Fresh-cut fruit and vegetable acousto-optic power fence sterilization and preservation method based on riboflavin enhanced by potassium iodide

Abstract

The invention discloses a potassium iodide enhanced riboflavin-based acousto-optic power fence sterilization and preservation method for fresh-cut fruits and vegetables, which comprises the following steps: (1) under a dark condition, firstly immersing the fresh-cut fruits and vegetables in a riboflavin-potassium iodide solution, and standing for 10-30 minutes; (2) under a dark condition, carrying out ultrasonic treatment on the fresh-cut fruits and vegetables in the riboflavin-potassium iodide solution for 10-15 minutes; then taking out, and drying in the shade for 30-35 minutes under a dark condition; and (3) treating for 10-20 minutes under blue light. The photodynamic sterilization treatment and the sonodynamic sterilization treatment are combined, meanwhile, the riboflavin is used as an acousto-optic sensitizer, and the potassium iodide is used for carrying out acousto-optic power enhancement, so that the sterilization efficiency is further improved, the treatment time is shortened, and the intensity of single treatment is reduced while efficient sterilization is ensured; therefore, the sensory quality and nutritional ingredients of the food can be better maintained.

Description

Technical Field

[0001] The invention relates to the technical field of fruit and vegetable preservation, and in particular to a sound and light dynamic fence sterilization and preservation method for fresh-cut fruits and vegetables based on potassium iodide-enhanced riboflavin. Background Art

[0002] Fresh-cut fruits and vegetables, also known as lightly or minimally processed fruits and vegetables, are fresh fruits and vegetables that undergo pre-processing steps such as selection, washing, peeling, cutting, disinfection, color protection, and packaging before being consumed directly or with minimal processing. Fresh-cut fruits and vegetables offer significant convenience compared to fresh fruits and vegetables, making them more suitable for the fast-paced modern lifestyle. Their standardized processing procedures, including rigorous cleaning and disinfection, effectively reduce the risk of microbial contamination. Furthermore, commercially processed fresh-cut fruits and vegetables offer excellent storage stability and portability. Industrial precision cutting improves raw material utilization, meeting the trend of healthy, ready-to-eat consumption while reducing resource waste, presenting broad development potential. However, during commercial processing, including processing, storage, transportation, and sales, fresh-cut fruits and vegetables are susceptible to mechanical damage, environmental exposure, and microbial contamination. These factors can induce physiological and biochemical reactions in the fruit and vegetable tissues, diminishing their commercial value and posing food safety risks.

[0003] After fresh fruits and vegetables are processed such as peeling and cutting, the protective effect of the skin on the internal tissue is destroyed, resulting in overflow of cell fluid, providing rich nutrients and a suitable acidic environment for the growth and reproduction of microorganisms, significantly increasing the risk of fresh-cut fruits and vegetables being contaminated by foodborne pathogens.

[0004] Besides foodborne pathogens, spoilage microorganisms are the most common source of contamination in fresh-cut fruits and vegetables. These contaminants primarily originate from the growing environment (such as soil, water, fertilizers, animals, and insects), cross-contamination during processing, and secondary contamination during storage. When spoilage bacteria multiply on or within fruits and vegetables, they break down nutrients like sugars and organic acids, producing acidic metabolites like lactic acid and acetic acid, leading to spoilage. Spoilage fungi multiply rapidly on or within fruits and vegetables under suitable humidity and temperature conditions, producing hyphae and spores. These hyphae and spores decompose nutrients in fruits and vegetables, causing them to mold and spoil.

[0005] During processing, fresh-cut fruits and vegetables are damaged, making it easier for microorganisms to invade and rapidly multiply. This not only causes them to spoil, but also reduces their nutritional value and safety. Therefore, to ensure the quality of fresh-cut fruits and vegetables, extend their shelf life, and protect consumer health, it is crucial to research and develop efficient sterilization and preservation technologies.

[0006] Common chemical sterilization methods for fresh-cut fruits and vegetables include oxidizing fungicides, alcohol disinfectants, surfactants, and gas fumigants. However, long-term use can lead to increased microbial resistance, reduced sterilization effectiveness, and chemical residues, posing food safety risks.

[0007] Physical sterilization methods are divided into heat and cold sterilization. Heat sterilization preserves fruits and vegetables through controlled temperature treatment. Key methods include pasteurization (short-term heating at 60-90°C), hot water immersion (45-55°C), and steam treatment. However, heat sterilization requires precise temperature control to avoid issues such as softening fruits and vegetables due to high temperatures or loss of nutrients (such as vitamin C degradation).

[0008] In the field of fresh-cut fruit and vegetable preservation, there are few studies on photodynamic enhancement, photoacoustic and optical barrier sterilization treatment, especially the research on photoacoustic and optical barrier sterilization treatment based on sensitizer enhancement has not been reported. Summary of the Invention

[0009] The object of the present invention is to provide a method for sterilizing and preserving fresh-cut fruits and vegetables by using an acoustic-photodynamic fence based on potassium iodide to enhance riboflavin. The method combines photodynamic and acoustic-dynamic sterilization treatments, and simultaneously uses riboflavin as an acoustic-photodynamic sensitizer and potassium iodide for acoustic-photodynamic enhancement to further improve the sterilization efficiency and reduce the processing time. While ensuring efficient sterilization, the intensity of a single treatment is reduced, thereby better maintaining the sensory quality and nutritional content of the food.

[0010] The technical solution adopted by the present invention to solve its technical problem is: A method for sterilizing and preserving fresh-cut fruits and vegetables using an acoustic and optical power fence based on potassium iodide-enhanced riboflavin comprises the following steps: (1) Under dark conditions, immerse fresh-cut fruits and vegetables in riboflavin-potassium iodide solution and let it stand for 10-30 minutes; (2) Ultrasonic treatment of fresh-cut fruits and vegetables in riboflavin-potassium iodide solution for 10-15 minutes in the dark; then remove and dry in the dark for 30-35 minutes; (3) Treat under blue light for 10-20 minutes.

[0011] Preferably, the final concentration of riboflavin in the riboflavin-potassium iodide solution is 100-150 μmol / L.

[0012] Preferably, the final concentration of potassium iodide in the riboflavin-potassium iodide solution is 12.5-20 mmol / L.

[0013] Preferably, the ultrasonic treatment frequency is 30 kHz and the power is 3 W.

[0014] As a preference, the blue light source is an LED blue light panel with an emission wavelength of 450nm and an illumination power of 32 mW / cm -2 .

[0015] Preferably, the fresh-cut fruits and vegetables are selected from one of apples, pears, bananas, watermelons, peaches, radishes, sweet potatoes, and potatoes.

[0016] The beneficial effects of the present invention are: By integrating multiple sterilization treatments and leveraging the cumulative and synergistic effects of different treatment technologies, this invention can effectively surpass the sterilization limits of a single technology and significantly improve overall sterilization efficiency. Furthermore, it can reduce the intensity of a single treatment while ensuring efficient sterilization, thereby better preserving the sensory quality and nutritional content of food.

[0017] The combined use of photodynamic and acoustic sterilization treatments, along with the use of riboflavin as an acoustic-photosensitizer and potassium iodide for acoustic-photodynamic enhancement, further improves sterilization efficiency and reduces processing time. This approach is ultimately applied to the sterilization and preservation of fresh-cut apples. This invention provides a new approach to preserving fresh-cut fruits and vegetables and a new path for the application of green physical synergistic sterilization technology in the post-harvest processing of agricultural products. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The in vitro bactericidal effects of different photodynamic treatments on Escherichia coli. The prefixes D and L represent darkness and light treatment, respectively; CK, KI, RF, and RF / KI represent PBS buffer solution treatment, potassium iodide treatment, riboflavin treatment, and potassium iodide-riboflavin combination treatment, respectively. Figure 2 Enhanced photodynamic sterilization treatment for the inactivation of Escherichia coli on fresh-cut apples; Figure 3 In vitro bactericidal effects of different photodynamic treatments on Penicillium expansum; Figure 4 Enhanced photodynamic sterilization treatment inactivates Penicillium expansum on fresh-cut apples; Figure 5 The bactericidal effect of enhanced photoacoustic barrier treatment on pathogens. (a) Escherichia coli; (b) Penicillium expansum. The prefixes L, S, and L+S represent light treatment, ultrasound treatment, and combined ultrasound and light treatment, respectively; CK, KI, RF, and RF / KI represent PBS buffer solution treatment, potassium iodide treatment, riboflavin treatment, and potassium iodide-riboflavin combination treatment, respectively. Figure 6 Enhanced sound and light dynamic barrier sterilization treatment of pathogens inoculated in fresh-cut apples. (a) Escherichia coli; (b) Penicillium expansum; Figure 7(a) Total aerobic bacteria; (b) yeast and fungi in fresh-cut apples during storage after enhanced sound-light dynamic barrier sterilization treatment; Figure 8 (a) Firmness; (b) TSS content; (c) weight loss rate of fresh-cut apples after enhanced sound-light dynamic fence sterilization during storage. Figure 9 Color of fresh-cut apples during storage after enhanced sound and light dynamic fence sterilization treatment. (a) L * value; (b) a * value; (c) b * Value; (d) Appearance of fresh-cut apples on the 0th and 7th days of storage. DETAILED DESCRIPTION

[0019] The technical solution of the present invention is further described in detail below through specific embodiments.

[0020] In the present invention, unless otherwise specified, the raw materials and equipment used can be purchased from the market or are commonly used in the art. The methods in the following examples, unless otherwise specified, are all conventional methods in the art.

[0021] Example 1: A method for sterilizing and preserving fresh-cut fruits and vegetables using an acoustic and optical power fence based on potassium iodide-enhanced riboflavin comprises the following steps: (1) Under dark conditions, fresh-cut apples were immersed in riboflavin-potassium iodide solution and allowed to stand for 20 min; the final concentration of riboflavin was 100 μmol / L, and the final concentration of potassium iodide was 12.5 mmol / L.

[0022] (2) Under dark conditions, fresh-cut fruits and vegetables in riboflavin-potassium iodide solution were ultrasonically treated for 10 min at a frequency of 30 kHz and a power of 3 W; then taken out and dried in the dark for 30 min; (3) Treated under blue light for 10 minutes. The blue light source used was an LED blue light panel with an emission wavelength of 450nm and an illumination power of 32 mW / cm -2 .

[0023] Example 2: A method for sterilizing and preserving fresh-cut fruits and vegetables using an acoustic and optical power fence based on potassium iodide-enhanced riboflavin comprises the following steps: (1) Under dark conditions, fresh-cut pears were immersed in riboflavin-potassium iodide solution and allowed to stand for 10 min; the final concentration of riboflavin was 150 μmol / L, and the final concentration of potassium iodide was 20 mmol / L.

[0024] (2) Under dark conditions, fresh-cut fruits and vegetables in riboflavin-potassium iodide solution were ultrasonically treated for 15 min at a frequency of 30 kHz and a power of 3 W; then taken out and dried in the dark for 35 min; (3) Treated under blue light for 20 minutes. The blue light source used was an LED blue light panel with an emission wavelength of 450nm and an illumination power of 32 mW / cm -2 .

[0025] Example 3: A method for sterilizing and preserving fresh-cut fruits and vegetables using an acoustic and optical power fence based on potassium iodide-enhanced riboflavin comprises the following steps: (1) Under dark conditions, fresh-cut peaches were immersed in riboflavin-potassium iodide solution and allowed to stand for 15 min; the final concentration of riboflavin was 120 μmol / L, and the final concentration of potassium iodide was 15 mmol / L.

[0026] (2) Under dark conditions, fresh-cut fruits and vegetables in riboflavin-potassium iodide solution were ultrasonically treated for 30 min at a frequency of 30 kHz and a power of 3 W; then taken out and dried in the dark for 35 min; (3) Treated under blue light for 15 minutes. The blue light source used was an LED blue light panel with an emission wavelength of 450nm and an illumination power of 32 mW / cm -2 .

[0027] Example 4: The present embodiment differs from Example 1 in that the raw materials are fresh-cut potatoes.

[0028] Example 5: The present embodiment differs from Example 1 in that the raw material is fresh-cut radish.

[0029] Experimental part: 1. Materials and Methods 1.1 Fruit material The experiment selected 'Red Fuji' apples as the research object, and selected fruits with basically uniform size and maturity, and free of diseases, insect pests and mechanical damage.

[0030] 1.2, bacterial solution Bacterial suspension Escherichia coli was purchased from Beijing Biorepository Center ( E. coli , ATCC25922). A single colony of E. coli was inoculated into 100 mL of tryptone soy broth (TSB) and incubated at 37°C in a shaker at 200 rpm for 12 h. 600=1.0 was centrifuged at 7000 rpm for 15 min, and then resuspended in PBS solution (0.01 M, pH 7.2) to obtain 10 8 CFU / mL of E. coli stock solution. Finally, the stock solution was diluted to 10 6 CFU / mL and used in subsequent experiments.

[0031] Fungal spore suspension Penicillium expansum ( P. expansum , CGMCC3.4042) was purchased from Beijing Center for Biological Collection and stored in a -80°C refrigerator before use. Potato dextrose agar (PDA) was purchased from Hangzhou Microbiological Reagent Co., Ltd. (Hangzhou, Zhejiang). Penicillium expansum was inoculated onto a PDA plate, cultured upside down in a 25°C incubator, and subcultured every 7 days. Under a sterile environment, 10 mL of sterile deionized water containing 0.1% Tween 80 was added to the PDA plate of Penicillium expansum cultured for 10 days, and then the surface was gently scraped with a spreader to resuspend the Penicillium expansum spores, which were then counted using a hemocytometer. Finally, about 10 were prepared by serial dilution. 5 CFU / mL of spore suspension.

[0032] 1.3 Photodynamic therapy Riboflavin (RF, Hefei Bomei Biotechnology Co., Ltd.), potassium iodide (KI, Beijing Solebold Technology Co., Ltd.). Riboflavin was dissolved in 0.1 mol / L NaOH to prepare a 4000 µmol / L riboflavin solution as a mother solution, which was subsequently diluted with PBS solution as a working solution. Potassium iodide was directly dissolved in PBS solution to prepare a 400mmol / L potassium iodide solution as a mother solution, which was subsequently diluted with PBS solution as a working solution. The light treatment was carried out in the fruit photodynamic device independently developed by our research group. The light source used was an LED blue light panel with an emission wavelength of 450nm and an illumination power of 32 mW / cm -2 .

[0033] 1.4 Acoustic Dynamics Processing An NSE-UPH-E30 ultrasonic processor (Nason Ultrasonic Technology Co., Ltd., China) was used. The processing frequency was 30 kHz, the power was 3 W, and the ultrasonic duration was 10 min.

[0034] Study on the Inhibitory Effect of Photodynamic Sterilization on the Growth of Escherichia coli in Vitro 1.5 Minimum inhibitory concentration The minimum inhibitory concentration (MIC) is an important indicator of antibacterial activity and refers to the lowest drug concentration that can inhibit the growth of pathogens in the culture medium after 18 to 24 hours of in vitro culture. In this study, the broth dilution method was used. 50 μL of riboflavin solution (final concentrations of 1600, 800, 400, 200, 100, and 0 μmol / L) and potassium iodide solution (final concentrations of 200, 100, 50, 25, 12.5, and 0 mmol / L) were added to a 96-well plate. Subsequently, Escherichia coli culture solution (10 6 100 µL of the 96-well plate (CFU / mL) was added and pipetted to mix thoroughly. The plate was then incubated in the dark for 20 minutes. The 96-well plate was then transferred to a photodynamic device and illuminated for 10, 20, and 30 minutes. After illumination, the plates were sealed with sealing film and incubated at 37°C for 24 hours. Finally, the absorbance at 600 nm was measured using a microplate reader. The experiment was repeated three times. The minimum inhibitory concentrations for E. coli were determined to be 100 µmol / L riboflavin and 12.5 mmol / L potassium iodide, which were used for subsequent experiments.

[0035] 1.6 In vitro antibacterial effect Take 500 μL of E. coli suspension (10 6 CFU / mL) were added to a 24-well plate. Subsequently, 500 µL of riboflavin-potassium iodide solution, riboflavin solution, potassium iodide solution, and PBS buffer solution were added, respectively, to achieve the minimum inhibitory concentration (100 µmol / L riboflavin and 12.5 mmol / L potassium iodide) of the above-mentioned solutions. These solutions were labeled as RF / KI, RF, KI, and PBS groups, respectively. Mixing was then performed by pipetting and incubated in the dark for 20 minutes. Each of these treatment groups was then exposed to light or darkness for 10 minutes. Finally, the efficacy of photodynamic sterilization treatment was evaluated using the colony count method. The following steps were performed: dilutions of the above groups were plated onto LB nutrient agar, incubated upside down in a 37°C incubator for 24 hours, and the number of colonies was observed and counted. The experiment was repeated three times.

[0036] 1.7 Study on the growth inhibition of Escherichia coli inoculated on the surface of fresh-cut apples treated with photodynamic sterilization Before the experiment, the apples were washed with deionized water and disinfected by spraying the surface with 75% ethanol solution. The cores of the apples were then removed and the apples were cut into wedges (each weighing approximately 20 ± 2 g) using a fruit slicer in a sterile laminar flow hood. The sliced ​​apples were used immediately in the experiment. 6CFU / mL) and immersed them for 10 minutes. After removal, the inoculated apples were placed on a sterile laminar flow hood for 30 minutes to air-dry and allow E. coli to better adhere to the surface of the fresh-cut apples. The inoculated fresh-cut apples were then randomly divided into four groups: immersed in RF / KI solution followed by light treatment (L-RF / KI), immersed in riboflavin solution followed by light treatment (L-RF), immersed in PBS buffer solution followed by light treatment (L-CK), and immersed in PBS buffer solution followed by darkness treatment (D-CK). After 10 minutes of immersion, the four groups were removed and placed in the dark at room temperature for 20 minutes. Subsequently, the L-RF / KI, L-RF, and L-CK samples were placed in uncovered sterile Petri dishes and exposed to light for 10 minutes. The D-CK group was treated in the dark for the same period of time. After treatment, bacteria on the apple surface were swatted into a PBS solution using a JN-400i homogenizer (Ningbo Jiangnan Instrument Factory, China). The solution was diluted and spread onto LB nutrient agar. The samples were incubated upside down at 37°C for 24 h before microbial counts were performed. The experiment was repeated three times.

[0037] Study on the Inhibitory Effect of Photodynamic Sterilization on the Growth of Penicillium expansum in Vitro 1.8 Determination of appropriate concentration First, a high concentration solution (riboflavin 800 μmol / L, potassium iodide 200 mmol / L) was used to 5 The spore suspension of 100 CFU / mL was treated with photodynamic pre-experiment, and the illumination time was set to 60, 90, and 120 min, respectively. The appropriate illumination time was finally determined by the plate counting method. Then, different concentrations of riboflavin solution (final concentration of 800, 600, 400, 200, 100, and 0 μmol / L) and potassium iodide solution (final concentration of 200, 150, 100, 50, 25, and 0 mmol / L) were mixed by the grid dilution plate method, and the 10 5 A spore suspension with a CFU / mL of spores was subjected to photodynamic sterilization for 120 minutes. Finally, the treated spore suspension was plated and incubated upside down in a 25°C incubator for 60 hours. The optimal photodynamic concentration was determined based on the colony count. The experiment was repeated three times. Through comprehensive analysis, the optimal parameters for Penicillium expansum were determined to be 200 µmol / L riboflavin, 50 mmol / L potassium iodide, and 120 minutes of light treatment, which were used in subsequent experiments.

[0038] 1.9 In vitro antibacterial effect Take 500 μL of spore suspension (10 5CFU / mL) were added to a 24-well plate. Then, 500 µL of riboflavin-potassium iodide solution, riboflavin solution, potassium iodide solution, and PBS buffer solution were added. The final concentrations of riboflavin and potassium iodide after mixing were all the appropriate concentrations (riboflavin 200 µmol / L, potassium iodide 50 mmol / L). These groups were labeled as RF / KI, RF, KI, and CK, respectively. Mixing was done by pipetting and incubating in the dark for 20 minutes. The different treatment groups were then exposed to light for 120 minutes, respectively, in the dark and in the light. The photodynamic bactericidal efficacy was evaluated using the colony count method. The following steps were performed: dilutions of the above groups were plated onto PDA nutrient agar, incubated upside down in a 25°C incubator for 60 hours, and the number of colonies was observed and counted. The experiment was repeated three times.

[0039] 1.10 Study on the in vivo growth inhibition of Penicillium expansum spores inoculated on the surface of fresh-cut apples treated with photodynamic sterilization The pre-experimental treatment was the same as in 2.1.5. The treated apple slices were soaked in a solution of Penicillium expansum spores (10 5 CFU / mL) and immersed in a sterile laminar flow hood for 30 minutes to air-dry, allowing spores to adhere to the surface of fresh-cut apples. The inoculated fresh-cut apples were then randomly divided into four groups: immersed in a riboflavin-potassium iodide solution followed by light exposure (L-RF / KI), immersed in a riboflavin solution followed by light exposure (L-RF), immersed in a PBS buffer solution followed by light exposure (L-CK), and immersed in a PBS buffer solution followed by darkness exposure (D-CK). After 10 minutes of immersion, the apples were removed and placed in the dark at room temperature for 20 minutes. Subsequently, the L-RF / KI, L-RF, and L-CK groups were placed in uncovered sterile Petri dishes and exposed to light for 120 minutes. The D-CK group was kept in the dark for the same period. Following treatment, bacteria on the apple surface were smeared with a homogenizer into a PBS solution, diluted, and plated onto PDA nutrient agar. The samples were incubated upside down in a 25°C incubator for 60 hours before microbial count analysis. The experiment was repeated 3 times.

[0040] 1.11 Study on the in vitro growth inhibition of pathogens treated with photoacoustic barrier sterilization 1.111 In vitro antibacterial studies on Escherichia coli Take 500 μL of E. coli suspension (10 6CFU / mL) were added to a 24-well plate. Then, 500 µL of riboflavin-potassium iodide solution, riboflavin solution, potassium iodide solution, and PBS buffer solution were added, respectively, to a final riboflavin concentration of 100 µmol / L and potassium iodide concentration of 12.5 mmol / L. These solutions were labeled as the RF / KI, RF, KI, and PBS groups, respectively. Mixing was then performed by pipetting and incubated in the dark for 20 minutes. The different treatment groups were then sonicated for 10 minutes, followed by 10 minutes in the dark and 10 minutes in the light, respectively. Finally, the bactericidal efficacy of the acoustic-photodynamic barrier was evaluated using the plate colony count method. The following steps were performed: the treated bacterial solution was diluted and plated onto LB nutrient agar. The solution was incubated upside down at 37°C for 24 hours, and the colonies were observed and counted. The experiment was repeated three times.

[0041] 1.112 In vitro antibacterial studies on Penicillium expansum Take 500 μL of Penicillium expansum spore suspension (10 5 CFU / mL) were added to a 24-well plate. Then, 500 µL of riboflavin-potassium iodide solution (final riboflavin concentration of 200 µmol / L, final potassium iodide concentration of 50 mmol / L) was added. This was labeled the RF / KI group and mixed thoroughly with a pipette. The mixture was then incubated in the dark for 20 minutes. The cells were then sonicated for 10 minutes using an acoustic dynamic device, followed by 120 minutes of either darkness or light exposure. The control group, the CK group, remained untreated. Finally, the plate colony count method was used to evaluate the bactericidal efficacy of the acoustic-photodynamic barrier. The following steps were performed: The above groups were diluted and plated onto PDA nutrient agar. The plates were incubated upside down at 25°C for 60 hours, and the colonies were observed and counted. The experiment was repeated three times.

[0042] 1.12 Study on the in vivo growth inhibition of pathogens in fresh-cut apples treated with photoacoustic fence sterilization 1.12 1 In vivo antibacterial study of Escherichia coli The photoacoustic fence sterilization treatment group was treated with ultrasound for 10 min and then irradiated with blue light for 10 min. The rest of the treatment was the same as 1.7.

[0043] 1.12 2 In vivo antibacterial studies of Penicillium expansum The acousto-photodynamic fence sterilization group was treated with ultrasound for 10 min and then irradiated with blue light for 120 min. The rest of the treatment was the same as in 1.10.

[0044] 1.12 3 In vivo growth inhibition study of protozoa Acoustic-photodynamic fence treatment sterilizes native bacteria on the surface of fresh-cut apples. The treatment steps for apple slices are the same as those in 1.7. Fresh-cut apple pieces were then randomly divided into three groups for treatment: (1) soaked in RF / KI solution and subjected to ultrasound combined with light treatment (L+S-RF / KI), (2) soaked in RF / KI solution and subsequently subjected to light treatment (L-RF / KI), and (3) soaked in PBS buffer solution and subsequently subjected to dark treatment (CK). After treatment, the bacteria on the surface of the apples were knocked off into PBS solution using a homogenizer, and then diluted and spread on LB nutrient agar. After incubation at 37°C for 24 hours, the bacteria count of the sample was performed; at the same time, it was also spread on PDA nutrient agar and incubated at 25°C for 60 hours, and yeast and fungi counts were performed. The experiment was repeated 3 times.

[0045] 1.13 Effects of photoacoustic fence sterilization on the storage quality of fresh-cut apples In addition, fresh-cut apples were randomly divided into two groups. The treated samples were stored in a 5°C cold storage for 7 days. Samples were taken on the 0th, 1st, 3rd, 5th and 7th day after treatment to measure relevant quality indicators.

[0046] 1.131 hardness The firmness of fresh-cut apples after different treatments was measured using a TA-XT2i texture analyzer (Stable Micro Systems, UK) with a probe diameter of 2 mm, a penetration rate of 1 mm / s, and a penetration distance of 10 mm. Hardness was defined as the maximum penetration force (N).

[0047] 1.132 Weight loss rate The weight loss rate of fresh-cut apples is measured using the following formula: in, m 1 Indicates the instantaneous weight of the fruit, m 0 Indicates the original weight.

[0048] 1.133 TSS content Fresh-cut apple pulp was squeezed to extract juice and filtered, and the TSS content of the juice was measured using a PR-101α portable handheld sugar meter (ATAGO, Japan).

[0049] 1.134 color difference The surface color of fresh-cut apples after different treatments was measured using a MiniScan XE Plus colorimeter (HunterLab, USA). Four locations on each wedge of apple were measured. L *、 a *、 b*The results are averaged.

[0050] result 2.1 Study on the inhibition of Escherichia coli growth by photodynamic sterilization In order to further determine the bactericidal ability of different treatment groups, in vitro experiments were conducted on E. coli. The results are as follows Figure 1 As shown. Under dark treatment, there was no significant difference in the four different solutions, and the number of E. coli remained basically the same. After 10 minutes of light treatment, L-CK and L-KI treatments could reduce the number of E. coli by 0.32 and 0.42 log, respectively. 10 CFU / mL, which is mainly due to the antibacterial activity of blue light; at the same time, L-RF treatment can reduce 1.60 log 10 CFU / mL; while the number of E. coli decreased by 3.62 log after L-RF / KI treatment 10 CFU / mL, the sterilization rate reached 99.9%. The sterilization effect of adding potassium iodide increased by 2.02 Log compared with the treatment with riboflavin alone. 10 The above results show that potassium iodide can significantly enhance the photodynamic bactericidal effect of riboflavin on Escherichia coli under blue light irradiation.

[0051] 2.2 Inhibitory effect of photodynamic treatment on Escherichia coli inoculated on the surface of fresh-cut apples The sterilization results of Escherichia coli inoculated on the surface of fresh-cut apples treated with photodynamic therapy are as follows Figure 2 As shown. The E. coli count in the D-CK group was 5.61 log 10 CFU / g; the number of Escherichia coli treated with light for 10 min (L-CK group) and riboflavin photodynamic sterilization treatment alone (L-RF group) decreased by 0.07 and 0.12 log, respectively 10 CFU / g, corresponding to a sterilization rate of 13% and 28%, and the sterilization effect was not significant. The E. coli count of the enhanced photodynamic sterilization treatment (L-RF / KI group) was 4.93 log 10 CFU / g, compared with the D-CK group, it can significantly reduce the number of bacteria on the surface of fresh-cut apples, reducing by about 0.62 log 10 CFU / g, with a sterilization rate of 82%, which is 2.91 times that of the L-RF group. The above results indicate that potassium iodide can significantly enhance the sterilization effect of riboflavin-mediated photodynamic treatment on Escherichia coli on fresh-cut apples.

[0052] 2.3 Photodynamic sterilization treatment inhibits the in vitro growth of Penicillium expansum spores The results of the fungal spore growth inhibition experiment in vitro were as follows: Figure 3As shown. Under dark conditions, whether riboflavin, potassium iodide, or a combination of the two was used, none of them could inactivate Penicillium expansum spores, and there was no significant difference from the control D-CK group. At the same time, under blue light irradiation for 120 min, neither light treatment alone (L-CK group) nor potassium iodide treatment alone (L-KI group) could kill Penicillium spores, and there was no bactericidal effect. The results were consistent with those of the dark treatment group. However, riboflavin photodynamic treatment alone (L-RF group) had a certain bactericidal effect on Penicillium spores, and the number of spores could be reduced by 0.14 log 10 CFU / mL, and the sterilization rate was 27.4%. This result proved that riboflavin-mediated photodynamic sterilization treatment could inactivate some spores.

[0053] Enhanced photodynamic sterilization treatment (L-RF / KI group) significantly improved the sterilization effect, completely inactivating 4.16 log of Penicillium spores. 10 CFU / mL, achieving a 100% sterilization rate, and increasing the sterilization effect by 4.02 log compared to the L-RF group 10 The above experimental results show that potassium iodide can significantly enhance the inactivation effect of riboflavin photodynamic sterilization on Penicillium expansum.

[0054] 2.4 Inhibitory effect of photodynamic sterilization on Penicillium expansum spores inoculated on the surface of fresh-cut apples The results of photodynamic treatment of the sterilization of fresh-cut apples inoculated with Penicillium expansum are as follows Figure 4 As shown. The spore count in the D-CK group was 3.71 log 10 CFU / g; only the blue light treatment (L-CK group) reduced the number of Penicillium expansum by 0.04 log 10 CFU / g, the sterilization rate was only 8.5%, and the sterilization effect was not significant; only riboflavin photodynamic sterilization treatment (L-RF group) reduced 0.17log compared with the D-CK group 10 CFU / g, the sterilization rate reached 31.3%, which was significantly different; the spore count of the enhanced photodynamic sterilization treatment (L-RF / KI group) was 2.82 log 10 CFU / g, significantly reduced by 0.89 log compared to the control 10 CFU / g, with a sterilization rate of 87.0%, which was 2.78 times that of the L-RF group. The above results indicate that potassium iodide can significantly enhance the sterilization effect of riboflavin-mediated photodynamic treatment on the surface of fresh-cut apples inoculated with Penicillium expansum.

[0055] 2.5 Analysis of in vitro growth inhibition of pathogens treated with photoacoustic barrier 2.5.1 In vitro inhibition results of Escherichia coli First, the sonodynamic sterilization treatment research was carried out. Figure 5a. The bacterial count in the control (CK group) was 8.76 log 10 CFU / mL. Ultrasonication alone (S-CK group) reduced the bacterial count by 2.17 log 10 CFU / mL, which was significantly different from the control. Single substance sonodynamic treatment (S-RF and S-KI groups) can further reduce the concentration of E. coli, reducing it by 2.80 and 2.61 log, respectively. 10 CFU / mL, indicating that the presence of riboflavin or potassium iodide can enhance the bactericidal efficacy of ultrasonic treatment. When riboflavin and potassium iodide were combined for ultrasonic treatment, that is, enhanced sonodynamic treatment (S-RF / KI group), the results showed that the bactericidal efficacy was further enhanced, and the number of E. coli was reduced by 3.91 log compared with the control. 10 The CFU / mL were further reduced by 1.11 and 1.29 log compared with the S-RF group and S-KI group, respectively. 10 The above results show that enhanced sonodynamic treatment also has an enhancement effect, and potassium iodide can significantly enhance the sonodynamic bactericidal effect mediated by riboflavin.

[0056] On the basis of sonodynamic treatment, photodynamic sterilization was further combined to perform fence sterilization. The results showed that ( Figure 5 a) Ultrasound combined with blue light treatment (L+S-CK group) reduced the number of E. coli by 2.27 log compared with the CK group. 10 CFU / mL, but compared with the S-CK group, it only decreased by 0.29 log 10 CFU / mL, and there was no significant difference. The experimental results are consistent with the conclusion of 2.1, that is, the 10-min illumination time of blue light treatment alone is not enough to have a significant bactericidal effect on E. coli, even on the basis of sonodynamic sterilization. On the other hand, the sonodynamic fence sterilization treatment based only on riboflavin or potassium iodide (single substance) (L+S-RF group and L+S-KI group) can better reduce the number of E. coli, reducing it by 3.95 and 3.72 log, respectively. 10 CFU / mL, further decreased by 1.15 and 1.10 log compared with the S-RF and S-KI groups, respectively. 10 The above results combined with the results of 2.1 show that the bactericidal efficiency of the acousto-photodynamic barrier treatment is stronger than that of the photodynamic or acoustodynamic sterilization alone.

[0057] The enhanced sound-light dynamic barrier sterilization treatment (L+S-RF / KI group) with riboflavin-potassium iodide showed the best sterilization effect, which reduced 5.99 log compared with CK. 10CFU / mL. Compared with L+S-RF, the number of E. coli in L+S-RF / KI was further reduced by 2.04 log 10 CFU / mL, indicating that potassium iodide can enhance the bactericidal effect of riboflavin sound and light dynamic fence treatment. At the same time, compared with the S-RF / KI group, the L+S-RF / KI treatment can further reduce the number of Escherichia coli by 2.08 log 10 This result, combined with the results of 2.1, shows that the bactericidal effect of enhanced photodynamic barrier treatment is significantly stronger than that of enhanced photodynamic or sonodynamic treatment.

[0058] 2.5.2 In vitro antibacterial results of Penicillium expansum The results of enhanced sound and light dynamic fence treatment of Penicillium expansum spores are as follows Figure 5 As shown in b. The number of expanded Penicillium spores in the CK group was 5.29 log 10 CFU / mL, S-RF / KI group could reduce 0.63 log 10 CFU / mL. The L+S-RF / KI group can further improve the bactericidal effect and significantly reduce 5.29 log 10 CFU / mL, achieving a sterilization rate of up to 100%, and the sterilization effect increased by 4.66 log compared with the S-RF / KI group 10 The above results show that the enhanced photoacoustic barrier sterilization treatment can significantly reduce the number of Penicillium expansum in vitro and achieve a good sterilization effect. On the other hand, the sterilization efficiency is better than that of the enhanced photodynamic or sonodynamic sterilization treatment, showing a synergistic enhancement effect.

[0059] 2.6 Effect of sound and light dynamic fence sterilization on pathogens inoculated on fresh-cut apples 2.6.1 In vivo inhibition results of Escherichia coli The results of the acoustic-optical dynamic fence treatment on the sterilization of Escherichia coli inoculated on the surface of fresh-cut apples are as follows Figure 6 (a) The number of E. coli in the CK group was 6.11 log 10 CFU / g. The S-RF / KI group can reduce 0.85 log 10 CFU / g, with a sterilization rate of 86.3%. The L-RF / KI group can reduce 0.78 log 10 CFU / g, with a sterilization rate of 83.7%, similar to the results in 2.2.2. The L+S-RF / KI group showed the strongest sterilization ability, effectively reducing the number of E. coli on the surface of fresh-cut apples by 2.01 log compared to the control CK group. 10CFU / g, with a sterilization rate of up to 99.0%. At the same time, the L+S-RF / KI group further reduced the number of CFU / g by 1.15 and 1.22 log compared with the S-RF / KI and L-RF / KI groups, respectively. 10 The above results show that the enhanced sound and light dynamic fence sterilization treatment has a good sterilization effect on Escherichia coli inoculated on the surface of fresh-cut apples, and is significantly stronger than the enhanced photodynamic sterilization and enhanced sound dynamic sterilization effects, showing a good synergistic effect.

[0060] 2.6.2 In vivo inhibition results of Penicillium expansum The results of the acoustic and optical dynamic fence treatment on the sterilization of Penicillium expansum inoculated on the surface of fresh-cut apples are as follows Figure 6 (b) The number of expanded Penicillium spores in the CK group was 4.36 log 10 Enhanced photodynamic and sonodynamic sterilization treatments (L-RF / KI group and S-RF / KI group) can reduce the number of spores by 0.44 and 0.78 log, respectively. 10 CFU / g, corresponding to sterilization rates of 62.7% and 83.0% respectively. The L+S-RF / KI group showed the strongest sterilization effect, significantly reducing 1.70 log compared to the control CK group. 10 CFU / g, with a sterilization rate of up to 98.0%. Compared with the S-RF / KI group and the L-RF / KI group, the number of CFU / g was further reduced by 1.27 and 0.92 log 10 The enhanced photoacoustic barrier treatment was more effective than the enhanced photodynamic or sonication treatment on Penicillium expansum spores inoculated on the surface of fresh-cut apples, demonstrating a synergistic enhancement effect.

[0061] 2.7 Effect of photoacoustic fence sterilization on the inhibition of native bacteria in fresh-cut apples Taking into account the industry's demand for rapid and efficient sterilization of fresh-cut apples, and the relatively low content of native bacteria on the surface of fresh-cut apples relative to the number of inoculated bacteria, the parameters for inhibiting native bacteria in fresh-cut apples using the sound-light dynamic fence sterilization treatment were finally determined as: riboflavin 100 µmol / L, potassium iodide 12.5 mmol / L, blue light irradiation 10 min, and ultrasonic treatment 10 min.

[0062] 2.7.1 Inhibition results of aerobic bacteria The results of enhanced sound and light dynamic fence sterilization treatment of native aerobic bacteria on the surface of fresh-cut apples are as follows Figure 7 (a) As shown. On the first day after sterilization, the bacterial count in the CK group was 2.78 log 10 CFU / g, while enhanced photodynamic sterilization treatment (L-RF / KI group) reduced 0.90 log 10CFU / g, achieving a sterilization rate of 84.7%, while the total number of bacteria in the enhanced sound and light dynamic fence sterilization treatment (L+S-RF / KI group) was below the detection limit, which means that 2.78 log of bacteria could be completely inactivated. 10 CFU / g (100% sterilization rate). While the number of aerobic bacteria on the surface of fresh-cut apples increased overall with storage time, the L-RF / KI and L+S-RF / KI groups continued to exhibit significant antibacterial effects. In particular, the L+S-RF / KI group consistently inhibited bacterial growth on the surface of fresh-cut apples, with the total bacterial count at 7 days of storage still lower than the initial colony count in the CK group on day 1, demonstrating sustained antibacterial activity during storage.

[0063] 2.7.2 Inhibition results of yeast and fungi Enhanced sound and light dynamic fence sterilization treatment of native yeast and fungi on the surface of fresh-cut apples Figure 7 (b) On the first day after sterilization, the fungal count in the CK group was 2.57 log 10 CFU / g, while L-RF / KI treatment had no significant bactericidal effect, while the enhanced sound and light dynamic fence sterilization treatment (L+S-RF / KI group) could significantly reduce the number of yeast and fungi, reducing by 0.83 log 10 CFU / g, with a sterilization rate of 85.4%. As storage time increased, the number of yeast and fungi on fresh-cut apples increased overall. However, on the 4th and 7th days of storage, the L+S-RF / KI treatment continued to show a sustained antibacterial effect, with yeast and fungi counts 1.26 and 1.39 log lower than those in the CK group, respectively. 10 CFU / g.

[0064] 2.8 Effects of photoacoustic barrier sterilization on the storage quality of fresh-cut apples In order to explore the effect of enhanced sound-light dynamic fence sterilization treatment on the storage quality of fresh-cut apples, the storage quality indicators such as fruit firmness, color difference, weight loss rate, and soluble solids content after treatment were measured.

[0065] 2.8.1 Hardness The hardness changes of fresh-cut apples during storage after enhanced sound and light dynamic fence sterilization treatment Figure 8 (a) As shown, the firmness of fresh-cut apples showed a slow overall decline with prolonged storage. Compared with the CK and L-RF / KI treatments, the firmness of fresh-cut apples treated with L+S-RF / KI showed no significant difference throughout the storage period, indicating that the enhanced acoustic-photodynamic barrier sterilization treatment and the enhanced photodynamic sterilization treatment had similar effects and did not negatively affect the firmness of fresh-cut apples.

[0066] 2.8.2 Soluble solids content Changes in total soluble solids (TSS) content of fresh-cut apples during storage after enhanced sound-light dynamic fence sterilization treatment Figure 8 (b) With extended storage, the TSS content of fresh-cut apples initially decreased and then leveled off. Compared with the CK group, the TSS content of fresh-cut apples treated with L+S-RF / KI showed no significant difference throughout the storage period, indicating that enhanced photoacoustic barrier sterilization did not adversely affect the TSS content of fresh-cut apples.

[0067] 2.8.3 Weight loss rate The weight loss rate of fresh-cut apples after enhanced sound and light dynamic fence sterilization during storage is shown as follows: Figure 8 (c). The overall weight loss rate of fresh-cut apples continued to increase with storage time. During the first five days of storage, the weight loss rate of fresh-cut apples in the L+S-RF / KI group was slightly lower than that in the CK group, but there was no significant difference. However, on the fifth and seventh days of storage, the weight loss rate of the L+S-RF / KI group was significantly lower than that of the CK treatment, indicating that the enhanced sound-light dynamic barrier sterilization treatment can effectively delay fruit water loss and reduce fruit weight loss rate in the later stages of storage. At the same time, there was no significant difference between the L+S-RF / KI group and the L-RF / KI group during the storage period, indicating that the enhanced sound-light dynamic barrier sterilization treatment and the enhanced photodynamic sterilization treatment are similar and do not have a negative impact on the weight loss rate of fresh-cut apples. In fact, they can effectively reduce water loss and reduce fruit weight loss in the later stages of storage.

[0068] 2.8.4 Color Difference Color changes of fresh-cut apples during storage after enhanced sound and light dynamic fence sterilization treatment Figure 9 The enhanced sound and light dynamic fence sterilization treatment group (L+S-RF / KI) and the enhanced light dynamic sterilization treatment group (L-RF / KI) were similar in that they could delay the decline in surface brightness of fresh-cut apples during storage and effectively reduce the browning of fresh-cut apple flesh.

[0069] summary: Taking fresh-cut apple pathogens (Escherichia coli and Penicillium expansum) as the research objects, the enhancing effect of potassium iodide on riboflavin-mediated sound-light dynamic barrier sterilization and the synergistic effect of enhanced sound-light dynamic barrier sterilization treatment were studied through in vitro antibacterial experiments. Then, the antibacterial effect of enhanced sound-light dynamic barrier sterilization treatment on two pathogens inoculated on the surface of fresh-cut apples was evaluated through in vivo antibacterial experiments. Finally, the antibacterial effect of native bacteria of fresh-cut apples was studied, and the effect of enhanced sound-light dynamic barrier sterilization treatment on the storage quality of fresh-cut apples was evaluated.

[0070] First, the enhancement effect of potassium iodide was studied through an in vitro antibacterial experiment on Escherichia coli. The results showed that potassium iodide can significantly improve the bactericidal effect of riboflavin-mediated photoacoustic barrier. The photoacoustic barrier sterilization with riboflavin alone can reduce the number of Escherichia coli by 3.95 log 10 CFU / mL, and the addition of potassium iodide can effectively increase 2.04 log 10 CFU / mL, the bactericidal effect ultimately reached 5.99 log 10 CFU / mL. Subsequently, the synergistic effect of enhanced photoacoustic barrier sterilization treatment was studied for two pathogenic bacteria, Escherichia coli and Penicillium expansum. The results showed that after enhanced photodynamic sterilization treatment, the number of Escherichia coli and Penicillium expansum decreased by 3.62 and 4.16 log, respectively. 10 CFU / mL; while enhanced sonication reduced them by 3.91 and 0.63 log, respectively 10 In contrast, the enhanced sound-light dynamic barrier sterilization treatment showed a stronger sterilization effect, which could reduce the number of Escherichia coli and Penicillium expansum by 5.99 log 10 CFU / mL and 5.29 log 10 CFU / mL. This result fully demonstrates that the enhanced photoacoustic barrier sterilization treatment has a significant synergistic effect, and its sterilization efficiency is better than that of single enhanced photodynamic or sonication treatment. Then, the two pathogenic bacteria inoculated on the surface of fresh-cut apples were sterilized with the barrier, and the results showed that the enhanced photoacoustic barrier sterilization treatment could reduce 2.01 and 1.70 log, respectively. 10 CFU / g, which is more bactericidal than enhanced photodynamic and sonodynamic treatments, fully demonstrating their combined synergistic effect.

[0071] This study further carried out an in vivo antibacterial experiment on the surface of fresh-cut apples. First, based on the industry's demand for efficient and rapid sterilization treatment, the optimal parameters of enhanced sound and light dynamics were determined by comprehensively considering the treatment time and the amount of sound and light sensitizer, that is, the final concentration of riboflavin was 100 µmol / L, the final concentration of potassium iodide was 12.5 mmol / L, the sound dynamics treatment was 10 min, and the photodynamic treatment was 10 min. Then, based on the optimal parameters, an enhanced sound and light dynamic fence sterilization treatment of the growth inhibition of native bacteria on the surface of fresh-cut apples was carried out. The experimental results showed that on the first day of storage, the aerobic bacteria on the surface of fresh-cut apples could be reduced by 0.90 log after enhanced photodynamic sterilization treatment. 10 CFU / g, with a sterilization rate of 84.7%, while the enhanced sound and light power fence treatment can reduce 2.78log 10 CFU / g bacterial count, achieving 100% sterilization; for yeast and fungi, enhanced sound and light dynamic fence treatment can reduce 0.83 log 10CFU / g, achieving a sterilization rate of 85.4%. Furthermore, the enhanced sound and light dynamic barrier sterilization treatment maintained excellent sustained antibacterial capabilities during the storage period of fresh-cut apples. Furthermore, the barrier sterilization treatment did not affect the firmness and soluble solids content of the flesh, and effectively inhibited browning of the flesh and slowed the increase in weight loss of fresh-cut apples.

[0072] The synergistic effect was calculated based on the in vivo bactericidal results that were closest to the actual results. The synergistic effect of the bactericidal factors was determined using the T / E ratio, where T represents the theoretical survival rate, which is the product of the survival rates of each single factor; E represents the survival rate of the microorganisms after the combined action; a TE ratio greater than 1 indicates synergistic effect (see "Practical Tutorial on Hospital Disinfection" by Xu Shiai et al., page 30, Hebei Science and Technology Press, publication date: 20140630).

[0073] For Escherichia coli: the survival rate of RF+KI+light sterilization was 16.27%, the survival rate of RF+KI+sound sterilization was 13.70%, the survival rate of RF+KI+sound and light sterilization was 0.98%, and the T / E ratio was 2.27.

[0074] For Penicillium expansum: the survival rate of RF+KI+light sterilization was 16.98%, the survival rate of RF+KI+sound sterilization was 37.26%, the survival rate of RF+KI+sound and light sterilization was 2.01%, and the T / E ratio was 3.14.

[0075] Obviously, in the present invention, under the same RF+KI background, the acoustic and light sterilization has obvious synergistic effects on bacteria and fungi.

[0076] Furthermore, for E. coli, the survival rate was 87% for RF+KI, 0.34% for sono- and photo-sterilization, and 0.00011% for RF+KI combined with sono- and photo-sterilization, resulting in a T / E ratio of 2680.95. For Penicillium expansum, the survival rate was zero for RF+KI combined with sono- and photo-sterilization, and the T / E ratio approached infinity. Clearly, the combination of RF+KI and photo-sterilization exhibits a significant synergistic effect.

[0077] The embodiment described above is only a preferred solution of the present invention and does not limit the present invention in any form. Other variations and modifications are possible without exceeding the technical solution described in the claims.

Claims

1. A method for sterilizing and preserving fresh-cut fruits and vegetables using an acoustic and optical power fence based on potassium iodide to enhance riboflavin, characterized in that: The steps include: (1) Under dark conditions, immerse fresh-cut fruits and vegetables in riboflavin-potassium iodide solution and let it stand for 10-30 minutes; (2) Ultrasonic treatment of fresh-cut fruits and vegetables in riboflavin-potassium iodide solution for 10-15 minutes in the dark; then remove and dry in the dark for 30-35 minutes; (3) Treat under blue light for 10-20 minutes.

2. The method for sterilizing and preserving fresh-cut fruits and vegetables by using a sound and light dynamic fence with potassium iodide to enhance riboflavin according to claim 1, characterized in that: The final concentration of riboflavin in the riboflavin-potassium iodide solution is 100-150 μmol / L.

3. The method for sterilizing and preserving fresh-cut fruits and vegetables by using a sound and light dynamic fence with potassium iodide to enhance riboflavin according to claim 1, characterized in that: The final concentration of potassium iodide in the riboflavin-potassium iodide solution is 12.5-20 mmol / L.

4. The method for sterilizing and preserving fresh-cut fruits and vegetables by using a sound and light dynamic fence with potassium iodide to enhance riboflavin according to claim 1, characterized in that: The ultrasonic treatment frequency was 30 kHz and the power was 3 W.

5. The method for sterilizing and preserving fresh-cut fruits and vegetables by using a sound and light dynamic fence with potassium iodide to enhance riboflavin according to claim 1, characterized in that: The blue light source used is an LED blue light panel with an emission wavelength of 450nm and an illumination power of 32mW / cm -2 .

6. The method for sterilizing and preserving fresh-cut fruits and vegetables by using a sound and light dynamic fence with potassium iodide to enhance riboflavin according to claim 1, characterized in that: The fresh-cut fruits and vegetables are selected from one of apples, pears, bananas, watermelons, peaches, radishes, sweet potatoes and potatoes.

Images