Cherry postharvest preservation method based on low-dose gamma-ray irradiation

Abstract

The invention belongs to the technical field of food preservation, and particularly relates to a postharvest cherry preservation method based on low-dose gamma-ray irradiation. The method comprises the following steps: picking cherries in a commodity mature period, irradiating the cherries with low-dose < 60 > Co-gamma rays, and storing the cherries on a shelf. The method is characterized in that the irradiation dose is selected in a targeted mode according to the variety of the cherries, the reduction of the hardness of the fruits can be effectively delayed, the accumulation of the content of soluble solids is promoted, and therefore the texture and flavor of the cherries are maintained, and the dose range is generally 25 Gy to 200 Gy. According to the method, variety-specific low-dose irradiation treatment is adopted, the commodity of cherries is effectively maintained, meanwhile, the edible quality (hardness and flavor) of the cherries is remarkably improved, the problems of fruit softening, flavor deterioration and the like caused by a traditional high-dose irradiation technology are solved, and an efficient, safe and quality-oriented new method is provided for preservation of the picked cherries.

Description

Technical Field

[0001] This invention belongs to the field of food preservation technology, specifically relating to a postharvest preservation method for cherries based on low-dose gamma-ray irradiation. Background Technology

[0002] Cherries are prized for their vibrant color, unique flavor, and rich nutritional value, including iron, vitamin C, anthocyanins, and various polyphenols. However, their post-harvest softening and aging process makes them more susceptible to mechanical damage, leading to spoilage and decay. Therefore, delaying post-harvest softening is crucial for maintaining fruit quality and extending shelf life.

[0003] Sweet cherries are fruits eaten with their skin on, and conventional chemical preservation methods (such as calcium chloride soaking) are prone to leaving residues and are not suitable for cherry preservation. Biological preservation methods (such as edible coatings) may also affect the flavor of the cherry fruit. Therefore, developing safe and efficient physical preservation technologies is of great practical significance.

[0004] 60Co-γ irradiation technology, due to its cold treatment and residue-free characteristics, is a promising physical preservation method. Existing research indicates that different radiation doses have varying effects on plant cells; excessively high doses can damage cell structure, while low doses may have positive effects on cell structure and physiological metabolism. They discovered that low doses of ionizing radiation can induce thickening of the cell wall of Chlorella and enhance its antioxidant capacity.

[0005] Current research on irradiation preservation of cherries mainly focuses on its insecticidal and bactericidal effects, with a common irradiation dose of 1000-2000 Gy. However, this dose range is considered high and can easily damage cell structure, leading to a decline in cherry quality and flavor. For example, Tian Zhuxi (2019) investigated the effects of short-wave ultraviolet irradiation and 60Co-γ irradiation on the storage quality of sweet cherries. Studies in food science and other fields have shown that after γ irradiation treatments of 1.5 kGy and 2.25 kGy, the firmness, stickiness, chewiness, and elasticity of cherry fruits were all lower than the control group. Furthermore, the role of low-dose irradiation in cherry preservation remains poorly understood.

[0006] Against this background, this study aims to explore the role of low-dose gamma radiation in maintaining the postharvest quality of cherries, in order to find an effective irradiation dose that is beneficial to maintaining cherry quality. Summary of the Invention

[0007] The purpose of this invention is to provide a method for preserving cherries with low-dose gamma irradiation, thereby solving the problem of fruit quality decline caused by existing high-dose irradiation.

[0008] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a method for postharvest preservation of cherries based on low-dose gamma-ray irradiation, the method comprising the following steps: (1) Harvest commercially ripe cherries that are free from mechanical damage and pests; (2) The cherries were subjected to low-dose 60Co-γ irradiation treatment; (3) Perform shelf quality analysis on the irradiated cherries; The specific dose of the irradiation treatment is selected and determined based on the cherry variety.

[0009] Preferably, the low dose ranges from 25 Gy to 200 Gy.

[0010] Preferably, the cherries preserved by low-dose irradiation can simultaneously achieve a range of gamma-ray irradiation doses that delay the decline in fruit firmness and promote the accumulation of soluble solids.

[0011] Preferably, the cherry is selected from the following varieties: Meizao and Xianfeng.

[0012] Preferably, when the cherry variety is Meizao, the low dose is 50 Gy-100 Gy; when the cherry variety is Xianfeng, the low dose is 25 Gy-35 Gy.

[0013] The present invention also provides a preserved cherry product, which is obtained by processing the method described in any of the above-mentioned methods.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) This invention provides a method for post-harvest preservation of cherries using low-dose γ-irradiation, which solves the technical defects of existing high-dose γ-irradiation treatment, such as reduced fruit firmness and quality deterioration.

[0015] (2) The low-dose treatment provided by the present invention significantly delays the decline in fruit firmness without increasing the rot rate and water loss rate of cherries, while promoting the accumulation of soluble solids content, thereby improving the edible quality and commercial value of cherries.

[0016] (3) This invention also conducted experiments on different cherry varieties with the same dose of γ-irradiation treatment. The results showed that different cherry varieties have different sensitivities to γ-irradiation dose. Therefore, when subjecting cherries to γ-irradiation treatment, it is necessary to determine the irradiation dose specifically based on the characteristics of the specific variety. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A graph showing the change in hardness of early-ripening cherries under different irradiation doses; Figure 2 A graph showing the TSS changes of early-ripening cherries under different irradiation doses; Figure 3 A graph showing the variation in the decay rate of early-ripening cherries under different irradiation doses; Figure 4 A graph showing the change in water loss rate of early-ripening cherries under different irradiation doses; Figure 5 Images showing the fruit condition of early-ripening cherries at different storage stages; Figure 6 A graph showing the change in hardness of Pioneer cherries under different irradiation doses; Figure 7 A graph showing the TSS changes of Pioneer cherry under different irradiation doses; Figure 8 A graph showing the change in the decay rate of Pioneer cherries under different irradiation doses; Figure 9 A graph showing the change in water loss rate of Pioneer cherries; Figure 10 Images showing the fruit condition of Pioneer cherries at different storage periods. Detailed Implementation

[0019] To further illustrate the present invention, the technical solutions provided by the present invention will be described in detail below with reference to the accompanying drawings and embodiments, but these should not be construed as limiting the scope of protection of the present invention.

[0020] Unless otherwise specified, the production processes, experimental methods, or testing methods involved in the embodiments of this invention are all conventional methods in the prior art, and their names and / or abbreviations are all conventional names in the field, which are very clear and distinct in the relevant application areas. Those skilled in the art can understand the conventional process steps based on the names and apply the corresponding equipment, and implement them according to conventional conditions or the conditions recommended by the manufacturer.

[0021] The various instruments, equipment, raw materials or reagents used in the embodiments of this invention are not subject to any special restrictions on their source. They are all conventional products that can be purchased through regular commercial channels and can be prepared according to conventional methods known to those skilled in the art.

[0022] Example 1: Screening of the Preservation Effect of Low-Dose γ-Irradiation on Early American Cherries The purpose of this embodiment is to determine the low-dose irradiation window that has the best overall preservation effect on "Meizao" (MZ) cherries from Yantai, Shandong.

[0023] Four treatment groups were set up: ① 0 Gy (control group, CK); ② 50 Gy; ③ 100 Gy; ④ 200 Gy. Each group had three replicates.

[0024] The harvested cherries were irradiated the following day. The irradiation source was 60Co-γ rays at a dose rate of 100 Gy / h. The samples were packaged in food-grade plastic boxes measuring 17.5 cm × 11.5 cm × 4.5 cm. After treatment, the cherries were stored at 20°C and 85% relative humidity, and samples were taken periodically for analysis.

[0025] Test indicators: Hardness, soluble solids content (TSS), decay rate and water loss rate were measured at 0.5 d, 2.5 d, 4.5 d and 6.5 d respectively.

[0026] The results are as follows Figure 1-4 As shown, γ-irradiation treatments of 50 Gy and 100 Gy can effectively delay the decline in firmness of "Meizao" cherries after harvest, promote the increase in TSS content, and reduce the decay rate without increasing the water loss rate, reflecting that they can effectively maintain the quality of cherries after harvest.

[0027] Figure 5 These are photos of "Meizao" cherries at different storage stages during the storage process.

[0028] Example 2: Screening of the Preservation Effect of Low-Dose γ-Irradiation on Pioneer Cherries This embodiment aims to determine the low-dose irradiation window that provides the best overall preservation effect for "XF" cherry varieties from Yantai, Shandong.

[0029] Four treatment groups were set up: ① 0 Gy (CK); ② 25 Gy; ③ 50 Gy; ④ 100 Gy. Each group had 3 replicates. The treatment, storage, and measured parameters were the same as in Example 1.

[0030] The results are as follows Figure 6-9 As shown, 25 Gy of γ-irradiation treatment can effectively delay the decline in firmness of "Pioneer" cherries after harvest and promote the increase in soluble solids content, reflecting that it can effectively maintain the quality of post-harvest cherries.

[0031] Figure 10 These are photos of "Pioneer" cherries at different storage stages during the storage process.

[0032] Example 3: Verification of differences in gamma irradiation dose sensitivity among varieties By selecting different varieties from Examples 1 and 2 above, it can be seen that, at the same dosage, irradiation doses of 50 Gy and 100 Gy can delay the decrease in postharvest firmness of "Meizao" cherry, but have no effect on "Xianfeng" cherry, and even promote the decrease in postharvest firmness.

[0033] This is sufficient to demonstrate that different cherries have different dose sensitivities to gamma irradiation.

[0034] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for postharvest preservation of cherries based on low-dose gamma-ray irradiation, characterized in that, The method includes the following steps: (1) Harvest commercially ripe cherries that are free from mechanical damage and pests; (2) The cherries were subjected to low-dose 60Co-γ irradiation treatment; (3) Perform shelf quality analysis on the irradiated cherries; The specific dose of the irradiation treatment is selected and determined based on the cherry variety.

2. The method according to claim 1, characterized in that, The low dose range is 25 Gy-200 Gy.

3. The method according to claim 1, characterized in that, The low-dose irradiation preservation method for cherries can simultaneously achieve a range of gamma-ray irradiation doses that delay the decline in fruit firmness and promote the accumulation of soluble solids.

4. The method according to claim 1, characterized in that, The cherries mentioned are selected from the following varieties: Meizao and Xianfeng.

5. The method according to claim 1, characterized in that, When the cherry variety is Meizao, the low dose is 50 Gy-100 Gy; when the cherry variety is Xianfeng, the low dose is 25 Gy-35 Gy.

6. A cherry preservation product, characterized in that, It is obtained by the method described in any one of claims 1-5.

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