TWI728643B - Method for making edible film from bamboo shoot husk extract and passion fruit husk extract - Google Patents

Abstract

A method of making an edible film, which includes: adding the ground and crushed bamboo shoot shells to a sodium hydroxide solution with a concentration of 2N to 10N, heating in a water bath at a temperature of 30°C to 90°C, and adding 75% to 95% ethanol and Place it at 4°C, filter the precipitate and dry it to obtain the hemicellulose extract; add the ground and crushed passion fruit husk to a hydrochloric acid solution with a concentration of 0.01N to 0.09N, and heat it in a water bath at 30°C to 90°C, and then Add 75% to 95% ethanol and place it at 4°C. Filter the precipitate and dry it to obtain the pectin extract; take the hemicellulose extract and the pectin extract in a weight ratio of 1:1 to 1:5, and Add 100ml of deionized water, heat to 80°C to 90°C to dissolve and mix, maintain a constant temperature between 35°C and 45°C until the film is formed, cool it and filter to obtain a film.

Description

Method for making edible film from bamboo shoot husk extract and passion fruit husk extract

The invention relates to an edible film, and particularly refers to a method for preparing an edible film from bamboo shoot shells and passion fruit shells.

Edible film is an edible packaging material that will not cause changes in the flavor and color of food. It is also often used as a carrier of nutrition fortifiers, antimicrobial agents and antioxidants. The edible film has the functions of preventing food dehydration, delaying the oxidation of oil and gas barrier, and the US FDA has recognized that the edible film should be a GRAS packaging material. In recent years, studies have mainly used natural biopolymers as raw materials, with the goal of reducing plastic products.

The central and southern part of my country is the main producing area of bamboo shoots. The abundance period is from July to September. The annual yield can reach an average of 17,100 metric tons per hectare, making it the highest yielding bamboo shoot species in my country. After the bamboo shoots are harvested, the peeled shells can be used as animal feed or buried in compost, but most of them are incinerated, which can easily cause air pollution. Studying the main components of bamboo shoot shells can find that there are cellulose (Cellulose), hemicellulose (Hemicellulose) and lignin (Lignin), which seems to have the possibility of preparing edible film, so how to use bamboo shoot shell waste to prepare edible film to solve Bamboo shoot husk waste and reduction of incineration air pollution are the primary issues to be solved by the present invention.

The main purpose of the present invention is to provide a method for preparing an edible film, which uses bamboo shoot husks as raw materials to achieve the effect of waste utilization and reduce air pollution caused by the original incineration of bamboo shoot husk waste.

In order to achieve the foregoing objective, the present invention provides a method for preparing an edible film from bamboo shoot husk extract and passion fruit husk extract, which includes: A. Pretreatment of bamboo shoot husk: a. Drying the bamboo shoot husk and grinding and crushing; b , Add 2N to 10N sodium hydroxide solution, and heat in a water bath at 30°C to 90°C; c. Add 75% to 95% ethanol and place it at 4°C, where the bamboo shoot shells-sodium hydroxide solution and ethanol The weight ratio is 1:4; d. The precipitate is filtered out and dried to obtain the hemicellulose extract; B. Pre-treatment of the passion fruit shell: a. Grind and crush the passion fruit shell after drying; b. Add concentration 0.01N to 0.09 N hydrochloric acid solution, heated in a water bath at a constant temperature of 30°C to 90°C; c. Add 75% to 95% ethanol and leave it at 4°C. The weight ratio of the passion fruit shell-hydrochloric acid solution to ethanol is 1:4; d , Filter the precipitate and dry it to obtain the pectin extract; C. Film preparation: a. Take the hemicellulose extract and the pectin extract in a weight ratio of 1:1 to 1:5, and add 100ml of deionized water; b. Heat to 80°C to 90°C to dissolve and mix; c. Maintain a constant temperature between 35°C and 45°C until the film is formed to obtain a film.

Preferably, in the pretreatment of the bamboo shoot husk, the concentration of the sodium hydroxide solution is 2N, the temperature of the water bath is 50° C., and the concentration of ethanol is 95%.

Preferably, in the pretreatment of passion fruit husk, the concentration of hydrochloric acid is 0.05N, the temperature of the water bath is 90°C, and the concentration of ethanol is 85%.

Preferably, in the heating and dissolving step of preparing the film, fatty acids and food plasticizers are further added.

It is not difficult to obtain an in-depth understanding of the above-mentioned objects and advantages of the present invention from the following detailed description of the selected embodiments and the accompanying drawings.

Figure 1 is a flow chart of the present invention in the pre-treatment stage of bamboo shoot husk; Figure 2 is a flow chart of the present invention in the pre-treatment stage of passion fruit husk; Figure 3 is a flow chart of the present invention in the film preparation stage.

The present invention provides a method for preparing an edible film, which mainly includes three steps: bamboo shoot husk pretreatment, passion fruit husk pretreatment, and film preparation. In this embodiment, the bamboo shoot shell is selected as bamboo shoot shell.

As shown in Figure 1, in the pretreatment stage of bamboo shoot shells, the bamboo shoot shells are first dried, ground and crushed, and sodium hydroxide solution with a concentration of 2N to 10N is added and immersed in a water bath at 30°C to 90°C. Heat at a constant temperature, then add 75% to 95% ethanol and place it in a refrigerator at 4°C for 24 hours. The weight ratio of bamboo shoot shell-sodium hydroxide solution to ethanol is 1:4, and then the precipitate is removed by filtration and dried , You can get the hemicellulose extract.

In the aforementioned bamboo shoot husk pretreatment stage, considering the desalination cost, film formation requirements and energy saving, the preferred process conditions are that the concentration of sodium hydroxide solution is 2N, the temperature of the water bath is 50°C, and the concentration of ethanol is 95%.

As shown in Figure 2, in the pre-treatment stage of passion fruit husks, the passion fruit husks are dried and then ground and crushed. The hydrochloric acid solution with a concentration of 0.01N to 0.09N is added, and it is immersed in a water bath of 30°C to 90°C and heated at constant , Then add 75% to 95% ethanol and place it in a refrigerator at 4°C for 24 hours, where the weight ratio of passion fruit shell-hydrochloric acid solution to ethanol is 1:4, and then remove the precipitate through filtration and dry it. The pectin extract is obtained.

In the aforementioned pre-treatment stage of passion fruit husk, considering the desalination cost, film formation requirements and energy saving, the preferred process conditions are that the concentration of hydrochloric acid is 0.05N, the temperature of the water bath is 90°C, and the concentration of ethanol is 85%.

Then proceed to the stages of film preparation. As shown in Figure 3, take the hemicellulose extract and pectin extract prepared above in a weight ratio of 1:1 to 1:5 (preferably process conditions are 1:4), and add 100ml of deionized water , And heat to 80℃ to 90℃ to dissolve and mix. At this time, add stearic acid, palmitic acid, lauric acid or butyric acid and other fatty acids, as well as glycerin, sorbitol or polyethylene glycol 400 (PEG-400) Wait for the food plasticizer, and then maintain a constant temperature between 35°C and 45°C until the film is formed to obtain a film. If the temperature of the fixed-temperature film formation is too low, the drying time will be prolonged, and the film may not be removed; on the contrary, if the temperature is too high, the film produced will be easier to rupture.

It can be seen from the table below that the film made of hemicellulose extract and pectin extract in a weight ratio of 1:4 has excellent strength and ductility.

It can be seen from the table below that the addition of fatty acids, especially stearic acid (SA), can effectively reduce the water solubility and water vapor permeability, that is, greatly improve the waterproof performance.

It can be seen from the table below that in the addition of food plasticizers, the addition of sorbitol is positively correlated in terms of thickness and water vapor permeability, while the deformation rate and opacity are negatively correlated, indicating that sorbitol has a film elastic performance , Optical performance and waterproof performance are worse than adding other plasticizers. The glycerin maintains the original mechanical and optical properties, and improves the water resistance.

However, the disclosure of the above embodiments is only used to illustrate the present invention, not to limit the present invention, so any replacement of equivalent elements should still belong to the scope of the present invention.

In summary, those skilled in the art can understand that this invention can clearly achieve the aforementioned purpose, and that it has actually complied with the provisions of the Patent Law, so it is necessary to file an application in accordance with the law.

Claims (5)

A method for preparing an edible film from bamboo shoot husk extract and passion fruit husk extract, which includes: A. Bamboo shoot husk pretreatment: a. After drying the bamboo shoot husk, grinding and crushing; b. Adding 2N to 10N hydrogen oxide Sodium solution, heated in a water bath at a constant temperature of 30°C to 90°C; c. Add 75% to 95% ethanol and place it at 4°C. The weight ratio of bamboo shoot shell-sodium hydroxide solution to ethanol is 1:4; d. Filter the precipitate and dry it to obtain the hemicellulose extract; B. Pretreatment of passion fruit husk: a. Dry the passion fruit husk and grind and crush; b. Add hydrochloric acid solution with a concentration of 0.01N to 0.09N and heat it at 30℃ Heat at a constant temperature in a water bath to 90°C; c. Add 75% to 95% ethanol and place it at 4°C, where the weight ratio of the passion fruit shell-hydrochloric acid solution to ethanol is 1:4; d. Filter the precipitate and dry it to obtain Pectin extract; C. Film preparation: a. Take the hemicellulose extract and pectin extract in a weight ratio of 1:1 to 1:5, and add 100ml of deionized water; b. Heat to 80°C to 90°C , Dissolve and mix, and add stearic acid and sweetener Oil; c. Maintain a constant temperature between 35°C and 45°C and wait for the film to be formed into a film. The method for preparing an edible film from the bamboo shoot husk extract and the passion fruit husk extract as described in claim 1, wherein the bamboo shoot husk is a hemp bamboo shoot husk. The method for preparing an edible film from bamboo shoot husk extract and passion fruit husk extract as described in claim 1, wherein, in the pretreatment of bamboo shoot husk, the concentration of sodium hydroxide solution is 2N, the water bath temperature is 50°C, and ethanol The concentration is 95%. The method for preparing an edible film from bamboo shoot husk extract and passion fruit husk extract as described in claim 1, wherein in the pretreatment of passion fruit husk, the concentration of hydrochloric acid is 0.05N, the temperature of the water bath is 90℃, and the temperature of ethanol is The concentration is 85%. The method for preparing an edible film from the bamboo shoot husk extract and the passion fruit husk extract as described in claim 1, wherein, in the film preparation step, the weight ratio of the hemicellulose extract to the pectin extract is 1:4 .

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