Method for improving properties of starch-base edible packaging film by adding hydrophilic colloid

Abstract

The invention discloses a method for improving properties of a starch-base edible packaging film by adding hydrophilic colloid. The starch-base edible film is prepared through the steps of uniformly mixing starch with hydrophilic colloid, then pasting, defoaming, forming a film and stripping the film; the method for improving the properties of the starch-base edible packaging film by adding the hydrophilic colloid comprises the steps of mixing starch with carboxy methylated cellulose (CMC) so as to form a starch-CMC compound, then lowering the viscosity, uniformly mixing with the hydrophilic colloid, defoaming, forming a film and stripping the film. The starch film prepared by common natural starch has good flexibility, is difficult to break and has wide application range; the method disclosed by the invention is simple and easy to operate and can completely substitute for the method for preparing the starch film by amylase.

Description

technical field

[0001] The invention relates to the fields of starch application and food packaging materials, in particular to a method for improving the performance of starch-based edible packaging films. Background technique

[0002] The food packaging film made of petroleum-based synthetic polymers has good strength, elongation at break, light transmittance, gas and water barrier properties, and low price. Therefore, petroleum-based non-degradable plastic films are widely used in food packaging. middle. With the non-renewable and increasing shortage of petroleum resources, as well as the environmental problems caused by extensive use, especially the main raw materials of various food small packaging films in my country are polyethylene or polyvinyl chloride, and the plasticizers added in the production process of these films And various processing aids will pose a threat to the safety of the packaged food, so it is imperative to develop a safe and environmentally friendl...

Examples

Embodiment 1

[0023] 25g of water, waxy sweet potato starch with an amylose content of 1% and guar gum were mixed in proportions of 100:0, 60:1, 40:1, 20:1 (mass ratio, g / g) Make a suspension with a mass fraction of 6% (on a dry basis), and then gelatinize in a boiling water bath for 30 minutes. The gelatinized sample is degassed and poured into a 10×10cm flat plate. The sample is spread evenly, and then placed in 4h in an oven at 50°C.

[0024] The prepared starch film was placed in a constant temperature and humidity chamber with a temperature of 23 °C and a relative humidity of 50% for 1 day, and then used for the determination of mechanical properties and color difference. As shown in Table 1, the thickness of all starch films is about 0.1mm, and after adding guar gum, the tensile strength of the starch film increases, the elongation at break decreases, and the color of the composite film is dark yellow. However, the elongation at break and the color difference parameter values ​​did n...

Embodiment 2

[0029] Mix 25g of water with 18% amylose content of ordinary cornstarch and xanthan gum at a compounding ratio of 100:0, 60:1, 40:1, 20:1 (mass ratio, g / g) and the compounding mass The suspension with a fraction of 4% (calculated on a dry basis) is then gelatinized in a boiling water bath for 30 minutes. The gelatinized sample is degassed and poured into a 10×10cm flat plate. The sample is spread evenly and placed at 50°C 4h in the oven.

[0030] The prepared starch film was placed in a constant temperature and humidity chamber with a temperature of 23 °C and a relative humidity of 50% for 1 day, and then used for the determination of mechanical properties and color difference. As shown in Table 2, the thickness of all starch films is about 0.1mm, and after adding xanthan gum, the tensile strength of the starch film increases, the brightness value of the composite film increases, and the color becomes brighter. However, the elongation at break and the color difference paramet...

Embodiment 3

[0034] Mix 25g of water, amylose content of 45% high amylose sweet potato starch and guar gum in a compounding ratio of 100:0, 60:1, 40:1, 20:1 (mass ratio, g / g) and the compounding mass The fraction is 5% (on a dry basis), the suspension is placed in a pressure bottle and swells in a boiling water bath for 15 minutes, and then placed in an oven at 130°C for 30 minutes. The gelatinized sample was degassed and poured into a flat plate of 10×10 cm. The sample was evenly spread, and then placed in an oven at 50°C for 4 hours.

[0035] The prepared starch film was placed in a constant temperature and humidity chamber with a temperature of 23 °C and a relative humidity of 50% for 1 day, and then used for the determination of mechanical properties and color difference. As shown in Table 3, the thickness of all starch films was around 0.1 mm, and after adding guar gum, the tensile strength of starch films increased and the elongation at break decreased. However, the elongation at br...

technical field

[0001] The invention relates to the fields of starch application and food packaging materials, in particular to a method for improving the performance of starch-based edible packaging films. Background technique

[0002] The food packaging film made of petroleum-based synthetic polymers has good strength, elongation at break, light transmittance, gas and water barrier properties, and low price. Therefore, petroleum-based non-degradable plastic films are widely used in food packaging. middle. With the non-renewable and increasing shortage of petroleum resources, as well as the environmental problems caused by extensive use, especially the main raw materials of various food small packaging films in my country are polyethylene or polyvinyl chloride, and the plasticizers added in the production process of these films And various processing aids will pose a threat to the safety of the packaged food, so it is imperative to develop a safe and environmentally friendl...

Examples

Embodiment 1

[0023] 25g of water, waxy sweet potato starch with an amylose content of 1% and guar gum were mixed in proportions of 100:0, 60:1, 40:1, 20:1 (mass ratio, g / g) Make a suspension with a mass fraction of 6% (on a dry basis), and then gelatinize in a boiling water bath for 30 minutes. The gelatinized sample is degassed and poured into a 10×10cm flat plate. The sample is spread evenly, and then placed in 4h in an oven at 50°C.

[0024] The prepared starch film was placed in a constant temperature and humidity chamber with a temperature of 23 °C and a relative humidity of 50% for 1 day, and then used for the determination of mechanical properties and color difference. As shown in Table 1, the thickness of all starch films is about 0.1mm, and after adding guar gum, the tensile strength of the starch film increases, the elongation at break decreases, and the color of the composite film is dark yellow. However, the elongation at break and the color difference parameter values ​​did n...

Embodiment 2

[0029] Mix 25g of water with 18% amylose content of ordinary cornstarch and xanthan gum at a compounding ratio of 100:0, 60:1, 40:1, 20:1 (mass ratio, g / g) and the compounding mass The suspension with a fraction of 4% (calculated on a dry basis) is then gelatinized in a boiling water bath for 30 minutes. The gelatinized sample is degassed and poured into a 10×10cm flat plate. The sample is spread evenly and placed at 50°C 4h in the oven.

[0030] The prepared starch film was placed in a constant temperature and humidity chamber with a temperature of 23 °C and a relative humidity of 50% for 1 day, and then used for the determination of mechanical properties and color difference. As shown in Table 2, the thickness of all starch films is about 0.1mm, and after adding xanthan gum, the tensile strength of the starch film increases, the brightness value of the composite film increases, and the color becomes brighter. However, the elongation at break and the color difference paramet...

Embodiment 3

[0034] Mix 25g of water, amylose content of 45% high amylose sweet potato starch and guar gum in a compounding ratio of 100:0, 60:1, 40:1, 20:1 (mass ratio, g / g) and the compounding mass The fraction is 5% (on a dry basis), the suspension is placed in a pressure bottle and swells in a boiling water bath for 15 minutes, and then placed in an oven at 130°C for 30 minutes. The gelatinized sample was degassed and poured into a flat plate of 10×10 cm. The sample was evenly spread, and then placed in an oven at 50°C for 4 hours.

[0035] The prepared starch film was placed in a constant temperature and humidity chamber with a temperature of 23 °C and a relative humidity of 50% for 1 day, and then used for the determination of mechanical properties and color difference. As shown in Table 3, the thickness of all starch films was around 0.1 mm, and after adding guar gum, the tensile strength of starch films increased and the elongation at break decreased. However, the elongation at br...

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