Chicken heart fruit preservation method

Abstract

The method comprises the following steps: pre-cooling for 6 hours at the temperature of 0-1 DEG C after harvesting, fumigating by using 1-methylcyclopropene with the concentration of 1 ppm, adding an ethylene absorption preservative, packaging by using a polyethylene preservation bag, and storing by applying a low-voltage electrostatic field at the temperature of 0-1 DEG C. After 6 months, good hardness and flavor are still kept. The method can effectively prolong the storage time of the Chinese flowering quince according to the physiological characteristics of the Chinese flowering quince.

Description

Technical Field

[0001] The invention belongs to the technical field of fruit and vegetable preservation, and in particular relates to a method for preserving jackfruit. Background Art

[0002] The heart-shaped apple is a small apple with high sugar and acid content, rich in anthocyanins and dietary fiber. The heart-shaped apple is highly sensitive to temperature, humidity and carbon dioxide. After being harvested, the heart-shaped apple has vigorous respiration and produces a large amount of ethylene, water and carbon dioxide, which is a huge challenge for the long-term storage of the heart-shaped apple. At present, the storage method of mature apples is applied to the storage of heart-shaped apples, but after 2 to 3 months of storage, softening and rotting will occur. Chinese patent CN117730904A proves that low-voltage electrostatic field is a new type of non-thermal processing technology, which can slow down the growth of microorganisms, reduce reactive oxygen species (ROS), and maintain the cell wall structure. These characteristics are beneficial to the storage of heart-shaped apples. However, the ethylene, water and carbon dioxide released by the vigorous respiration of heart-shaped apples still need to be further resolved. Summary of the invention

[0003] The purpose of the invention is to provide a preservation method for the jackfruit which can effectively prolong the storage period of the jackfruit according to the physiological characteristics of the jackfruit.

[0004] Select fruits with smooth surface, no damage, no pests and diseases, and no other impurities for use. The pre-cooling process takes 6 hours, and the temperature of the fruit needs to be reduced to 1±0.5℃ as soon as possible; the fruit is fumigated with 1-MCP, the 1-MCP concentration is any value between 1-3 ppm, and the treatment time is any value between 8 and 12 hours; the silicon-aluminum ratio of the molecular sieve used in the ethylene absorption preservative is any one of 10:20, 45:55, and 85:95; the ratio of potassium permanganate molecular sieve to calcium hydroxide powder in the ethylene absorption preservative is any value between 2:1 and 3. The output voltage of the low-voltage electrostatic field is 2000-3000V, and the output current is 3-5mA.

[0005] The invention provides a method for maintaining the quality of heart-shaped fruit for a long time. The growth rate of microorganisms is reduced by a low-voltage electrostatic field, 1-methylcyclopropene inhibits the release of ethylene, and an ethylene preservative can regulate the ethylene, carbon dioxide concentration and humidity in the package. The invention achieves the purpose of storing high-quality heart-shaped fruit by using a combination of multiple means. The preservative prepared in the method is 1-methylcyclopropene to inhibit the ethylene generation rate of the fruit, and then potassium permanganate absorbs the released ethylene, and sodium chloride is used as a deliquescent salt for regulating humidity balance to stabilize the humidity in the package in combination with absorbent paper. In order to solve the safety risk that potassium permanganate may be in direct contact with the fruit, molecular sieves with different silicon-aluminum ratios are used to load potassium permanganate and sodium chloride, and the porous and large surface area characteristics of the molecular sieve are used to achieve continuous absorption of ethylene and avoid direct contact between potassium permanganate and the fruit. The low-voltage electrostatic field can inhibit the growth of microorganisms, delay biochemical reactions, retain moisture and maintain the stability of cell structure, and further delay fruit aging. This method is a preservation method developed for the physiological characteristics of heart-shaped fruit and can achieve long-term storage of heart-shaped fruit. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 : is the potassium permanganate loading of different embodiments.

[0007] Figure 2 The concentration of carbon dioxide in the headspace of different embodiments and comparative examples is shown in FIG.

[0008] Figure 3 The ethylene concentration in the headspace of different embodiments and comparative examples is shown in FIG. DETAILED DESCRIPTION

[0009] The present invention is described below by specific embodiments. Unless otherwise specified, the technical means used in the present invention are methods known to those skilled in the art. In addition, the embodiments should be understood as illustrative rather than limiting the scope of the present invention, and the essence and scope of the present invention are limited only by the claims. For those skilled in the art, various changes or modifications to the material composition and dosage in these embodiments, without departing from the essence and scope of the present invention, also belong to the protection scope of the present invention.

[0010] Example 1

[0011] S1. Select fruits with smooth surface, no damage, no pests and diseases, and no other impurities, pre-cool them at 0-1℃ for 6 hours to reduce the center temperature of the packaging to 1±0.5℃ as soon as possible, and then fumigate with 1-methylcyclopropene at a concentration of 1ppm for 12 hours.

[0012] S2. Place the fumigated fruits in a clean, perforated 0.03 mm polyethylene fresh-keeping bag.

[0013] S3. Add a pack of ethylene absorbing preservative, place a piece of absorbent paper on the top, and tie it with a rubber band; the preparation method of the ethylene absorbing preservative is as follows: first place the molecular sieve in a 150°C forced air drying oven for 12 hours to remove moisture from the material. The silicon-aluminum ratio of the molecular sieve is 10:20. The dried molecular sieve is completely immersed in a 5% (w / v) potassium permanganate solution and a 10% (w / v) sodium chloride solution, and immersed in a negative pressure environment for 12 hours. The immersed molecular sieve is dried until completely dry. The molecular sieve is mixed with calcium hydroxide powder in a ratio of 2:3, and then packaged into small non-woven bags (10 g per bag).

[0014] S4. The packaged heart-shaped fruits are stored at a temperature of 1±0.5°C and a low-voltage electrostatic field is applied. The output voltage of the low-voltage electrostatic field is 2500V and the output current is 4mA.

[0015] Example 2

[0016] S1. Select fruits with smooth surface, no damage, no pests and diseases, and no other impurities, pre-cool them at 0-1℃ for 6 hours to reduce the center temperature of the packaging to 1±0.5℃ as soon as possible, and then fumigate with 1-methylcyclopropene at a concentration of 1ppm for 12 hours.

[0017] S2. Place the fumigated fruits in a clean, perforated 0.03 mm polyethylene fresh-keeping bag.

[0018] S3. Add a pack of ethylene absorbing preservative, place a piece of absorbent paper on the top, and tie it with a rubber band; the preparation method of the ethylene absorbing preservative is as follows: first place the molecular sieve in a 150°C forced air drying oven for 12 hours to remove moisture from the material. The silicon-aluminum ratio of the molecular sieve is 45:55. The dried molecular sieve is completely immersed in a 5% (w / v) potassium permanganate solution and a 10% (w / v) sodium chloride solution, and immersed in a negative pressure environment for 12 hours. The immersed molecular sieve is dried until completely dry. The molecular sieve is mixed with calcium hydroxide powder in a ratio of 2:3, and then packaged into small non-woven bags (10g per bag).

[0019] S4. The packaged heart-shaped fruits are stored at a temperature of 1±0.5°C and a low-voltage electrostatic field is applied. The output voltage of the low-voltage electrostatic field is 2500V and the output current is 4mA.

[0020] Example 3

[0021] S1. Select fruits with smooth surface, no damage, no pests and diseases, and no other impurities, pre-cool them at 0-1℃ for 6 hours to reduce the center temperature of the packaging to 1±0.5℃ as soon as possible, and then fumigate with 1-methylcyclopropene at a concentration of 1ppm for 12 hours.

[0022] S2. Place the fumigated fruits in a clean, perforated 0.03 mm polyethylene fresh-keeping bag.

[0023] S3. Add a pack of ethylene absorbing preservative, place a piece of absorbent paper on the top, and tie it with a rubber band; the preparation method of the ethylene absorbing preservative is as follows: first place the molecular sieve in a 150°C forced air drying oven for 12 hours to remove moisture from the material. The silicon-aluminum ratio of the molecular sieve is 85:95. The dried molecular sieve is completely immersed in a 5% (w / v) potassium permanganate solution and a 10% (w / v) sodium chloride solution, and immersed in a negative pressure environment for 12 hours. The immersed molecular sieve is dried until completely dry. The molecular sieve is mixed with calcium hydroxide powder in a ratio of 2:3, and then packaged into small non-woven bags (10g per bag).

[0024] S4. The packaged heart-shaped fruits are stored at a temperature of 1±0.5°C and a low-voltage electrostatic field is applied. The output voltage of the low-voltage electrostatic field is 2500V and the output current is 4mA.

[0025] Example 4

[0026] S1. Select fruits with smooth surface, no damage, no pests and diseases, and no other impurities, pre-cool them at 0-1℃ for 6 hours to reduce the center temperature of the packaging to 1±0.5℃ as soon as possible, and then fumigate with 1-methylcyclopropene at a concentration of 1ppm for 12 hours.

[0027] S2. Place the fumigated fruits in a clean, perforated 0.03 mm polyethylene fresh-keeping bag.

[0028] S3. Add a pack of ethylene absorbing preservative, place a piece of absorbent paper on the top, and tie it with a rubber band; the preparation method of the ethylene absorbing preservative is as follows: first place the molecular sieve in a 150°C forced air drying oven for 12 hours to remove moisture from the material. The silicon-aluminum ratio of the molecular sieve is 45:55. The dried molecular sieve is completely immersed in a 5% (w / v) potassium permanganate solution and a 10% (w / v) sodium chloride solution, and immersed in a negative pressure environment for 12 hours. The immersed molecular sieve is dried until completely dry. The molecular sieve is mixed with calcium hydroxide powder in a ratio of 2:1, and then packaged into small non-woven bags (10 g per bag).

[0029] S4. The packaged heart-shaped fruits are stored at a temperature of 1±0.5°C and a low-voltage electrostatic field is applied. The output voltage of the low-voltage electrostatic field is 2500V and the output current is 4mA.

[0030] Comparative Example 1

[0031] S1. Select fruits with smooth surface, no damage, no pests and diseases, and no other impurities, and pre-cool them at 0-1℃ for 6 hours to reduce the center temperature of the packaging to 1±0.5℃ as soon as possible.

[0032] S2. Place the fruit in a clean, perforated 0.03 mm polyethylene fresh-keeping bag.

[0033] S3. The packaged heart-shaped fruits are stored at a temperature of 1±0.5°C.

[0034] Comparative Example 2

[0035] S1. Select fruits with smooth surface, no damage, no pests and diseases, and no other impurities, and pre-cool them at 0-1℃ for 6 hours to reduce the center temperature of the packaging to 1±0.5℃ as soon as possible.

[0036] S2. Place the fruit in a clean, perforated 0.03 mm polyethylene fresh-keeping bag.

[0037] S3. The packaged heart-shaped fruits are stored at a temperature of 1±0.5°C and a low-voltage electrostatic field is applied. The output voltage of the low-voltage electrostatic field is 2500V and the output current is 4mA.

[0038] Comparative Example 3

[0039] S1. Select fruits with smooth surface, no damage, no pests and diseases, and no other impurities, pre-cool them at 0-1℃ for 6 hours to reduce the center temperature of the packaging to 1±0.5℃ as soon as possible, and then fumigate with 1-methylcyclopropene at a concentration of 1ppm for 12 hours.

[0040] S2. Place the fumigated fruits in a clean, perforated 0.03 mm polyethylene fresh-keeping bag.

[0041] S3. Add a pack of ethylene absorbing preservative, place a piece of absorbent paper on the top, and tie it with a rubber band; the preparation method of the ethylene absorbing preservative is as follows: first place the molecular sieve in a 150°C forced air drying oven for 12 hours to remove moisture from the material. The silicon-aluminum ratio of the molecular sieve is 45:55. The dried molecular sieve is completely immersed in a 5% (w / v) potassium permanganate solution and a 10% (w / v) sodium chloride solution, and immersed in a negative pressure environment for 12 hours. The immersed molecular sieve is dried until completely dry and packaged into small non-woven bags (10 g per bag).

[0042] S4. The packaged heart-shaped fruits are stored at a temperature of 1±0.5°C and a low-voltage electrostatic field is applied. The output voltage of the low-voltage electrostatic field is 2500V and the output current is 4mA.

[0043] Comparative Example 4

[0044] S1. Select fruits with smooth surface, no damage, no pests and diseases, and no other impurities, pre-cool them at 0-1℃ for 6 hours to reduce the center temperature of the packaging to 1±0.5℃ as soon as possible, and then fumigate with 1-methylcyclopropene at a concentration of 1ppm for 12 hours.

[0045] S2. Place the fumigated fruits in a clean, perforated 0.03 mm polyethylene fresh-keeping bag.

[0046] S3. Add a pack of ethylene absorbing preservative, place a piece of absorbent paper on the top, and tie it with a rubber band; the preparation method of the ethylene absorbing preservative is as follows: first place the molecular sieve in a 150°C forced air drying oven for 12 hours to remove moisture from the material. The silicon-aluminum ratio of the molecular sieve is 45:55. The dried molecular sieve is completely immersed in a 5% (w / v) potassium permanganate solution and immersed in a negative pressure environment for 12 hours. The immersed molecular sieve is dried until completely dry. The molecular sieve is mixed with calcium hydroxide powder in a ratio of 2:1 and packaged into small non-woven bags (10 g per bag).

[0047] S4. The packaged heart-shaped fruits are stored at a temperature of 1±0.5°C and a low-voltage electrostatic field is applied. The output voltage of the low-voltage electrostatic field is 2500V and the output current is 4mA.

[0048] Test Case

[0049] The preparation methods of the embodiments and comparative examples were used to preserve the heart-shaped fruit, and the following tests were performed.

[0050] Potassium permanganate loading: Prepare a potassium permanganate standard solution, use a UV-visible spectrophotometer to measure the absorbance of the solution at 525nm, and draw a solution concentration-absorbance standard curve. Grind 5g of the impregnated molecular sieve beads into powder, mix in 100mL of deionized water and shake for 2 hours, centrifuge at 6000g for 10min, measure the absorbance of the supernatant at 525nm, and calculate the potassium permanganate loading.

[0051] Determination of weight loss rate: Determine the weight of the fruit on the 180th day of storage, and calculate the weight loss rate according to the following formula and express it as a percentage.

[0052]

[0053] Hardness measurement: Three points were evenly selected on the equator of the fruit, and the hardness of the fruit on the 180th day of storage was measured using a GY-3 digital fruit hardness tester.

[0054] Sugar content determination: Fifteen fruits from each treatment were selected, the pulp was squeezed and the juice was mixed, and the sugar content of the juice was determined using a handheld refractometer and expressed as a percentage (%).

[0055] Acidity determination: Fifteen fruits from each treatment were selected, the pulp was squeezed and the juice was mixed, and the acidity content of the juice was determined using a PAL-BX / ACID 40 acidometer and expressed as a percentage (%).

[0056] Headspace carbon dioxide and ethylene concentration determination: Headspace carbon dioxide and ethylene concentration were determined by F-950 gas analyzer.

[0057] Table 1

[0058] Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Decay rate (%) 2.3% 1.3% 1.2% 1.4% 30.6% 25.7% 2.1% 1.7% humidity(%) 82.6% 84.6% 84.9% 83.4% 75.6% 76.4% 84.5% 79.2% Weight loss rate (%) 1.76±0.24 1.07±0.26 0.98±0.16 2.77±0.22 12.23±0.23 8.78±0.17 3.05±0.25 3.91±0.12 <![CDATA[Hardness (kg / cm 2 )]]> 10.61±0.34 10.94±0.58 10.97±0.76 10.70±1.06 6.85±1.25 8.47±1.45 10.09±0.84 9.63±1.39 Soluble solid content (%) 14.34±0.22 14.70±0.32 14.42±0.28 14.28±0.41 12.65±0.54 13.77±0.65 14.56±0.32 13.76±0.35 acidity(%) 1.24±0.06 1.29±0.07 1.35±0.10 1.36±0.11 0.97±0.07 1.05±0.09 1.30±0.08 1.26±0.05

[0059] Table 1 is the basic index of different embodiments and comparative examples on the 90th day. As shown in Table 1, after using the preservative and 1-MCP fumigation, the decay rate of the heart fruit decreased significantly. The decay rate of the untreated comparative example 1 was as high as 30.6%, while the embodiment 3 fumigated with 1-MCP was only 1.2%. This is because 1-MCP inhibited the generation of ethylene, and the preservative absorbed the released ethylene. At the same time, the hardness, acidity and sugar content of the fruit changed less after treatment. In comparative example 4, since sodium chloride was not added, its weight loss rate was higher than that of embodiment 4, because an appropriate amount of sodium chloride can maintain the humidity in the package and slow down the water loss of the fruit.

[0060] Table 2

[0061] Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Decay rate (%) 5.3% 3.3% 3.2% 6.4% 74.4% 71.3% 6.1% 5.7% humidity(%) 83.2% 84.9% 83.3% 82.3% / / 79.5% 74.3% Weight loss rate (%) 8.42±1.18 6.41±1.79 6.27±1.60 6.70±1.85 / / 10.72±1.98 15.04±1.29 <![CDATA[Hardness (kg / cm 2 )]]> 10.62±0.43 11.54±0.45 11.85±0.35 10.02±0.48 / / 9.08±0.56 9.28±0.37 Soluble solid content (%) 13.39±0.15 14.59±0.49 14.39±0.29 13.73±0.48 / / 13.15±0.22 12.81±0.22 acidity(%) 1.09±0.14 1.15±0.16 1.09±0.14 1.05±0.23 / / 1.00±0.23 0.92±0.15

[0062] Table 2 shows the basic indicators of different embodiments and comparative examples at the 180th day. As shown in Table 2, at the 180th day, since the decay rate of comparative examples 1 and 2 exceeded 70%, other indicators were no longer measured, and the fruits of the embodiment group still had good quality. Figure 1 It can be seen that molecular sieves with a high silicon-aluminum ratio have a better potassium permanganate loading rate. Potassium permanganate can absorb carbon dioxide and ethylene, slowing down the quality deterioration of fruits. However, the potassium permanganate loading rates of molecular sieves with a silicon-aluminum ratio of 45:55 and 85:95 are similar, and the price of 85:95 is higher, so the molecular sieve with a silicon-aluminum ratio of 45:55 will be mainly used as the base material in the future.

[0063] Figure 2 and Figure 3 It was respectively explained that the concentrations of ethylene and carbon dioxide in the bag were reduced by 1-MCP treatment and the addition of preservatives, thus achieving the effect of preserving the fruit.

Claims

1. A method for preserving pineapple, characterized in that: The method is implemented as follows: S1. Select fruits with smooth surface, no damage, no pests and diseases, and no other impurities, pre-cool them at 0-1℃ for 6 hours to reduce the center temperature of the packaging to 1±0.5℃ as soon as possible, and then fumigate them with 1-methylcyclopropene at a concentration of 1-3ppm for 8-12 hours; S2. Place the selected fruits in a clean, perforated 0.03 mm polyethylene fresh-keeping bag; S3, add a pack of ethylene absorbing preservative, place a piece of absorbent paper on the top, and tie it with a rubber band; the preparation method of the ethylene absorbing preservative is: first place the molecular sieve in a blast drying oven at 150°C for 12 hours to remove moisture from the material, the silicon-aluminum ratio of the molecular sieve is any one of 10:20, 45:55, and 85:95, the dried molecular sieve is completely immersed in a solution containing 5% (w / v) potassium permanganate and 10% (w / v) sodium chloride, and immersed in a negative pressure environment for 12 hours, the immersed molecular sieve is dried until completely dry, mixed with calcium hydroxide powder in a ratio of 2: (1-3), and then packaged into small non-woven bags (10g per bag); S4. The packaged heart-shaped fruit is stored at a temperature of 1±0.5°C and a low-voltage electrostatic field is applied. The output voltage of the low-voltage electrostatic field is 2000-3000V and the output current is 3-5mA.

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