A method for preserving yellow peaches using anti-fog and antibacterial packaging combined with ozone treatment

Abstract

This invention discloses a method for preserving yellow peaches using anti-fogging and antibacterial packaging combined with ozone treatment, belonging to the agricultural field and relating to fruit and vegetable preservation. This invention claims protection for a method for preserving yellow peaches using anti-fogging and antibacterial packaging combined with ozone treatment, wherein the yellow peaches are stored in a sealed anti-fogging and antibacterial packaging container containing ozone. This invention discovers that the combined treatment of anti-fogging and antibacterial packaging and ozone can synergistically maintain the post-harvest storage quality of yellow peaches through both physical anti-fogging and enhanced fruit's own antioxidant defense. This invention utilizes Jin Zhengjun, a commonly used method in this field. q Value analysis revealed that when anti-fogging and antibacterial packaging was combined with ozone for 2 and 4 days of preservation treatment of yellow peaches, it could synergistically delay the accumulation of MDA (Jin Zhengjun). q (The value is much higher than 1.15), which plays a synergistic role in delaying the ripening and senescence of yellow peaches. Therefore, anti-fogging and antibacterial packaging combined with ozone treatment has the potential to be developed into a method for preserving yellow peaches.

Description

Technical Field

[0001] This invention belongs to the agricultural field and relates to the preservation of fruits and vegetables, specifically to a method for preserving yellow peaches using anti-fog and antibacterial packaging combined with ozone treatment. Background Technology

[0002] Peach( Prunus persica Yellow peaches (L.) are one of the most widely cultivated and popular fruits globally, possessing significant economic value and rich in vitamins, phenolic compounds, and various trace minerals. As an important variety of peach, yellow peaches are grown in Shandong, Hubei, Guizhou, Hunan, Hebei, Gansu, and other regions due to their high yield and stable economic benefits, especially in Yanling, Mayang, Ningxiang, Huaihua, Loudi, and Yiyang in Hunan Province. The county-level specialty agricultural industry, represented by the Yanling yellow peach industry, provides strong support for consolidating the effective connection to rural revitalization. However, yellow peaches are typical climacteric fruits, with the harvest season concentrated in the hot and humid months of July and August. The fruit has a high water content, making it susceptible to mechanical damage and microbial contamination, resulting in a short shelf life. At room temperature, they deteriorate rapidly within 5-7 days, mainly manifesting as water loss, softening, microbial decay, and browning, ultimately leading to a significant decline in their commercial and economic value. With the increasing production of yellow peaches year by year, there is an urgent need to study safe and pollution-free green preservation technologies to maintain the storage quality of yellow peaches, delay ripening, and reduce post-harvest losses.

[0003] Ozone (O3) is an allotrope of oxygen (O2). It is unstable at room temperature and spontaneously decomposes into oxygen, with a half-life of approximately 22 minutes. The atomic oxygen produced after O3 decomposition has extremely strong oxidizing power, rapidly penetrating and damaging the cell walls and membranes of microorganisms, and permeating their tissues to inhibit normal physiological metabolism and reproductive processes, thus achieving sterilization and preservation. In 2001, the U.S. Food and Drug Administration approved ozone as a food additive for processing, storage, and treatment, and recognized it as a "generally recognized safe" substance. In fruit and vegetable preservation, O3 not only has sterilization and preservation functions but also effectively maintains the firmness of fruits and vegetables, inhibits ethylene release, delays aging, and enhances disease resistance. Due to its easy decomposition and residue-free characteristics, O3 has been used as a novel and effective physical preservation method to maintain the quality of post-harvest fruits, and has been applied to fruits such as pears, persimmons, kiwifruit, apricots, cantaloupes, 'Kyoho' grapes, apples, and 'Wenzhou tangerines'.

[0004] Yellow peaches have a high metabolic rate after harvest and a high water content. During storage, they release a large amount of water, maintaining a high humidity level inside the packaging. When storage temperatures fluctuate, water vapor easily condenses on the inner wall of ordinary PE packaging bags, forming mist-like water droplets. These condensation droplets reduce packaging transparency, interfering with the observation of the fruit's freshness and color. Furthermore, accumulated water droplets easily drip onto the fruit surface or accumulate on the packaging substrate, providing favorable conditions for microbial growth, thus accelerating fruit spoilage and shortening shelf life. The occurrence of condensation inside the packaging mainly depends on the ambient temperature and humidity, as well as the surface characteristics of the materials. When the ambient temperature inside the packaging fluctuates and drops below the dew point temperature, water vapor in the high-humidity air near the wall reaches saturation, condensing into liquid water droplets on the packaging material surface. Anti-fog and antibacterial packaging combines both anti-fog and antibacterial functions, compensating for the shortcomings of either single function alone. This packaging significantly reduces condensation and fogging during the storage and sale of fruits and vegetables, improving their appearance; it also inhibits the growth of pathogenic microorganisms, maintains the quality of fruits and vegetables, and extends their shelf life, showing promising application prospects in fruit and vegetable preservation. However, its application in the preservation of yellow peaches has not yet been reported.

[0005] In order to develop a method for preserving yellow peaches and improve the preservation effect, this invention is proposed. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for preserving yellow peaches by combining anti-fog and antibacterial packaging with ozone treatment.

[0007] The above-mentioned objective of this invention is achieved through the following technical solution: A method for preserving yellow peaches by combining anti-fog and antibacterial packaging with ozone treatment involves storing the yellow peaches in a sealed anti-fog and antibacterial packaging container containing ozone.

[0008] In one specific embodiment, the anti-fog and antibacterial packaging container is an anti-fog and antibacterial packaging bag.

[0009] In one specific embodiment, the anti-fog and antibacterial packaging container is made of PE / PET material and loaded with cinnamaldehyde.

[0010] In a specific embodiment, the present invention demonstrates through experiments that placing fresh yellow peaches in a PE / PET anti-fogging and antibacterial packaging bag loaded with cinnamaldehyde, followed by ozone inflation and sealing treatment, can synergistically maintain the post-harvest storage quality of yellow peaches through both physical anti-fogging and enhanced fruit's own antioxidant defense.

[0011] In one specific embodiment, the ozone concentration is 30~50 mg / m³. 3 .

[0012] In one specific embodiment, the ozone concentration is 35~45 mg / m³. 3.

[0013] In one specific embodiment, the ozone concentration was 42.86 mg / m³. 3 .

[0014] In one specific embodiment, the storage temperature is 4~12℃.

[0015] In one specific embodiment, the storage temperature is 6~10℃.

[0016] In one specific embodiment, the storage temperature is 8°C.

[0017] In one specific embodiment, the storage time is ≤12 days, preferably ≤4 days, and more preferably 2 or 4 days.

[0018] In specific embodiments, experiments have demonstrated that when anti-fog and antibacterial packaging is combined with ozone for 2 and 4 days of preservation treatment of yellow peaches, the two can synergistically delay the accumulation of MDA and play a role in delaying the ripening and senescence of yellow peaches.

[0019] Beneficial effects: 1. This invention discovers that the combined treatment of anti-fogging and antibacterial packaging with ozone can synergistically maintain the post-harvest storage quality of yellow peaches through both physical anti-fogging and enhanced fruit's own antioxidant defense. In terms of appearance, the combined treatment can effectively maintain the appearance quality of yellow peaches and significantly delay the deterioration of peel aging. The decrease in value inhibited a The increased levels of antioxidants maintained the bright yellow color of the fruit and reduced browning symptoms. In terms of texture and flavor, the combined treatment delayed the decline in fruit firmness and the degradation of TA, thus better preserving the fruit's taste and flavor. Simultaneously, this treatment inhibited fruit respiration, reducing the consumption of nutrients such as sugars and acids. More importantly, the combined treatment significantly enhanced the fruit's antioxidant defense capabilities, increased SOD activity, maintained a high GSH content, and resulted in significantly better DPPH free radical scavenging rates, ABTS cation free radical scavenging rates, and FRAP levels during storage compared to the control. The enhanced antioxidant capacity effectively restored cellular redox balance, reduced membrane lipid peroxidation, decreased MDA content in the fruit, and effectively inhibited POD activity, thereby delaying senescence and inhibiting browning.

[0020] 2. MDA, as an indicator of lipid peroxidation in plants, is an indicator of the degree of postharvest oxidative damage in fruits and an important parameter reflecting fruit ripening and senescence. This invention utilizes MDA, a commonly used indicator in this field. q Value analysis revealed that when anti-fogging and antibacterial packaging was combined with ozone for 2 and 4 days of preservation treatment of yellow peaches, it could synergistically delay the accumulation of MDA (Jin Zhengjun). q (The value is much higher than 1.15), which plays a synergistic role in delaying the ripening and senescence of yellow peaches. Attached Figure Description

[0021] Figure 1 The appearance changes of yellow peaches with different treatments in Example 1 at different storage times; Figure 2 This is a comparison of the anti-fogging effects of ordinary PE packaging and anti-fogging and antibacterial packaging in Example 1; Figure 3 The color difference L of yellow peaches during storage under different treatments in Example 1. (A) a (B) and b The influence of (C) value; Figure 4 The effect of different treatments in Example 1 on the firmness of yellow peaches during storage; Figure 5 The effects of different treatments in Example 1 on TSS (A) and TA (B) of yellow peaches during storage; Figure 6 The effect of different treatments in Example 1 on the respiration rate of yellow peaches during storage; Figure 7 The effect of different treatments in Example 1 on the MDA content of yellow peaches during storage; Figure 8 The effects of different treatments in Example 1 on the activities of SOD(A) and POD(B) in yellow peaches during storage; Figure 9 The effects of different treatments in Example 1 on the activities of DPPH (A), ABTS (B), FRAP (C), and GSH (D) in yellow peaches during storage. Detailed Implementation

[0022] The substantive content of the present invention will be described in detail below with reference to specific embodiments. However, those skilled in the art should know that the scope of protection of the present invention should not be limited to these specific embodiments.

[0023] Example 1: I. Experimental Materials, Reagents, and Instruments 1. Materials and Reagents The 'Jinxiu' yellow peaches were purchased in August 2024 from the Maojiaqiao Fruit Wholesale Market in Changsha, Hunan Province. Only freshly picked fruits of uniform size, free from mechanical damage and pests / diseases, were selected. The standard packaging bags were purchased from a local supermarket and are made of food-grade PE. The anti-fog and antibacterial packaging bags were purchased from Zhongke Youguo (Guangzhou) Biotechnology Co., Ltd., and are made of PE / PET and loaded with cinnamaldehyde antibacterial agent.

[0024] NaOH (analytical grade) was purchased from Sinopharm Chemical Reagent Co., Ltd.; the reagent kits for superoxide dismutase (SOD), peroxidase (POD), reduced glutathione (GSH), ferric reducing antioxidant power (FRAP) assay, 1,1-diphenyl-2-picrylhydrazyl (DPPH) content, 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonicacid) (ABTS) free radical scavenging rate, and malondialdehyde (MDA) content determination were purchased from Suzhou Keming Biotechnology Co., Ltd.

[0025] 2. Instruments and Equipment ELISA reader - SYNERGY H1M, BioTek Instruments, Inc., USA; Portable acid-glucose meter - PAL-BX / acidl type, ATAGO Japan Co., Ltd. Ultrasonic Cell Disruptor - SCIENTZ-IID, Ningbo Xinzhi Biotechnology Co., Ltd.; Precision Analyzer-BSA 124S, Guangzhou Shouke Instrument Technology Co., Ltd.; Portable handheld colorimeter - CHROMA METER CR-400, Konica Minolta, Inc., Japan; Tabletop Refrigerated Centrifuge 5430 R, Eppendorf, Germany; Texture analyzer - CT-3, Brookfield Engineering Laboratories, Inc. VS-1000A Free Radical Sterilization Packaging Machine, Zhongke Youguo (Guangzhou) Biotechnology Co., Ltd. Fruit and vegetable respiration meter 3051H, Zhejiang Top Cloud Agriculture Technology Co., Ltd.

[0026] II. Experimental Methods 1. Sample processing The fruits were randomly divided into 4 groups, with 45 fruits per group and 3 replicates per group, each replicate containing 15 fruits. The control group (CK) used standard PE packaging; the AP group used anti-fog and antibacterial packaging alone; the AP+O3 group used anti-fog and antibacterial packaging combined with ozone treatment; and the PE+O3 group used standard PE packaging combined with ozone treatment. Ozone inflation and sealing were performed using a free radical sterilization packaging machine, with a vacuuming time of 4.0 s, an inflation time of 5 s, a sealing time of 0.7 s, and an ozone concentration of 42.86 mg / m³. 3 The sealed packaged yellow peaches were stored at 8℃ and 90%–95% relative humidity. Physiological indicators of the yellow peaches were measured at 0, 2, 4, 8, and 12 days of storage. The remaining pulp was diced, frozen in liquid nitrogen, and stored at -80℃.

[0027] 2. Fruit peel color difference measurement The color difference of the fruit was measured using a CHROMA METER CR-400 portable handheld colorimeter. Before measurement, the instrument was calibrated using a standard white sample. Then, the brightness (L) was measured at three different locations evenly selected on the equatorial plane of each yellow peach. ), red-green value (a ) and blue-green value (b The results are averaged.

[0028] 3. Hardness Measurement Fruit firmness was determined using a CT3 texture analyzer. The probe was a TA39 model with a diameter of 2 mm. Test conditions: TPA mode, trigger point load: 6.8 g, test speed: return speed The test was performed twice, and the hardness was expressed as the maximum force (g). Three locations were evenly selected on the equatorial plane of each fruit for measurement, and the average value was taken.

[0029] 4. Determination of Total Soluble Solids (TSS) and Titratable Acidity (TA) Content Peel and pit each yellow peach, removing the red flesh around the pit. Chop the remaining flesh and mix thoroughly. Extract juice using a JYZ-V5PLUS smart juicer. Quickly transfer the juice into 50 mL centrifuge tubes and centrifuge at 4℃ and 8000 r / min for 10 min. Collect the supernatant and measure the total saturation solution (TSS) using an ATAGO PAL-BX / ACID F5 portable saccharimetric analyzer. Three biological replicates were performed for each treatment, with each replicate containing five fruits.

[0030] The TA content in the fruit was determined by titration. 0.1 g of liquid nitrogen-frozen yellow peach sample was weighed, ground in a mortar, and transferred to a 100 mL volumetric flask. The mortar was rinsed with distilled water and transferred to the flask as well. The mixture was then brought to the mark and shaken well. After standing for 30 min, the extract was filtered. 20.0 mL of the filtrate was accurately measured into an Erlenmeyer flask, and 2–3 drops of 1% phenolphthalein indicator were added. Titration was performed with standardized NaOH solution until the solution initially turned pink and the color did not fade within 30 seconds, indicating the endpoint. The volume of NaOH solution used was recorded. A blank titration was performed using distilled water instead of the filtrate. Each sample was measured three times, and the average value was taken.

[0031] ; Where: V—total volume of sample extract, mL; V S —Volume of filtrate taken during titration, mL; C —Molar concentration of sodium hydroxide titrant, mol / L; V1 —Volume of NaOH solution consumed in titrating the filtrate, mL; V0 —Volume of NaOH solution consumed in titrating distilled water, mL; W —Sample weight, g; f —Conversion factor for malic acid, . .

[0032] 5. Respiratory rate measurement The respiration rate of fruits was measured using a fruit and vegetable respiration meter. Three fruits were randomly selected, weighed, and placed in a 2 L respiration chamber. The chamber was sealed, and the air pump was turned on to expel air for 5 minutes. Then, the measurement program was started, and data were collected every 15 seconds. Concentration data were measured continuously for 15 min. Fruit volume was determined using the water displacement method for calculating respiration rate. Three biological replicates were set up for each treatment, with each replicate containing 3 fruits.

[0033] 6. Determination of fruit membrane lipid peroxidation-related indicators, oxidase activity, and total antioxidant capacity. MDA content, SOD and POD activity, and the free radical scavenging abilities of FRAP, DPPH, ABTS, and GSH were determined using a kit.

[0034] 7. Data Processing and Analysis Data processing and chart creation were performed using Excel and Origin 2018. One-way ANOVA was conducted using DPS 20.05 Advanced Edition, and the significance of differences was tested using Duncan's new multiple range test. P <0.05. Data in the figures are expressed as mean ± standard error. Statistical differences are based on comparisons between the treatment and control groups at the same time point, labeled with letters a to d. No label indicates no significant difference. P > 0.05).

[0035] III. Experimental Results 1. Effects of different treatments on the appearance of yellow peaches during storage The appearance of fruit directly reflects its freshness and influences consumers' purchasing decisions. The changes in appearance of yellow peaches treated differently and stored for different periods are shown below. Figure 1 As shown, at 0 days, the surface of the yellow peach fruit was smooth, spotless, and glossy. With prolonged storage, the fruit moisture content gradually decreased, the peel color gradually darkened, and brown spots appeared, indicating fruit senescence. The browning symptoms on the surface of the yellow peach fruit varied significantly among different treatment groups. In the CK group, obvious brown spots appeared on the fruit surface on the 8th day of storage. In contrast, the fruit in the AP+O3 group maintained a good appearance throughout the storage period, with a uniform yellow surface and no obvious browning. This result indicates that 42.86 mg / m 3 Ozone treatment did not cause surface damage to yellow peaches and significantly delayed the onset of adverse symptoms. The PE+O3 group showed the second-best preservation effect, with slight browning on the fruit surface at 12 days of storage. The AP group showed browning on the fruit surface at both 8 and 12 days of storage.

[0036] Intense respiration accelerates the aging of fresh fruit, causing a decrease in firmness and quality loss due to the consumption of respiratory substrates; simultaneously, the heat generated by aerobic respiration is mainly released from the fruit surface through the evaporation of moisture. Anti-fogging and antibacterial packaging combines both anti-fogging and antibacterial functions, effectively preventing condensation on the inner walls of the packaging and inhibiting the growth and reproduction of pathogenic microorganisms. Figure 2 As shown, in ordinary PE packaging, water vapor condenses on the inner wall of the packaging due to fruit respiration, water loss, or temperature fluctuations, resulting in significant fogging. Anti-fogging and antibacterial packaging effectively reduces the degree of fogging. The anti-fogging mechanism is speculated to be that the anti-fogging agent on the inner surface of the packaging material rapidly adsorbs water vapor through migration, and utilizes the hydrogen bonding between its hydrophilic groups and water molecules to uniformly and stably disperse it on the inner surface of the packaging, preventing water vapor from condensing into fog. This indicates that anti-fogging and antibacterial packaging has significant application potential in the preservation of fresh agricultural products with high respiration rates.

[0037] 2. Effects of different treatments on the color of yellow peach peel The color of the yellow peach peel directly reflects the fruit's ripeness, freshness, and commercial value, and is an important appearance indicator for evaluating the effectiveness of different preservation treatments. The CIELAB colorimetric system is typically used for evaluation, where L... The value represents brightness; a higher value indicates a brighter fruit color, while browning will reduce it. Represents redness and greenness; a positive value indicates a reddish tint, which increases as brown substances accumulate during epidermal browning; b The value represents the yellow-blue tint, with a positive value indicating a yellowish hue, reflecting the golden-yellow base color of the peach. This value decreases as freshness declines. As storage time increases, the L value of the 'Jinxiu' yellow peach skin... The overall value shows a downward trend. Figure 3 (A) Among them, AP+O3 showed the best performance in maintaining color stability, effectively delaying the decline in the brightness of yellow peaches and helping to prolong visual freshness. At storage days 4, 8, and 12, the L... The values ​​were 73.53±1.32, 74.06±1.18, and 72.84±0.61, respectively, all significantly higher than those of the CK group (70.52±0.20, 70.65±0.61, and 69.74±0.13) and the PE+O3 group (71.31±0.09, 71.21±0.54, and 71.13±0.67). Figure 3 As shown in C, the b of the 'Jinxiu' yellow peach fruit in each treatment Similarly, the overall trend was downward. On the 8th and 12th days of storage, the b of the fruits in the AP+O3 group... The a value was significantly lower than that of the control group and the other two groups, indicating that it could better maintain the golden yellow color of the peaches. During storage, the a value of the AP+O3 group was significantly lower than that of the control group and the other two groups. The value variation range was small, especially on the 12th day of storage, the a value of the AP+O3 group was relatively small. The smallest value was 2.74±0.20, indicating that AP+O3 can delay the color change of 'Jinxiu' yellow peaches during storage. Figure 3 (B) On days 4, 8, and 12 of storage, the AP and PE+O3 groups showed significant differences compared to the control (CK), but their effects were significantly lower than those of AP+O3. These results are consistent with observations of the fruit's appearance, indicating that the combined treatment of anti-fog and antibacterial packaging with ozone (AP+O3) effectively inhibited browning of the 'Jinxiu' yellow peach, better preserving its proper color. Therefore, the combined treatment of ozone and anti-fog and antibacterial packaging has a good effect on maintaining fruit color.

[0038] 3. Effects of different treatments on the firmness of yellow peaches Firmness is a key indicator of fruit quality, reflecting the fruit's structural integrity, water retention capacity, and freshness, directly affecting its taste, shelf life, and market value. The changes in fruit firmness over time under different treatments are shown below. Figure 4 As shown, the fruit firmness of all treatment groups decreased with prolonged storage time, but the rate and magnitude of the decrease varied significantly among different treatments. Specifically, the fruit firmness of the AP group and the AP+O3 group was consistently significantly higher than that of the CK group during storage (2 days to 12 days). P<0.05), while the PE+O3 group showed no significant difference in fruit firmness compared to the CK group at the end of storage (12 days). These results indicate that while ozone treatment alone has a certain protective effect, its effectiveness in maintaining firmness is not as good as the synergistic treatment of anti-fog and antibacterial packaging + ozone treatment, especially in the later stages of storage. Therefore, the combined treatment of anti-fog and antibacterial packaging and ozone can effectively delay the decline in fruit firmness and slow down fruit senescence.

[0039] 4. Effects of different treatments on the TSS and TA content of yellow peaches Soluble solids (TSS) are a key indicator of fruit maturity and overall quality, reflecting sugar accumulation and its retention during storage. Figure 5 As shown in Figure A, during storage, except for PE+O3, the TSS (Total Sugar Saturation) of yellow peaches in other treatment groups showed a trend of first increasing and then decreasing. The CK (Category CK) showed the most significant upward trend, reaching a peak of 13.2% ± 0.1 on day 8 of storage, while the TSS content dropped to its lowest point on day 12 of storage, at 9.07% ± 0.06 (a decrease of 31.29%). The TSS increase and decrease trends in AP+O3 were relatively gradual. During the same period (day 8), the TSS value only increased to 10.37% ± 0.06, while on day 12 of storage, the TSS also showed a certain degree of decrease, at 9.8% ± 0 (a decrease of 5.50%), which was 5.69 times greater than that of the AP+O3 group. Ozone treatment delayed the accumulation of TSS, demonstrating excellent sugar preservation and quality control capabilities, as the TSS of both the AP+O3 and PE+O3 groups was significantly lower than that of the AP and CK groups from day 2 to day 8 of storage. This is likely due to the preservation of sugar levels by reducing the respiration rate. This protective effect may stem from ozone treatment strengthening cell structure—by reinforcing cell walls and reducing oxidative damage, it helps sugars remain intact for longer. In the later stages of storage, the total sugar level (TSS) of yellow peaches decreases due to respiration. At 12 days of storage, AP+O3 significantly decreased (…). P The TSS of yellow peach fruit was maintained by < 0.05, indicating that the combined treatment of AP+O3 is more helpful in slowing down sugar metabolism and inhibiting the decline of TSS.

[0040] Titratable acid (TA) content is a crucial factor influencing fruit flavor and quality, acting as a matrix in fruit respiration and gluconeogenesis. The decrease in TA content during fruit storage is due to the consumption of organic acids as substrates for respiration and their involvement in sugar synthesis during fruit ripening. For example... Figure 5As shown in Figure B, the TA content of yellow peaches in all treatments showed a continuous decreasing trend during storage. Specifically, the TA content of the AP+O3 group was significantly higher than that of the CK group throughout the entire storage period (2 days to 12 days); the TA content of the AP group was significantly higher than that of the CK group in the early stage of storage (2 days to 4 days), but showed no significant difference from the CK group in the later stage of storage (8 days to 12 days); while the PE+O3 group was significantly higher than the CK group only at 2 days of storage, and showed no significant difference from the CK group at other time points. p <0.05%, especially on storage days 4 and 8 (0.49%±0.014 and 0.39%±0.009), while the CK, AP, and PE+O3 groups were (0.38%±0.012 and 0.32±0.005%; 0.44%±0.048 and 0.32%±0.013; 0.42%±0.005 and 0.35%±0.003), respectively. These results indicate that the combined AP+O3 treatment can effectively delay the conversion and degradation of organic acids in yellow peaches, which is beneficial for extending storage time and slowing down the loss of fruit flavor. Li et al.'s research shows that... Ozone treatment can better maintain the TA content of grapes and preserve the quality of fresh grapes, which is consistent with the results of this study. In addition, ozone treatment at appropriate concentrations can maintain high firmness, soluble solids and titratable acid content in kiwifruit and Korla pears, delay the softening, ripening and senescence of apples and melons, and effectively extend the shelf life of fruits.

[0041] 5. Effects of different treatments on the respiration rate of yellow peaches Respiration intensity refers to the amount of oxygen absorbed or carbon dioxide released per unit weight of fruit per unit time. It is an important indicator reflecting the metabolic strength of a fruit. The respiration intensity of climacteric fruits is closely related to their maturity; the higher the respiration intensity, the more nutrients the fruit consumes, the faster the fruit ages, and the shorter its storage life. Figure 6 As shown, the respiration intensity of both the CK and AP groups peaked on day 2 of storage, but the AP group (93.30±0.30) was significantly lower than that of the CK group (106.61±0.95), indicating that anti-fogging and antibacterial packaging alone can also inhibit the respiration of yellow peaches. The AP+O3 and PE+O3 groups peaked on day 4, at 76.90±2.70 and 82.78±0.28 respectively, and were significantly lower than those of the CK group (95.25±2.81) and the AP group (93.77±2.94), with the AP+O3 group having the lowest respiration intensity. P<0.05). From day 4 onwards, the respiration intensity of the PE+O3 group began to decrease rapidly, indicating that ozone treatment alone had a weakening inhibitory effect on respiration in the later stages of storage; while the respiration intensity of the AP+O3 group changed gradually and still showed an upward trend after 12 days of storage. These results suggest that ozone treatment can delay the onset of the fruit's respiration peak, thereby extending the storage period. This may be because the negative oxygen ions produced by ozone decomposition can neutralize the positive charge generated by respiration, inhibit the generation and release of endogenous ethylene, reduce the activity of related enzymes, thereby weakening respiration, reducing sugar and acid consumption, slowing nutrient loss, and extending the fruit's storage period.

[0042] 6. Effects of different treatments on MDA content in yellow peaches MDA, as an indicator of lipid peroxidation in plants, is an indicator of the degree of postharvest oxidative damage in fruits and an important parameter reflecting fruit ripening and senescence. MDA content is directly related to the degree of cell membrane lipid peroxidation; a higher MDA content indicates a greater degree of cell membrane lipid peroxidation. Figure 7 As shown, the MDA content of both the AP+O3 and PE+O3 groups remained low throughout the storage period, with the AP+O3 group exhibiting the lowest MDA content, 35% lower than the control (CK) at day 12. The MDA content of the PE+O3 group was significantly lower than other groups in the later stages of storage (days 8-12). These results indicate that anti-fogging and antibacterial packaging combined with ozone treatment delayed the accumulation of MDA content.

[0043] The average MDA content of each group of yellow peaches is shown in Table 1.

[0044] Table 1. Average MDA content of yellow peaches in each group ; Table 1 shows that the MDA content inhibition in the AP+O3 group was extremely significant at 2 and 4 days. Using the MDA content of the CK group as a reference, the relative inhibition rates of the AP, PE+O3, and AP+O3 groups were calculated to reflect the contributions of anti-fog and antibacterial packaging treatment, ozone treatment, and anti-fog and antibacterial packaging + ozone treatment to MDA content inhibition. The commonly used method in this field, Jin Zhengjun, was employed. q The value method is used to determine whether there is a synergistic effect between anti-fog and antibacterial packaging treatment and ozone treatment on MDA content inhibition. The calculation formula is as follows: q =E a+b / (E a +E b -E a ×E b ), where: E a and E b The MDA content inhibition rates of anti-fogging and antibacterial packaging treatment alone and ozone treatment alone are E a+bThe formula represents the inhibition rate of MDA content in the combined treatment; the numerator represents the "measured combined effect", the denominator is the "expected combined effect", and the q value is the ratio of the two. q <0.85 indicates an antagonistic effect, 0.85≤ q <1.15 indicates an additive effect. q A synergistic effect of ≥1.15 is defined. The results are shown in Table 2.

[0045] Table 2. Contribution and synergistic effect of anti-fog and antibacterial packaging, ozone alone and combined treatment on MDA content inhibition. ; The results indicate that anti-fog and antibacterial packaging combined with ozone can synergistically delay the accumulation of MDA in yellow peaches after 2 and 4 days of preservation treatment, thus playing a role in delaying the ripening and senescence of yellow peaches.

[0046] 7. Effects of different treatments on the activity of antioxidant enzymes in yellow peaches Superoxide dismutase (SOD) activity is a key indicator for measuring the antioxidant defense capacity of fruits, reflecting their response to oxidative stress during storage. For example... Figure 8 As shown in Figure A, the SOD activity in all treatments of yellow peaches showed an increasing trend with prolonged storage time. Among them, the SOD activity in the AP+O3 group was significantly higher than that in other treatments during storage from 4 to 12 days. P <0.05), indicating that the appropriate concentration of ozone combined with anti-fogging and antibacterial packaging synergistic treatment has a strong promoting effect on SOD activity, and can effectively activate and maintain the antioxidant defense system of yellow peach fruit.

[0047] POD is an important oxidoreductase in fruits and vegetables, catalyzing the reaction of H2O2 with phenolic substances to form quinones. Working in coordination with SOD, it maintains normal dynamic levels of free radicals and plays a crucial role in postharvest fruit senescence and free radical scavenging. Enzymatic browning is generally considered a direct result of POD oxidizing phenolic substances to produce quinone compounds under external stimuli such as environmental changes, further forming dark-colored substances. Figure 8 As shown in Figure B, due to vigorous respiration and metabolism in the fruit, internal substances such as phenols are consumed, resulting in significant fluctuations in POD activity in the CK group. From day 2 to day 8 of storage, the activity continuously decreased to a low level, at which point the fruit's internal homeostasis collapsed, leading to irreversible quality deterioration. Combined with changes in other indicators, this drastic fluctuation is presumed to be caused by metabolic disorders within the fruit. In contrast, the POD activity in the treatment groups showed smaller fluctuations, exhibiting a steady and slow upward trend. In response to aging, the AP+O3 group exhibited a stress response, with a significant increase in POD activity from day 2 to day 8 of storage. However, due to the depletion of endogenous nutrients, the response could not be sustained, and POD activity decreased from day 8 to day 12 of storage. These results indicate that the AP+O3 group effectively inhibited POD activity.

[0048] 8. Effects of different treatments on the total antioxidant capacity of yellow peaches To comprehensively evaluate the effects of different treatments on the total antioxidant capacity of yellow peach fruits, this study measured the changes in GSH content, DPPH, FRAP, and ABTS free radical scavenging rate of yellow peach fruits in each treatment group during storage. Figure 9 As shown in Figure A, the DPPH free radical scavenging rate of yellow peach fruits in all groups showed a continuous decreasing trend with the extension of storage time. Among them, the CK group showed the fastest decrease, reaching only 7.75%±1.42 at the end of storage (12 days), which was significantly lower than the three treatment groups. The DPPH free radical scavenging rate of the AP+O3 group was significantly higher than that of the CK, AP, and PE+O3 groups at all storage stages, reaching 24.87%±1.55 at the end of storage (12 days). The above results indicate that all three treatment groups can significantly improve the antioxidant capacity of the fruit, with the AP+O3 group showing the best effect. The ABTS free radical scavenging rate of yellow peach fruits under different treatments showed different trends during storage (see Figure A). Figure 9 (B) Among them, the CK and PE+O3 groups showed a decreasing trend, while the AP and AP+O3 groups showed an increasing and then decreasing trend. In the early stage of storage (2 days), the ABTS free radical scavenging rate of the fruit in the AP+O3 group was significantly higher than that in the AP group, but significantly lower than that in the control group; in the storage period of 4 to 12 days, the ABTS free radical scavenging rates of both the AP group and the AP+O3 group were significantly higher than those in the CK and PE+O3 groups.

[0049] like Figure 9 As shown in Figure C, on day 2 of storage, the FRAP radical scavenging rate of the AP+O3 group was significantly higher than that of other treatment groups, and 19.42% higher than that of the control group. P <0.05). However, by day 8 of storage, the FRAP radical scavenging rate in the AP+O3 group was 23.66% higher than that in the control group (CK). P <0.05). GSH is an important antioxidant in plants, which can maintain cellular redox balance and is an important component of the antioxidant defense system. From day 2 to day 12 of storage, the GSH content of both the AP+O3 group and the PE+O3 group was significantly higher than that of the control (CK) (see...). Figure 9 (D) The AP group showed significantly higher levels of GSH than the control group (CK) from day 2 to day 4 of storage, but from day 8 to day 12 of storage, there was no significant difference between the AP and CK groups. AP+O3 treatment maintained a high level of GSH in yellow peaches during storage. GSH, with its strong reducing ability, can directly neutralize intracellular ROS. The increased activity of ROS-scavenging enzymes and the enhanced antioxidant capacity significantly improved the ABTS, DPPH, and FRAP free radical scavenging abilities of yellow peaches.

[0050] To cope with the stress of reactive oxygen species, plants have evolved enzymatic (SOD, POD) and non-enzymatic (GSH) antioxidant defense systems to enhance their antioxidant capacity. Among these, SOD can catalyze superoxide anion free radicals (SOD, POD, and GSH). Disparaging into Subsequently Under the influence of POD, it decomposes into and This helps maintain cellular homeostasis and reduce oxidative damage to cell membranes. In this study, the combined AP+O3 treatment maintained higher SOD and POD activities in the fruit, which may explain the lower MDA content in the treated group. This study also observed that the combined AP+O3 treatment maintained higher levels of GSH, ABTS, and DPPH free radical scavenging rates in post-harvest yellow peaches during storage. Therefore, it can be inferred that the combined AP+O3 treatment can significantly enhance the antioxidant capacity of yellow peaches, restore redox balance, reduce oxidative damage to cell membranes, and thus effectively inhibit fruit browning.

[0051] In summary, this embodiment used the fruit of the main yellow peach variety 'Jinxiu' as the test material to systematically evaluate the regulatory effects of anti-fogging and antibacterial packaging, ozone, and their combined treatment on the postharvest storage quality of yellow peaches. The results showed that the combined treatment of anti-fogging and antibacterial packaging and ozone could synergistically maintain the postharvest storage quality of yellow peaches through both physical anti-fogging and enhanced fruit's own antioxidant defense. In terms of appearance, the combined treatment could effectively maintain the appearance quality of the yellow peaches and significantly delay the deterioration of peel aging. The decrease in value inhibited a The increased levels of ozone maintained the fruit's bright yellow color and reduced browning symptoms. In terms of texture and flavor, the combined treatment delayed the decline in fruit firmness and the degradation of TA, better preserving the fruit's taste and flavor. Simultaneously, this treatment inhibited fruit respiration, reducing the consumption of nutrients such as sugars and acids. More importantly, the combined treatment significantly enhanced the fruit's antioxidant defense capabilities, increased SOD activity, maintained a high GSH content, and resulted in significantly better DPPH free radical scavenging rates, ABTS cation free radical scavenging rates, and FRAP levels during storage compared to the control. The enhanced antioxidant capacity effectively restored cellular redox balance, reduced membrane lipid peroxidation, decreased MDA content in the fruit, and effectively inhibited POD activity, thereby delaying senescence and inhibiting browning. Considering all indicators, the combined preservation effect of anti-fog antibacterial packaging and ozone treatment was superior to using either anti-fog antibacterial packaging or ozone treatment alone, indicating a significant synergistic effect. Therefore, this combined treatment can be used as a safe and efficient physical preservation technology to extend the shelf life of yellow peaches and for post-harvest commercial preservation.

[0052] Example 2: This embodiment provides a method for preserving yellow peaches for 2-4 days using anti-fog and antibacterial packaging combined with ozone treatment. The yellow peaches are placed in an anti-fog and antibacterial packaging bag containing ozone and sealed for storage. The ozone concentration is 42.86 mg / m³. 3 Store at 8℃.

[0053] The purpose of the above embodiments is to specifically illustrate the substantive content of the present invention, but those skilled in the art should know that the scope of protection of the present invention should not be limited to the specific embodiments.

Claims

1. A method for preserving yellow peaches using anti-fog and antibacterial packaging combined with ozone treatment, characterized in that: Store the yellow peaches in a sealed, anti-fog, and antibacterial packaging container containing ozone.

2. The method according to claim 1, characterized in that: The anti-fog and antibacterial packaging container is an anti-fog and antibacterial packaging bag.

3. The method according to claim 1 or 2, characterized in that: The anti-fog and antibacterial packaging container is made of PE / PET material and loaded with cinnamaldehyde.

4. The method according to claim 3, characterized in that: Ozone concentration of 30~50 mg / m³ 3 .

5. The method according to claim 4, characterized in that: Ozone concentration of 35~45 mg / m³ 3 .

6. The method according to claim 5, characterized in that: The ozone concentration was 42.86 mg / m³. 3 .

7. The method according to claim 3, characterized in that: The storage temperature is 4~12℃.

8. The method according to claim 7, characterized in that: The storage temperature is 6~10℃.

9. The method according to claim 8, characterized in that: Store at 8℃.

10. The method according to claim 3, characterized in that: The storage time is ≤12 days, preferably ≤4 days, and more preferably 2 or 4 days.

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