Preparation Method for Humic Acid Type Fruit Bagging-free Film Agent and Application thereof

Abstract

A humic acid type fruit bagging-free film agent and an application thereof are provided. The humic acid type fruit bagging-free film agent is prepared by: dissolving sodium alginate into water, adding TWEEN-20 and SPAN-20 after stirring evenly, and stirring for mixing to form sodium alginate solution; dissolving humic acid potassium into water, adding glycerin then mixing to form humic acid potassium solution; stirring the sodium alginate solution and the humic acid potassium solution evenly to form agent A; and dissolving calcium chloride into water to obtain agent B. When in use, the agent A is sprayed onto a fruit surface, and then agent B is sprayed. It can not only be antibacterial, anti- freezing and pest-resistant, but also shorten film-forming duration and have better film-forming property. Shading performance is improved, and problems of rough fruit surface, serious rust and dim color caused by using paper bagging can be solved.

Claims

1. A humic acid type fruit bagging-free film agent, comprising: an agent A and an agent B, wherein the agent A is configured to be sprayed onto a fruit surface, and then the agent B is configured to be sprayed immediately after the agent A is sprayed to form a humic acid type fruit bagging-free film on the fruit surface; wherein the agent A is prepared by the following steps: (1) dissolving sodium alginate into water, stifling evenly, then adding TWEEN-20 and SPAN-20, and stifling for mixing to form a sodium alginate solution; wherein a mass ratio of the sodium alginate: the water: the TWEEN-20: the SPAN-20 is (5˜8): (60˜65): (0.5˜0.8): (0.5˜0.8); (2) dissolving humic acid potassium into water completely, adding glycerin, then mixing completely and evenly to form a humic acid potassium solution; wherein a mass ratio of the humic acid potassium: the water: the glycerin is (0.3˜0.5): (35˜40): (1˜1.2); and (3) stifling the sodium alginate solution prepared by the step (1) and the humic acid potassium solution prepared by the step (2) fully until they become a homogeneous system, thereby forming the agent A; wherein a volume ratio of the sodium alginate solution prepared in the step (1) to the humic acid potassium solution prepared in the step (2) is 1:1; wherein the agent B is a calcium chloride solution.

2. The humic acid type fruit bagging-free film agent according to claim 1, wherein a mass concentration of calcium chloride in the agent B is (1.5˜2) %.

3. An application method of the humic acid type fruit bagging-free film agent according to claim 1, wherein the humic acid type fruit bagging-free film agent is applied to a fruit surface; wherein when in use, spraying the agent A onto the fruit surface and then spraying the agent B, thereby forming a humic acid type fruit bagging-free film on the fruit surface.

4. (canceled)

5. The application method according to claim 3, wherein a film-forming duration of the humic acid type fruit bagging-free film is 5-10 seconds (s) after spraying the agent A and the agent B.

Description

DETAILED DESCRIPTION OF EMBODIMENTS

[0023] The invention relates to a humic acid type fruit bagging-free film agent and an application method of humic acid type fruit bagging-free film agent. The humic acid type fruit bagging-free film agent (also referred to as bagging-free film agent for humic acid type fruit) exemplarily consists of agent A and agent B. In actual use, the agent A is sprayed first and then the agent B is sprayed, and at the same time, the agent A can be mixed with pesticide and micronutrient fertilizer for use, and a film may be quickly formed within 3-10 seconds (s).

[0024] A principle of the invention is as follows: calcium chloride, as a cross-linking agent of sodium alginate, will chelate with the sodium alginate. The composite crosslink system of humic acid macromolecule and linear natural macromolecule sodium alginate as lamellar structure mainly exists in the form of hydrogen bond, and form a three-dimensional network crosslinking structure. Because active groups of the sodium alginate are evenly distributed in the cross-linked composite system, after contacting with calcium chloride, molecular chains of the sodium alginate are more tightly combined and the synergy is stronger. Therefore, the interaction between chains eventually leads to the formation of a three-dimensional grid structure, that is, the gel state, which makes the prepared liquid film have good tensile strength, thickness and flexibility, thus greatly improving the comprehensive performance of the product film.

[0025] Specifically, the preparation method of the humic acid type fruit bagging-free film agent may include the following steps:

[0026] (1) dissolving sodium alginate into water, stirring evenly, then adding TWEEN-20 (also referred to as polysorbate-20, its molecular formula is C.sub.26H.sub.50O.sub.10) and SPAN-20 (also referred to as sorbitan monolaurate, its molecular formula is C.sub.8H.sub.34O.sub.6), and stirring for mixing to form a sodium alginate solution, where a mass ratio of the sodium alginate: the water: the TWEEN-20: the SPAN-20 is (5˜8): (60˜65): (0.5˜0.8): (0.5˜0.8);

[0027] (2) dissolving humic acid potassium into water completely, adding glycerin, then mixing completely and evenly to form a humic acid potassium solution, where a mass ratio of the humic acid potassium: the water: the glycerin is (0.3˜0.5): (35˜40): (1˜1.2);

[0028] (3) stirring the sodium alginate solution prepared by the step (1) and the humic acid potassium solution prepared by the step (2) fully until they become a homogeneous system, thereby forming the agent A, where a volume ratio of the sodium alginate solution prepared in the step (1) to the humic acid potassium solution prepared in the step (2) is 1:1; and

[0029] (4) dissolving calcium chloride into water to obtain the agent B. In an application, spraying the agent A is carried out before spraying the agent B onto the fruit surface, where a mass concentration of the calcium chloride is (1.5˜2) %.

[0030] The invention will be further described in detail with specific embodiments, which are meant to explain the invention rather than limit it.

Embodiment 1

[0031] (1) 5 kg of sodium alginate is dissolved into 60 kg of water, 0.5 kg of TWEEN-20 and 0.5 kg of SPAN-20 are added, fully dissolved, stirred for mixing to form a sodium alginate solution;

[0032] (2) 0.3 kg of humic acid potassium is dissolved into 40 kg of water, mixed evenly, 1 kg of glycerin are added, and stirred evenly to obtain a humic acid potassium solution;

[0033] (3) the sodium alginate solution prepared by step the (1) and the humic acid potassium solution prepared by the step (2) are fully stirred according to a volume ratio of 1:1 until they become a homogeneous system, thereby forming agent A; and

[0034] (4) 1.5 kg of calcium chloride is dissolved into 100 kg of water, fully dissolved, and thereby obtaining agent B.

Embodiment 2

[0035] (1) 8 kg of sodium alginate is dissolved into 65 kg of water, 0.8 kg of TWEEN-20 and 0.8 kg of SPAN-20 are added, fully dissolved, stirred for mixing to form a sodium alginate solution;

[0036] (2) 0.5 kg of humic acid potassium is dissolved into 35 kg of water, mixed evenly, 1.2 kg of glycerin are added, and stirred evenly to obtain a humic acid potassium solution;

[0037] (3) the sodium alginate solution prepared by the step (1) and the humic acid potassium solution prepared by the step (2) are fully stirred according to a volume ratio of 1:1 until they become a homogeneous system, thereby forming agent A; and

[0038] (4) 2 kg of calcium chloride is dissolved into 100 kg of water, fully dissolved, and thereby obtaining agent B.

Embodiment 3

[0039] (1) 6 kg of sodium alginate is dissolved into 60 kg of water, 0.6 kg of TWEEN-20 and 0.6 kg of SPAN-20 are added, fully dissolved, stirred for mixing to form a sodium alginate solution;

[0040] (2) 0.4 kg of humic acid potassium is dissolved into 40 kg of water, mixed evenly, 1.1 kg of glycerin are added, and stirred evenly to obtain a humic acid potassium solution;

[0041] (3) the sodium alginate solution prepared by the step (1) and the humic acid potassium solution prepared by the step (2) are fully stirred according to a volume ratio of 1:1 until they become a homogeneous system, thereby forming agent A; and

[0042] (4) 1.8 kg of calcium chloride is dissolved into 100 kg of water, fully dissolved, and thereby obtaining agent B.

Embodiment 4

[0043] (1) 7 kg of sodium alginate is dissolved into 63 kg of water, 0.8 kg of TWEEN-20 and 0.8 kg of SPAN-20 are added, fully dissolved, stirred for mixing to form a sodium alginate solution;

[0044] (2) 0.3 kg of humic acid potassium is dissolved into 37 kg of water, mixed evenly, 1.0 kg of glycerin are added, and stirred evenly to obtain a humic acid potassium solution;

[0045] (3) the sodium alginate solution prepared by the step (1) and the humic acid potassium solution prepared by the step (2) are fully stirred according to a volume ratio of 1:1 until they become a homogeneous system, thereby forming agent A; and

[0046] (4) 2 kg of calcium chloride is dissolved into 100 kg of water, fully dissolved, and thereby obtaining agent B.

[0047] The application performance test of the humic acid type fruit bagging-free film agent is conducted in the demonstration area of Baota District, Yan'an, Shaanxi Province, China, and the experimental crop is apple. The control group bags apples with conventional plastic bags. The experimental group 1 uses the bagging-free film prepared by the applicant's earlier Chinese patent Publication No.CN107155739A. The experimental group 2 takes the products prepared in Embodiment 1, and apples are subject to spraying to form films. The effects of different bagging methods on apple growth are observed and explored.

[0048] The experimental results are as follows.

[0049] (a) the bagging-free film applied in the experimental group 1 takes 0.8-1h to form a film after spraying, and the humic acid fruit bagging-free film applied in experimental group 2 may quickly form a film within 5 s after spraying, which greatly shortens the film forming duration.

[0050] (b) the apples are observed after bagging and spraying agents to form film, it is found that the apples in the two experimental groups grow relatively well, and the apples in the experimental group 2 develop rapidly. From the 40th day after bagging, it is observed that the apples are relatively larger in size and have a higher rate of full red in the colored area. The specific experimental results are shown in Table 1.

TABLE-US-00001 TABLE 1 Growth of apples after bagging Group/Days 20 30 40 50 60 70 Control group Good Good With poor With poor With poor With poor growth growth color and color and color, many color, many spots spots spots and spots and fruit fruit dropping. dropping. Experimental Good Good Good Good Good Good group 1 growth growth growth, with growth, with growth, with growth, with relatively full relatively full relatively full relatively full fruit and fruit and fruit and fruit and transparent transparent transparent transparent color. color. color. color. Experimental Good Good With With With big With big group 2 growth growth relatively relatively fruit, smooth fruit, shallow big fruit, big fruit, surface, and small smooth smooth shallow and fruit dots, surface and surface and small fruit and bright bright color. bright color. dots and color. bright color

[0051] From the table, it can be seen that the fruit of experimental group 2 is bigger, the fruit surface is smoother, the fruit develops faster, larger than that of bagged apples and experimental group 2, the specific gravity is larger, the fruit surface is smooth and delicate, the fruit dot is shallow and small, and the color is bright.

[0052] (c) the sweetness and hardness of apples in the control group, the experimental group 1 and the experimental group 2 are tested, and the test results are shown in Table 2.

TABLE-US-00002 TABLE 2 Sugar content Average hardness Group (%) (kgf/cm.sup.2) Control group 10.6 6.73 Experimental group 1 13.7 8.16 Experimental group 2 16.3 9.77

[0053] It can be seen from the table that the bagging-free film prepared by the above-mentioned Chinese patent Publication No. CN107155739A in the experimental group 1 and humic acid fruit bagging-free film prepared in the experimental group 2 may improve the sugar content and hardness of apples. Compared with the bagging-free film previously proposed by the applicant, the performance of humic acid fruit bagging-free film prepared by the invention is improved, and the preparation method is also improved. The applicable fruits are not limited to apples, but also may be applied to kiwi fruit, pear, pomegranate, grape and other fruits.

[0054] What has been described above is only the illustrated embodiment of the invention, and it does not limit the invention in any way. Any simple modification, change and equivalent structural transformation of the above embodiments according to the technical essence of the invention still falls within the protection scope of the technical solution of the invention.