 3 hours, and then the gelatin solution was obtained by suction filtration;

7) Spray drying: spray drying to obtain a freshwater fish scale gelatin product.

An easily degradable food fresh-keeping film based on fish scale gelatin is prepared. The easily degradable food fresh-keeping film based on fish scale gelatin comprises the following components in parts by weight: 35% of freshwater fish scale gelatin, 3% of wheat starch, 0.03% of vitamin C, 100u/ml glucoamylase 2%; 2% magnesium chloride solution, 0.75% clove essential oil, and the rest are deionized water, totaling 100%.

The preparation method of the easily degradable food fresh-keeping film of fish scale gelatin matrix comprises the following steps:

(1) adding freshwater fish scale gelatin in deionized water by the described parts by weight, dissolving at 50 ° C, and cooling to room temperature after dissolving completely to obtain a fish scale gelatin solution;

(2) in the described fish scale gelatin solution, wheat starch, saccharifying enzyme, magnesium chloride solution, vitamin C are dissolved in the described fish scale gelatin solution by the described parts by weight, and the mixed solution is obtained;

(3) add essential oil to the described mixed solution by the described parts by weight, ultrasonically disperse for 15min, then homogenize twice under 20MPa through a micro-jet homogenizer, and adjust pH to 4.0 with citric acid and edible alkali solution;

(4) Put the mixed solution into a water bath at 80°C for 15 minutes, and then place it in a high-temperature steam oven at 110°C to form a film by the solution casting method.

Example 2

The difference between this example and Example 1 is that wheat starch, saccharification enzyme and magnesium chloride solution are not added. The rest of the formula and process are the same as in Example 1.

Comparative Example 1

Purchased commercially available ordinary plastic wrap.

The fresh-keeping films obtained in the above-mentioned Examples 1 and 2 and Comparative Example 1 were divided into six groups, and all were laid in the soil according to an area of 1 m2 for landfill treatment, and each example was recorded as 2, 5, 7, 10, For the degradation conditions of 15 and 20 days, the soil used is the soil in the same position, after mixing. The plastic wrap was buried at a depth of 20 cm in the soil layer. The percentage of the remaining plastic wrap before degradation was recorded, and the specific data are shown in Table 1 below.

Table 1

2 days 5 days 7 days 10 days 15 days 20 days Example 1 100% 95% 35% 10% 0% 0% Example 2 100% 100% 88% 85% 80% 76% Comparative Example 1 100% 100% 100% 100% 100% 99%

It can be clearly seen from the above table that the degradation speed can be quickly accelerated by using the embodiment 1 of the present invention compared with the non-adding degradation accelerator, and the degradation accelerator added in the process of the present invention can effectively increase the amount of Aspergillus oryzae in the soil. Reproduction speed, accelerate the degradation of protein.

Claims (5)

1. the easily degradable food preservative film of a fish scale gelatin matrix, is characterized in that, described preservative film is made up of following component proportions by weight percentage: freshwater fish scale gelatin 30%～40%, wheat starch 1%～5%, vitamin C 0.01%-0.05%, clove essential oil 0.05%-0.1%, 100u/ml saccharification enzyme 1%-5%, 5%, magnesium chloride solution 1-3%, the rest are deionized water. 2. the degradable food preservative film of fish scale gelatin matrix as claimed in claim 1, is characterized in that, preparation method is made up of the following steps: (1) adding freshwater fish scale gelatin in deionized water by the described weight percentage, dissolving at 50～60 ℃, cooling to room temperature after dissolving completely, obtaining fish scale gelatin solution; (2) adding wheat starch, saccharifying enzyme, magnesium chloride and vitamin C to the fish scale gelatin solution according to the weight percentage, and dissolving at 25° C. to obtain a mixed solution; (3) adding essential oil to the mixed solution by the weight percentage, ultrasonically dispersing for 15～20min, then homogenizing twice through a microjet homogenizer at 20～30MPa, and adjusting the pH to 4.0～6.0; (4) Put the mixture into a water bath at 75～85℃ for 15～40min, and then place it in a high temperature steam oven at 110～120℃ to form a film by solution casting method. 3. freshwater fish scale gelatin according to claim 2 is characterized in that being prepared by the following method: 1) Washing: Soak fresh freshwater fish scales in deionized water, drain, wash twice, shake well each time, drain and squeeze dry with nylon gauze for the last time; 2) Alkaline washing: fish scales are treated with edible alkali solution, shaken and left to soak for 1 hour, drained, and then soaked again with edible alkali solution; 3) Secondary water washing: 5 times of water washing, 4min each time, and drained. Squeeze dry with nylon gauze one last time; 4) Pickling: the fish scales are treated with citric acid solution, shaken and left to soak for 1 hour, drained, and then soaked again with citric acid solution; 5) Three times of water washing: 5 times of water washing, 4min each time, and drained. Squeeze dry with nylon gauze one last time; 6) Hot water extraction: fish scales were extracted with deionized water with a material-to-liquid ratio of 1:4 in a 65°C water bath for 3 hours, and then the gelatin solution was obtained by suction filtration; 7) Spray drying: spray drying to obtain a freshwater fish scale gelatin product. 4. the preparation method of the easily degradable food preservative film of fish scale gelatin matrix according to claim 2, is characterized in that, described freshwater fish scale is selected from one or more mixing in grass carp, herring, silver carp. 5. the preparation method of the easily degradable food preservative film of fish scale gelatin matrix according to claim 2, is characterized in that, described edible alkali solution concentration is 0.3mol/L, and citric acid solution concentration is 0.05mol/L; The material-to-liquid ratio of alkali solution to fish scale/citric acid solution is 1/5～1/10g/ml, and all raw materials are food grade.