阅读说明：本技术 一种杨梅微生态绿色保鲜剂及其制备方法 (Waxberry microecological green preservative and preparation method thereof ) 是由 祝子坪 李娜 李钧敏 谢振达 于 2021-06-08 设计创作，主要内容包括：本发明公布了一种杨梅微生态绿色保鲜剂及其制备方法,属于果蔬保鲜领域,主要解决杨梅常温下储藏期较短的难题。本发明为液体微生态保鲜剂,由对人体有益的活性微生物和成膜剂组成,活性微生物为桑黄菌和酵母菌,成膜剂为黄秋葵多糖和壳聚糖。活性微生物通过拮抗作用抑制杨梅腐败菌,成膜剂形成膜来抑制杨梅呼吸,减缓杨梅衰老,从而延长杨梅保鲜期。本发明所用活性微生物和成膜剂均可食用,安全可靠,保鲜效果好,能使杨梅常温储藏期延长3～4天,所用原料价格低廉、有益于推广。(The invention discloses a micro-ecological green preservative for waxberries and a preparation method thereof, belongs to the field of fruit and vegetable preservation, and mainly solves the problem of short storage period of the waxberries at normal temperature. The invention relates to a liquid microecological preservative which consists of active microorganisms beneficial to human bodies and a film-forming agent, wherein the active microorganisms are phellinus igniarius and saccharomycetes, and the film-forming agent is okra polysaccharide and chitosan. The active microorganisms inhibit the waxberry putrefying bacteria through antagonism, and the film-forming agent forms a film to inhibit the waxberry respiration and slow the waxberry aging, thereby prolonging the waxberry preservation period. The active microorganisms and the film-forming agent can be eaten, so that the method is safe, reliable, good in preservation effect, low in price of raw materials and beneficial to popularization, and the normal-temperature storage period of the waxberries can be prolonged by 3-4 days.)

1. A preparation method of a waxberry microecological green preservative is characterized by comprising the following steps:

s1, fermenting and culturing the phellinus igniarius by adopting a fermentation culture medium,

s2, inoculating yeast into the culture solution obtained in the step S1 to continue fermentation culture,

s3, adding okra polysaccharide extracting solution and chitosan into the fermentation liquor obtained in the step S2, stirring and dissolving, wherein the adding amount of the okra polysaccharide extracting solution is 60-90 mL/L, and the adding amount of the chitosan is 5-15 g/L, and filtering to obtain the waxberry microecological preservative.

2. The preparation method of the micro-ecological green fresh-keeping agent for waxberries according to claim 1, wherein the fermentation medium adopted in the step S1 comprises the following components in percentage by mass: 5.16% of mulberry twig powder, 2.38% of wheat bran, 4.85% of rice bran, 0.094% of monopotassium phosphate, 0.054% of magnesium sulfate and the balance of water; boiling and heating for 10min, filtering with 8 layers of gauze, sterilizing the filtrate with sterilizing pot at 121 deg.C for 20min, and cooling.

3. The preparation method of the micro-ecological green fresh-keeping agent for waxberries according to claim 1, which is characterized by comprising the following steps: after the phellinus igniarius is inoculated in the step S1, performing shake flask culture at 28 ℃ under the condition of 120r/min, and stopping fermentation when the number of bacteria balls reaches 1-3/mL; and crushing the obtained fermentation liquor to obtain sterile balls by using a tissue crusher under the aseptic condition, and then performing static culture for 4-12 hours.

4. The preparation method of the micro-ecological green fresh-keeping agent for waxberries according to claim 1, which is characterized by comprising the following steps: in the step S2, the fermentation condition of the yeast is 25 ℃, 130r/min, and the fermentation time is 10-20 h.

5. The preparation method of the micro-ecological green fresh-keeping agent for waxberries according to claim 1, which is characterized by comprising the following steps: the okra polysaccharide extracting solution is prepared by adding 7-13 g of okra dry powder into 1L of water, extracting at 50-80 ℃ for 40-60 min, and the concentration of the extracted okra polysaccharide is 30-45 mg/L.

6. The preparation method of the micro-ecological green fresh-keeping agent for waxberries according to claim 1, which is characterized by comprising the following steps: step S1, inoculating Phellinus Linteus seed solution with culture medium volume of 5%; step S2 was inoculated with yeast seed solution at 5% of the volume of the medium.

7. The preparation method of the micro-ecological green fresh-keeping agent for waxberries according to claim 1, which is characterized by comprising the following steps: inoculating the phellinus igniarius into a PDB culture medium, and performing shake-flask culture at 28 ℃ and 120r/min for 3d to obtain a seed solution; inoculating the yeast into PDB culture medium, shaking at 25 deg.C and 130r/min, and culturing for 1d to obtain seed liquid.

8. A micro-ecological antistaling agent for waxberry prepared by the preparation method of claim 1.

Technical Field

The invention relates to a food preservative, in particular to a red bayberry microecological green preservative and a preparation method thereof, and belongs to the technical field of fruit and vegetable preservation.

Background

The waxberry (Myrica rubra Sieb. et Zucc) is a special fruit in China, and the cultivation area accounts for more than 99% of the whole world. The fruit is mainly produced in the south areas of the Yangtze river basin such as Fujian, Zhejiang, Guangdong and Jiangxi, the fruit is bright in color, sour and sweet, palatable and rich in nutrition, is rich in multiple vitamins, cellulose, mineral substances, zinc, iron, potassium and other trace elements and amino acids and other nutrient substances, has the effects of helping digestion, increasing appetite, astringing, diminishing inflammation, relieving diarrhea, preventing and resisting cancer, dispelling summer heat, promoting the secretion of saliva or body fluid and the like, has edible and medicinal values, and is very popular with consumers. The waxberry is mainly eaten fresh, and can also be made into preserved fruits, wine and the like. The waxberry is ripe in high-temperature rainy seasons, and the fruit belongs to berries and is formed by polymerizing pulp columns, is soft and juicy, is not wrapped by exocarp, is easy to be infected by mechanical damage and pathogenic microorganisms after being picked, causes rotten and deteriorated pulp, is not beneficial to storage, has the shelf life of only 2-3 days at room temperature, and has the saying of color change in one day, flavor change in two days and full change of flavor and fragrance in three days. The harvesting period of the waxberries is centralized, so that the production and marketing pressure is high in the peak period of the market, and the economic benefit of the waxberries is seriously influenced. Therefore, the research on how to prolong the fresh-keeping period and the supply period of the waxberry fruits and discuss an effective storage means has great significance for the development of the waxberry industry.

The storage and preservation method of the waxberries mainly comprises low-temperature storage, preservative treatment, radiation preservation, modified atmosphere preservation and the like. The chemical preservative has limited preservation effect on the waxberries, and the residue of the preservative brings adverse effects on human health and environment, so that the chemical preservative is not easy to be accepted by consumers; low temperature refrigeration can reduce fruit quality and flavor mouthfeel, affecting outward shipping and distribution. The radiation preservation and the controlled atmosphere storage have certain effect on the preservation of the waxberries, but the equipment investment is large, the cost is high, and the popularization is difficult. Therefore, the development of the room-temperature preservation technology which is low in cost, pollution-free, nuisanceless and simple and convenient to operate is particularly important when the preservation research is carried out on the waxberries. Researches show that the postharvest decay of the waxberry fruits is mainly caused by fungi, wherein the types of the fungi mainly comprise verticillium myriophyllum, penicillium citrinum, trichoderma viride, ascomycetes, fusarium oxysporum and the like, and the penicillium citrinum and the verticillium myricae are main pathogenic bacteria. If the waxberry fruits are stored at room temperature, the waxberry fruits lose edibility at the 4 th day due to fungal infection.

Disclosure of Invention

The invention aims to provide a green micro-ecological preservative capable of effectively prolonging the preservation period of waxberries so as to solve the problem of short storage period of the waxberries at room temperature.

The technical scheme adopted by the invention for solving the technical problem is as follows:

a preparation method of a waxberry microecological green preservative comprises the following steps:

s1, fermenting and culturing the phellinus igniarius by adopting a fermentation culture medium,

s2, inoculating yeast into the culture solution obtained in the step S1 to continue fermentation culture,

s3, adding okra polysaccharide extracting solution and chitosan into the fermentation liquor obtained in the step S2, stirring and dissolving, wherein the adding amount of the okra polysaccharide extracting solution is 60-90 mL/L, and the adding amount of the chitosan is 5-15 g/L, and filtering to obtain the red bayberry microecological green preservative.

When in use, the micro-ecological green preservative for waxberries is sprayed until the surfaces of the waxberries are slightly wet to form water films but do not drip, and the waxberries are placed in an indoor ventilation place to be dried, boxed and stored at room temperature.

Antagonism is a phenomenon commonly existing among microorganisms in nature, and a microecological preparation consisting of probiotics has obvious curative effects on regulating intestinal flora of human and animals, promoting nutrient absorption and keeping intestinal health. Based on the antagonism principle, the invention screens microorganisms which are beneficial or harmless to human bodies to inhibit waxberry putrefying bacteria in the microecological range and can delay the waxberry putrefaction. In order to delay the natural aging process of the waxberries, the film forming agent of polysaccharides is used for forming a film to inhibit the respiration of the waxberries, so that the effect of prolonging the freshness date of the waxberries is achieved.

The waxberry microecological preservative consists of beneficial active microorganisms and a film-forming agent, and tests prove that the two bacteria, namely the phellinus igniarius and the wine special yeast RW, are screened from phellinus igniarius, wild lactic acid bacteria I, wild lactic acid bacteria II, beer yeast, the wine special yeast SY and the wine special yeast RW and serve as the active microorganisms, and the film-forming agent is chitosan and okra polysaccharide. The active microorganisms inhibit the waxberry putrefying bacteria through antagonism, and the film-forming agent forms a film to inhibit the waxberry respiration and slow the waxberry aging, thereby prolonging the waxberry preservation period. The active microorganisms and the film-forming agent can be eaten, so that the method is safe, reliable, good in preservation effect, low in price of raw materials and beneficial to popularization, and the storage period of the waxberries at room temperature can be prolonged by 3-4 days.

The Phellinus linteus is purchased from China general microbiological culture Collection center (CGMCC), the strain number is 5.95, the Chinese is named Phellinus igniarius, and the Latin is named Phellinus igniarius.

The wine special yeast RW is purchased from Angel Yeast GmbH, product Standard number: Q/YB.J02.05.

Preferably, the fermentation medium adopted in step S1 has the following composition in percentage by mass: 5.16% of mulberry twig powder, 2.38% of wheat bran, 4.85% of rice bran, 0.094% of monopotassium phosphate, 0.054% of magnesium sulfate and the balance of water; boiling and heating for 10min, filtering with 8 layers of gauze, sterilizing the filtrate with sterilizing pot at 121 deg.C for 20min, and cooling.

Preferably, in the step S1, the phellinus igniarius is inoculated and cultured in a shake flask at 28 ℃ under the condition of 120r/min, and the fermentation is stopped when the number of bacteria balls reaches 1-3/mL; and crushing the obtained fermentation liquor to obtain sterile balls by using a tissue crusher under the aseptic condition, and then performing static culture for 4-12 hours.

Preferably, in step S2, the fermentation conditions of the yeast are 25 ℃, 130r/min, and the fermentation time is 10-20 h, preferably 12-18 h.

Preferably, the okra polysaccharide extracting solution is prepared by adding 7-13 g of okra dry powder into 1L of water, extracting at 50-80 ℃ for 40-60 min, and the concentration of the extracted okra polysaccharide is 30-45 mg/L.

Preferably, step S1 is performed by inoculating phellinus igniarius seed solution with a volume of 5% of the culture medium; step S2 was inoculated with yeast seed solution at 5% of the volume of the medium.

Preferably, the phellinus igniarius is inoculated in a PDB culture medium and cultured in a shake flask at 28 ℃ and 120r/min for 3d to form seed liquid, and the microzyme is inoculated in the PDB culture medium and cultured in a shake flask at 25 ℃ and 130r/min for 1d to form seed liquid.

The preparation method is used for preparing the micro-ecological green preservative for the waxberries.

The invention has the beneficial effects that:

1. the invention adopts microorganisms beneficial to human bodies to inhibit the growth of waxberry putrefying bacteria, and uses okra polysaccharide and chitosan to form a film to inhibit the respiration of waxberries, thereby prolonging the freshness keeping period of the waxberries, prolonging the storage period by 3-4 days when the waxberries are stored at room temperature, and having the characteristics of green and safety.

2. The preservative is microbial fermentation liquor, the polysaccharides are okra polysaccharide and chitosan, and the used materials are low in cost, convenient to use and easy to popularize.

Drawings

FIG. 1 is a yeast fermentation growth curve.

FIG. 2 is a photograph comparing the waxberries of each group in the waxberry preservation comparison experiment.

Detailed Description

The technical solution of the present invention will be further specifically described below by way of specific examples. It is to be understood that the practice of the invention is not limited to the following examples, and that any variations and/or modifications may be made thereto without departing from the scope of the invention.

In the present invention, all the parts and percentages are by mass, and the equipment and raw materials used are commercially available or commonly used in the art. The methods in the following examples are conventional in the art unless otherwise specified.

Phellinus linteus is purchased from China general microbiological culture Collection center (CGMCC), the strain number is 5.95, the Chinese translation name is Phellinus igniarius, and the Latin chemical name is Phellinus igniarius.

The yeast is wine special yeast RW which is purchased from Angel Yeast GmbH, product Standard number: Q/YB.J02.05.

The okra polysaccharide extracting solution is prepared by adding 7-13 g of okra dry powder into 1L of water, extracting at 50-80 ℃ for 40-60 min, wherein the concentration of the extracted okra polysaccharide is 30-45 mg/L.

The method for measuring the weight loss rate, the good fruit rate, the mildew rate, the rotten fruit rate, the fruit cracking rate and the storage period in the parameter optimization process comprises the following steps:

(1) weight loss ratio

Weighing 50 picked fresh waxberries, calculating the average mass of each waxberry, and recording as M₀Storing for a certain time t, weighing, calculating the average mass of each particle, and recording as M_tAnd the weight loss rate of the waxberries at the storage time t is as follows:

weight loss rate = [ (M)₀-M_t)/M₀]×100%

(2) Good fruit rate

The red bayberry fruit is good, 50 fruits are randomly selected each time during storage, the number of the good fruits is counted, and the good fruit rate is calculated according to the following formula:

good fruit rate = (number of good fruits/total number of investigated fruits) × 100%

(3) Rate of mildew

Randomly selecting 50 waxberries each time during storage, checking mildew spots one by one, regarding the waxberries as mildew fruits, and calculating the mildew rate according to the following formula:

mildew rate = (number of mildew fruits/total number of investigated fruits) × 100%

(4) Rate of rotten fruit

Randomly selecting 50 red bayberries each time during storage, checking one by one, collapse of fruit pulp columns, exuding a large amount of juice, and regarding soft rot of the fruits as rotten fruits, wherein the rotten fruit rate is calculated according to the following formula:

rotten fruit rate = (rotten fruit number/survey total fruit number) × 100%

(5) Rate of fruit cracking

Randomly selecting 50 red bayberries each time during storage, checking one by one, regarding the crack as a cracked fruit when the crack length is longer than 5mm and the width is more than 3mm, and calculating the rotten fruit rate according to the following formula:

fruit cracking rate = (number of cracked fruits/total number of investigated fruits) × 100%

(6) Shelf life

And 7 persons form a sensory evaluation group, the appearance, the smell, the texture and the rotten degree of the waxberry fruits are comprehensively graded every 6 hours, and then the average value is taken, and the storage period is determined when the average value is more than or equal to 3.5 minutes. Sensory evaluation criteria: and 5, dividing: the fruit shape is correct, the coloring is bright, the fruit surface is clean, the meat columns are full, the special fragrance of the waxberries is provided, and the waxberries are not rotten; and 4, dividing: the fruit shape is normal, the coloring is good, the fragrance is light, and the meat columns are full; and 3, dividing: the fruit is partially shrunken, the color is off-color and has meat thorn; and 2, dividing: the fruit has shriveled appearance, and part of the fruit is mildewed and has slight peculiar smell; 1 minute: the fruits are soft and rotten and have a heavy rotten smell.

In order to ensure the accuracy of the test and ensure the consistency of the test raw materials, the waxberry used for carrying out various process parameter optimization tests in the invention is the Dongkui waxberry provided by Wuyan mountain poplar professional cooperative society in Xiju, Zhejiang, and the waxberry is a high-quality fruit which is eight-ripe, uniform in size, bright in color and free of mechanical damage and plant diseases and insect pests on the surface and is transported back to a laboratory by a foam box with an ice bag.

Example screening method of components of micro-ecological green preservative for waxberries

(1) Screening of microorganisms

Main spoilage bacteria of the waxberry, namely penicillium citrinum and verticillium myrica are separated from rotten waxberry, phellinus igniarius, lactobacillus I (separated from yoghourt), lactobacillus II (separated from pickled Chinese cabbage), beer yeast (purchased from Angel yeast, Inc.), special wine yeast SY (purchased from Angel yeast, Inc.), and special wine yeast RW (purchased from Angel yeast, Inc.) are respectively inoculated on the same PDA plate for antagonistic experiments, and the antagonistic effect is shown in table 1.

TABLE 1 antagonistic effect of major spoilage bacteria and probiotics of Myrica rubra

Antagonistic bacteria

Phellinus igniarius

Lactic acid bacteria I

Lactic acid bacteria II

Beer yeast

Special yeast SY for wine

Special yeast RW for wine

Penicillium citrinum

+++

+

++

-

++

++

Myricerus communis

++

-

+

+

++

+++

Note: -: no antagonism, no boundary between two colonies; +: slight antagonism, two colonies have obvious boundary lines, the boundary lines are thinner, and the width is less than 5 mm; the positive and negative colonies have moderate antagonism, two colonies have obvious boundary lines, the boundary lines are thick, and the width is more than 5 mm; the two colonies have a clear boundary, the boundary is thicker and the width is more than 1 cm.

As can be seen from Table 1, the yeast RW for Phellinus linteus and wine has better antagonistic action with Penicillium citrinum and Gliocladium myriophyllum. Selecting Phellinus igniarius and wine special yeast RW, fermenting in PDB culture medium respectively, spraying fermentation liquid on the surface of the Baripe waxberries, airing, storing at room temperature for 4 days, and inspecting the weight loss rate, the good fruit rate, the mildew rate, the rotten fruit rate, the fruit cracking rate and the storage period of the waxberries. As a result, the fruit yield of the waxberries treated by the phellinus igniarius and yeast fermentation liquor is respectively improved by 8.84% and 12.03% compared with that of untreated control, the mildew rate is respectively reduced by 11.36% and 15.31%, the weight loss rate, the rotten fruit rate and the fruit cracking rate are not changed, and the storage period is respectively prolonged by 12h and 18h, which shows that the phellinus igniarius and the wild yeast can prolong the storage period of the waxberries, so that the phellinus igniarius and the yeast RW special for wine are selected as the fresh-keeping microorganisms.

(2) Media screening

Preparing a seed culture medium PDB and fermentation culture media I, II and III according to the previous test results and references, sterilizing at 121 ℃ for 20min, and cooling to room temperature. Inoculating Phellinus linteus into PDB culture medium, shaking at 28 deg.C and 120r/min, and culturing for 3d to obtain seed solution; inoculating the yeast into PDB culture medium, shaking at 25 deg.C and 130r/min, and culturing for 1d to obtain seed liquid. Inoculating 5mL of phellinus igniarius seed solution into each 100mL of fermentation medium, shaking and culturing at 28 ℃ and 120r/min for 3d, crushing the phellinus igniarius seed solution by using a tissue crusher under aseptic conditions until bacterial balls disappear, standing and culturing for 6h, then inoculating 5mL of saccharomycete seed solution into each 100mL of fermentation medium, shaking and culturing at 25 ℃ and 130r/min for 1d, filtering the fermentation liquor by using single-layer gauze, spraying the filtrate on the surface of waxberry, drying in the air and storing at room temperature for 4 d. And (4) inspecting the weight loss rate, the good fruit rate, the mildew rate, the rotten fruit rate, the fruit cracking rate and the storage period of the waxberries. The results show that the good fruit rate of the waxberries treated by the culture media I, II and III is respectively improved by 15.17%, 17.62% and 21.48% compared with the normal storage control, the mildew rate is respectively reduced by 21.34%, 27.63% and 36.39%, and the weight loss rate, the rotten fruit rate and the fruit cracking rate are not obviously changed, which shows that the culture medium III has better effect of prolonging the storage period of the waxberries, so the culture medium III is preferred.

The formula of each culture medium is as follows:

seed medium (PDB medium): boiling 200g of potato in boiling water for 15min, filtering with 8 layers of gauze, taking the filtrate, adding 20g of glucose, adding tap water to 1000mL, and keeping the pH natural.

Medium i (modified PDA medium): 200g of potatoes and 20g of mulberry plants, 20g of glucose is added into the filtrate, tap water is added to 1000mL, and the pH is natural.

And (3) a culture medium II: 51.6g of wheat bran powder, 13.8g of rice bran, 0.94g of monopotassium phosphate and 0.54g of magnesium sulfate, adding tap water to 1000mL, boiling in boiling water for 15min, filtering with 8 layers of gauze, and keeping the pH value natural.

And (3) a culture medium III: 15g of mulberry twig powder, 32g of wheat bran, 18g of rice bran, 0.94g of monopotassium phosphate and 0.54g of magnesium sulfate, adding tap water to 1000mL, boiling in boiling water for 15min, filtering by 8 layers of gauze, and keeping the pH value natural.

(3) Optimization of bacterium ball crushing and standing culture time

Phellinus linteus is filamentous fungus, mycelium is wound into mycelium pellets during shake flask fermentation, mycelium fragments in fermentation liquor are less, in order to increase the mycelium fragments, a tissue pulverizer is used for pulverizing the mycelium pellets, and the broken mycelium fragments are subjected to static culture to recover growth activity.

Inoculating phellinus igniarius into a culture medium III, performing shake culture at 28 ℃ and 120r/min for 3d, dividing fermentation liquor into two parts, inoculating wine-specific yeast RW to one part, continuing to ferment for 1d as a control, crushing the other part to an aseptic ball by using a tissue crusher under an aseptic condition, performing standing culture for 4, 8, 12 and 16 hours, inoculating wine-specific yeast RW, continuing to ferment for 1d, filtering by using a single-layer gauze, spraying filtrate on the surface of waxberry, storing the filtrate at room temperature for 4d after drying, and inspecting the weight loss rate, the good fruit rate, the mildew rate, the rotten fruit rate, the fruit cracking rate and the storage period of the waxberry. The results show that the good fruit rate of the red bayberries is improved by 2.33%, 6.46%, 5.15% and 5.02% after the treatment for 4 times, the mildew rate is reduced by 3.69%, 7.82%, 6.64% and 6.51%, and the weight loss rate, the rotten fruit rate and the fruit cracking rate are not obviously changed, which indicates that the phellinus igniarius can recover the growth state better after standing culture for 4-12 hours, the number of bacteria in the culture solution is large, and the storage period of the red bayberries is prolonged better.

(4) Yeast fermentation time optimization

Inoculating Phellinus linteus into culture medium III, shake-culturing at 28 deg.C and 120r/min for 3d, inoculating wine-specific yeast RW seed solution with fermentation liquid volume of 5%, fermenting, respectively taking fermentation liquid at 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24h under aseptic condition, filtering with 4 layers of gauze, taking filtrate, and measuring OD 600nm absorbance, with the result shown in FIG. 1. As can be seen from FIG. 1, the yeast is in logarithmic growth phase for about 10h to 20h, preferably 12h to 18h, which is in the middle of logarithmic growth phase, and the cells grow vigorously.

(5) Film-forming agent optimization

On the basis of the previous experiment, chitosan and okra polysaccharide are selected as film forming agents, okra polysaccharide is prepared by adding water into okra for extraction, the concentration of polysaccharide is 35mg/mL, and the addition of okra polysaccharide extract and chitosan (okra polysaccharide extract mL/chitosan g) in every 1L of yeast RW fermentation liquor special for phellinus igniarius and wine is respectively as follows: 120/0, 90/5, 60/10, 30/15 and 0/20, dissolving and filtering, spraying the filtrate on the surface of waxberry, airing and storing for 4 days at room temperature, and examining the weight loss rate, the good fruit rate, the mildew rate, the rotten fruit rate, the cracked fruit rate and the storage period of the waxberry by taking the waxberry without being treated by a preservative as a control.

The results were: and 5 polysaccharides are proportioned and treated, the weight loss rate of the waxberries is respectively reduced: 7.29%, 9.52%, 10.83%, 16.18%, 11.41%, the good fruit rate improves respectively: 33.57%, 41.48%, 62.15%, 82.14%, 31.61%, the mildew rate decreases respectively: 35.36%, 51.34%, 63.52%, 89.47% and 65.58%, and the rotten fruit rate is respectively reduced: 6.25%, 9.56%, 9.67%, 11.26% and 9.13%, respectively, the fruit cracking rate is reduced: 4.16%, 5.23%, 5.38%, 7.26%, 6.17%, respectively, the storage period is prolonged: 2. 2, 3, 4 and 3 d. According to the experimental result, the fresh-keeping effect is good when the addition amount of the chitosan is 5-15 g/L and the addition amount of the okra polysaccharide extracting solution is 60-90 mL/L.

Example 1

The preparation method of the waxberry microecological preservative specifically comprises the following steps: a fermentation medium is prepared according to the following components, and the formula of the medium is as follows: 5.16% of mulberry twig powder, 2.38% of wheat bran, 4.85% of rice bran, 0.094% of monopotassium phosphate, 0.054% of magnesium sulfate and the balance of tap water, and sterilizing the culture medium for 20min at 121 ℃ in a sterilizing pot. Inoculating phellinus igniarius seed liquid with 5% of fermentation liquid volume, performing shake culture at 28 ℃ and 120r/min, stopping fermentation when the number of bacteria balls reaches 2/mL, crushing the bacteria balls by using a tissue crusher under aseptic conditions until the bacteria balls disappear, performing static culture at 28 ℃ for 6h, inoculating wild saccharomycete seed liquid with 5% of fermentation liquid volume, performing shake culture at 25 ℃ and 130r/min for 16h, adding 60mL of okra polysaccharide extracting solution and 12g of chitosan into every 1L of fermentation liquid, stirring and dissolving, and filtering by 4 layers of gauze to obtain the waxberry microecological preservative.

Spraying the micro-ecological antistaling agent on the surfaces of the eight ripe waxberries without diseases, insect pests and mechanical damage until the waxberries are slightly wet and do not drip, airing, putting the waxberries in plastic baskets in time, putting the dried waxberries in each basket for 2.5kg, and storing the waxberries in a carton at room temperature, wherein the storage period is prolonged by 3.5 days compared with that of a control without the antistaling agent.

Example 2

The preparation method of the waxberry microecological preservative specifically comprises the following steps: preparing a fermentation medium according to a formula, wherein the formula of the culture medium is as follows: 5.16% of mulberry twig powder, 2.38% of wheat bran, 4.85% of rice bran, 0.094% of monopotassium phosphate, 0.054% of magnesium sulfate and the balance of tap water, and sterilizing the culture medium for 20min at 121 ℃ in a sterilizing pot. Inoculating phellinus igniarius seed liquid with 5% of fermentation liquid volume, performing shake culture at 28 ℃ and 120r/min, stopping fermentation when the number of bacteria balls reaches 3/mL, crushing the bacteria balls by using a tissue crusher under aseptic conditions until the bacteria balls disappear, performing static culture at 28 ℃ for 8h, inoculating wild saccharomycete seed liquid with 5% of fermentation liquid volume, performing shake culture at 25 ℃ and 130r/min for 18h, adding 80mL of okra polysaccharide extracting solution and 10g of chitosan into every 1L of fermentation liquid, stirring and dissolving, and filtering by 4 layers of gauze to obtain the waxberry microecological preservative.

Spraying the micro-ecological antistaling agent on the surfaces of the eight ripe waxberries without diseases, insect pests and mechanical damage until the waxberries are slightly wet and do not drip, airing, putting the waxberries in plastic baskets in time, putting the dried waxberries in each basket for 2.5kg, and storing the waxberries in a carton at room temperature, wherein the storage period is prolonged by 4 days compared with that of a control without the antistaling agent.

Example 3

The preparation method of the waxberry microecological preservative specifically comprises the following steps: preparing a fermentation medium according to a formula, wherein the formula of the culture medium is as follows: 5.16% of mulberry twig powder, 2.38% of wheat bran, 4.85% of rice bran, 0.094% of monopotassium phosphate, 0.054% of magnesium sulfate and the balance of tap water, and sterilizing the culture medium for 20min at 121 ℃ in a sterilizing pot. Inoculating phellinus igniarius seed liquid with 5% of fermentation liquid volume, performing shake culture at 28 ℃ and 120r/min, stopping fermentation when the number of bacteria balls reaches 1/mL, crushing the bacteria balls by using a tissue crusher under aseptic conditions until the bacteria balls disappear, performing static culture at 28 ℃ for 10h, inoculating wild saccharomycete seed liquid with 5% of fermentation liquid volume, performing shake culture at 25 ℃ and 130r/min for 15h, adding 90mL of okra polysaccharide extracting solution and 12g of chitosan into every 1L of fermentation liquid, stirring and dissolving, and filtering by 4 layers of gauze to obtain the waxberry microecological preservative.

Spraying the micro-ecological antistaling agent on the surfaces of the eight ripe waxberries without diseases, insect pests and mechanical damage until the waxberries are slightly wet and do not drip, airing, putting the waxberries in plastic baskets in time, putting the dried waxberries in each basket for 2.5kg, and storing the waxberries in a carton at room temperature, wherein the storage period is prolonged by 4 days compared with that of a control without the antistaling agent.

Example 4

The preparation method of the waxberry microecological preservative specifically comprises the following steps: preparing a fermentation medium according to a formula, wherein the formula of the culture medium is as follows: 5.16% of mulberry twig powder, 2.38% of wheat bran, 4.85% of rice bran, 0.094% of monopotassium phosphate, 0.054% of magnesium sulfate and the balance of tap water, and sterilizing the culture medium for 20min at 121 ℃ in a sterilizing pot. Inoculating phellinus igniarius seed liquid with 5% of fermentation liquid volume, performing shake culture at 28 ℃ and 120r/min, stopping fermentation when the number of bacteria balls reaches 2/mL, crushing the bacteria balls by using a tissue crusher under aseptic conditions until the bacteria balls disappear, performing static culture at 28 ℃ for 8h, inoculating wild saccharomycete seed liquid with 5% of fermentation liquid volume, performing shake culture at 25 ℃ and 130r/min for 16h, adding 70mL of okra polysaccharide extracting solution and 10g of chitosan into every 1L of fermentation liquid, stirring and dissolving, and filtering by 4 layers of gauze to obtain the waxberry microecological preservative.

Spraying the micro-ecological antistaling agent on the surfaces of the eight ripe waxberries without diseases, insect pests and mechanical damage until the waxberries are slightly wet and do not drip, airing, putting the waxberries in plastic baskets in time, putting the dried waxberries in each basket for 2.5kg, and storing the waxberries in a carton at room temperature, wherein the storage period is prolonged by 3.5 days compared with that of a control without the antistaling agent.

Comparative example waxberry preservation comparative experiment

The fresh picked waxberries are averagely divided into 3 parts, and the waxberries are placed in a common packaging box for room temperature storage (NC), spraying of a microecological green preservative (prepared in the embodiment 1 of the invention) room temperature storage (EG) and spraying of 0.5% potassium sorbate room temperature storage (PC) respectively. The waxberry is a high-quality fruit which is eight ripe, uniform in size, bright in color and free of mechanical damage and plant diseases and insect pests on the surface.

When the waxberry is stored for 0d, 4d and 7d, the weight loss rate, the mildew rate and the like of each group of waxberry are counted.

The weight loss ratio of the waxberries under room temperature storage (NC), room temperature storage (EG) by spraying the microecological green preservative and room temperature storage (PC) by spraying 0.5 percent of potassium sorbate is respectively as follows: 6.29%, 4.12% and 6.13%, and the good fruit rate is respectively as follows: 35.36%, 65.26% and 60.96%, and the mildew rates are respectively: 54.27%, 5.96% and 6.51%, the rotten fruit rate is: 14.38%, 12.75% and 14.26%, and the fruit cracking rate is respectively as follows: 8.52%, 7.93% and 8.55%, and the storage periods are respectively as follows: 3.5d, 7.5 d and 7d, and fig. 2 is a photo comparison of each group of waxberries.

The embodiments are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same or similar parts among the embodiments are referred to each other. The device disclosed by the embodiment corresponds to the method disclosed by the embodiment, so that the description is simple, and the relevant points can be referred to the method part for description.

The micro-ecological green antistaling agent for the waxberry and the preparation method thereof provided by the invention are introduced in detail. The principles and embodiments of the present invention are explained herein using specific examples, which are presented only to assist in understanding the method and its core concepts. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.