Preservative and method for storage and preservation of picked longan by using preservative

Abstract

The invention discloses a preservative and a method for storage and preservation of picked longan by using the preservative. The preservative comprises the following components: melatonin, tea polyphenol, arthrinium and chitosan. Through the treatment of the preservative, the disease resistance of the longan can be improved, the occurrence of the postharvest rot phenomenon of the longan caused by pathogenic bacteria and the like is remarkably reduced, the postharvest quality of longan fruits is maintained, and the shelf life is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of fruit preservation, and particularly to a preservative and a method for postharvest storage and preservation of longan using the preservative. Background Art

[0002] Longan, also known as Guiyuan, together with litchi, banana, and pineapple, is one of the four famous fruits in South China. Longan is rich in glucose, sucrose, protein, etc., and has a relatively high iron content. It can not only increase heat energy and supplement nutrition, but also promote the regeneration of hemoglobin to enrich the blood. Therefore, it is deeply loved by consumers.

[0003] However, the maturity period of longan is short, and it is prone to browning, rotting, and quality deterioration after harvesting, mainly due to microbial infection, oxidative stress, and enzymatic browning.

[0004] Traditional preservation methods such as low-temperature storage, controlled atmosphere preservation, and chemical fungicides (such as sulfur dioxide) have certain effects, but there are problems such as drug residues, environmental pollution, high equipment requirements, high costs, and affecting the fruit flavor. Therefore, these preservation methods have certain limitations in actual application.

[0005] Therefore, it is extremely necessary to seek a green, safe, and effective postharvest preservation method for longan. Summary of the Invention

[0006] In view of this, the present invention provides a preservative and a method for postharvest storage and preservation of longan using the preservative. After being treated with the preservative, the disease resistance of longan can be improved, the occurrence of postharvest rot of longan caused by pathogens and the like can be significantly reduced, the postharvest quality of longan fruits can be maintained, and the shelf life can be extended.

[0007] To solve the above problems, the present invention adopts the following technical solutions:

[0008] A preservative, the components of the preservative include the following components: melatonin, tea polyphenols, Arthrinium arundinis, and chitosan.

[0009] Further, the Arthrinium arundinis is named strain LX1911, and was deposited at the Guangdong Provincial Microbial Culture Collection Center (abbreviated as GDMCC, Institute of Microbiology, Postcode: 510070) on May 8, 2021, Address: 5th Floor, Building 59, No. 100 Compound, Xianlie Middle Road, Guangzhou, and the deposit number is GDMCC No. 61639.

[0010] Further, the method includes the following steps: mixing the effective components of the preservative, wherein: the concentration of melatonin is 0.05 - 0.5 mmol / L, the concentration of tea polyphenols is 0.1 - 1.0%, the concentration of chitosan is 0.5 - 1%, and the balance is water;

[0011] In a 100% system composed of the above components, the strain LX1911 is added so that its final concentration in the system is 106 - 108 CFU / mL.

[0012] The present invention also provides a method for post - harvest storage and preservation of longan, and the method includes the following steps:

[0013] (1) Pick fresh longan fruits without pests and mechanical damage;

[0014] (2) Immerse the longan fruits in the preservative for 10 - 12 min, take out the longan fruits, air - dry them at room temperature, then put them into a polyethylene bag and seal it for storage.

[0015] Further, the storage conditions are normal - temperature storage at 26 ± 2 °C, or low - temperature storage at 4 - 6 °C.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The present invention provides a preservative and a method for post - harvest storage and preservation of longan using the preservative. Based on the problems that current chemical preservatives may have pesticide residues and high controlled - atmosphere preservation costs, the present application proposes a means of using a green and safe preservative to achieve longan preservation. Specifically, the preservative is composed of melatonin, tea polyphenols, Arthrinium sp. and chitosan, wherein Arthrinium sp. is the strain LX1911 preserved by the applicant in the Guangdong Provincial Microbial Culture Collection Center. Through experiments, it is found that longan treated with the preservative of the present application can still remain fresh after long - term storage, and its decay rate is low.

[0018] In the present application, by compounding melatonin, tea polyphenols and Arthrinium sp. in the preservative, melatonin can inhibit the accumulation of reactive oxygen species and delay fruit senescence, tea polyphenols can reduce browning, and the strain LX1911 inhibits the growth of a variety of pathogenic bacteria through competitive inhibition. Adding chitosan enhances the adhesion of the preservative and extends the action time of the preservative; using the component combination of the preservative of the present application and then storing it by sealing with a polyethylene bag can store longan at room temperature. The composite preservative has strong synergistic effects, delays browning and decay, and has no chemical residues, meeting the green food standard. Detailed Embodiments

[0019] The following examples can help those skilled in the art understand the present invention more comprehensively, but cannot limit the present invention in any way.

[0020] Example 1

[0021] This example provides a preservative, which is prepared by the following method:

[0022] Mix the active ingredients of the preservative, where the concentration of melatonin is 0.5 mmol / L, the concentration of tea polyphenols is 0.1%, the concentration of chitosan is 0.5%, and the balance is water;

[0023] Add the strain LX1911 to the 100% system composed of the above components, so that its final concentration in the system is 10 6 -10 8 CFU / mL.

[0024] The above strain is the strain LX1911 preserved in the Guangdong Provincial Microbial Culture Collection Center on May 8, 2021, with the preservation number GDMCC No. 61639.

[0025] Example 2

[0026] This example provides a preservative, which is prepared by the following method:

[0027] Mix the active ingredients of the preservative, where the concentration of melatonin is 0.1 mmol / L, the concentration of tea polyphenols is 0.5%, the concentration of chitosan is 0.7%, and the balance is water;

[0028] Add the strain LX1911 to the 100% system composed of the above components, so that its final concentration in the system is 10 6 -10 8 CFU / mL.

[0029] The above strain is the strain LX1911 preserved in the Guangdong Provincial Microbial Culture Collection Center on May 8, 2021, with the preservation number GDMCC No. 61639.

[0030] Example 3

[0031] This example provides a preservative, which is prepared by the following method:

[0032] Mix the active ingredients of the preservative, where the concentration of melatonin is 0.5 mmol / L, the concentration of tea polyphenols is 0.1%, the concentration of chitosan is 1%, and the balance is water;

[0033] Add the strain LX1911 to the 100% system composed of the above components, so that its final concentration in the system is 10 6 -10 8 CFU / mL.

[0034] The above strain is the strain LX1911 preserved in the Guangdong Provincial Microbial Culture Collection Center on May 8, 2021, with the preservation number GDMCC No. 61639.

[0035] Example 4:

[0036] This example provides a method for post - harvest storage and preservation of longan. The method includes soaking and preserving longan with the preservative prepared in the manner of Example 2, and comprises the following steps:

[0037] (1) Pick fresh longan fruits without pests and mechanical damage;

[0038] (2) Soak the longan fruits in the preservative for 10 minutes, take out the longan fruits, air - dry them at room temperature, then put them into a polyethylene bag, seal the bag, and store them. The storage conditions are normal - temperature storage at 27°C.

[0039] Example 5:

[0040] This example provides a method for post - harvest storage and preservation of longan. The method includes soaking and preserving longan with the preservative prepared in the manner of Example 2, and comprises the following steps:

[0041] (1) Pick fresh longan fruits without pests and mechanical damage;

[0042] (2) Soak the longan fruits in the preservative for 12 minutes, take out the longan fruits, air - dry them at room temperature, then put them into a polyethylene bag, seal the bag, and store them. The storage conditions are low - temperature storage at 5°C.

[0043] Test Example:

[0044] To illustrate the practical effect of the longan preservation and storage of this application, the applicant conducts the following test:

[0045] Compare the preservation effects of longan under different group treatments. The grouping is as follows:

[0046] The first group: Conduct longan preservation treatment in the manner of Example 4 of this application and store it at 27°C;

[0047] The second group: Conduct longan preservation treatment in the manner of Example 4 of this application and store it at 5°C;

[0048] The third group: Remove strain LX1911, and the other methods are the same as the first group;

[0049] The fourth group: Remove strain LX1911, and the other methods are the same as the second group;

[0050] The fifth group: The strain is Lactobacillus plantarum CICC 23121 purchased commercially, and the other methods are the same as the third group;

[0051] Group 6: The strain was Lactobacillus plantarum CICC 23121 purchased commercially, and the other methods were the same as those in Group 4;

[0052] Group 7: Blank control group, soaked with water instead of the preservative and then stored at 27°C;

[0053] Group 8: Blank control group, soaked with water instead of the preservative and then stored at 5°C.

[0054] Compare the preservation effects of longan after the above treatments, as shown in Table 1:

[0055] Table 1 Storage days and rotting rate of longan

[0056]

[0057]

[0058] It can be seen from the results in Table 1 that using the preservative of the present application in combination with the preservation method of the present application can extend the shelf life of longan. Although Group 2 was stored at a low temperature, the rotting rate was similar to that of the present application's normal temperature storage. This shows that after soaking with the preservative of the present application, longan can be effectively stored at normal temperature for a long time. This research can greatly reduce the preservation cost of longan. Groups 3 to 6 show that removing the strain of the present application or replacing the strain of the present application cannot achieve the above-mentioned preservation effect. In addition, the applicant unexpectedly found that low-temperature storage after removing the strain of the present application has a better effect than normal-temperature storage. This may be because the strain LX1911 of the present application can make the germs that cause rot at normal temperature unable to play a role in some way. In the case of Groups 7 and 8, instead of soaking with the preservative, water was used as a control, and serious rotting occurred after 10 days. The present application has developed the application of the strain LX1911 in longan preservation for the first time, and has a very broad market prospect.

[0059] The above description is a detailed description of the preferred feasible embodiments of the present invention, but the embodiments are not intended to limit the scope of the patent application of the present invention. Any equivalent changes or modifications made under the technical spirit disclosed by the present invention shall fall within the scope of the patent covered by the present invention.

Claims

1. A preservative, characterized in that, The components of the preservative include the following components: melatonin, tea polyphenols, Arthrinium arundinis, and chitosan.

2. The preservative according to claim 1, characterized in that, The Arthrinium arundinis is strain LX1911 deposited at the Guangdong Microbial Culture Collection Center on May 8, 2021, with the deposit number GDMCC No. 61639.

3. The preparation method of the preservative according to any one of claims 1-2, characterized in that, The method includes the following steps: mixing the active components of the preservative, wherein: the concentration of melatonin is 0.05 - 0.5 mmol / L, the concentration of tea polyphenols is 0.1 - 1.0%, the concentration of chitosan is 0.5 - 1%, and the balance is water; In the 100% system composed of the above components, add the strain LX1911 so that its final concentration in the system is 10 6 -10 8 CFU / mL.

4. A method for postharvest storage and preservation of longan using a preservative prepared by the method as described in claim 3, characterized in that, The method includes the following steps: (1) Pick fresh longan fruits without pests and mechanical damage; (2) Immerse the longan fruits in the preservative for 10 - 12 min, take out the longan fruits, air-dry them at room temperature, then put them into a polyethylene bag and seal it, and store them.

5. The method according to claim 4, characterized in that The storage conditions are normal temperature storage at 26 ± 2 °C, or low-temperature storage at 4 - 6 °C.

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