阅读说明：本技术 一种有利于长期维持葡萄品质的贮存方法 (Storage method beneficial to maintaining quality of grapes for long time ) 是由 于丽娟 李雪瑞 李宏 屈云慧 何顺龙 付坚 普红梅 崔光芬 王海丹 金鹏程 张顺 于 2021-09-14 设计创作，主要内容包括：本发明公开了一种有利于长期维持葡萄品质的贮存方法,具体包括：葡萄达到采收成熟度后,果梗留长采收；挑出烂果、病果等瑕疵果后,表面消毒、清水清洗后晾干或吹干表面水分；用适当浓度营养液处理葡萄果梗；将处理后的葡萄串置于常规冷库中长期贮藏。本发明所述的方法适用于葡萄长期贮存,能延长葡萄贮存时间至150天及以上,不仅能延缓果梗干褐,维持其伸展性和绿色,而且能维持葡萄果粒硬实、不掉粒、且保持较高的花青素含量。该技术不仅显著地延长了葡萄贮藏期,提升葡萄长期贮藏品质,而且具有高效低成本,无毒副作用等优点,具有明显的经济效益和社会效益。(The invention discloses a storage method beneficial to maintaining the quality of grapes for a long time, which specifically comprises the following steps: after the grapes reach harvest maturity, the fruit stalks are left to grow and harvested; picking out defective fruits such as rotten fruits, diseased fruits and the like, and then carrying out surface disinfection and cleaning with clean water and then airing or drying the surface moisture; treating grape stalks with a nutrient solution with a proper concentration; and (4) placing the treated grape bunch in a conventional refrigeration house for long-term storage. The method is suitable for long-term storage of the grapes, can prolong the storage time of the grapes to 150 days or more, can delay the dry browning of the stems of the grapes and maintain the extensibility and the greenness of the stems of the grapes, can maintain the hard and solid grape fruits, can not fall off the grape fruits, and can keep higher anthocyanin content. The technology not only obviously prolongs the storage period of the grapes and improves the long-term storage quality of the grapes, but also has the advantages of high efficiency, low cost, no toxic or side effect and the like, and has obvious economic and social benefits.)

1. A storage method for facilitating long-term maintenance of grape quality is characterized in that the long-term maintenance of the grape quality is promoted by delaying the dry browning of grape stalks, and comprises the following specific steps:

A. harvesting: after the grapes reach harvest maturity, harvesting the fruit stalks with the length of 5-8 cm;

B. pretreatment: picking out defective fruits such as rotten fruits, diseased fruits and the like, and then carrying out surface disinfection by using chlorine dioxide, cleaning by using clear water, and then airing or drying the surface moisture;

C. and (3) reprocessing: treating grape fruit stalks with a nutrient solution containing 0.002-0.004 g/L of nitrogen, 0.002-0.004 g/L of phosphorus, 0.002-0.004 g/L of potassium, 0.00001-0.00003 g/L of calcium magnesium sulfur and 0.0002-0.0003 g/L of iron, copper, manganese, zinc, molybdenum and boron trace elements;

D. and (3) storage: and (4) storing the treated grape bunch in an environment of 1-5 ℃.

2. A storage method facilitating the long-term maintenance of grape quality according to claim 1, wherein the fruit stalks left in step A are harvested 5 to 8 cm long.

3. A storage method according to claim 1, wherein the chlorine dioxide surface disinfection in step B is performed for 5-10 min at 30-50 mg/L chlorine dioxide.

4. The storage method for the long-term maintenance of grape quality as claimed in claim 1, wherein the step C further comprises fumigating the grape with 1-MCP at a concentration of 1.0-2.0 μ L/L for 18-24 h.

5. The method for the long-term storage of grapes according to claim 1, further comprising the step of bagging the grapes with modified atmosphere bags before the step D.

Technical Field

The invention belongs to the technical field of fruit preservation, and particularly relates to a storage method beneficial to maintaining the quality of grapes for a long time.

Background

The grapes are popular with consumers, and the grape yield of China is wholly rising in recent years according to the data of the national statistical bureau, and the grape yield reaches 1419.54 ten thousand tons in 2019; and the grape wine is mainly eaten by fresh food, and accounts for about 80 percent of the total yield of the grapes in China. The grape industry needs to realize the annual fresh food sale, long-term storage and long-distance transportation are indispensable important links, but the grape storage period is short, the phenomena of dry and brown fruit stalks, threshing and the like are easy to occur in the storage and transportation process, and the product quality and the economic value are seriously influenced. The dry and brown fruit stalks are not only not beneficial to the long-term preservation of the grapes and the long-term quality maintenance, but also obviously reduce the appearance of the grapes when the grapes are sold and seriously reduce the economic value of the grapes. Loss of water, degradation of chlorophyll and loss of nutrition are main reasons for the dry browning of grape stalks, but no production technology capable of effectively relieving the dry browning of grape stalks exists at present. Nitrogen is a protein, nucleic acid and a constituent element of chlorophyll in a plant body, and chlorophyll a and chlorophyll b are nitrogen-containing compounds; phosphorus is a constituent element of various important macromolecules such as nucleic acid, protein and enzyme in the plant body; the potassium has high distribution amount in the organs and tissues with active plant metabolism, and has the effects of ensuring the smooth progress of various metabolic processes, promoting the growth of plants and the like. The nutrient solution treatment provides water and nutrient elements for the grape fruit stalks, which is beneficial to delaying the chlorophyll degradation of the grape fruit stalks and maintaining the water content and extensibility of the grape fruit stalks, thereby maintaining the quality of the grapes and realizing the long storage of the grapes.

Disclosure of Invention

The invention aims to provide a storage method which is beneficial to maintaining the quality of grapes for a long time.

The invention aims to realize the purpose of promoting the long-term maintenance of the grape quality by delaying the dry browning of grape stalks, and specifically comprises the following steps:

A. harvesting: after the grapes reach harvest maturity, harvesting the fruit stalks with the length of 5-8 cm;

B. pretreatment: picking out defective fruits such as rotten fruits, diseased fruits and the like, and then carrying out surface disinfection by using chlorine dioxide, cleaning by using clear water, and then airing or drying the surface moisture;

C. and (3) reprocessing: treating grape fruit stalks with a nutrient solution containing 0.002-0.004 g/L of nitrogen, 0.002-0.004 g/L of phosphorus, 0.002-0.004 g/L of potassium, 0.00001-0.00003 g/L of calcium magnesium sulfur and 0.0002-0.0003 g/L of iron, copper, manganese, zinc, molybdenum and boron trace elements;

D. and (3) storage: and (4) storing the treated grape bunch in an environment of 1-5 ℃.

The method is suitable for long-term storage of grapes, can prolong the storage time of the grapes to 150 days or more, can delay the dry browning of the stems of the grapes and maintain the extensibility and the greenness of the stems of the grapes, can maintain the hardness and the quality of the grape fruits without dropping the grape fruits, and can keep higher anthocyanin content. The technology not only obviously prolongs the storage period of the grapes and improves the long-term storage quality of the grapes, but also has the advantages of high efficiency, low cost, no toxic or side effect and the like, and has obvious economic and social benefits.

Drawings

FIG. 1 is a schematic diagram of nutrient solutions with different concentrations for delaying degradation of chlorophyll in grape pedicel;

FIG. 2 is a schematic diagram showing the maintenance of water content in grape stem tissue by nutrient solutions of different concentrations;

FIG. 3 is a schematic diagram of the nutrient solution with different concentrations for keeping the grape stalks extensible;

FIG. 4 is a schematic diagram of the maintenance of grape firmness by nutrient solutions of different concentrations;

FIG. 5 is a schematic diagram of the nutrient solution with different concentrations for maintaining the grape endurance;

FIG. 6 is a schematic diagram of nutrient solutions of different concentrations maintaining the anthocyanin content in grape pericarp.

Detailed Description

The present invention is further illustrated by the following examples, but is not limited thereto in any way, and any modifications or alterations based on the teachings of the present invention are within the scope of the present invention.

The storage method beneficial to maintaining the quality of the grapes for a long time promotes the maintenance of the quality of the grapes for a long time by delaying the dry browning of the grape stalks, and specifically comprises the following steps:

A. harvesting: after the grapes reach harvest maturity, harvesting the fruit stalks with the length of 5-8 cm;

B. pretreatment: picking out defective fruits such as rotten fruits, diseased fruits and the like, and then carrying out surface disinfection by using chlorine dioxide, cleaning by using clear water, and then airing or drying the surface moisture;

C. and (3) reprocessing: treating grape fruit stalks with a nutrient solution containing 0.002-0.004 g/L of nitrogen, 0.002-0.004 g/L of phosphorus, 0.002-0.004 g/L of potassium, 0.00001-0.00003 g/L of calcium magnesium sulfur and 0.0002-0.0003 g/L of iron, copper, manganese, zinc, molybdenum and boron trace elements;

D. and (3) storage: and (4) storing the treated grape bunch in an environment of 1-5 ℃.

And D, harvesting the fruit stalks with the length of 5-8 cm.

And B, the surface disinfection of chlorine dioxide in the step B is carried out for 5-10 min by 30-50 mg/L of chlorine dioxide.

And C, before the step C, fumigating the mixture for 18-24 hours by 1.0-2.0 mu L/L1-MCP.

And D, before storage, the step of bagging by adopting a modified atmosphere bag is also included.

The invention is further illustrated by the following specific examples:

example 1

Harvesting grape stalks with similar sizes and maturity by remaining 6 cm long; picking out defective fruits such as rotten fruits and diseased fruits, soaking in 40 mg/L chlorine dioxide solution for 8 min, cleaning with clear water for 3 times, and naturally drying surface water;

fumigating the grapes sterilized on the surface of the chlorine dioxide solution for 20 hours by using 1-MCP with the concentration of 1.5 mu L/L, and then treating the grapes with a nutrient solution, wherein the nutrient solution contains 0.003g/L of nitrogen, 0.003g/L of phosphorus, 0.003g/L of potassium, 0.00002g/L of calcium, magnesium and sulfur and 0.00025g/L of iron, copper, manganese, zinc, molybdenum and boron microelements;

and bagging the grapes treated by the nutrient solution by using a modified atmosphere bag, and storing at the temperature of 1 ℃ for 188 days.

Example 2

Harvesting grape stalks with similar sizes and maturity by remaining 5 cm long; picking out defective fruits such as rotten fruits and diseased fruits, soaking in 30 mg/L chlorine dioxide solution for 10 min, cleaning with clear water for 3 times, and naturally drying surface water;

fumigating the grapes sterilized on the surface of the chlorine dioxide solution for 24 hours by using 1-MCP with the concentration of 1.0 mu L/L, and then treating the grapes with a nutrient solution, wherein the nutrient solution contains 0.002g/L of nitrogen, 0.002g/L of phosphorus, 0.002g/L of potassium, 0.00001g/L of calcium, magnesium, sulfur and 0.0002g/L of iron, copper, manganese, zinc, molybdenum, boron trace elements;

bagging the grapes processed by the nutrient solution by using a modified atmosphere bag, and storing at the temperature of 1 ℃ for 168 days.

Example 3

Harvesting grape stalks with similar sizes and maturity by remaining the length of 8 cm; picking out defective fruits such as rotten fruits and diseased fruits, soaking in 50 mg/L chlorine dioxide solution for 5 min, cleaning with clear water for 3 times, and naturally drying surface water;

fumigating the grapes sterilized on the surface of the chlorine dioxide solution for 16 h by using 1-MCP with the concentration of 2.0 mu L/L, and then treating the grapes with a nutrient solution, wherein the nutrient solution contains 0.004g/L of nitrogen, 0.004g/L of phosphorus, 0.004g/L of potassium, 0.00003g/L of calcium, magnesium, sulfur and 0.0003g/L of iron, copper, manganese, zinc, molybdenum, boron trace elements;

bagging the grapes treated by the nutrient solution by using a modified atmosphere bag, and storing at 1 ℃ for 159 days.

Experimental example 1

The tests were carried out in example 1 (nutrient solution concentration 1), example 2 (nutrient solution concentration 2) and example 3 (nutrient solution concentration 3) by the following methods:

first, test scheme

1. Test materials

The grape fruits are produced in Binchuan county of Yunnan province, the variety is 'red grape', the fruits with consistent size and no damage and disease are selected, immediately treated and warehoused. The chemical reagents mainly comprise nutrient solution, chlorine dioxide and the like; packaging the treated modified atmosphere bag, and storing in a refrigerator at 1 deg.C.

2. Storage method

The method uses the common fresh-keeping bag package without nutrient solution treatment as a contrast; respectively treating the red grape bunch with nutrient solutions with different concentrations, and bagging the treated red grape bunch with modified atmosphere bags; storing in a refrigerator at 1 deg.C, and observing and measuring related indexes every 30 d; each treatment was repeated 3 times.

3. Analysis of measured index

1) Browning of fruit stalks

Measuring chlorophyll by spectrophotometry. Weighing 1g of sample, cutting up the sample, putting the cut sample into a 10 mL centrifuge tube, adding 5 mL of absolute ethyl alcohol, reacting for 2 hours in a dark place, measuring the light absorption values at 663 nm and 645 nm, and measuring 3 parallels in each treatment. Combined formula "leaf green (a + b) = [ (8.02 a = a:" leaf green (a): "leaf green (a):" formula: "leaf green (a:" leaf green (a): "leaf green (a:" leaf green (a₆₆₃+20.49A₆₄₅)*V]V (1000 × M) (V: volume of extract; M: mass of sample), the total chlorophyll content was calculated.

2) Water content of fruit stem

And (3) determining by adopting a drying method: weighing M₀g sample, dried to constant weight at 105 deg.C, cooled to room temperature and measured for weight, M₁. According to the formula "water content (%) = (M)₀-M₁)/M₀", calculating the water content.

3) Hardness of fruit grain

The pressure distance test was performed using a texture analyzer using a disc probe with a diameter of 75 mm, measuring 10 replicates per treatment. Test parameters are as follows: the sensing element 50N, the deformation amount 30%, the descending speed, the extrusion speed and the ascending speed are all 60 mm/min, and the height of the probe is 30 mm.

4) Fruit grain tensile force resistance

Tension resistance: the measurements were made using an intelligent electronic tensile tester, and each treatment was repeated 21 times and averaged.

5) Content of anthocyanin in pericarp

Extraction: weighing 3g pericarp into 50 mL centrifuge tube, extracting with 10 mL boiling waterTaking supernatant after 30 min; the precipitate is extracted in 10 mL of boiling water for 30 min, and the two supernatants are mixed to a constant volume of 25 mL. And (3) determination: taking 1 mL of solution to be detected, adding 5 mL of acidic ethanol, shaking up, developing for 30 min, and determining the light absorption value at 535 nm. According to the formula "anthocyanidin (mg/g FW) = [ (A535/V) =_Measuring)*101.83]/M” (V_Measuring: the volume used in the determination; m: sample mass), calculating the anthocyanin content of the sample.

Second, test results

1. Delay the chlorophyll degradation of grape stems

The browning of grape stalks is closely related to the degradation of chlorophyll. The effect of different concentrations of nutrient solutions on the chlorophyll content of grape fruit stems is shown in fig. 1. As can be seen from FIG. 1, the total chlorophyll content of the grape stalks tended to decrease during storage. However, after 150 days of storage, the chlorophyll content of the grape stems treated by the nutrient solution + modified atmosphere bag in the comparative example 1, the nutrient solution + modified atmosphere bag in the example 2 and the nutrient solution + modified atmosphere bag in the example 3 is respectively reduced by 0.035 mg/g FW, 0.017 mg/g FW, 0.019 mg/g FW and 0.023 mg/g FW. The chlorophyll content in the fruit stalks is the nutrient solution + modified atmosphere bag in example 1 > the nutrient solution + modified atmosphere bag in example 2 > the nutrient solution + modified atmosphere bag in example 3 > the control. The results show that the nutrient solution and modified atmosphere bag treatment in example 1 are more favorable for delaying the degradation of chlorophyll in the fruit stalks, and the preservation effect of the nutrient solution with different concentrations on the grape stalks is shown in figure 3. As shown in FIG. 3, the grape stalks treated with the nutrient solution and the modified atmosphere bag in example 1 were kept green after being stored for 150 days, except for browning in the secondary axis.

2. Keeping the moisture and extensibility of the grape stem tissue

The effect of nutrient solution treatment of different concentrations on the water content of the grape fruit stem tissue is shown in fig. 2. As can be seen from FIG. 2, the water content of the tissue decreased with the increase of the storage time. After 150 days of storage, the tissue water content of the control sample is obviously reduced, and the moisture loss of the fruit stalks of the nutrient solution and the air-conditioned bag in the example 1 is minimum; compared with 0d, 35.08%, 22.62%, 28.36% and 25.61% of the nutrient solution + modified atmosphere bag treatment in the control, the example 1, the example 2 and the example 3 were lost. The results show that the nutrient solution and modified atmosphere bag treatment in the example 1 are more beneficial to keeping the water content of the fruit stalk tissues. Furthermore, as can be seen from FIG. 3, the grape stalks treated by the nutrient solution and modified atmosphere bag in example 1 are kept stretched and not dried after being stored for 150 days.

3. Keeping the hardness of grape fruit grains

During storage and shelf life, the grape flesh tissue is softened, which directly affects the eating quality, processing quality and storage quality of the grapes. The effect of different concentrations of nutrient solution on the hardness of grape fruit pieces is shown in fig. 4. During storage the pulp hardness of grapes tends to decrease gradually. In the early storage period, due to the fresh-keeping effect of a cold storage, the grape pulp treated by the contrast and nutrient solution maintains certain hardness, and the difference is not obvious; but the softening of the grape pulp tissue can be effectively relieved by the treatment of the nutrient solution in the middle and later stages, and the effect of relieving the grape pulp tissue is as follows: example 1 nutrient solution + modified atmosphere bag > example 2 nutrient solution + modified atmosphere bag > example 3 nutrient solution + modified atmosphere bag.

4. Keep the grape fruit grain to resist the pulling force, prevent the grain from dropping

The pull resistance of the fruit handle refers to the external force required by the shedding of the grape fruit grains and the fruit stem parts, and is an index for representing the difficulty degree of the grape grain shedding. As can be seen in fig. 5, the grape fruit pieces exhibited a tendency to decay in tensile resistance throughout storage. After 60 days of storage, the tensile strength of the fruit grains of the comparison, the nutrient solution + modified atmosphere bag in example 1, the nutrient solution + modified atmosphere bag in example 2 and the nutrient solution + modified atmosphere bag in example 3 is respectively reduced by 0.45N, 036N, 040N and 0.39N; example 1 minimal drop in nutrient solution + modified atmosphere bags. Overall, the degree of decay in tensile resistance during the entire storage period: example 1 nutrient solution + modified atmosphere bag < example 3 nutrient solution + modified atmosphere bag < example 2 nutrient solution + modified atmosphere bag < control; thus, the tensile strength of the nutrient solution + modified atmosphere bag of example 1 was the greatest after 150 days of storage. This shows that the nutrient solution + modified atmosphere bag treatment of example 1 is effective in maintaining the grape stalks tensile strength.

5. Maintaining the anthocyanin content of grape pericarp

The grape peel contains a large amount of anthocyanin which belongs to flavonoid compounds and is closely related to the color, quality, flavor and the like of grape fruits, so that the stress resistance and disease resistance of the grape fruits can be enhanced, and the quality of the picked grape fruits can be improved; the anthocyanin has various health care functions for human bodies and can be widely applied to the field of foods. As can be seen from fig. 6, the content of anthocyanins in the control group increased first and then decreased as the storage time extended during the entire storage period, while the content of anthocyanins in 3 examples increased all the time; when the anthocyanin content is stored for 150 days, the nutrient solution + modified atmosphere bag (107.20 mg/g FW) in the example 1, the nutrient solution + modified atmosphere bag (93.10 mg/g FW) in the example 2, the nutrient solution + modified atmosphere bag (98.46 mg/g FW) in the example 3 and the control (89.06 mg/g FW) are sequentially arranged from high to low, and the anthocyanin content in all the 3 examples is obviously higher than that in the control. The results show that the nutrient solution and the modified atmosphere bag treatment can promote the flavor formation of the grapes and well maintain the anthocyanin content in the grapes.