Preparation method of Chinese herbal medicine essential oil slow-release agent and application of Chinese herbal medicine essential oil slow-release agent in strawberry preservation

Abstract

The invention discloses a preparation method of a Chinese herbal medicine essential oil slow-release agent and application of the Chinese herbal medicine essential oil slow-release agent in strawberry preservation, and the preparation method comprises the following steps: at room temperature, weighing a certain amount of 7-butyl sultone-beta-cyclodextrin, adding a proper amount of water, heating and dissolving in a water bath to prepare a 7-butyl sultone-beta-cyclodextrin saturated solution, standing and cooling; weighing a proper amount of Chinese herbal medicine essential oil, dropwise adding the Chinese herbal medicine essential oil into a certain amount of food-grade ethanol, oscillating uniformly, slowly dropwise adding the mixture into a 7-butyl sultone-beta-cyclodextrin saturated solution, and stirring at a constant temperature; the preparation method comprises the following steps: adding the peppermint essential oil into a stirrer, stirring, cooling, carrying out suction filtration, washing an inclusion compound with a small amount of petroleum ether, putting into a dryer, taking out and weighing after a period of time, adjusting the core-wall ratio to 1: 1-3: 1, adjusting the curing time to 3-5 hours, and adjusting the reaction time to 30-60 minutes, thereby obtaining the peppermint essential oil slow-release agent with a good embedding rate, and preserving strawberries for 12 days by using the novel preservative. The peppermint essential oil is applied to strawberry preservation, the eating quality of strawberries can be safely, environmentally friendly and efficiently kept, and the storage period of the strawberries is prolonged.

Description

Technical Field

[0001] The present invention belongs to the technical field of post-harvest storage of strawberries, and particularly relates to a preparation method of a Chinese herbal medicine essential oil sustained-release agent and its application in strawberry preservation. Background Art

[0002] The decay and deterioration of strawberry fruits are closely related to their own metabolism and the infection of harmful microorganisms such as bacteria. Due to the softness of the fruits, thin skins and juicy nature of strawberries, they are extremely prone to being knocked during picking, storage and transportation, resulting in mechanical damage and biological diseases, thus losing their edible value. Currently, with the rise of fresh food e-commerce, the requirement for immediate delivery is to maintain stable quality within 48 hours, which forces innovation in preservation technology. The export volume of strawberries in China to Southeast Asia, the Middle East, etc. continues to grow, and the problem of long-distance sea transportation preservation needs to be solved. In addition, the demand for reducing cold chain energy consumption promotes the development of new preservation technologies. Therefore, it is urgent to find a suitable preservation method to extend the shelf life of strawberries. Chinese herbal medicine essential oil is a highly volatile liquid extracted from Chinese herbal medicine, which is a compound containing aldehydes, ketones, terpenes, etc., and has an obvious inhibitory effect on harmful microorganisms such as bacteria. Good results have been achieved on fruits and vegetables such as grapes, tomatoes, winter jujubes, okra, and red fragrant pears, but its application on strawberries is still very few. Chinese herbal medicine has the characteristics of being green, safe, environmentally friendly and efficient, but its extract is extremely volatile in the air, thus affecting the use effect. Therefore, problems such as the stability and persistence of the use of Chinese herbal medicine essential oil still need to be solved. Summary of the Invention

[0003] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a strawberry preservation method based on Chinese herbal medicine essential oil. The scheme and steps are as follows:

[0004] 1) Weigh a certain amount of 7-butanesulfonic acid lactone-β-cyclodextrin, add an appropriate amount of water, heat and dissolve it in a water bath to prepare a saturated solution of 7-butanesulfonic acid lactone-β-cyclodextrin, and let it stand and cool.

[0005] 2) Weigh an appropriate amount of Chinese herbal medicine essential oil and drop it into a certain amount of food-grade ethanol. After shaking evenly, slowly drop it into the saturated solution of 7-butanesulfonic acid lactone-β-cyclodextrin, and stir at a constant temperature for a certain period of time to allow the two to react fully and then take it out.

[0006] 3) After cooling, place it in the refrigerator for refrigeration, take it out, filter by suction, wash the clathrate with a small amount of petroleum ether, put it into a dryer for drying, take it out and weigh it after a period of time to obtain the Chinese herbal medicine essential oil clathrate.

[0007] 4) Single-factor experiment on embedding Chinese herbal medicine essential oil

[0008] On the basis of screening many Chinese herbal medicine essential oils, it is determined through the size of antibacterial properties that peppermint essential oil has the strongest antibacterial property and can be used for further embedding.

[0009] Taking the embedding rate as the evaluation index, three factors including the core-wall ratio, reaction time, and curing time were selected as the objects for single-factor investigation. Under the conditions of core-wall ratios of 1:4, 1:2, 1:1, 2:1, 3:1, reaction times of 10, 20, 30, 40, 50 min, and curing times of 1, 2, 3, 4, 5 h, the embedding rate of Chinese herbal essential oil was measured to finally determine the effects of the single factors of core-wall ratio, reaction time, and curing time on the embedding rate of Chinese herbal essential oil microcapsules.

[0010] 5) Response surface optimization test for embedding Chinese herbal essential oil

[0011] On the basis of the single-factor experiment, with the core-wall ratio, reaction time, and curing time as independent variables and the embedding rate as the response value, the optimal process parameters for the 7-butanesulfonic acid lactone-β-cyclodextrin inclusion complex of Chinese herbal essential oil were screened, obtaining a core-wall ratio of 1:1 to 3:1, a curing time of 3 to 5 h, and a reaction time of 30 to 60 min.

[0012] 6) Preservation test of strawberries

[0013] The determined formula of Chinese herbal essential oil after embedding was applied to strawberry preservation, and various indexes related to strawberry quality were measured, and the quality indexes were measured every 2 days during storage.

[0014] The beneficial effects of the present invention are as follows: Chinese herbal peppermint essential oil has a good bactericidal effect. After being embedded by cyclodextrin, it can be used for strawberry preservation, retaining the excellent flavor and nutritional value of strawberries, and having advantages such as good application effect, environmental protection, and economy. Description of the drawings

[0015] Figure 1 It is the maximum absorption wavelength of peppermint essential oil.

[0016] Figure 2 It is the standard curve of peppermint essential oil.

[0017] Figure 3 It is the effect of the core-wall ratio on the embedding rate of peppermint essential oil microcapsules.

[0018] Figure 4 It is the effect of the reaction time on the embedding rate of peppermint essential oil microcapsules.

[0019] Figure 5 It is the effect of the curing time on the embedding rate of peppermint essential oil microcapsules.

[0020] Figure 6 It is the good fruit rate during strawberry storage.

[0021] Figure 7 It is the rotting rate during strawberry storage.

[0022] For those of ordinary skill in the art, without creative efforts, other related drawings can be obtained based on the above drawings. Detailed implementation mode

[0023] The present invention will be further described in detail below in conjunction with the drawings and specific embodiments. It should be noted that the following embodiments are illustrative and not restrictive, and the protection scope of the present invention cannot be limited by the following embodiments.

[0024] The experimental materials, experimental reagents, experimental instruments and equipment used in the present invention are as follows:

[0025] (1) Experimental materials

[0026] Strawberries: Purchased from Hongqi Farmers' Market, Xiqing District, Tianjin;

[0027] (2) Experimental reagents

[0028] Peppermint essential oil: Shanghai Yuanye Bio-Technology Co., Ltd.;

[0029] 7-butanesulfonyl-β-cyclodextrin: Sinopharm Chemical Reagent Co., Ltd.;

[0030] (3) Instruments and equipment

[0031] Ultraviolet spectrophotometer, Shanghai Mepuda Instrument Co., Ltd.;

[0032] Electronic balance, Mettler-Toledo;

[0033] DC-0515 constant temperature water bath, Shanghai Hengping Instrumentation Co., Ltd.;

[0034] The present invention is a preparation method of a Chinese herbal medicine essential oil sustained-release agent and its application in strawberry preservation, which is carried out according to the following steps:

[0035] 1) Weigh a certain amount of 7-butanesulfonyl-β-cyclodextrin, add an appropriate amount of water, heat and dissolve it in a water bath to prepare a saturated solution of 7-butanesulfonyl-β-cyclodextrin, and let it stand and cool;

[0036] 2) Weigh an appropriate amount of Chinese herbal medicine essential oil and drop it into a certain amount of food-grade ethanol. After shaking evenly, slowly drop it into the saturated solution of 7-butanesulfonyl-β-cyclodextrin, stir at a constant temperature for a certain time to make the two react fully, and then take it out;

[0037] 3) After cooling, place it in the refrigerator for refrigeration, take it out, filter by suction, wash the inclusion compound with a small amount of petroleum ether, put it into a dryer for drying, take it out and weigh it after a period of time to obtain the Chinese herbal medicine essential oil inclusion compound;

[0038] 4) Single-factor experiment on embedding Chinese herbal medicine essential oil

[0039] To accurately calculate the encapsulation efficiency of essential oils, a full-wavelength scan was performed on peppermint essential oil ( Figure 1 ), and its standard curve was plotted ( Figure 2 );

[0040] Taking the encapsulation efficiency as the evaluation index, three factors, namely the core-wall ratio, reaction time, and curing time, were selected as the objects of single-factor investigation; under the conditions of core-wall ratios of 1:4, 1:2, 1:1, 2:1, 3:1, reaction times of 10, 20, 30, 40, 50 min, and curing times of 1, 2, 3, 4, 5 h, the encapsulation efficiency of Chinese herbal medicine essential oil was measured, and finally the effects of the single factors of core-wall ratio ( Figure 3 ), reaction time ( Figure 4 ), and curing time ( Figure 5 ) on the encapsulation efficiency of peppermint essential oil microcapsules were determined;

[0041] 5) Response surface optimization experiment for encapsulation of Chinese herbal medicine essential oil

[0042] On the basis of the single-factor experiment, with the core-wall ratio (A), reaction time (B), and curing time (C) as independent variables and the encapsulation efficiency as the response value, a response surface experiment was designed (Table 1) to screen the optimal process parameters for the encapsulation of Chinese herbal medicine essential oil with 7-butanesulfonic acid lactone-β-cyclodextrin. The optimal levels obtained were a core-wall ratio of 1:1, a reaction time of 40 min, and a curing time of 4 h (Table 2), and the encapsulation efficiency of the essential oil was the highest under these conditions;

[0043] Table 1 Design table of response surface experiment for peppermint essential oil

[0044]

[0045] Table 2 Results of response surface optimization experiment for peppermint essential oil

[0046]

[0047] Note: ** indicates extremely significant (P < 0.01), and * indicates significant (P < 0.05)

[0048] 6) Storage experiment of strawberries

[0049] After encapsulating the determined formula of Chinese herbal medicine essential oil, it was applied to strawberry preservation, and the good fruit rate ( Figure 6 ) and rot rate ( Figure 7 ), which are quality indicators related to strawberry quality, were measured every 2 days.

[0050] The results showed that compared with the control, the treatment with peppermint essential oil microcapsules had a better water retention effect on strawberry fruits, could effectively maintain the good fruit rate of strawberry fruits, and maintain their commerciality.

[0051] This example shows that the encapsulated peppermint essential oil can be used for strawberry preservation, retaining the excellent flavor and nutritional value of strawberries. The above provides an exemplary description of the present invention. It should be noted that any simple deformation, modification, or equivalent substitution that can be made by those skilled in the art without creative efforts falls within the protection scope of the present invention without departing from the core of the present invention.

Claims

1. A method for preparing a Chinese herbal essential oil sustained-release agent and its application in strawberry preservation, characterized in that: The following steps are involved: 1) Weigh a certain amount of 7-butane sultone-β-cyclodextrin, add an appropriate amount of water, heat in a water bath to dissolve, to prepare a saturated solution of 7-butane sultone-β-cyclodextrin, and let stand to cool; 2) Weigh an appropriate amount of Chinese herbal essential oil and drip it into a certain amount of food-grade ethanol. After oscillation, slowly drip it into a saturated solution of 7-butane sultone-β-cyclodextrin. Stir at a constant temperature for a certain period of time to allow the two to react fully and then take it out; 3) After cooling, place in a refrigerator for refrigeration, take out, filter, wash the inclusion compound with a small amount of petroleum ether, put into a dryer for drying, take out and weigh after a period of time, and obtain the Chinese herbal medicine essential oil inclusion compound; 4) Single factor experiment of Chinese herbal essential oil embedding Taking the embedding rate as the evaluation index, the three factors of core-to-wall ratio, reaction time and curing time were selected as the objects of single factor investigation; the embedding rate of Chinese herbal essential oil was determined under the conditions of core-to-wall ratio of 1:4, 1:2, 1:1, 2:1, 3:1, reaction time of 10, 20, 30, 40, 50min, and curing time of 1, 2, 3, 4, 5h, and finally the influence of single factor core-to-wall ratio, reaction time and curing time on the embedding rate of Chinese herbal essential oil microcapsules was determined; 5) Response surface optimization experiment of Chinese herbal medicine essential oil embedding On the basis of single factor experiment, Design-Expert V8.06 software was used, according to the Box-Behnken experimental design principle, to select the influence on the embedding rate of Chinese herbal essential oil microcapsules, with core-to-wall ratio, reaction time and curing time as independent variables and embedding rate as response value, to screen the optimal process parameters of Chinese herbal essential oil 7-butane sultone-β-cyclodextrin inclusion complex and prepare sustained-release agent; 6) Storage test of strawberries The determined Chinese herbal essential oil is embedded and used to preserve strawberries. During the storage period, various indicators related to strawberry quality are measured every 2 days. The test data are collated and analyzed to determine the preservation effect.

2. The strawberry preservation method according to claim 1, characterized in that: In the step 1), the prepared Chinese herbal essential oil is peppermint essential oil.

3. The strawberry preservation method according to claim 1, characterized in that: In step 5), the embedding technical conditions are a core-to-wall ratio of 1:1 to 3:1, a curing time of 3 to 5 hours, and a reaction time of 30 to 60 minutes.

4. The strawberry preservation method according to claim 1, characterized in that: In step 6), the quality indicators include the good fruit rate and the rot rate of the strawberry fruits.

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