Food freezing fresh-keeping liquid

Abstract

The invention discloses a food freezing fresh-keeping solution which is subacid electrolyzed water containing sodium chloride with the mass concentration of 5-10%, calcium chloride with the mass concentration of 1-5%, herba houttuyniae polysaccharide with the mass concentration of 0.5-1% and tamarind polysaccharide with the mass concentration of 0.1-1%. The fresh-keeping liquid utilizes the synergistic effect of all the components, effectively inhibits the growth of microorganisms, maintains the nutritional ingredients, taste and appearance of food, prolongs the fresh-keeping period, and the components are green and safe. The fresh-keeping agent can be applied to freezing and fresh-keeping of foods such as fruits and vegetables, and is used for freezing and storing after soaking or spraying. The problems that an existing freezing preservation technology is poor in safety, poor in preservation effect and the like are solved, and good application prospects are achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of food preservation, and particularly relates to a freezing preservation liquid using slightly acidic electrolyzed water as a carrier and combined with specific food-grade additives. Background Art

[0002] In the field of food freezing preservation, there are many problems with traditional preservation technologies. Currently, other preservation formulations on the market also have their respective defects. Some traditional preservation formulations rely on chemically synthesized substances, such as certain sulfur-containing compounds, benzoic acid and its salts, etc. Although these chemical substances have a certain preservation effect, their safety is highly questioned. Sulfur-containing compounds may leave sulfur dioxide residues in food, and excessive intake can irritate the human respiratory tract and digestive system, and even cause allergic reactions; long-term consumption of benzoic acid and its salts may burden organs such as the human liver and kidneys. Moreover, as the microbial drug resistance continues to increase, the ability of these chemically synthesized preservatives to inhibit the growth of microorganisms gradually weakens, and the preservation effect is greatly reduced.

[0003] Facing the dilemma of traditional preservation technologies, slightly acidic electrolyzed water, as a new type of preservation material, has shown certain potential in the field of food preservation in recent years. Slightly acidic electrolyzed water has unique physical and chemical properties. Its effective chlorine component (mainly existing in the form of hypochlorous acid HClO) can destroy the cell membrane structure, proteins, nucleic acids and other biological macromolecules of microorganisms, thereby exerting a powerful antibacterial effect and effectively inhibiting the growth and reproduction of harmful microorganisms commonly found on the surface of food, such as Escherichia coli, Staphylococcus aureus, Listeria, etc. At the same time, slightly acidic electrolyzed water can also slow down the oxidation process of food to a certain extent. For fruits and vegetables, it can inhibit the activity of polyphenol oxidase, reduce the browning phenomenon caused by oxidation of fruits and vegetables, and maintain their color and appearance quality; for meat products, it can reduce the rate of fat oxidation, reduce the generation of odor substances, and extend the shelf life of food.

[0004] However, it is difficult to fully meet the needs of food freezing and preservation by relying solely on slightly acidic electrolyzed water. In this context, the advantages of Houttuynia cordata polysaccharide and Tamarind polysaccharide are highlighted. Houttuynia cordata polysaccharide has a wide range of sources and can be extracted from the common Houttuynia cordata. It not only has good antibacterial properties, but can also interfere with the normal growth and reproduction of microorganisms by regulating the metabolic pathways in microbial cells. It also has a certain antioxidant capacity, which can effectively remove free radicals generated by food during storage and slow down the oxidation and deterioration of food. Tamarind polysaccharide also has significant advantages. It has excellent film-forming properties and can form a dense and stable protective film on the surface of food. This protective film can not only effectively block the invasion of external microorganisms and reduce the risk of food contamination, but also reduce the rate of water loss inside the food, maintain the moisture content of the food, and maintain the taste and texture of the food. In addition, the antibacterial properties of tamarind polysaccharide cannot be ignored. The specific groups in its structure can interact with the cell membrane of microorganisms, destroy the integrity of the cell membrane, and thus inhibit the growth and reproduction of microorganisms.

[0005] Existing food freezing preservation technologies and formulas are difficult to simultaneously meet the requirements of safety, effectiveness, low cost, and wide sources. The preservation effect of existing preservation technologies is often unsatisfactory and cannot effectively inhibit the growth of microorganisms, resulting in quality degradation and deterioration of food during frozen storage. In addition, in a low-temperature environment, the formation of ice crystals during the freezing process of food will damage the cell structure, leading to water loss, and thus making the taste of the food worse and the texture rougher; at the same time, oxidation reactions will continue to occur, accelerating the deterioration of the food and causing the loss of nutrients in the food. For example, the content of antioxidant ingredients such as vitamin C and vitamin E will decrease significantly. Therefore, it is of great practical significance to develop a green, safe and efficient food freezing preservation solution. Summary of the invention

[0006] The present invention provides a food freezing fresh-keeping liquid, which can effectively inhibit the growth of microorganisms in the freezing process of food through the synergistic effect of various components, prevent cell damage, reduce ice crystal formation and maintain the comprehensive fresh-keeping effect of food texture. The fresh-keeping liquid of the present invention is safe, reliable, green and environmentally friendly.

[0007] In order to achieve the above-mentioned invention object, the present invention adopts the following technical solution: 1. Use an electrolytic water generator to produce slightly acidic electrolytic water with a pH of 5.0-6.5 and an effective chlorine concentration of 100-140ppm; 2. Preparation of preservative solution Prepare a freezing preservation solution with slightly acidic electrolyzed water at a ratio of 5-10% sodium chloride, 1-5% calcium chloride, 0.5-1% houttuynia cordata polysaccharide, and 0.1-1% tamarind polysaccharide, and control the temperature at 0-4°C; 3. Immerse the food in a freezing preservation liquid at 0 - 4°C for 5 - 30 minutes, drain the water, and quickly place it in frozen storage at -20°C; or evenly spray the preservation liquid at 0 - 4°C on the surface of the food, and place it in frozen storage at -20°C after natural air drying.

[0008] Both the tamarind polysaccharide and houttuynia polysaccharide mentioned above are conventional commercially available products.

[0009] Advantages and technical effects of the present invention: The food freezing preservation liquid of the present invention has significant advantages and good technical effects. It combines components such as slightly acidic electrolyzed water, calcium chloride, sodium chloride, houttuynia polysaccharide, and tamarind polysaccharide. These components act synergistically to enhance the comprehensive performance of the freezing preservation liquid, more effectively inhibit the growth of harmful microorganisms, slow down the oxidative deterioration of food, and extend the shelf life compared to traditional formulations. While lowering the freezing point, the present invention enhances the stability of slightly acidic electrolyzed water and the entire preservation liquid, reduces the decomposition of the effective chlorine component, and ensures the persistence of antibacterial performance. In maintaining the food quality, each component plays a role from different aspects. By enhancing the moisture retention performance, it effectively reduces the water loss of food during freezing, avoiding the influence on taste and texture due to water shortage. At the same time, it can significantly inhibit the formation of ice crystals and reduce the damage degree of ice crystals to the food cell structure, thereby ensuring that the food can still maintain a good form after undergoing the freezing and thawing processes. In addition, this freezing preservation liquid can be reused with a small loss per use, and the component sources are extensive and the cost is low, which not only improves economic benefits but also conforms to the environmental protection concept, reduces resource waste, and has obvious advantages in large-scale food freezing preservation applications. Description of the drawings

[0010] Figure 1 For the freezing point test results; Figure 2 For the hardness test results; Figure 3 For the relative conductivity (Figure A) and weight loss rate (Figure B) test results; Figure 4 For the antibacterial test results; In the above figures, ABC are Examples 1 - 3, and DEF are Comparative Examples 1 - 3. Detailed implementation manners

[0011] The following further illustrates the substantial content of the present invention in conjunction with the drawings and examples. The examples are only for better understanding of the present invention but not limited to the scope of the present invention. The methods in the examples are conventional methods unless otherwise specified, and the reagents used are conventional commercially available reagents or reagents prepared according to conventional methods unless otherwise specified; Example 1

[0012] 1. An electrolyzed water generator is used. A sodium chloride solution with a mass concentration of 0.05% is used as the electrolyte. Through electrolysis in an electrolytic cell, an inert electrode is used for the anode and a stainless - steel electrode is used for the cathode, with an oxidation - reduction potential of 800 mV. Slightly acidic electrolyzed water with a pH of 5.0 and an available chlorine concentration of 140 ppm is prepared. 2. According to the mass concentrations of 10% sodium chloride, 5% calcium chloride, 1% houttuynia polysaccharide, and 1% tamarind polysaccharide, a freezing preservation solution is prepared with slightly acidic electrolyzed water, and the temperature of the preservation solution is controlled at 4°C. 3. The matsutake is soaked in the 4°C preservation solution for 30 minutes, drained, and quickly frozen and stored at - 20°C. Example 2

[0013] 1. An electrolyzed water generator is used. A sodium chloride solution with a mass concentration of 0.1% is used as the electrolyte. Through electrolysis in an electrolytic cell, an inert electrode is used for the anode and a stainless - steel electrode is used for the cathode, with an oxidation - reduction potential of 800 mV. Slightly acidic electrolyzed water with a pH of 6.0 and an available chlorine concentration of 120 ppm is prepared. 2. According to the mass concentrations of 7.5% sodium chloride, 2.5% calcium chloride, 0.75% houttuynia polysaccharide, and 0.5% tamarind polysaccharide, a freezing preservation solution is prepared with slightly acidic electrolyzed water, and the temperature of the preservation solution is controlled at 4°C. 3. The matsutake is soaked in the 4°C preservation solution for 15 minutes, drained, and quickly frozen and stored at - 20°C. Example 3

[0014] 1. An electrolyzed water generator is used. A sodium chloride solution with a mass concentration of 0.15% is used as the electrolyte. Through electrolysis in an electrolytic cell, an inert electrode is used for the anode and a stainless - steel electrode is used for the cathode, with an oxidation - reduction potential of 800 mV. Slightly acidic electrolyzed water with a pH of 6.5 and an available chlorine concentration of 100 ppm is prepared. 2. According to the mass concentrations of 5% sodium chloride, 1% calcium chloride, 0.5% houttuynia polysaccharide, and 0.1% tamarind polysaccharide, a freezing preservation solution is prepared with slightly acidic electrolyzed water, and the temperature of the preservation solution is controlled at 4°C. 3. The matsutake is soaked in the 4°C preservation solution for 5 minutes, drained, and quickly frozen and stored at - 20°C.

[0015] Comparative Example 1: The preparation method and usage method are the same as those in Example 1, except that calcium chloride and sodium chloride are not added.

[0016] Comparative Example 2: The preparation method and usage method are the same as those in Example 1, except that houttuynia polysaccharide is not added.

[0017] Comparative Example 3: The preparation method and usage method are the same as those in Example 1, except that tamarind polysaccharide is not added.

[0018] Example 4: Detection of the freshness preservation performance of the freshness preservation liquid prepared in the above examples 1. Freezing point Place the freshness preservation liquid at -40°C, and use a thermocouple temperature sensor to detect the freezing point of the frozen freshness preservation liquid. Place the temperature sensing probe of the thermocouple temperature sensor at the center of the freshness preservation liquid, read the readings of the temperature sensor, and observe the change of the central temperature of the freshness preservation liquid over time until the temperature remains unchanged; The results are shown in Figure 1 , it can be seen from the figure that the experimental groups adding sodium chloride and calcium chloride have a lower freezing point than those without addition. Due to the characteristics of sodium chloride and calcium chloride, they will completely ionize in water, and the ions will insert between water molecules, destroying the normal structure of water molecules to form ice crystals, so that water molecules need a lower temperature to aggregate to form ice crystals, thus reducing the freezing point of the freshness preservation liquid and making it not easy to freeze in a low-temperature environment; due to the characteristics of houttuynia polysaccharide and tamarind polysaccharide, during the cooling process, the network structure formed by tamarind polysaccharide will hinder the movement and aggregation of water molecules, and have a certain hindering effect on the formation and growth of ice crystals.

[0019] 2. Hardness Soak the matsutake mushrooms with the freshness preservation liquid prepared in the above examples, place them in a sealed bag, store them at -20°C for 48 h, take them out of the sealed bag after natural thawing, use absorbent paper to absorb the moisture on the surface of the sample until no more excess moisture oozes out, and then use a texture analyzer (TA.XT Plus, UK) to measure its texture. Specifically, it is a total texture TPA experiment: the probe is P / 50; the parameters are set as follows: the pre-test speed is 1.5 mm / s, the test speed is 0.5 mm / s, the post-test speed is 2 mm / s, the trigger force is 25 g, and the test is repeated 3 times to measure the overall hardness of the matsutake mushrooms; The results are shown in Figure 2 , it can be seen from the figure that adding sodium chloride and calcium chloride to the freshness preservation liquid helps to maintain the hardness of the food during frozen freshness preservation.

[0020] 3. Relative conductivity and weight loss rate Soak the matsutake mushrooms with the freshness preservation liquid prepared in the above examples, place them in a sealed bag, store them at -20°C for 48 h, take them out of the sealed bag after natural thawing, use absorbent paper to absorb the moisture on the surface of the sample until no more excess moisture oozes out, and then measure the relative conductivity and weight loss rate of the matsutake mushrooms; (1) Relative conductivity experiment: For each group of 10 g of matsutake mushroom samples, immerse them in 30 mL of distilled water at 25°C for 60 min, and the initial conductivity (L 0 ) is measured by a conductivity meter. Subsequently, boil the above samples for 10 min, cool them to room temperature, and measure the final conductivity (L 1 ), The relative conductivity is calculated according to the following formula: (1); (2) Weight loss rate experiment: Weigh the matsutake samples before preservation using an electronic balance and record the results as W. 0 After the preservation is completed, weigh the weight of each group of samples and record the result as W 1 , the weight loss rate of all embodiments was calculated according to the following formula: (2) Among them, W 0 is the initial weight of the matsutake before preservation; W 1 This is the weight of the matsutake after preservation.

[0021] Results Figure 3 The higher the relative conductivity, the greater the damage to the food cell structure during the preservation process. The results show that adding sodium chloride and calcium chloride helps maintain the structural stability of food during the freezing preservation process, maintains the texture of food, and prevents cell damage caused by ice crystal formation during the freezing process. Houttuynia cordata polysaccharide helps reduce water loss in food during the freezing preservation process.

[0022] 4. Antibacterial The matsutake was soaked in the preservative solutions of the experimental group and the control group and then placed in a sealed bag and stored at -20℃ for 48h. After natural thawing, it was taken out of the sealed bag and the surface moisture of the sample was absorbed with absorbent paper until no more excess moisture was exuded, and the total colony count of the matsutake was determined. Specifically, under sterile conditions, the matsutake sample (25g) was ground into a homogenate in 225mL of physiological saline, 1mL of the 1:10 sample solution was sucked with a 1mL pipette, and slowly injected into a sterile test tube containing 9ml of diluent along the tube wall (be careful not to let the tip of the pipette touch the surface of the diluent), and the sample was shaken and mixed on an oscillator to make a 1:100 sample solution. According to the estimation of the sample contamination status, a 10-fold serial dilution sample solution was prepared. After each incremental dilution, a 1mL sterile pipette was used. 1mL of the gradient dilution solution was added to the sterilized nutrient agar medium, and the total colony count of the epiphytic bacteria of the matsutake was determined at 37℃ for 2d according to GB4789.2-2022.

[0023] The results are as follows Figure 4 As shown in the figure, adding tamarind polysaccharides and houttuynia cordata polysaccharides to the preservative solution can effectively inhibit the total colony count. The specific groups of tamarind polysaccharides can destroy the cell membrane of microorganisms and inhibit their growth and reproduction; houttuynia cordata polysaccharides interfere with their normal growth by regulating the metabolic pathways in microbial cells. The two work together to enhance the effect of the preservative solution in inhibiting the total colony count.

[0024] according to Figures 1-4The comprehensive score of the preservation liquid is carried out, in which the hardness and relative conductivity each account for 10% of the total score, the weight loss rate accounts for 20% of the total score, and the freezing point and antibacterial property account for 30% of the total score. The score of each item in each example is counted according to the ranking. The first place is counted as 6 points, the sixth place is counted as 1 point, and so on. The comprehensive score of the preservation effect of the preservation liquid in different examples is shown in the following table;

[0025] As shown in Table 1, the comprehensive scores of Examples 1-3 are all higher than those of Comparative Examples 4-6 (p<0.05). Among them, the comprehensive score of Example 1 is much higher than that of other examples (p<0.05). Therefore, the frozen preservation liquid prepared by the present invention has a good preservation function.

Claims

1. A food freezing and fresh-keeping liquid, characterized in that: The invention is slightly acidic electrolyzed water containing 5-10% by mass concentration of sodium chloride, 1-5% by mass concentration of calcium chloride, 0.5-1% by mass concentration of houttuynia cordata polysaccharide, and 0.1-1% by mass concentration of tamarind polysaccharide.

2. The food freezing and fresh-keeping liquid according to claim 1, characterized in that: Slightly acidic electrolyzed water pH=5.0~6.5, effective chlorine concentration 100~140ppm.

3. The food freezing and fresh-keeping liquid according to claim 1, characterized in that: When using food freezing preservative solution, soak the food in 0~4℃ preservative solution for 5~30 minutes, drain the water and quickly put it into the freezer at -20℃ for preservation; or spray 0~4℃ preservative solution evenly on the surface of the food, wait for it to dry naturally and then put it into the freezer at -20℃ for preservation.

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