阅读说明：本技术 一种百香果的保鲜方法 (Passion fruit fresh-keeping method ) 是由 周磊 刘伟 钟智炜 于 2021-10-14 设计创作，主要内容包括：本发明提出了一种百香果的保鲜方法,涉及果蔬保鲜技术领域；其特征在于包括以下步骤：筛选、消毒杀菌、抗菌涂膜及智能微孔包装贮藏。本发明通过将智能微孔包装与抗菌涂膜技术相结合,克服了百香果在传统气调包装下的乙烯和水分积聚、腐败长菌、二氧化碳伤害等问题,有效抑制了百香果在贮藏过程中出现的失水皱缩、腐败变质等影响品质的现象,延长了百香果的保鲜时间,使得百香果在室温的贮藏条件下保藏期达20天以上。(The invention provides a method for preserving passion fruit, and relates to the technical field of fruit and vegetable preservation; the method is characterized by comprising the following steps: screening, sterilizing, antibacterial coating and intelligent micropore packaging and storage. According to the invention, by combining the intelligent microporous packaging technology with the antibacterial coating technology, the problems of ethylene and moisture accumulation, spoilage and bacteria growth, carbon dioxide damage and the like of the passion fruit under the traditional modified atmosphere packaging are solved, the phenomena of water loss shrinkage, spoilage and deterioration and the like which affect the quality of the passion fruit in the storage process are effectively inhibited, the preservation time of the passion fruit is prolonged, and the storage period of the passion fruit under the storage condition of room temperature is up to more than 20 days.)

1. A method for preserving passion fruit is characterized by comprising the following steps:

(1) screening: selecting Passion fruit with maturity of 8-9 and uniform size, collecting, placing in ventilated place to dissipate field heat, removing secondary fruit, diseased fruit and mechanically damaged fruit,

(2) and (3) disinfection and sterilization: soaking the passion fruit treated in the step (1) in a sodium hypochlorite disinfectant, disinfecting, sterilizing, fishing out, and naturally drying in the air;

(3) antibacterial coating: dipping the passion fruit treated in the step (2) in an antibacterial coating liquid, taking out after the surface of the fruit is covered with a film, and naturally drying; the formula of the antibacterial film coating liquid mainly comprises the following raw materials: chitosan, potassium sorbate, ginger essential oil and tween, and the solvent is acetic acid solution. The preparation method comprises the following steps: A. firstly, adding chitosan into an acetic acid solvent, placing the mixture on a stirrer, and stirring the mixture at a high speed at room temperature to completely dissolve the chitosan to prepare a chitosan solution; B. adding potassium sorbate into the chitosan solution, stirring at high speed at room temperature, and dissolving to obtain a mixed solution; C. adding ginger essential oil and tween into the mixed solution, and mixing uniformly; dispersing in a high-speed shearing dispersion emulsifying machine, and standing to obtain the antibacterial coating liquid;

(4) intelligent microporous packaging and storage: and (3) filling the coated passion fruit into an intelligent microporous packaging bag, and storing at room temperature.

2. The method of claim 1, wherein: in the step (2), the volume concentration of the sodium hypochlorite disinfectant is 0.1-0.5%.

3. The method of claim 1, wherein: in the step (2), the soaking time is 2-5min, and the air drying time is 2-5 h.

4. The method of claim 1, wherein: in the step (3), the mass concentration of the chitosan is 0.5-2%, the mass concentration of the potassium sorbate is 0.1-1%, the mass concentration of the ginger essential oil is 0.5-1.5%, the mass concentration of the tween is 0.1-1%, and the volume concentration of the acetic acid is 0.5-2%.

5. The method of claim 1, wherein: in the step (3), the dipping time is 3-5min, the air drying time is 5-10h, the rotating speed of the high-speed shearing dispersion emulsifying machine is 5000-10000rpm, and the dispersion time is 1-3 min.

6. The method of claim 1, wherein: in the step (4), the intelligent microporous packaging bag is made of biaxially oriented polypropylene (BOPP), the size is 250 x 350mm, the single-layer thickness is 0.01-0.04mm, 5-20 micropores are uniformly distributed on the surface, the pore diameter is 50-300 mu m, and the air permeability of each pore is 50-500 mL/d.

Technical Field

The invention relates to the technical field of fruit and vegetable preservation, in particular to a method for preserving passion fruit.

Background

Passion fruit (Passiflora edulis Sims) also known as passion flower, passion fruit, and passion fruit, belongs to the Passiflora genus of the Passifloraceae family, and is a famous tropical and subtropical characteristic berry; the passion fruit planting areas in China are mainly distributed in areas such as Guangxi and Yunnan. The passion fruit has smooth surface, elliptic or round shape, high color, fragrance, taste and nutrition of fruit juice, and contains various aromatic substances, amino acids essential to human body, vitamins, reducing sugar and other compounds; has rich nutrition. In addition, the passion fruit also has the health care effects of diminishing inflammation, relieving pain, reducing blood fat and blood pressure, protecting skin, beautifying and the like, and has the medicinal values of calming, resisting bacteria, resisting inflammation, resisting tumors and the like.

Passion fruit is mainly eaten fresh, and the market demand is rising year by year. But because the fruit belongs to typical breath jump type fruits, the postharvest respiration and transpiration effects are large, the ethylene response is rapid, and the water loss is serious; the quality of the picked fruits is rapidly reduced, and the phenomena of shrinkage, rot and the like are easily caused, so that the shelf life is shortened, and the commodity value of the fruits is further reduced. Therefore, proper storage conditions are very important to maintain the post-harvest quality of the passion fruit.

At present, the passion fruit preservation method mainly comprises physical, chemical and biological methods, such as a low-temperature preservation method, a heat treatment preservation method, an air-conditioning preservation method, a coating preservation method and the like, but the low-temperature storage cost is too high, the practical application is inconvenient, the limitation on most tropical and subtropical fruits is large, and the cold damage to the fruits is easy to cause. The heat treatment and the film coating treatment can not solve the problems of easy shrinkage, serious water loss and the like of the passion fruit and can not keep good storage quality of the fruit. The modified atmosphere packaging can achieve the purposes of reducing the water loss of the fruits, preventing shrinkage and prolonging the storage period by the high-humidity environment generated in the bag. However, there are also problems with conventional modified atmosphere packaging: fruits are easy to rot and grow bacteria under a high-humidity environment for a long time, and fruits with high respiratory rate are easy to breathe without oxygen; along with the continuous accumulation of carbon dioxide, the carbon dioxide can also be damaged to the fruit, thereby reducing the commodity value of the fruit. And the whole permeability and diffusivity performance of the film can be enhanced by the intelligent microporous package, so that the breathing intensity, transpiration and the like of the fruits and vegetables are reduced by adjusting the gas microenvironment in the package, and the fresh-keeping effect of the fruits and vegetables can be effectively enhanced. In addition, some safe and nontoxic bacteriostatic preservatives are added into the edible coating, so that the bacteriostatic ability of the edible coating can be enhanced, and the edible coating does not have adverse effect on food. Therefore, the intelligent micropore packaging and the antibacterial coating technology are combined, and the problems that the passion fruit is easy to grow bacteria and decay and the like during single modified atmosphere packaging can be effectively solved; has extremely important significance for prolonging the preservation period of the passion fruit.

Disclosure of Invention

As mentioned above, the invention aims to solve the problems of water loss and shrinkage, putrefaction and deterioration and the like during the storage of the passion fruit and provide a method for preserving the passion fruit with good preservation effect and long time. The specific technical scheme is as follows:

the invention provides a method for preserving passion fruit, which comprises the following steps:

(1) screening: selecting Passion fruit with maturity of 8-9 and uniform size, collecting, placing in ventilated place to dissipate field heat, removing secondary fruit, diseased fruit and mechanically damaged fruit,

(2) and (3) disinfection and sterilization: soaking the passion fruit treated in the step (1) in a sodium hypochlorite disinfectant, disinfecting, sterilizing, fishing out, and naturally drying in the air;

(3) antibacterial coating: dipping the passion fruit treated in the step (2) in an antibacterial coating liquid, taking out after the surface of the fruit is covered with a film, and naturally drying; the formula of the antibacterial film coating liquid mainly comprises the following raw materials: chitosan, potassium sorbate, ginger essential oil and tween, and the solvent is acetic acid solution. The preparation method comprises the following steps: A. firstly, adding chitosan into an acetic acid solvent, placing the mixture on a stirrer, and stirring the mixture at a high speed at room temperature to completely dissolve the chitosan to prepare a chitosan solution; B. adding potassium sorbate into the chitosan solution, stirring at high speed at room temperature, and dissolving to obtain a mixed solution; C. adding ginger essential oil and tween into the mixed solution, and mixing uniformly; dispersing in a high-speed shearing dispersion emulsifying machine, and standing to obtain the antibacterial coating liquid;

(4) intelligent microporous packaging and storage: and (3) filling the coated passion fruit into an intelligent microporous packaging bag, and storing at room temperature.

Further, in the step (2), the volume concentration of the sodium hypochlorite is 0.1-0.5%.

Further, in the step (2), the soaking time is 2-5min, and the air drying time is 2-5 h.

Further, in the step (3), the mass concentration of the chitosan is 0.5-2%, the mass concentration of the potassium sorbate is 0.1-1%, the mass concentration of the ginger essential oil is 0.5-1.5%, the mass concentration of the tween is 0.1-1%, and the volume concentration of the acetic acid is 0.5-2%.

Further, in the step (3), the dipping time is 3-5min, the air drying time is 5-10h, the rotating speed of the high-speed shearing dispersion emulsifying machine is 5000-10000rpm, and the dispersion time is 1-3 min.

Further, in the step (4), the intelligent microporous packaging bag is made of biaxially oriented polypropylene (BOPP), the size is 250 x 350mm, the single-layer thickness is 0.01-0.04mm, 5-20 micropores are uniformly distributed on the surface, the pore diameter is 50-300 μm, and the air permeability of each pore is 50-500 mL/d.

Compared with the prior art, the invention has the following advantages:

the preservation method provided by the invention adopts a method of combining intelligent microporous packaging with antibacterial coating, wherein the intelligent microporous packaging can enhance the overall permeation and diffusion performance of the film and automatically adjust the gas microenvironment conditions in the packaging, so that the respiration intensity, transpiration and the like of the fruits are reduced, the fruits are prevented from carrying out anaerobic respiration and generating carbon dioxide damage, and the purpose of prolonging the preservation time is achieved; the antibacterial coating can inhibit the growth of microorganisms such as mold and the like, maintain good quality of fruits in a high-humidity environment and further improve the fresh-keeping effect. The two are simple and convenient to operate, and can effectively solve the quality deterioration problems of serious fruit dehydration, spoilage and growth of bacteria and the like after being combined, and maintain good commodity value of the fruits.

Drawings

FIG. 1 is a graph showing the change in appearance and interior of passion fruit of different treatment groups after 20 days of storage;

Detailed Description

The invention will be better understood from the following examples. However, it is easily understood by those skilled in the art that the contents described in the embodiments are only for illustrating the present invention and should not be limited to the invention described in detail in the claims.

The embodiment of the invention provides a method for preserving passion fruit, which comprises the following steps:

(1) screening: selecting Passion fruit with maturity of 8-9 and uniform size, collecting, placing in ventilated place to dissipate field heat, removing secondary fruit, diseased fruit and mechanically damaged fruit,

(2) and (3) disinfection and sterilization: soaking the passion fruit treated in the step (1) in a sodium hypochlorite disinfectant, disinfecting, sterilizing, fishing out, and naturally drying in the air;

(3) antibacterial coating: dipping the passion fruit treated in the step (2) in an antibacterial coating liquid, taking out after the surface of the fruit is covered with a film, and naturally drying; the formula of the antibacterial film coating liquid mainly comprises the following raw materials: chitosan, potassium sorbate, ginger essential oil and tween, and the solvent is acetic acid solution. The preparation method comprises the following steps: A. firstly, adding chitosan into an acetic acid solvent, placing the mixture on a stirrer, and stirring the mixture at a high speed at room temperature to completely dissolve the chitosan to prepare a chitosan solution; B. adding potassium sorbate into the chitosan solution, stirring at high speed at room temperature, and dissolving to obtain a mixed solution; C. adding ginger essential oil and tween into the mixed solution, and mixing uniformly; dispersing in a high-speed shearing dispersion emulsifying machine, and standing to obtain the antibacterial coating liquid;

(4) intelligent microporous packaging and storage: and (3) filling the coated passion fruit into an intelligent microporous packaging bag, and storing at room temperature.

In the embodiment of the invention, in the step (2), the volume concentration of the sodium hypochlorite is 0.5%.

In the embodiment of the invention, in the step (2), the soaking time is 5min, and the air drying time is 5 h.

In the embodiment of the invention, in the step (3), the mass concentration of chitosan is 0.5-2%, the mass concentration of potassium sorbate is 0.1-1%, the mass concentration of ginger essential oil is 0.5-1.5%, the mass concentration of tween is o.5%, and the volume concentration of acetic acid is 1%.

In the embodiment of the invention, in the step (3), the dipping time is 5min, the air drying time is 8h, the rotating speed of the high-speed shearing dispersing emulsifying machine is 10000rpm, and the dispersing time is 3 min.

In the embodiment of the invention, in the step (4), the intelligent microporous packaging bag is made of biaxially oriented polypropylene (BOPP), the size is 250 x 350mm, the single-layer thickness is 0.03mm, 5-20 micropores are uniformly distributed on the surface, the pore diameter is 50-300 mu m, and the air permeability of each pore is 50-500 mL/d.

The present invention will be described in detail with reference to examples.

Example 1A method for preserving passion fruit comprises the following steps:

(1) screening: selecting the passion fruit with the maturity of 8-9 and consistent size, placing the passion fruit in a ventilated place to dissipate field heat after harvesting, and simultaneously removing secondary fruits, diseased fruits and fruits with mechanical damage;

(2) and (3) disinfection and sterilization: soaking the passion fruit treated in the step (1) in a sodium hypochlorite disinfectant with the volume concentration of 0.5% for 5min, sterilizing, taking out, and naturally drying for 5 h;

(3) antibacterial coating: firstly, 0.5g of chitosan is added into 100mL of acetic acid solution with the volume concentration of 1 percent, placed on a stirrer and stirred at high speed at room temperature to completely dissolve the chitosan, thus preparing 0.5 percent chitosan solution; adding 0.1g of potassium sorbate into 0.5 percent of chitosan solution, stirring at high speed at room temperature, and dissolving to obtain a mixed solution; adding 0.5g of ginger essential oil and 0.5g of tween into the mixed solution, and uniformly mixing; dispersing in a 10000rpm high-speed shearing dispersion emulsifying machine for 3min, and standing to obtain the antibacterial coating liquid; and (3) putting the passion fruit treated in the step (2) into an antibacterial coating liquid for soaking for 5min, taking out after the surface of the fruit is covered with a film, and naturally drying for 8 h.

(4) Intelligent microporous packaging and storage: the passion fruit after being coated with the film and dried in the air is put into an intelligent micropore packaging bag with the size of 250 multiplied by 350mm, the single layer thickness of 0.03mm, the surface of the packaging bag is uniformly distributed with 5 micropores, the pore diameter of the micropore packaging bag is 50 mu m, and the single pore air permeability of the micropore packaging bag is 50mL/d, and the passion fruit is stored at room temperature.

Example 2A method for preserving passion fruit comprises the following steps:

(1) screening: selecting Passion fruit with maturity of 8-9 and uniform size, collecting, placing in ventilated place to dissipate field heat, removing secondary fruit, diseased fruit and mechanically damaged fruit,

(2) and (3) disinfection and sterilization: soaking the passion fruit treated in the step (1) in a sodium hypochlorite disinfectant with the volume concentration of 0.5% for 5min, sterilizing, taking out, and naturally drying for 5 h;

(3) antibacterial coating: firstly, adding 1g of chitosan into 100mL of 1% acetic acid solution by volume concentration, placing the mixture on a stirrer, and stirring at high speed at room temperature to completely dissolve the chitosan to prepare 1% chitosan solution; adding 0.5g of potassium sorbate into 1% chitosan solution, stirring at high speed at room temperature, and dissolving to obtain a mixed solution; adding 1g of ginger essential oil and 0.5g of tween into the mixed solution, and uniformly mixing; dispersing in a 10000rpm high-speed shearing dispersion emulsifying machine for 3min, and standing to obtain the antibacterial coating liquid; and (3) putting the passion fruit treated in the step (2) into an antibacterial coating liquid for soaking for 5min, taking out after the surface of the fruit is covered with a film, and naturally drying for 8 h.

(4) Intelligent microporous packaging and storage: the passion fruit after being coated with the film and dried in the air is put into an intelligent micropore packaging bag with the size of 250 multiplied by 350mm, the single layer thickness of 0.03mm, the surface of the packaging bag is uniformly distributed with 5 micropores, the pore diameter of the micropore packaging bag is 50 mu m, and the single pore air permeability of the micropore packaging bag is 50mL/d, and the passion fruit is stored at room temperature.

Example 3A method for preserving passion fruit comprises the following steps:

(1) screening: selecting Passion fruit with maturity of 8-9 and uniform size, collecting, placing in ventilated place to dissipate field heat, removing secondary fruit, diseased fruit and mechanically damaged fruit,

(2) and (3) disinfection and sterilization: soaking the passion fruit treated in the step (1) in a sodium hypochlorite disinfectant with the volume concentration of 0.5% for 5min, sterilizing, taking out, and naturally drying for 5 h;

(3) antibacterial coating: firstly, adding 2g of chitosan into 100mL of 1% acetic acid solution, placing the mixture on a stirrer, and stirring the mixture at a high speed at room temperature to completely dissolve the chitosan to prepare a 2% chitosan solution; adding 1g of potassium sorbate into the 2% chitosan solution, stirring at high speed at room temperature, and dissolving to obtain a mixed solution; adding 1.5g of ginger essential oil and 0.5g of tween into the mixed solution, and uniformly mixing; dispersing in a 10000rpm high-speed shearing dispersion emulsifying machine for 3min, and standing to obtain the antibacterial coating liquid; and (3) putting the passion fruit treated in the step (2) into an antibacterial coating liquid for soaking for 5min, taking out after the surface of the fruit is covered with a film, and naturally drying for 8 h.

(4) Intelligent microporous packaging and storage: the passion fruit after being coated with the film and dried in the air is put into an intelligent micropore packaging bag with the size of 250 multiplied by 350mm, the single layer thickness of 0.03mm, the surface of the packaging bag is uniformly distributed with 5 micropores, the pore diameter of the micropore packaging bag is 50 mu m, and the single pore air permeability of the micropore packaging bag is 50mL/d, and the passion fruit is stored at room temperature.

Example 4The difference from the example 1 is that in the step (4), 10 pores with the diameter of 100 μm and the single-pore air permeability of 100mL/d are uniformly distributed on the surface of the intelligent microporous packaging bag.

Example 5The difference from the example 2 is that in the step (4), 10 pores with the diameter of 100 μm and the single-pore air permeability of 100mL/d are uniformly distributed on the surface of the intelligent microporous packaging bag.

Example 6The difference from the example 3 is that 10 pores with the diameter of 100 μm and the single-pore air permeability of 100mL/d are uniformly distributed on the surface of the intelligent microporous packaging bag in the step (4).

Example 7The difference from the example 1 is that in the step (4), 20 pores with the diameter of 200 μm and the single-pore air permeability of 200mL/d are uniformly distributed on the surface of the intelligent microporous packaging bag.

Example 8The difference from the example 2 is that in the step (4), 20 pores with the diameter of 200 μm and the single-pore air permeability of 200mL/d are uniformly distributed on the surface of the intelligent microporous packaging bag.

Example 9The difference from the example 3 is that in the step (4), 20 pores with the diameter of 200 μm and the single-pore air permeability of 200mL/d are uniformly distributed on the surface of the intelligent microporous packaging bag.

Comparative example 1The difference from example 9 is that the smart microwell package process of step (4) was not performed.

Comparative example 2The difference from example 9 is that in step (4), a non-porous and air-permeable BOPP packaging bag is used for packaging.

Comparative example 3The difference from example 9 is that the antibacterial coating treatment of step (3) was not performed.

In order to demonstrate the effectiveness of the method for preserving passion fruit, the applicant carried out the following tests:

screening passion fruits with similar size, consistent maturity and similar skin color, and selecting 50 passion fruits in each group; the passion fruit was treated according to the preservation method of the above examples and comparative examples, while untreated passion fruit was selected as a blank, noting that each package contained about 400 grams of passion fruit. The quality change of the passion fruit after 20 days of storage is observed, the test result is shown in table 1, and the appearance and internal change are shown in fig. 1.

TABLE 1 Effect of different treatments on the quality of Passion fruit after 20 days storage

As can be seen from table 1 and fig. 1: compared with a blank control group, the examples and the comparative examples have the fresh-keeping effect on the passion fruit. The embodiments 3, 6 and 9 have good fresh-keeping effect on the passion fruit, and can obviously delay the increase of the weight loss rate of the passion fruit and the reduction of the nutritional quality.

Compared with the embodiment 9, the intelligent microporous packaging treatment is not carried out on the passion fruit in the comparative example 1, the weight loss rate of the passion fruit reaches 40.7% after 20 days, and the content of the vitamin C and the total phenol is sharply reduced, which shows that the intelligent microporous packaging is helpful for delaying the water loss and shrinkage of the fruit, maintaining the good storage quality of the passion fruit and having the fresh-keeping effect.

Compared with the embodiment 9, the non-porous and airtight BOPP packaging bag is selected for packaging treatment in the comparative example 2, the passion fruit growth rate is up to 67.5% after 20 days, and the loss of the vitamin C and the total phenol content is serious, so that the intelligent microporous packaging bag can prevent moisture, carbon dioxide and the like from being continuously accumulated in the bag, reduce the damage of the intelligent microporous packaging bag to fruits, maintain the good storage quality of the passion fruit, and has the effect of enhancing the freshness preservation.

Compared with the example 9, the antibacterial coating treatment is not carried out on the passion fruit in the comparative example 3, the passion fruit has the bacteria growth rate of 60.3% after 20 days, and the content of the vitamin C and the total phenol is continuously reduced, so that the antibacterial coating treatment is beneficial to inhibiting the growth of microorganisms, overcoming the problem that the fruit is easy to decay and grow bacteria under a high-humidity environment, maintaining the storage quality of the passion fruit and having a good fresh-keeping effect.

In the embodiment, microporous packaging bags with different air permeability and antibacterial coating liquid with different concentration ratios are selected. The results of examples 1, 2 and 3 show that the preservative effect on the passion fruit is optimal when the mass concentration of chitosan, potassium sorbate and ginger essential oil in the antibacterial film coating liquid is 2%, 1% and 1.5%, respectively. The results of examples 3, 6 and 9 show that the intelligent microporous packaging bag with 20 micropores, 200 mu m pore diameter and 200mL/d single-pore ventilation has better effect on delaying the quality reduction of fruits. The comprehensive results show that the effect of the embodiment 9 is optimal, the bacteria growth rate is lowest, the respiration intensity of the fruits is obviously reduced, and the postharvest quality of the fruits is maintained to the maximum extent.

The above description is only a preferred embodiment of the present invention, and it is obvious to those skilled in the art that modifications may be made without departing from the scope of the present invention, and such modifications are also within the scope of the present invention.