Chitosan-pectin-salicylic acid composite film for preventing and treating Psidium guajava Linn. cold damage, and preparation method of chitosan-pectin-salicylic acid composite film

Abstract

The invention belongs to the technical field of agricultural product preservation, and particularly discloses a chitosan-pectin-salicylic acid composite film for preventing and treating Psidium guajava Linn. cold damage, and a preparation method of the chitosan-pectin-salicylic acid composite film. The chitosan-pectin-salicylic acid composite film is prepared from the following components in parts by weight: 1.0-5.0 parts of glycerol, 0.5-5.0 parts of salicylic acid, 2.0-6.0 parts of chitosan, and 1.0-5.0 parts of pectin. The chitosan-pectin-salicylic acid composite film can effectively inhibit the occurrence of the cold damage in a low-temperature storage process of the harvested Psidium guajava Linn. and maintain the freshness of the Psidium guajava Linn., the cold damage index of the Psidium guajava Linn. in an untreated group is 0.68 when the Psidium guajava Linn. is stored to the tenth day, the water loss rate is 2.14 times of that of the treated group, and the cold damage index of the Psidium guajava Linn. treated by the composite film disclosed by the invention is only 0.16.

Description

technical field

[0001] The invention belongs to the technical field of fresh-keeping of agricultural products, in particular to a chitosan-pectin-salicylic acid composite film for preventing and treating guava chilling damage and a preparation method thereof. Background technique

[0002] Guava, also known as Guava, Naba, Qiuguo, Jiyaguo, etc., is one of the excellent subtropical fruit varieties that Guangdong Province has focused on developing in recent years. Guava is rich in soluble sugar, vitamin C, vitamin A and vitamin B, trace elements such as calcium, phosphorus, iron, potassium, soluble protein and various polyphenols. It has medicinal effects such as quenching thirst, lowering blood sugar, astringent and antidiarrheal, has high health care functions and high economic value, and is deeply favored by domestic and foreign consumers. Guava is a typical climacteric fruit, which is prone to fruit softening and rot after harvest. Therefore, at present, guava fruit is mai...

Examples

Embodiment 1

[0030] A kind of chitosan-pectin-salicylic acid composite film prevents and treats the method for guava chilling injury, comprises the steps:

[0031] 1) Preparation of membrane solution: Weigh 2.0 g of chitosan into 100 mL of water (concentration: 2.0 g / 100 mL), stir at 25° C. for 60 min, and add acetic acid dropwise while stirring to adjust the pH of the solution to 5.0. Then add glycerin, pectin and salicylic acid in sequence, and then conduct ultrasonic defoaming on the membrane liquid, the ultrasonic power is 300W, the ultrasonic temperature is 25°C, and the ultrasonic time is 5min.

[0032] 2) Film coating: Soak the guava in the chitosan-pectin-salicylic acid composite film solution for 2min, then drain and let it dry naturally.

[0033] 3) Storage: the dried mangoes are stored in an environment with a relative humidity of 88% at room temperature.

Embodiment 2～3

[0035] In Examples 2 to 3, the preparation method of the chitosan-pectin-salicylic acid composite film to prevent and treat guava chilling damage is the same as in Example 1, except that the amount of salicylic acid added is different. For details, see Table 1.

technical field

[0001] The invention belongs to the technical field of fresh-keeping of agricultural products, in particular to a chitosan-pectin-salicylic acid composite film for preventing and treating guava chilling damage and a preparation method thereof. Background technique

[0002] Guava, also known as Guava, Naba, Qiuguo, Jiyaguo, etc., is one of the excellent subtropical fruit varieties that Guangdong Province has focused on developing in recent years. Guava is rich in soluble sugar, vitamin C, vitamin A and vitamin B, trace elements such as calcium, phosphorus, iron, potassium, soluble protein and various polyphenols. It has medicinal effects such as quenching thirst, lowering blood sugar, astringent and antidiarrheal, has high health care functions and high economic value, and is deeply favored by domestic and foreign consumers. Guava is a typical climacteric fruit, which is prone to fruit softening and rot after harvest. Therefore, at present, guava fruit is mai...

Examples

Embodiment 1

[0030] A kind of chitosan-pectin-salicylic acid composite film prevents and treats the method for guava chilling injury, comprises the steps:

[0031] 1) Preparation of membrane solution: Weigh 2.0 g of chitosan into 100 mL of water (concentration: 2.0 g / 100 mL), stir at 25° C. for 60 min, and add acetic acid dropwise while stirring to adjust the pH of the solution to 5.0. Then add glycerin, pectin and salicylic acid in sequence, and then conduct ultrasonic defoaming on the membrane liquid, the ultrasonic power is 300W, the ultrasonic temperature is 25°C, and the ultrasonic time is 5min.

[0032] 2) Film coating: Soak the guava in the chitosan-pectin-salicylic acid composite film solution for 2min, then drain and let it dry naturally.

[0033] 3) Storage: the dried mangoes are stored in an environment with a relative humidity of 88% at room temperature.

Embodiment 2～3

[0035] In Examples 2 to 3, the preparation method of the chitosan-pectin-salicylic acid composite film to prevent and treat guava chilling damage is the same as in Example 1, except that the amount of salicylic acid added is different. For details, see Table 1.

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