Waxberry preservative as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of fruit preservation, and particularly relates to a waxberry preservative as well as a preparation method and application thereof. The waxberry preservative is obtained by electrolyzing a mixed solution of calcium chloride and food-grade acetic acid, the effective chlorine concentration of the preservative is 10-80 mg / L, and the pH value is 5.0-6.5. The instant sterilization of the electrolyzed water and the continuous bacteriostasis of the vacuum precooling are combined, and calcium ions in the electrolyzed water are utilized to strengthen the cell structure and induce the self resistance response of the waxberries, so that the spanning from passive preservation to active resistance enhancement is realized, the shelf life of the waxberries can be remarkably prolonged, the nutrition and sensory quality of the waxberries can be maintained, and the method is green, safe and free of residues.

Description

Technical Field

[0001] This invention belongs to the field of fruit preservation technology, specifically relating to a preservative for bayberries, its preparation method, and its application. Background Technology

[0002] Yangmei ( Myrica rubra As a high-value berry with Chinese characteristics, it has vigorous postharvest respiration and soft, juicy tissue, making it extremely susceptible to mechanical damage and microbial infection, leading to rot, juice loss, flavor deterioration, and rapid degradation of nutrients (such as anthocyanins and ascorbic acid).

[0003] To address the aforementioned industry challenges, existing technologies have proposed various solutions, mainly relying on low-temperature storage combined with physical or chemical treatment, but all of them have significant limitations.

[0004] In recent years, some physical and non-thermal sterilization technologies have been explored for the preservation of bayberries. Analysis of existing patents and literature reveals that current technologies mainly focus on single technologies or simple physical combinations, failing to address the problem from a systemic and synergistic perspective. Specifically: While the single electrolytic water soaking treatment used in existing patent CN113662036A has the advantages of being green and safe, its sterilization effect is instantaneous and cannot continuously inhibit microbial regeneration during subsequent storage. Moreover, the single oxidative stress is insufficient to strongly activate the systemic resistance response of the fruit. The single vacuum precooling technology involved in patent CN109463429B can achieve rapid cooling, but it is essentially physical preservation and does not have an active sterilization function. Its effect on bayberries with high initial colony counts is limited, and simple cooling cannot effectively delay the oxidative degradation of nutrients. Furthermore, although patent CN117730902A integrates cleaning and vacuum precooling into the equipment, its core is to improve process efficiency. The cleaning agents used have a wide range of components. More importantly, this integrated technology does not solve the problem of whether the surface moisture brought by the pretreatment will aggravate the weight loss problem during the vacuum precooling process, nor does it reveal whether there is a biochemical synergistic effect between specific chemical components and physical processes.

[0005] In summary, existing technologies are either applications of a single technology or combinations of physical processes, neither of which involve the use of a specific chemical component (Ca). 2+ H + The deep synergy between electrolyzed water and vacuum precooling physical field achieves a systematic preservation effect, ranging from "surface sterilization" and "rapid antibacterial action" to "internal induced resistance", "structural strengthening" and "component stability".

[0006] Therefore, there is an urgent need to develop a novel composite preservation method with synergistic enhancement effects. Summary of the Invention

[0007] The purpose of this invention is to provide a preservative for bayberries, its preparation method, and its application. The bayberry preservative described in this invention, combined with the physical stress of vacuum precooling, can activate the bayberry fruit's own defense metabolic pathways, promote the biosynthesis of bioactive substances with antioxidant functions, significantly extend the shelf life of bayberries, maintain their nutritional and sensory quality, and is green, safe, and residue-free.

[0008] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a bayberry preservative, which is prepared by electrolysis of a mixture of 0.5-2% calcium chloride and 0.01-0.1% acetic acid.

[0009] Preferably, the volume ratio of 0.5-2% calcium chloride and 0.01-0.1% acetic acid in the mixture is (0.2-8):1.

[0010] Preferably, the effective chlorine concentration of the bayberry preservative is 10-80 mg / L, and the pH value is 5.0-6.5; the electrolysis process is carried out in a slightly acidic electrolyzed water generator; the voltage of the slightly acidic electrolyzed water generator is 12 V.

[0011] The present invention also provides a method for preparing a bayberry preservative, comprising mixing a 0.5-2% calcium chloride solution and a 0.01-0.1% acetic acid solution, and then electrolyzing the mixture to obtain the bayberry preservative; The mixing ratio of the 0.5-2% calcium chloride solution and the 0.01-0.1% acetic acid solution is (0.2-8):1; the electrolysis process is carried out in a slightly acidic water electrolyzer; the voltage of the slightly acidic water electrolyzer is 12 V.

[0012] This invention also provides a method for preserving bayberries, comprising the following steps: S1. Soak the bayberries in the above-mentioned bayberry preservative to sterilize them; S2. After soaking and sterilizing the bayberries, drain off the surface water and immediately put them into a vacuum precooler for precooling. S3. Pack the pre-cooled bayberries into a freezer bag and store them in the refrigerator.

[0013] Preferably, the solid-liquid ratio of the bayberry and the bayberry preservative in step S1 is 1:(2-5); the soaking and sterilization process is: stirring and soaking at 20±2℃ for 2-10 minutes.

[0014] Preferably, the pre-cooling process described in step S2 involves pre-cooling the bayberry at an absolute pressure of 500~800 Pa in a vacuum chamber until the center temperature is 2~6℃.

[0015] Preferably, the refrigerated storage conditions in step S3 are storage at 2~6℃.

[0016] This invention also provides the application of the above-mentioned bayberry preservative or the above-mentioned method in inhibiting the postharvest microbial growth of bayberries or delaying the decay of bayberries.

[0017] This invention also provides the application of the above-mentioned bayberry preservative or the above-mentioned method in inducing postharvest phenylpropane metabolism in bayberries and enhancing their stress resistance.

[0018] The beneficial effects of this invention are: 1. Synergistic sterilization and bacteriostasis: The effective components in the electrolyzed water can kill microorganisms on the surface of the bayberry; the subsequent vacuum precooling process rapidly cools down the water and creates a low-oxygen environment, which inhibits the regrowth and reproduction of microorganisms in a long-term manner.

[0019] 2. Inducing fruit resistance response: The combination of mild oxidative stress from water electrolysis and physical stress from vacuum precooling can activate the fruit's own defense metabolic pathways and promote the biosynthesis of bioactive substances with antioxidant functions.

[0020] 3. Multiple quality preservation mechanisms: Calcium ions introduced into the water through electrolysis help maintain the integrity of cell structure; the acidic environment is conducive to the stability of anthocyanins; this method can effectively slow down the oxidative degradation of ascorbic acid.

[0021] 4. Green and safe: The entire processing uses water and food-grade additives as raw materials, with no harmful chemical residues, meeting the requirements of modern food safety for green preservation technology. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 Flowchart of the bayberry preservation process; Figure 2 Bar chart showing the changes in the decay rate of bayberries in different treatment groups during storage; Figure 3 A graph showing the changes in total phenol content of bayberries in different treatment groups during storage; Figure 4 Bar chart showing the changes in microbial indicators of bayberries in different treatment groups during storage; Figure 5 Curves showing the changes in ascorbic acid levels in bayberries from different treatment groups during storage; Figure 6 The graph shows the changes in anthocyanin levels in bayberries from different treatment groups during storage. Detailed Implementation

[0024] This invention provides a preservative for bayberries, its preparation method, and its application. The bayberry preservative is prepared by electrolysis of a mixture of 0.5-2% calcium chloride and 0.01-0.1% acetic acid; the volume ratio of 0.5-2% calcium chloride to 0.01-0.1% acetic acid in the mixture is (0.2-8):1; the prepared bayberry preservative has an effective chlorine concentration of 10-80 mg / L and a pH value of 5.0-6.5.

[0025] Preservation treatment of bayberries using the bayberry preservative prepared in this invention includes: soaking bayberries in electrolyzed water with an effective chlorine concentration of 10-80 mg / L and a pH of 5.0-6.5 for 2-10 minutes; then immediately performing vacuum pre-cooling treatment, with an absolute pressure of 500-800 Pa in the vacuum chamber, until the temperature at the center of the fruit drops to 2-6℃; and finally storing them at a low temperature of 2-6℃.

[0026] This invention combines the instant sterilization of electrolyzed water with the continuous antibacterial effect of vacuum precooling. It also utilizes calcium ions in electrolyzed water to strengthen cell structure and induce the bayberry's own resistance response, thus achieving a leap from "passive preservation" to "active resistance enhancement". This can significantly extend the shelf life of bayberries, maintain their nutritional and sensory quality, and is green, safe and residue-free.

[0027] To further illustrate the present invention, the technical solutions provided by the present invention will be described in detail below with reference to the accompanying drawings and embodiments, but these should not be construed as limiting the scope of protection of the present invention.

[0028] Unless otherwise specified, the production processes, experimental methods, or testing methods involved in the embodiments of this invention are all conventional methods in the prior art, and their names and / or abbreviations are all conventional names in the field, which are very clear and distinct in the relevant application areas. Those skilled in the art can understand the conventional process steps based on the names and apply the corresponding equipment, and implement them according to conventional conditions or the conditions recommended by the manufacturer.

[0029] The various instruments, equipment, raw materials or reagents used in the embodiments of this invention are not subject to any special restrictions on their source. They are all conventional products that can be purchased through regular commercial channels and can be prepared according to conventional methods known to those skilled in the art.

[0030] Example 1 1.1 Preparation of preservative for bayberries Prepare an electrolyzed water solution containing 1% calcium chloride and 0.05% food-grade acetic acid in a 2:1 ratio. Electrolyze the solution using a slightly acidic electrolyzed water generator (12 V voltage, 5 minutes per L of solution) to obtain an effective chlorine concentration of 30±5 mg / L and a pH of 5.8±0.2.

[0031] 1.2 Preservation treatment of bayberries Take 1 kg of freshly picked, undamaged "Biji" variety bayberries and immerse them in 2 L of the above-mentioned electrolyzed water (solid-liquid ratio 1:2), and gently stir for 5 minutes at 20±2℃.

[0032] After being removed from the water, drain off any remaining surface moisture and immediately place the fruit into a vacuum precooler. Set the absolute pressure of the vacuum chamber to 600 Pa and precool until the center temperature of the bayberry fruit drops to 4±1℃.

[0033] The processed bayberries were packed into 0.03 mm thick PE preservation bags and stored in a 4℃ cold storage.

[0034] Waxberries treated under the same conditions but soaked in distilled water were used as a control group.

[0035] Example 2 2.1 Preparation of Waxberry Preservative Prepare electrolyzed water containing 1.5% calcium chloride and 0.03% food-grade acetic acid in a ratio of 0.8:1. Electrolyze the mixed aqueous solution in an electrolyzed water generator (voltage 12 V, electrolysis time of 1 L of mixed solution for 5 minutes) to obtain electrolyzed water with an effective chlorine concentration of 45±5 mg / L and a pH value of 6.0±0.2.

[0036] 2.2 Process flow for preserving bayberries The process of preserving bayberries is as follows: Figure 1 As shown.

[0037] Take 2 kg of freshly picked "Dongkui" bayberries without mechanical damage, immerse them in 6 L of the above-mentioned electrolyzed water (solid-liquid ratio 1:3), and gently stir for 8 minutes at 22±2℃.

[0038] After being removed from the water, the surface moisture was drained, and the fruit was immediately subjected to vacuum pre-cooling treatment. The absolute pressure of the vacuum chamber was set to 700 Pa, and the fruit was pre-cooled until the temperature at the center of the fruit dropped to 3±1℃.

[0039] The processed bayberries were packed into 0.03 mm thick PE preservation bags and stored in a 2℃ cold storage.

[0040] Testing revealed that the bayberries treated using the method of this invention, after 12 days of low-temperature storage, exhibited the following advantages compared to the control group: The test results of the rot rate of bayberries are as follows: Figure 2As shown, the results indicate that the rot rate of bayberries treated with the bayberry preservative prepared in this application was significantly reduced by more than 20%.

[0041] Results of microbial count detection on the surface of bayberries as follows Figure 3 As shown, the results indicate that the number of microorganisms (total colony count) on the surface of bayberries treated with the bayberry preservative prepared in this application was effectively controlled, with a reduction of more than 2.0 log CFU / g.

[0042] The quality test results of the bayberries are as follows: Figure 4-6 As shown, the total phenols, anthocyanins, and ascorbic acid content of bayberries treated with the bayberry preservative prepared in this application are significantly increased, by more than 20%, more than 20%, and more than 35%, respectively.

[0043] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A preservative for red bayberry, characterized by comprising, The preservative is prepared by electrolysis of a mixture of 0.5-2% calcium chloride and 0.01-0.1% acetic acid.

2. The preservative agent for waxberry according to claim 1, characterized in that, The volume ratio of the mixture of 0.5-2% calcium chloride and 0.01-0.1% acetic acid is (0.2-8):

1.

3. The preservative agent for waxberry as claimed in claim 1, characterized in that, The effective chlorine concentration of the preservative is 10-80 mg / L, and the pH value is 5.0-6.5; the electrolysis is performed in a micro-acid electrolytic water generator; and the voltage of the micro-acid electrolytic water generator is 12 V.

4. A method for preparing a preservative for red bayberry, characterized by, The preservative is prepared by electrolysis of a mixture of 0.5-2% calcium chloride and 0.01-0.1% acetic acid. The volume ratio of the mixture of 0.5-2% calcium chloride and 0.01-0.1% acetic acid is (0.2-8):1; the electrolysis is performed in a micro-acid electrolytic water generator; and the voltage of the micro-acid electrolytic water generator is 12 V.

5. A method for preserving the freshness of a red bayberry, characterized by, The method comprises the following steps: S1, immersing the waxberry in the preservative of claim 1 for sterilization; S2, immediately placing the sterilized waxberry in a vacuum pre-cooling machine after draining the free water on the surface; S3, packing the pre-cooled waxberry in a preservative bag for cold storage.

6. The method of claim 5, wherein, The solid-liquid ratio of the waxberry and the preservative in step S1 is 1:(2-5); and the sterilization process is stirring and immersing at 20±2℃ for 2-10 minutes.

7. The method of claim 5, wherein, The pre-cooling process in step S2 is pre-cooling to a center temperature of 2-6℃ under an absolute pressure of 500-800 Pa in a vacuum chamber.

8. The method of claim 5, wherein, The cold storage condition in step S3 is 2-6℃.

9. The waxberry preservative of claim 1 or the method of claim 5 is used for inhibiting the growth of microorganisms or delaying the decay of the waxberry.

10. The waxberry preservative of claim 1 or the method of claim 5 is used for inducing the postharvest phenylpropanoid metabolism of the waxberry and improving the stress resistance of the waxberry.

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