Strawberry preserving composite packaging film and preparation method thereof

Abstract

The invention provides a preparation method of a strawberry preserving composite packaging film. The method mainly comprises the following steps: carrying out film casting on a film-forming liquid with chitosan, corn starch and cinnamyl aldehyde as raw materials and then carrying out hot press molding on the film and an electrostatic spinning film with chitosan, corn starch and cinnamyl aldehyde as raw materials. The invention also provides the packaging film prepared by the method. The packaging film and the preparation method have the beneficial effects that the preparation method is simple to operate, the raw materials widely exit in nature, and the composite film is formed fast; the adopted three main raw materials, namely chitosan, corn starch and cinnamyl aldehyde, are all natural substances and are food grade, so compared with many existing food packaging materials, the raw materials are lower in environmental pollution, have better biocompatibility and are safer to food; the obtained composite packaging film has excellent preservation effects on strawberries, can conduce to increasing the length for preservation of the strawberries and lengthening the strawberry selling time to 15 days or over and brings greater economic benefits to the markets.

Description

technical field

[0001] The invention belongs to the field of fresh-keeping of fruits and vegetables, and in particular relates to a strawberry fresh-keeping composite packaging film and a preparation method thereof. Background technique

[0002] Strawberry fruit is bright in color, unique in flavor, rich in bioactive ingredients such as vitamins, folic acid and phenols, known as the "Queen of Fruits". However, after strawberry is picked, it is very easy to spoil and deteriorate. It will change color, taste, soften and rot within 1 to 2 days at room temperature, causing serious economic losses. Even if low temperature preservation is used, it generally does not exceed 7 days.

[0003] Among the current fresh-keeping methods, immersing strawberries in a specific fresh-keeping solution is a relatively common method, which avoids the disadvantage of high cost of controlled-atmosphere fresh-keeping, and also prevents the influence of quick-freezing and cold storage on the taste ...

Examples

Embodiment 1

[0031] Dissolve 3g of chitosan in 97ml of 90% acetic acid solution, stir magnetically until completely dissolved, add 60g of cornstarch into 940ml of distilled water, gelatinize at 80°C, and mix the gelatinized starch and the dissolved chitosan solution according to Mixing at a mass ratio of 2:1, adding 0.2mg / kg of essential oil, adding 20mg / kg of glycerin as a plasticizer, stirring and mixing, ultrasonic defoaming, to obtain a spinning solution; using an electrospinning spinning device Spinning, the specification of the electrospinning syringe is 50ml, the needle specification is flat, No. 7 needle, the electric field strength is 2.0kv / cm, and the distance is 7-10cm. After the completion, the electrospinning nano-membrane is obtained.

Embodiment 2

[0033] Dissolve 1g of chitosan in 99g of 1% acetic acid solution, magnetically stir until completely dissolved, add 60g of cornstarch to 940ml of distilled water, gelatinize at 80°C, and mix the gelatinized starch and the dissolved chitosan solution according to the mass Mix at a ratio of 1:1, add 0.2mg / kg of essential oil, add 20mg / kg of glycerin as a plasticizer, stir and mix, ultrasonic defoaming, the pattern is a square Teflon pattern with a side length of 5cm A patterned film was prepared on the patterned template by tape casting, and the drying temperature was controlled at 50°C.

Embodiment 3

[0035] Take out the patterned film after drying in Example 2, place it on the front end of the receiving plate device for electrospinning, and use the spinning solution to carry out electrospinning. The specification of the electrospinning syringe is 50ml, and the needle specification is flat, No. , the electric field strength is 2.0Kv / cm, the distance is 7-10cm, and the spinning is completed, that is, the composite packaging film of electrospun nano-film and sheet film is obtained.

technical field

[0001] The invention belongs to the field of fresh-keeping of fruits and vegetables, and in particular relates to a strawberry fresh-keeping composite packaging film and a preparation method thereof. Background technique

[0002] Strawberry fruit is bright in color, unique in flavor, rich in bioactive ingredients such as vitamins, folic acid and phenols, known as the "Queen of Fruits". However, after strawberry is picked, it is very easy to spoil and deteriorate. It will change color, taste, soften and rot within 1 to 2 days at room temperature, causing serious economic losses. Even if low temperature preservation is used, it generally does not exceed 7 days.

[0003] Among the current fresh-keeping methods, immersing strawberries in a specific fresh-keeping solution is a relatively common method, which avoids the disadvantage of high cost of controlled-atmosphere fresh-keeping, and also prevents the influence of quick-freezing and cold storage on the taste ...

Examples

Embodiment 1

[0031] Dissolve 3g of chitosan in 97ml of 90% acetic acid solution, stir magnetically until completely dissolved, add 60g of cornstarch into 940ml of distilled water, gelatinize at 80°C, and mix the gelatinized starch and the dissolved chitosan solution according to Mixing at a mass ratio of 2:1, adding 0.2mg / kg of essential oil, adding 20mg / kg of glycerin as a plasticizer, stirring and mixing, ultrasonic defoaming, to obtain a spinning solution; using an electrospinning spinning device Spinning, the specification of the electrospinning syringe is 50ml, the needle specification is flat, No. 7 needle, the electric field strength is 2.0kv / cm, and the distance is 7-10cm. After the completion, the electrospinning nano-membrane is obtained.

Embodiment 2

[0033] Dissolve 1g of chitosan in 99g of 1% acetic acid solution, magnetically stir until completely dissolved, add 60g of cornstarch to 940ml of distilled water, gelatinize at 80°C, and mix the gelatinized starch and the dissolved chitosan solution according to the mass Mix at a ratio of 1:1, add 0.2mg / kg of essential oil, add 20mg / kg of glycerin as a plasticizer, stir and mix, ultrasonic defoaming, the pattern is a square Teflon pattern with a side length of 5cm A patterned film was prepared on the patterned template by tape casting, and the drying temperature was controlled at 50°C.

Embodiment 3

[0035] Take out the patterned film after drying in Example 2, place it on the front end of the receiving plate device for electrospinning, and use the spinning solution to carry out electrospinning. The specification of the electrospinning syringe is 50ml, and the needle specification is flat, No. , the electric field strength is 2.0Kv / cm, the distance is 7-10cm, and the spinning is completed, that is, the composite packaging film of electrospun nano-film and sheet film is obtained.

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