CN104886243A - A preservative for storing postharvest crystal grapes at room temperature and a preservation method thereof - Google Patents

Abstract

The invention discloses a postharvest storage preservative for crystal grapes at normal temperature, which comprises the following components according to the molar concentration: 0.05-0.20mmol/L salicylic acid, 0.05-0.20mmol/L sodium nitroprusside and 50-200mmol /L of calcium chloride. The invention also discloses a post-harvest storage and fresh-keeping method for crystal grapes at normal temperature, specifically: selecting fresh fruit, preparing a fresh-keeping agent, and fresh-keeping treatment. The rate of decline slowed down significantly, and the nutritive substances of the fruit could still be kept at a high level after storage for 2 months.

Description

Post-harvest storage preservative and method for crystal grapes at room temperature

technical field

The invention belongs to the technical field of post-harvest storage and fresh-keeping of fruits and vegetables, in particular to a post-harvest storage and fresh-keeping agent for crystal grapes at normal temperature, and also relates to a post-harvest storage and fresh-keeping method for crystal grapes at normal temperature.

Background technique

Crystal Grape is a European and American hybrid variety with unknown parents. It is widely loved by consumers because of its early maturity, strong fruit aroma and excellent taste. This variety is currently mainly planted in the Yunnan-Guizhou Plateau. It has strong resistance to biotic and abiotic stress, wide adaptability, and stable yield. It occupies an important position in the grape planting industry in the Yunnan-Guizhou Plateau. Because crystal grapes have the characteristics of solute fruit texture, extremely soft and juicy fruit after ripening, easy to break, easy to fall off after harvesting, high fruit infection rate and rot rate, resulting in concentrated supply period and short delivery time , it is difficult to obtain stable and efficient economic benefits. Yet, up to now, also do not find a kind of method that effectively solves this kind postharvest storage and preservation. Therefore develop a kind of post-harvest storage and fresh-keeping technology of crystal grapes that is really effective under normal temperature conditions, develop a kind of preservative that can prolong the storage and fresh-keeping time under normal temperature, and establish supporting normal temperature storage and fresh-keeping technical regulations, which will promote the development and improvement of the crystal grape industry. Economic benefits are of great significance.

After searching the literature, we have not seen any published content about the development of storage and fresh-keeping technology for crystal grapes in the Yunnan-Guizhou Plateau at room temperature after harvest.

Contents of the invention

The object of the present invention is to provide a post-harvest storage preservative for crystal grapes at normal temperature.

Another object of the present invention is to provide a method for post-harvest storage and preservation of crystal grapes at room temperature, which solves the problem of short storage time of crystal grapes at room temperature in the prior art.

The first technical scheme adopted by the present invention is a post-harvest storage preservative for crystal grapes at normal temperature, which comprises the following components according to the molar concentration: 0.05-0.20mmol/L salicylic acid, 0.05-0.20mmol/L salicylic acid Sodium nitroprusside and 50-200mmol/L calcium chloride.

Further, the molar concentration ratio of the salicylic acid solution, sodium nitroprusside and calcium chloride is 1:1:100.

The second technical scheme adopted in the present invention is a post-harvest storage and fresh-keeping method for crystal grapes at normal temperature, comprising the following steps:

Step 1, the selection of fresh crystal grapes,

Step 2, preparing preservative,

Step 3, fresh-keeping treatment,

Step 4. After the fruit is dried, put it into a special white paper bag for crystal grapes for full bloom;

Step 5, storing the well-filled crystal grapes.

The present invention is also characterized in that,

The selection of fresh fruit in step 1 is specifically to select 9 to 10 ripe crystal grapes.

The preservative prepared in step 2 is specifically: weighing 0.05-0.20mmol/L salicylic acid according to the molar concentration, 0.05-0.20mmol/L sodium nitroprusside and 50-200mmol/L calcium chloride, and dissolving them with distilled water; The preservative is prepared by mixing prepared salicylic acid solution, sodium nitroprusside solution and calcium chloride solution.

The fresh-keeping treatment in step 3 specifically includes: soaking the selected crystal grape ears in an aqueous preservative solution for 30-120 minutes, after soaking, take out the fruit ears, place them in a ventilated place, and dry the water on the surface of the fruit.

In step 4, after the fruit is dried, put it into a special white paper bag for grapes for storage. The specific steps are: after the fruit is dried, put it into a special white paper bag for grapes, tie the bag tightly, and place it flat in a plastic fruit basket with a length of 40cm, a width of 30cm, and a height of 20cm , two layers were placed in each basket.

In step 5, the crystal grapes in full bloom are stored by moving the plastic baskets filled with grapes into a cool and airtight room and stacking them together, keeping the room temperature at 20-25°C and relative humidity at 85%-90% for storage for 30- 60 days.

The beneficial effects of the present invention are: the storage and preservation period of crystal grapes that are not resistant to storage can be extended to more than 60 days under normal temperature conditions, and the fruit decay rate, fruit shedding rate and bacterial contamination rate are greatly reduced, and the fruit contains The amount of water, the content of nutritive substances in the pulp, the content of organic acids and pigment substances are kept at a relatively high level, and the original commodity value is maintained. Up to the present, also do not have the postharvest storage fresh-keeping technology of crystal grape under any effective normal temperature condition. Compared with the existing fresh-keeping technology of other grape varieties (such as Red Globe, etc.), the advantages of this technology are embodied in the following aspects: 1. It does not require refrigeration facilities, and it can be stored and kept fresh at room temperature without investing a lot of energy. The purchase of refrigeration equipment with funds can greatly save manpower and material resources, and can be accepted by the majority of fruit farmers. 2. It does not need electricity and other energy sources for refrigeration, which saves energy and is environmentally friendly. 3. Compared with the chemical treatment methods of other grape varieties at present, this method does not need to use SO ₂ gas fumigation, the treatment method is safe, simple and efficient, and will not pollute the environment. 4. The concentration of chemical treatment is low, which is safe for human body. 5. After chemical treatment, the rate of decline of fruit nutrients and peel pigments can be significantly slowed down in the process of storage and preservation. After 2 months of storage, fruit nutrients can still be maintained at a relatively high level.

Detailed ways

In order to make the purpose of the present invention and the technical solution clearer, the present invention uses specific examples to select the fresh fruit, select the concentration of the fresh-keeping agent, the composition of the fresh-keeping agent, the method and time of the fresh-keeping agent treatment, bagging and storage environment conditions , storage time and fruit edible quality after storage and other technologies have been fully described to prove the correctness of the research results, but it is not that the present invention is limited to these examples.

The invention provides a fresh-keeping agent for post-harvest storage of crystal grapes at normal temperature, which comprises the following components according to the molar concentration: 0.05-0.20mmol/L salicylic acid, 0.05-0.20mmol/L sodium nitroprusside and 50-200mmol/L L of calcium chloride.

The present invention also provides a post-harvest storage and preservation method for crystal grapes at normal temperature, comprising the following steps:

1), fresh fruit selection,

Choose 9 to 10 ripe crystal grapes;

2), prepare antistaling agent,

Weigh the salicylic acid of 0.05-0.20mmol/L according to the molar concentration, the sodium nitroprusside of 0.05-0.20mmol/L and the calcium chloride of 50-200mmol/L are dissolved in distilled water; the prepared salicylic acid solution, Sodium nitroprusside solution and calcium chloride solution are mixed to prepare preservative;

Step 3, fresh-keeping treatment,

Soak the selected crystal grape ears in an aqueous preservative solution for 30-120 minutes. After soaking, take out the ears, place them in a ventilated place, and dry the water on the surface of the fruit;

Step 4. After the fruit is dried, put it into a special white paper bag for grapes, tie the mouth of the bag tightly, and place it flat in a plastic fruit basket with a length of 40cm, a width of 30cm, and a height of 20cm, and place two layers in each basket;

Step 5, move the plastic baskets full of grapes into a cool airtight room and stack them together, keep the room temperature at 20-25°C and the relative humidity at 85-90% for storage for 30-60 days. Wherein, the storage environment conditions (room temperature 20-25 ℃ (when the temperature is above freezing point, the lower the storage and preservation effect is better), relative humidity 85%-90%), when above freezing point, properly reduce the storage temperature, which can effectively prolong the storage and preservation time. Time; when stored for 30 days, the fruit rot index was 2.41%, the amount of fruit colonies was 0.11%, the fruit weight loss rate was 2.57%, the fruit hardness was 2.92kg/cm ² , and the fruit drop rate was 2.09%; when stored for 60 days, the fruit The rot index was 5.24%, the fruit infection rate was 3.12%, the fruit weight loss rate was 4.01%, the fruit hardness was 2.89kg/cm ² , and the fruit drop rate was 4.21%. When stored for 90 days, the fruit rot index was 11.24%. The fruit colony amount was 9.23%, the fruit weight loss rate was 10.01%, the fruit hardness was 2.58kg/cm ² , and the fruit shedding rate was 13.12%. It can be seen that when the storage time exceeds 60 days, the fruit weight loss rate, rot index, fruit colony amount, and fruit weight loss rate of crystal grapes all increase significantly. Therefore, the safe storage and preservation time is set at 30-60 days.

After 60 days of storage, the contents of soluble solids, soluble sugar, glucose, soluble protein, free amino acid, vitamin C, titratable acid and other nutrients in grape fruit decreased, but they could still be maintained at a relatively high level. The content of chlorophyll, carotenoids, total phenols and total flavonoids in the pericarp also decreased, but it did not affect its commercial value.

Below in conjunction with concrete experimental result the beneficial effect of the present invention is illustrated:

1. Selection and processing of fresh fruit

Since the grapes are not ripe, it is necessary to choose fruits with a maturity of 90%-100%. But the fruit should not be overripe, because the skin of overripe fruit is easy to break, the anti-extrusion force is greatly reduced, and the fruit grains are easy to fall off and rot. In addition, it should be noted that the selected fruit is free from diseases and insect pests, and the fruit looks beautiful and neat.

In order to determine how many ripe grapes are selected for good storage and preservation effect, the research was carried out without any chemical treatment, put the harvested grapes of different maturity into special paper bags for grapes, store them at room temperature for 60 days, and then measure each index. Grapes are non-climactrophic fruits without post-ripening. As can be seen from Table 1, the fruit with a maturity of 80% will not ripen again during storage, and the fruit after storage has poor taste, weak fragrance, sour taste, and low edible value; but the fruit should not be overripe, because ripe The peel of the fruit whose ripeness exceeds 100% is easy to crack, fall off, and rot, and the fruit grains have a high bacterial infection rate and low hardness. Compared with other maturity degrees, these indicators are significantly different. See Table 1 for details. Therefore, it is necessary to select fruits with a maturity of 90%-100%. In addition, it is necessary to pay attention to the fact that the selected fruits are free from diseases and insect pests, and the appearance of the fruits is beautiful and uniform.

Table 1 Effects of different maturity levels on postharvest storage and preservation of crystal grapes

Note: Different letters on the same column indicate significant differences at the P<0.05 level; data are the average of 5 repetitions. The same below.

2. Concentration of fresh-keeping agents

The best concentration of salicylic acid (SA) is 0.1mmol/L, the best effect of sodium nitroprusside (SNP) concentration is 0.1mmol/L, and the best effect of calcium chloride (CaCl ₂ ) concentration is 100mmol/L. All reagents are of analytical grade and prepared with distilled water, ready for use or stored in a refrigerator at 4°C for a short period of time.

In order to screen out the appropriate treatment agent and treatment concentration, this study first found out by consulting a large amount of data that the most used agents in postharvest storage and preservation of fruits are salicylic acid (SA), sodium nitroprusside (SNP) and calcium chloride. (CaCl ₂ ), where the concentrations of SA and SNP are mostly 0.05, 0.10 and 0.20mmol/L, and the concentrations of CaCl ₂ are mostly 50, 100 and 200mmol/L. The treatment method is to soak the easy fruit prepared with various agents for 60 minutes, take out the ear, fully dry it in a ventilated place, put it in a special paper bag for grapes, store it at room temperature for 60 days, and then measure each index. It can be seen from Table 2 that soaking crystal grape ears with different concentrations of SA for 60 minutes can significantly reduce the fruit weight loss rate, rot index, fruit shedding rate and bacterial infection rate, but cannot significantly increase the peel hardness. 0.10mmol/L SA treatment. It can also be seen from Table 3 that after treatment with different concentrations of SNP, the fruit weight loss rate and rot index can also be significantly reduced, especially for reducing the bacterial infection rate of the fruit grains, but the fruit hardness cannot be significantly increased, and the fruit grains fall off. The rate increased significantly, and the comprehensive effect of 0.10mmol/L SNP treatment was the best. Table 4 shows that after CaCl ₂ treatment, although the bacterial infection rate of fruit grains cannot be significantly reduced, and the fruit rot index is relatively high, it has a very significant effect in reducing the fruit shedding rate and improving fruit firmness.

Table 2 Effects of different concentrations of salicylic acid (SA) on postharvest storage and preservation of crystal grapes

Table 3 Effects of different concentrations of sodium nitroprusside (SNP) treatment on postharvest storage and preservation of crystal grapes

Table 4 Effects of different concentrations of calcium chloride (CaCl ₂ ) on postharvest storage and preservation of crystal grapes

3. Combination of fresh-keeping agents

From the above research, it can be known that SA, SNP and CaCl ₂ have their own advantages and disadvantages. If the three can be used in combination, they can learn from each other and obtain better fresh-keeping effect. This experiment was set up in order to verify the effects of various combinations of chemical agents on postharvest storage and preservation of grapes. The combinations are shown in Table 5. After soaking the fruit with the solutions prepared by each agent for 60 minutes, take out the ears, dry them fully in a ventilated place, put them in special paper bags for grapes, store them fresh at room temperature for 60 days, and then measure the indicators. It can be seen from Table 5 that after the treatment of 0.10mmol/L SA+0.10mmol/L SNP+100mmol/L CaCl ₂ , considering the weight loss rate, fruit shedding rate, rot index, fruit infection rate and fruit firmness all reached an optimal level. Therefore, the treatment agent selected in this program is 0.10mmol/L SA+0.10mmol/L SNP+100mmol/L CaCl ₂ fruit dipping treatment.

Table 5 Effects of different combinations of three agents on postharvest storage and preservation of crystal grapes

4. The method and time of preservative treatment

In order to screen out the best preservative treatment time, this study adopts 0.10mmol/L SA+0.10mmol/L SNP+100mmol/L CaCl ₂ for 30-120min. The specific treatment method is to soak the selected crystal grape ears in the aqueous preservative solution for 30-120 minutes, take out the ears, place them in a ventilated place, dry the surface moisture of the fruits, store them in special paper bags for grapes, and store them at room temperature. index. Then the fruit ears were dried, put into special paper bags for grapes, stored and kept fresh at room temperature for 60 days, and then measured each index. It can be seen from Table 6 that different fruit soaking time treatments can significantly reduce the weight loss rate, fruit shedding rate, rot index, and fruit infection rate of fruit after storage, and significantly improve the fruit firmness after storage. When the treatment time exceeds 60 minutes, there is no significant difference in the indicators with the increase of the treatment time. Considering the two aspects of saving time and improving work efficiency, the treatment effect of preservative for 60 minutes is the best.

Table 6 Effect of fruit soaking time on postharvest storage and preservation of crystal grapes

5. Bag and place

In order to determine which kind of fruit bag has the best storage and preservation effect, three kinds of fruit bags were selected in this study. The specific treatment method was to soak the selected crystal grape ears in an aqueous preservative solution for 60 minutes, then take out the fruit ears and place them in a ventilated place. place, dried the surface moisture of the fruit, put them into three kinds of fruit bags and stored them at room temperature for 60 days, then measured the indexes. It can be seen from Table 7 that among the three kinds of fruit bags, the advantage of the plastic fresh-keeping bag is that it can significantly reduce the weight loss rate, but the rot index and fruit contamination rate are significantly higher than the other two kinds of fruit bags; while the disadvantages of ordinary paper bags are: The weight loss rate is too high; considering comprehensively, the storage and preservation effect of grape special paper bags is the best. The method of fruit placement is as follows: after soaking the medicine, dry the ears and put them into a special white paper bag for grapes, tie the mouth of the bag tightly, and place them flat in plastic fruit baskets with a length of 40cm, a width of 30cm, and a height of 20cm. The plastic baskets full of grapes were moved into a cool and airtight room and piled up together. Note that the fruit baskets should not be too large, and the grapes in each basket should not be placed too much, otherwise it is easy to squeeze each other and cause rotten fruit.

Table 7 Effects of fruit bags made of different materials on postharvest storage and preservation of crystal grapes

6. Storage environment conditions

Since this program is carried out at room temperature (20-25°C), the appropriate storage and preservation temperature is not screened, but when the temperature is higher than the freezing point, the lower the storage and preservation temperature, the better the effect. Through consulting the data, it is found that at about -1°C, the relative humidity of the air suitable for grape storage and preservation is 90%-95%. However, under normal temperature conditions, it is necessary to properly screen the relative humidity of the air. The specific treatment method is to place the selected crystal grape ears in 0.10mmol/L SA+0.10mmol/L SNP+100mmol/L CaCl ₂ preservative aqueous solution After soaking for 60 minutes, take out the ear, place it in a ventilated place, dry the surface moisture of the fruit, store it in a special fruit bag for grapes at room temperature and store it in different relative humidity environments, and measure various indicators after 60 days. It was found that when the relative air humidity reached 95%, although the fruit weight loss rate was significantly lower than other treatments, the fruit shedding rate, rot index, and fruit infection rate were significantly higher than other treatments, but the relative air humidity was lower than 80%. % causes the weightlessness rate to be too large again, has a strong impact on the commodity value of grape. Therefore, after comprehensive consideration, it is believed that the relative air humidity suitable for storage and preservation of crystal grapes at room temperature is between 85% and 90%.

Table 8 Effect of relative air humidity on postharvest storage and preservation of crystal grapes

7. Storage time

In order to clarify the effect of storage time on postharvest storage and preservation of crystal grapes, this study was carried out. The specific treatment method is to soak the selected crystal grape ears in 0.10mmol/L SA+0.10mmol/L SNP+100mmol/L CaCl ₂ preservative aqueous solution for 60 minutes, then take out the ears, place them in a ventilated place, and dry the fruits The surface moisture is stored in a special fruit bag for grapes at room temperature and stored for 60 days to measure various indicators. The results found that with the extension of storage time, the weight loss rate, fruit shedding rate, rot index and fruit infection rate of grape fruit increased significantly, but after the 60th day of storage, the weight loss rate, fruit shedding rate, rot The index and the bacterial infection rate of fruit grains increased significantly, so it is considered that the storage and preservation period of this program is advisable to be 60 days.

Table 9 Effect of storage time on postharvest storage and preservation of crystal grapes

8. Eating quality of stored fruit

In order to detect the effect of storage on the eating quality of fruit, this experiment was set up. The specific treatment method is to soak the selected crystal grape ears in 0.10mmol/L SA+0.10mmol/L SNP+100mmol/L CaCl ₂ preservative aqueous solution for 60 minutes, then take out the ears, place them in a ventilated place, and dry the fruits The surface moisture is stored in a special fruit bag for grapes at room temperature and stored for 60 days to measure various indicators. It can be seen from Table 10 that with the prolongation of storage time, the contents of soluble solids, titratable acid, vitamin C, soluble protein and free proline in fruit juice all decreased significantly, and after 30 days of storage, the decline rate significantly slowed down; in the storage process, the soluble sugar content increased, and the glucose content did not change significantly, because the fruit starch was gradually decomposed into soluble sugar during the storage process, and the solid-acid ratio gradually increased significantly during the storage process , the taste gradually becomes sweeter. Table 11 shows that during the storage process, chlorophyll a, chlorophyll b, chlorophyll a+b, carotenoids, total phenols and total flavonoids gradually decreased, and the decline in the first 30 days was greater than that in the last 30 days. Although during the storage process, most of the nutrients and peel pigment content of the fruit showed a downward trend, but after 60 days of storage and preservation, the nutrients still remained at a relatively high level, especially the content of soluble sugar and glucose It is not significantly reduced, and the content of pigment substances is also relatively high, so the storage and preservation scheme is feasible.

Table 10 Juice nutrient content of 'Crystal' grapes during storage

Table 11 Contents of skin pigments in ‘Crystal’ grapes during storage

Example 1

A post-harvest storage and preservation method for crystal grapes at normal temperature, select 9 mature crystal grapes; weigh 0.10mmol/L salicylic acid, 0.10mmol/L sodium nitroprusside and 100mmol/L calcium chloride according to molar concentration , dissolved in distilled water; the prepared salicylic acid solution, sodium nitroprusside solution and calcium chloride solution were mixed to prepare a preservative; the prepared salicylic acid solution, sodium nitroprusside solution and calcium chloride solution were mixed to prepare a preservative Antistaling agent; soak the selected crystal grape ears in the aqueous preservative solution for 60 minutes. After soaking, take out the ears, place them in a ventilated place, and dry the surface moisture of the fruit; put the fruit into a special white paper bag for grapes after drying. Tighten the mouth of the bag, and place it flat in plastic fruit baskets with a length of 40cm, a width of 30cm, and a height of 20cm, and place two layers in each basket; move the plastic baskets full of grapes into a cool and airtight room and stack them together to keep the room temperature Store at 20° C. and relative humidity of 85% for 60 days.

Example 2

Select 9.5 mature crystal grapes; weigh 0.05mmol/L salicylic acid according to the molar concentration, 0.05mmol/L sodium nitroprusside and 50mmol/L calcium chloride, dissolve with distilled water; prepare salicylic acid solution , sodium nitroprusside solution and calcium chloride solution are mixed to prepare a preservative; the selected crystal grape ears are placed in the aqueous preservative solution and soaked for 120 minutes. After soaking, take out the fruit ears, place them in a ventilated place, and dry the fruit surface Moisture; after the fruit is dried, put it into a special white paper bag for grapes, tie the mouth of the bag tightly, and place it flat in a plastic fruit basket with a length of 40cm, a width of 30cm, and a height of 20cm, and place two layers in each basket; put the plastic basket full of grapes Move into a cool airtight room and stack together, keep room temperature 22 ℃, relative humidity 87% and store for 45 days.

Example 3

Select 10 ripe crystal grapes; weigh 0.20mmol/L salicylic acid according to molar concentration, 0.20mmol/L sodium nitroprusside and 200mmol/L calcium chloride, dissolve with distilled water; prepare salicylic acid solution , sodium nitroprusside solution and calcium chloride solution are mixed to prepare a preservative; the selected crystal grape ears are placed in the aqueous preservative solution and soaked for 30 minutes. After soaking, take out the fruit ears, place them in a ventilated place, and dry the fruit surface Moisture; after the fruit is dried, put it into a special white paper bag for grapes, tie the mouth of the bag tightly, and place it flat in a plastic fruit basket with a length of 40cm, a width of 30cm, and a height of 20cm, and place two layers in each basket; put the plastic basket full of grapes Move into a cool airtight room and stack together, keep room temperature 25 ℃, relative humidity 90% and store for 30 days.

Example 4

Select 9.2 mature crystal grapes; weigh 0.05mmol/L salicylic acid according to molar concentration, 0.20mmol/L sodium nitroprusside and 50mmol/L calcium chloride, dissolve with distilled water; prepare salicylic acid solution , sodium nitroprusside solution and calcium chloride solution are mixed to prepare a preservative; the selected crystal grape ears are placed in the aqueous preservative solution and soaked for 45 minutes. After soaking, take out the fruit ears, place them in a ventilated place, and dry the fruit surface Moisture; After the fruit is dried, put it into a special white paper bag for grapes, tie the mouth of the bag tightly, and place it flat in a plastic fruit basket with a length of 40cm, a width of 30cm, and a height of 20cm, and place two layers in each basket; put the plastic basket full of grapes Move into a cool airtight room and stack together, keep room temperature 22 ℃, relative humidity 89% and store for 40 days.

Example 5

Select 9.8 ripe crystal grapes; weigh 0.20mmol/L salicylic acid according to molar concentration, 0.05mmol/L sodium nitroprusside and 200mmol/L calcium chloride, dissolve with distilled water; prepare salicylic acid solution , sodium nitroprusside solution and calcium chloride solution are mixed to prepare a preservative; the selected crystal grape ears are placed in the aqueous preservative solution and soaked for 100 minutes. After soaking, take out the fruit ears, place them in a ventilated place, and dry the fruit surface Moisture; after the fruit is dried, put it into a special white paper bag for grapes, tie the mouth of the bag tightly, and place it flat in a plastic fruit basket with a length of 40cm, a width of 30cm, and a height of 20cm, and place two layers in each basket; put the plastic basket full of grapes Move into a cool airtight room and stack together, keep room temperature 24 ℃, relative humidity 89% and store for 50 days.

Claims (8)

1. a post-harvest storage preservative for crystal grapes at normal temperature, characterized in that, comprises the following components according to molar concentration: the salicylic acid of 0.05-0.20mmol/L, the sodium nitroprusside of 0.05-0.20mmol/L and 50 -200mmol/L calcium chloride. 2. the postharvest storage preservative of crystal grape under normal temperature according to claim 1, is characterized in that, further, the molar concentration ratio of described salicylic acid solution, sodium nitroprusside and calcium chloride is 1:1: 100. 3. a postharvest storage and fresh-keeping method of crystal grapes at normal temperature is characterized in that, comprising the following steps: Step 1, the selection of fresh crystal grapes, Step 2, preparing preservative, Step 3, fresh-keeping treatment, Step 4. After the fruit is dried, put it into a special white paper bag for crystal grapes for full bloom; Step 5, storing the well-filled crystal grapes. 4. The post-harvest storage and fresh-keeping method of crystal grapes at room temperature according to claim 3, wherein the selection of fresh fruit in the step 1 is specifically selecting 9 to 10 ripe crystal grapes. 5. the post-harvest storage and fresh-keeping method of crystal grapes under normal temperature according to claim 3, is characterized in that, preparing preservative in described step 2 is specifically: according to the salicylic acid of weighing 0.05-0.20mmol/L according to molar concentration 0.05-0.20mmol/L sodium nitroprusside and 50-200mmol/L calcium chloride are dissolved in distilled water; the prepared salicylic acid solution, sodium nitroprusside solution and calcium chloride solution are mixed to prepare a preservative. 6. The post-harvest storage and fresh-keeping method of crystal grapes under normal temperature according to claim 3, characterized in that, the fresh-keeping treatment in said step 3 is specifically: placing the selected crystal grape ears in an aqueous preservative solution and soaking them for 30- After 120 minutes, after soaking, take out the ears, place them in a ventilated place, and dry the water on the surface of the fruits. 7. The post-harvest storage and fresh-keeping method of crystal grapes under normal temperature according to claim 3, characterized in that, after the fruit is dried in the step 4, it is packed into a special white paper bag for grapes to be placed in full bloom. Put grapes in a special white paper bag, tie the mouth of the bag tightly, and place it flat in a plastic fruit basket with a length of 40cm, a width of 30cm, and a height of 20cm, with two layers in each basket. 8. The post-harvest storage and preservation method for crystal grapes at room temperature according to claim 3, characterized in that, storing the crystal grapes in full bloom in said step 5 is specifically moving the plastic baskets filled with grapes into a cool and airtight container. Stacked together in the room, keep room temperature 20-25 ℃, relative humidity 85%-90% and store for 30-60 days.