阅读说明：本技术 基于超声辅助等离子活化水进行果蔬清洗及保鲜的方法 (Method for cleaning and preserving fruits and vegetables based on ultrasonic-assisted plasma activated water ) 是由 孙大文 潘园园 成军虎 韩忠 于 2019-11-07 设计创作，主要内容包括：本发明属于果蔬清洗和保鲜技术领域,涉及一种基于超声辅助等离子活化水进行果蔬清洗及保鲜的方法,包括：S1、将无菌食盐水置于大气压射频放电等离子体喷头下；S2、启动高压射频发生器,通过钢瓶向大气压射频放电等离子体喷头内通入气源,中枢电极产生的等离子体对无菌食盐水进行处理,得到等离子体活化水；S3、新鲜采摘的果蔬分选、分级、预冷处理后,按一定比例置于步骤S2获得的等离子体活化水中进行超声波清洗杀菌；S4、将清洗杀菌后的果蔬晾干水分后进行包装储存。本发明能够克服单一等离子活化水保鲜技术的缺点,有效发挥保鲜技术的优势,在提高杀菌保鲜效率的同时,有效降解果蔬表面农残和污垢,大大地延长了果蔬的保鲜贮藏期和食用安全性。(The invention belongs to the technical field of fruit and vegetable cleaning and fresh-keeping, and relates to a method for cleaning and keeping fruits and vegetables based on ultrasonic-assisted plasma activated water, which comprises the following steps: s1, placing the sterile salt solution under an atmospheric pressure radio frequency discharge plasma nozzle; s2, starting the high-voltage radio-frequency generator, introducing a gas source into the atmospheric pressure radio-frequency discharge plasma nozzle through the steel cylinder, and treating the sterile saline water by the plasma generated by the central electrode to obtain plasma activated water; s3, sorting, grading and pre-cooling the fresh picked fruits and vegetables, and putting the fruits and vegetables into the plasma activated water obtained in the step S2 according to a certain proportion for ultrasonic cleaning and sterilization; and S4, airing the cleaned and sterilized fruits and vegetables, and packaging and storing. The invention can overcome the defects of a single plasma activated water preservation technology, effectively exert the advantages of the preservation technology, improve the sterilization and preservation efficiency, effectively degrade pesticide residues and dirt on the surfaces of the fruits and the vegetables, and greatly prolong the preservation and storage period and the edible safety of the fruits and the vegetables.)

1. The method for cleaning and preserving fruits and vegetables based on ultrasonic-assisted plasma activated water is characterized by comprising the following steps:

s1, placing the sterile salt solution under an atmospheric pressure radio frequency discharge plasma nozzle;

s2, starting the high-voltage radio-frequency generator, introducing a gas source into the atmospheric pressure radio-frequency discharge plasma nozzle through the steel cylinder, and treating the sterile saline water by the plasma generated by the central electrode to obtain plasma activated water;

s3, sorting, grading and pre-cooling the fresh picked fruits and vegetables, and putting the fruits and vegetables into the plasma activated water obtained in the step S2 according to a certain proportion for ultrasonic cleaning and sterilization;

and S4, airing the cleaned and sterilized fruits and vegetables, and packaging and storing.

2. The method for cleaning and refreshing fruits and vegetables according to claim 1, wherein the concentration of the sterile saline solution is 0.5-1.0%.

3. The fruit and vegetable cleaning and fresh-keeping method according to claim 1, characterized in that the distance between the sterile salt water and the lower end of the atmospheric injection frequency discharge plasma nozzle is 1-5 mm.

4. The fruit and vegetable cleaning and fresh-keeping method according to claim 1, wherein the frequency of the high-voltage radio frequency generator is 20 to 80Hz, and the power is controlled to be 500 to 1000W.

5. The method for cleaning and refreshing fruits and vegetables according to claim 1, wherein the air source is food-grade artificial air.

6. The fruit and vegetable cleaning and fresh-keeping method according to claim 1 or 5, characterized in that the flow rate of the air source is 5-25L/min.

7. The method for cleaning and refreshing fruits and vegetables according to claim 1, wherein the time for the plasma treatment of the sterile saline solution is 5-20 min.

8. The method for cleaning and refreshing fruits and vegetables according to claim 1, wherein S3 comprises: sorting fresh picked fruits and vegetables, pre-cooling, subpackaging in sterile sealed bags, adding the plasma activated water obtained in S2, sealing, controlling the mass ratio of the fruits and vegetables to the plasma activated water, and then performing ultrasonic cleaning and sterilization.

9. The method for cleaning and refreshing fruits and vegetables according to claim 1 or 8, wherein the mass ratio of the fruits and vegetables to the plasma activated water is 1:3-1: 5.

10. The fruit and vegetable cleaning and fresh-keeping method according to claim 1 or 8, characterized in that the temperature of ultrasonic cleaning and sterilization is 20-50 ℃, the time is 5-20 min, the power is 500-600W, and the ultrasonic frequency is 20-60 kHz.

Technical Field

The invention belongs to the technical field of fruit and vegetable cleaning and fresh-keeping, and relates to a method for cleaning and keeping fruits and vegetables based on ultrasonic-assisted plasma activated water.

Background

The fruits and vegetables are very popular with consumers due to the abundant vitamins and minerals. However, some dirt and pesticide residues are inevitably present on the surfaces of fruits and vegetables, which seriously affect the edible safety and the sensory quality of consumers. The microorganisms remained on the surfaces of the fruits and the vegetables are the main cause of rapid spoilage of the fruits and the vegetables, and the quality and the safety of the fruits and the vegetables are seriously influenced by the problems. The rotten fruits and vegetables in China are up to 8000 ten thousand tons every year, which causes huge economic loss. Therefore, it is necessary to find an effective fruit and vegetable fresh-keeping technology.

At present, the novel cold plasma non-thermal processing technology has great market application prospect in the field of food due to low temperature, short action time, high treatment efficiency, safety and no chemical residue. The atmospheric pressure low temperature plasma activated water is activated water with high acidity and high oxidation-reduction potential obtained by treating an aqueous solution by an atmospheric pressure low temperature plasma device, can effectively avoid heat accumulation possibly generated by direct plasma treatment, and gradually becomes a research hotspot. For example, patent CN107333870A discloses a method for preserving fruits by using an atmospheric pressure low temperature plasma activation liquid (see the chinese patent application of the university of beijing, "a method for preserving fruits by using an atmospheric pressure low temperature plasma activation liquid", published as 2017, 11, 10, and publication number CN108132708A), patent CN107691982A discloses a method for rapidly removing organophosphorus pesticides remaining on the surfaces of vegetables and fruits based on plasma (see the chinese patent application of shenzhen advanced technology research institute, "a method for rapidly removing organophosphorus pesticides remaining on the surfaces of vegetables and fruits", published as 2018, 02, 16, and publication number CN107691982A), patent CN109805249A discloses a method for cleaning and preserving fruits and vegetables based on electromagnetic induction coupling radio frequency discharge plasma (see the chinese patent application of the university of south china "electromagnetic induction coupling radio frequency discharge plasma apparatus and method for cleaning and preserving fruits and vegetables", publication date is 2019, 05 and 28, and publication number is CN 109805249A). However, the effect of direct treatment of fruits and vegetables by plasma for sterilization and preservation is undoubted, but the effect of direct treatment of microorganisms on the surfaces of fruits and vegetables by activated water mediated by plasma is relatively limited, the acidification of the activated water is relatively serious, and the surfaces of fruits and vegetables cannot be effectively cleaned. Therefore, the key point of finding a technology for improving the sterilization efficiency of the plasma activated water and effectively degrading the pesticide residues and dirt on the surface is high.

Disclosure of Invention

Aiming at the defects and shortcomings of the prior art, the invention provides a method for cleaning and preserving fruits and vegetables based on ultrasonic-assisted plasma activated water.

The invention is realized by adopting the following technical scheme:

the method for cleaning and preserving fruits and vegetables based on ultrasonic-assisted plasma activated water comprises the following steps:

s1, placing the sterile salt solution under an atmospheric pressure radio frequency discharge plasma nozzle;

s2, starting the high-voltage radio-frequency generator, introducing a gas source into the atmospheric pressure radio-frequency discharge plasma nozzle through the steel cylinder, and treating the sterile saline water by the plasma generated by the central electrode to obtain plasma activated water;

s3, sorting, grading and pre-cooling the fresh picked fruits and vegetables, and putting the fruits and vegetables into the plasma activated water obtained in the step S2 according to a certain proportion for ultrasonic cleaning and sterilization;

and S4, airing the cleaned and sterilized fruits and vegetables, and packaging and storing.

Preferably, the sterile saline solution has a concentration of 0.5 to 1.0%.

Preferably, the distance between the sterile salt water and the lower end of the atmospheric pressure injection frequency discharge plasma nozzle is 1-5 mm.

Preferably, the frequency of the high-voltage radio frequency generator is 20-80 Hz, and the power is controlled to be 500-1000W.

Preferably, the air source is food grade artificial air.

Preferably, the flow rate of the gas source is 5-25L/min.

Preferably, the plasma is used for treating the sterile saline solution for 5-20 min.

Preferably, S3 includes: sorting fresh picked fruits and vegetables, pre-cooling, subpackaging in sterile sealed bags, adding the plasma activated water obtained in S2, sealing, controlling the mass ratio of the fruits and vegetables to the plasma activated water, and then performing ultrasonic cleaning and sterilization.

Preferably, the mass ratio of the fruits and vegetables to the plasma activated water is 1:3-1: 5.

Preferably, the temperature for ultrasonic cleaning and sterilization is 20-50 ℃, the time is 5-20 min, the power is 500-600W, and the ultrasonic frequency is 20-60 kHz.

The method for cleaning and refreshing the fruits and vegetables has the following advantages and beneficial effects:

(1) the invention can overcome the defects of a single plasma activated water preservation technology, can effectively exert the advantages of the preservation technology, effectively degrade pesticide residues and dirt on the surfaces of fruits and vegetables while improving the sterilization and preservation efficiency, and greatly prolong the preservation storage period and the edible safety of the fruits and vegetables.

(2) The invention can degrade pesticide residue on the surface of the fruits and vegetables well on the basis of removing dirt on the surfaces of the fruits and vegetables, can effectively improve the efficiency of killing microorganisms remaining on the surfaces of the fruits and vegetables, and can not cause influence and secondary pollution on the quality of the fruits and vegetables after treatment.

(3) The ultrasonic-assisted plasma activated water treatment is adopted, the treatment conditions are mild, the sterilization and pesticide residue degradation efficiency is improved, simultaneously, dirt on the surfaces of fruits and vegetables can be effectively cleaned, the quality attributes such as color and luster of food are slightly affected after the treatment, and the treatment is completely green and has no chemical residue.

(4) The ultrasonic-assisted plasma activated water is adopted for cleaning and refreshing fruits and vegetables, the operation process is simple, the treatment efficiency is high, the energy consumption is low, and the method is green, safe, efficient, energy-saving and environment-friendly.

(5) By utilizing the advantages of the plasma active water, no organophosphorus pesticide is detected after the plasma active water is treated for 15min by ultrasonic assistance, and the shelf life of fruits and vegetables can be effectively prolonged to more than 20 days.

Drawings

Fig. 1 is a process flow chart of a method for cleaning and refreshing fruits and vegetables based on ultrasonic-assisted plasma activated water in one embodiment of the invention.

Detailed Description

The present invention will be described in further detail with reference to examples and drawings, but the present invention is not limited thereto.

A method for cleaning and refreshing fruits and vegetables based on ultrasonic-assisted plasma activated water comprises the following steps:

s1, placing the sterile salt solution under an atmospheric pressure radio frequency discharge plasma nozzle;

in a preferred embodiment, the sterile saline concentration is 0.5-1.0%.

The distance between the sterile salt water and the lower end of the atmospheric pressure radio frequency discharge plasma nozzle is 1-5 mm.

S2, starting the high-voltage radio-frequency generator, introducing a gas source into the atmospheric pressure radio-frequency discharge plasma nozzle through the steel cylinder, and treating the salt water by the plasma generated by the central electrode to obtain plasma activated water;

in a preferred embodiment, the frequency of the high-voltage radio frequency generator is 20-80 Hz, and the power is controlled to be 500-1000W.

The air source is food-grade artificial air.

The flow rate of the gas source is 5-25L/min.

The time for the plasma to treat the sterile saline solution is 5-20 min.

S3, sorting, grading and pre-cooling the fresh picked fruits and vegetables, and putting the fruits and vegetables into the plasma activated water obtained in the step S2 according to a certain proportion for ultrasonic cleaning and sterilization.

In this embodiment, the freshly picked fruits and vegetables are sorted, then precooled to remove field heat, then packaged into sterile sealed bags, sealed after adding the plasma activated water obtained in S2, controlled in a certain ratio with respect to the plasma activated water, and then subjected to ultrasonic cleaning and sterilization.

In a preferred embodiment, the mass ratio of the fruits and vegetables to the plasma activated water is 1:3-1: 5.

The ultrasonic treatment temperature is 20-50 ℃, the time is 5-20 min, the power is 500-600W, and the ultrasonic frequency is 20-60 kHz.

And S4, airing the cleaned and sterilized fruits and vegetables, and packaging and storing.

The method for cleaning and refreshing fruits and vegetables according to the present invention will be described in further detail with reference to the following specific examples.