CN107912526A - A kind of preparation method and application of nitric oxide donator type chitosan nano antistaling agent - Google Patents

Abstract

The invention relates to a preparation method of a nitric oxide donor type chitosan nano preservative, and its components and mass fractions are: 3-12 parts of chitosan, 10-15 parts of glutathione, and 10-10 parts of organic acid 20 parts, 0.5-1 part of sodium tripolyphosphate, 1.5-3.5 parts of sodium nitrite, 4000 parts of water; the nitric oxide donor type chitosan nano preservative prepared by the present invention contains chitosan and can release nitric oxide The glutathione carrier component combines the dual fresh-keeping effects of chitosan and nitric oxide, which can achieve better fresh-keeping effects and can significantly delay the process of dehydration, softening and aging of fruits and vegetables; at the same time, the preservative is green and non-toxic The poison is edible, and the preparation process is simple, which can be more convenient and widely used, and has great application potential in the field of fruit and vegetable preservation.

Description

Preparation method and application of a kind of nitric oxide donor chitosan nano preservative

technical field

The invention belongs to the technical field of fresh-keeping of fruits and vegetables, and relates to a preparation method and application of a nitric oxide donor chitosan nano-preservative.

Background technique

Due to physiological aging and mechanical damage of fruits and vegetables before and after picking, the storage quality is easy to decline, or even rot and deteriorate, which affects economic benefits. At present, the common measures to slow down the decline in the storage quality of fruits and vegetables are low-temperature storage and combined with chemical preservation. Nitric oxide, as a regulator of fruit ripening, can inhibit fruit ripening and senescence. A large number of studies have proved that treating fruits with an appropriate concentration of nitric oxide can inhibit ethylene production and prolong the storage time of postharvest fruits. At present, nitric oxide is mostly used in the treatment of fruit preservation by gas fumigation or solution immersion. Since nitric oxide is a gas, its storage, transportation and use conditions are relatively harsh, which is inconvenient in the fresh-keeping industry. Therefore, donor-type preservatives that can slowly release nitric oxide gas need to be studied urgently.

Contents of the invention

In order to solve the above problems, the invention provides a nitric oxide donor type chitosan nano preservative; chitosan (polyglucosamine (1-4)-2-amino-β-D glucose) is abundant in nature A natural linear cationic biopolymer containing a large number of hydrophilic groups such as hydroxyl and amino groups. Due to its low cost, easy biodegradation and good film-forming properties, it can inhibit the growth of microorganisms and inhibit the respiration intensity when attached to the surface of fruits and vegetables; The invention organically combines chitosan and nitric oxide donors through nanotechnology, and utilizes the dual fresh-keeping effects of chitosan and nitric oxide, which can not only form a film to inhibit bacteria, but also inhibit respiration and ethylene production, which can achieve a more Effective preservation effect.

A nitric oxide donor type chitosan nano preservative, its components and mass fractions are: 3-12 parts of chitosan, 10-15 parts of glutathione, 10-20 parts of organic acid, tripolyphosphoric acid 0.5-1 part of sodium, 1.5-3.5 parts of sodium nitrite, 4000 parts of water.

The organic acid is citric acid, acetic acid, malic acid or lactic acid.

The present invention also provides a preparation method of nitric oxide donor type chitosan nano preservative, the preparation steps are as follows:

(1) 10-20 parts of organic acid and 3-12 parts of chitosan were sequentially added to 1000 parts of water, and stirred evenly to obtain solution 1.

(2) Add 10-15 parts of glutathione to 1000 parts of water, add 0.5-1 part of sodium tripolyphosphate to 1000 parts of water, add 1.5-3.5 parts of sodium nitrite to 1000 parts of water, stir evenly to obtain solutions 2. Solution 3, Solution 4.

(3) Add solution 2 into solution 1 and stir for 90 minutes to obtain solution 5.

(4) Add solution 3 to solution 5 dropwise, and stir evenly to obtain solution 6.

(5) Add solution 4 into solution 6, and stir for 45 minutes in the dark to prepare chitosan nano preservative.

Soaking, smearing or spraying fruits and vegetables with the nitric oxide donor type chitosan nano preservative prepared by the present invention, and storing them at normal temperature or low temperature after drying can significantly delay the dehydration process, softening process and aging process of fruits and vegetables.

Compared with the existing fruit and vegetable preservatives, the nitric oxide donor chitosan nano preservative prepared by the present invention contains chitosan and a glutathione carrier component that can release nitric oxide, and combines chitosan and a The double fresh-keeping effect of nitrogen oxide can achieve better fresh-keeping effect, and can significantly delay the dehydration process, softening process and aging process of fruits and vegetables; at the same time, this preservative is green, non-toxic and edible, and the preparation process is simple, which can be obtained more conveniently and Wider application has great application potential in the field of fruit and vegetable preservation.

Description of drawings

Fig. 1 is the effect of fresh-keeping agent of the present invention on the change of postharvest hardness of strawberry fruit under room temperature.

As can be seen from the change of hardness in Fig. 1, within 0-60 hours of postharvest treatment storage time, the hardness decline of the strawberry fruit that embodiment 1 product handles is obviously slower than the fruit that does not use antistaling agent process, illustrates that antistaling agent of the present invention can Significantly delays the softening process of strawberry fruit.

Fig. 2 is the effect of preservative of the present invention on postharvest color difference change of strawberry fruit under room temperature.

The lower the color difference, the darker the fruit color, and the older the fruit. As can be seen from the change in color difference in Fig. 2, within 0-60 hours of post-harvest treatment storage time, the color difference degree of strawberry fruit has become a downward trend, and the color difference degree of strawberry fruit processed by the product of Example 2 is lower than that without preservative treatment The fruit is slow, illustrating that the antistaling agent of the present invention can obviously delay the aging process of the fruit.

Fig. 3 is the effect of the antistaling agent of the present invention on the postharvest water loss rate of cucumber fruits at room temperature.

As can be seen from the change of dehydration rate in Fig. 3, within 0-12 days of post-harvest treatment storage time, the dehydration rate of the cucumber fruit processed by the product of Example 2 rises obviously slower than the fruit that does not use preservative treatment, illustrating the present invention Preservatives can significantly delay the water loss process of cucumber fruit.

Detailed ways

The present invention will be further described in detail below in conjunction with the examples, and the given examples are only to illustrate the present invention, and do not limit the scope of the present invention. All reagents adopted in the embodiment are commercially available, and its manufacturer and batch number are as follows:

Chitosan: purchased from Shanghai Yuanye Biotechnology Co., Ltd., batch number: A24M8X36696;

Glutathione: purchased from Shanghai Yuanye Biotechnology Co., Ltd., batch number: Q19M8N36347;

Sodium tripolyphosphate: purchased from Tianjin Kaitong Chemical Reagent Co., Ltd., batch number: 20161020;

Acetic acid: purchased from Tianjin Kaitong Chemical Reagent Co., Ltd., batch number: 20160616;

Citric acid: purchased from Tianjin Kaitong Chemical Reagent Co., Ltd., batch number: 20160815;

Sodium nitrite: purchased from Tianjin Kaitong Chemical Reagent Co., Ltd., batch number: 20160428.

Example 1

A nitric oxide donor type chitosan nano freshness preservation agent comprises the following components: chitosan, glutathione, acetic acid, sodium tripolyphosphate, sodium nitrite and water.

The preparation method of chitosan nano preservative comprises the following steps:

(1) 15 parts of acetic acid and 4 parts of chitosan were sequentially added to 1000 parts of water, and stirred evenly to obtain solution 1.

(2) Add 12 parts of glutathione to 1000 parts of water, 0.6 part of sodium tripolyphosphate to 1000 parts of water, 2.8 parts of sodium nitrite to 1000 parts of water, stir well to obtain solution 2, solution 3 and solution respectively 4.

(3) Add solution 2 into solution 1 and stir for 90 minutes to obtain solution 5.

(4) Add solution 3 to solution 5 dropwise, and stir evenly to obtain solution 6.

(5) Add solution 4 into solution 6, and stir for 45 minutes in the dark to prepare chitosan nano preservative.

The chitosan nano preservative prepared above is applied to the preservation of strawberry fruit. The specific method is: purchase freshly picked fresh strawberries, subtract diseased, green and mechanically damaged parts, and ensure that the fruit is fresh and uniform. The prepared chitosan nano preservative is directly sprayed on the surface of strawberry fruit, dried and stored at room temperature.

As can be seen from the change of hardness in Fig. 1, within 0-60 hours of postharvest treatment storage time, the hardness of the strawberry fruit after the treatment of the chitosan nano-preservative prepared by the present embodiment is significantly lower than that of the fruit without preservative treatment. slow, indicating that the antistaling agent of the present invention can obviously delay the softening process of strawberry fruit.

At the same time, the lower the color difference, the darker the fruit color and the more aging the fruit. As can be seen from the change in color difference in Figure 2, the color difference of strawberry fruit has a downward trend in the post-harvest treatment storage time of 0-60 hours. The fruit processed by the antistaling agent is slower, indicating that the antistaling agent of the present invention can obviously delay the senescence process of the fruit.

Example 2

A nitric oxide donor type chitosan nano-preservation agent comprises the following components: chitosan, glutathione, citric acid, sodium tripolyphosphate, sodium nitrite and water.

The preparation method of chitosan nano preservative comprises the following steps

(1) 15 parts of citric acid and 4 parts of chitosan were sequentially added to 1000 parts of water, and stirred evenly to obtain solution 1.

(2) Add 12 parts of glutathione to 1000 parts of water, 0.6 part of sodium tripolyphosphate to 1000 parts of water, 2.8 parts of sodium nitrite to 1000 parts of water, stir well to obtain solution 2, solution 3 and solution respectively 4.

(3) Add solution 2 into solution 1 and stir for 90 minutes to obtain solution 5.

(4) Add solution 3 to solution 5 dropwise, and stir evenly to obtain solution 6.

(5) Add solution 4 into solution 6, and stir for 45 minutes in the dark to prepare chitosan nano preservative.

The chitosan nano preservative prepared above is applied to the preservation of cucumber fruit. The specific method is: purchase freshly picked fresh cucumbers, and subtract diseased, small and mechanically damaged parts to ensure freshness and uniformity of the fruit. The prepared chitosan nano preservative was directly sprayed on the surface of cucumber fruit, dried and stored at room temperature.

As can be seen from the change of water loss rate in Fig. 3, in post-harvest treatment storage time 0-12 days, the water loss rate of cucumber fruit after the treatment of chitosan nano preservative prepared by the present embodiment is significantly higher than that without preservative The processed fruit is slow, indicating that the antistaling agent of the present invention can obviously delay the water loss process of cucumber fruit.

Claims (6)

1. A nitric oxide donor type chitosan nano preservative, is characterized in that, each component and massfraction thereof are: 3-12 parts of chitosan, 10-15 parts of glutathione, 10-15 parts of organic acid 20 parts, 0.5-1 part of sodium tripolyphosphate, 1.5-3.5 parts of sodium nitrite, 4000 parts of water. 2. a kind of nitric oxide donor type chitosan nano preservative according to claim 1, is characterized in that, described organic acid is citric acid, acetic acid, malic acid or lactic acid. 3. the preparation method of a kind of nitric oxide donor type chitosan nano preservative as claimed in claim 1, is characterized in that, step is as follows: 1) Add 10-20 parts of organic acid and 3-12 parts of chitosan to 1000 parts of water in turn, and stir evenly to obtain solution 1; 2) Add 10-15 parts of glutathione to 1000 parts of water, add 0.5-1 part of sodium tripolyphosphate to 1000 parts of water, add 1.5-3.5 parts of sodium nitrite to 1000 parts of water, stir evenly to obtain solution 2 , solution 3, solution 4; 3) Add solution 2 to solution 1, and stir for 90 minutes to obtain solution 5; 4) Add solution 3 dropwise to solution 5, and stir evenly to obtain solution 6; 5) Add solution 4 to solution 6, and stir for 45 minutes in the dark to prepare chitosan nano preservative. 4. the application of a kind of nitric oxide donor type chitosan nano preservative as claimed in claim 1 in delaying fruit and vegetable dehydration process, softening process and aging process, is characterized in that, soaks, smears or sprays with preservative Fruits and vegetables should be stored at room temperature or low temperature after drying. 5. the application of a kind of nitric oxide donor type chitosan nano preservative as claimed in claim 1 in delaying the process of cucumber fruit dehydration. 6. the application of a kind of nitric oxide donor type chitosan nano preservative as claimed in claim 1 in delaying the softening process and the aging process of strawberry fruit.