Long-term preservation method of additive-free drinks

Abstract

The invention relates to a long-term preservation method for additive-free drinks and beverages. The long-term preservation method comprises the following steps: a, carrying out CO2 deoxygenation pretreatment on a container to be filled; b, quickly filling and sealing; c, deep quick-freezing; and d, freezing and storing. According to the method disclosed by the invention, the long-term preservation of the additive-free drinks and drinks in an oxygen-free frozen storage environment is realized in a manner that the drinks are not in contact with air in the whole filling process and are immediately quickly frozen after being sealed. Compared with an existing fresh-keeping and quality-guaranteeing method, the fresh-keeping method has the following advantages that firstly, the beverage is not subjected to high temperature, original material components in the beverage are protected (reserved) to the maximum extent, and therefore the original fresh flavor and taste of the product are kept; and 2, the treatment efficiency is high, air in a container to be filled is squeezed by food-grade CO2 gas, the replacement efficiency is higher, the effect is better, the oxygen isolation effect on drinks is remarkably improved, the drinks are efficiently ensured to be frozen in an oxygen-free environment, and the high-end quality and the longer refreshing time of products are ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of food preservation technology, and in particular to a long-term preservation method for non-additive alcoholic beverages. BACKGROUND

[0002] With the upgrading of consumption and the enhancement of health awareness, pure natural and non-additive drinks are increasingly popular in the market. So-called "non-additive" means that no non-naturally occurring chemical substances such as chemical preservatives (sorbic acid potassium, sulfite, etc.) are added to the product. However, "non-additive" also brings technical difficulties and challenges to the production and preservation of the product: the drink itself is extremely sensitive to oxygen. Due to the inability to add chemical preservatives, oxygen in the air will cause a series of deterioration reactions in the drink in a very short time, including: oxidative deterioration (comprehensive decline in color, aroma, and taste quality of the drink), degradation of nutritional components, and mold growth and corruption caused by microbial reproduction. In the existing drink preservation technology, the preservation (preservation) method without using chemical preservatives is usually high-temperature sterilization (high-temperature filling, pasteurization, UHT (ultra-high-temperature instantaneous sterilization)). Pasteurization uses low-temperature long-time or high-temperature short-time treatment, for example, 63℃ for 30 minutes or 72℃-75℃ for 15-20 seconds. UHT uses high-temperature short-time sterilization at 135℃-150℃, usually for 2-4 seconds. Pasteurization cannot completely kill all microorganisms, and needs to be stored in cold storage (2℃-8℃), with a shelf life of only 3-10 days; UHT can more thoroughly eliminate microorganisms (including spores) due to high-temperature instantaneous treatment, and the shelf life of the product can be up to 3-6 months.

[0003] However, for drinks that are extremely sensitive to heat, such as craft beer and fruit juice drinks, it is not feasible to obtain a longer shelf life through high-temperature sterilization, because high temperatures will cause significant changes (decrease) in the quality of the drink. Especially for pasteurization, the impact on the quality of heat-sensitive drinks is significant, and the shelf life of the drink is also very short; and using UHT equipment, even if the high-temperature sterilization time is very short, it will also have some impact on the quality of heat-sensitive drinks, and since UHT equipment is expensive, it requires higher investment and energy consumption, and is only suitable for large and medium-sized enterprises to configure and use.

[0004] Currently, there is also a "nitrogen charging preservation method" on the market, that is, by charging nitrogen into the product container to "expel" the air therein, to achieve the purpose and effect of product oxygen isolation and preservation. However, since the specific gravity of nitrogen is close to that of air and lighter than air, the replacement efficiency of using nitrogen to replace the air in the container is usually low, resulting in poor oxygen isolation effect and high cost. SUMMARY

[0005] The technical problem to be solved by the present invention is to provide a method for long-term preservation of additive-free alcoholic beverages, so as to overcome the defects and deficiencies of the prior art as described in the background art.

[0006] The technical solution adopted by this invention to solve its technical problem is: a method for long-term preservation of additive-free alcoholic beverages, comprising the following steps: a. CO2 oxygen removal pretreatment of the container to be filled: The clean container to be filled is sent into a relatively closed filling chamber filled with food-grade CO2 gas via a conveyor belt. Then, the CO2 gas inlet pipe is inserted to the bottom of the container to be filled, and food-grade CO2 gas is introduced until the oxygen concentration in the headspace of the container to be filled is detected by an oxygen concentration monitor installed on the CO2 gas inlet pipe as being below 1%. At this point, the introduction of food-grade CO2 gas is stopped, and the CO2 gas inlet pipe is quickly withdrawn from the container to be filled; b. Rapid filling and sealing: After the CO2 gas inlet tube exits the container to be filled, the filling port of the filling equipment located in the filling chamber immediately and rapidly fills the container filled with food-grade CO2 gas. The filling liquid level is below the rim of the container, and the filled beverage has been sterilized by membrane filtration. After the filling port leaves the container, the capping machine located in the filling chamber immediately seals the container. c. Deep quick-freezing: The capped product is immediately sent to the quick-freezing equipment, which cools the beverage from the filling temperature to below -18℃ within 30 minutes. d. Frozen storage: The quick-frozen product is immediately transferred to a freezer at -35℃ to -18℃ for storage.

[0007] Furthermore, in step a above, by installing an oxygen concentration monitor and a CO2 gas inlet pipe in the filling chamber, the oxygen concentration in the filling chamber is monitored in real time and food-grade CO2 gas is replenished to the filling chamber in a timely manner to maintain a high concentration of CO2 gas environment in the filling chamber. The air that is displaced by the food-grade CO2 gas in the filling container enters the filling chamber and is eventually displaced from the filling chamber by the high concentration of food-grade CO2 gas in the filling chamber.

[0008] To elaborate further, the purity of the food-grade CO2 gas mentioned in step a above is ≥99.9%.

[0009] Furthermore, in step b above, the volume of the headspace from the filling level of the container to the edge of the container opening is 2% to 5% of the total volume of the container.

[0010] Furthermore, the quick-freezing equipment described in step c above uses liquid nitrogen quick-freezing, strong air circulation quick-freezing, or plate contact quick-freezing; during the quick-freezing process, the beverage takes ≤15 minutes to pass through its maximum ice crystal formation zone.

[0011] The beneficial effects of this invention are as follows: By using food-grade CO2 gas to pre-purge the air from the container to be filled, the filling process is entirely in a CO2 gas environment, ensuring that the beverage is not exposed to air throughout the filling process. The beverage is then quickly sealed and immediately frozen, achieving long-term preservation of additive-free beverages in an anaerobic frozen storage environment. Compared with existing preservation methods, this method has the following significant advantages: 1. The beverage does not undergo high-temperature treatment, completely avoiding "heat damage" and maximizing the protection (preservation) of the original components, thus maintaining the product's original fresh flavor and taste; 2. It has high processing efficiency and low cost. Using food-grade CO2 gas, which is relatively cheaper and significantly heavier than air, to purge the air from the container results in higher replacement efficiency and better effect, significantly improving the oxygen barrier effect and effectively ensuring the beverage is frozen in an anaerobic environment, guaranteeing the product's high-end quality and relatively long shelf life. Detailed Implementation

[0012] The present invention will be further illustrated below with reference to specific embodiments. These embodiments are only some, not all, of the embodiments described herein.

[0013] Example 1

[0014] A method for long-term preservation of additive-free alcoholic beverages includes the following steps: a. CO2 Oxygen Removal Pretreatment of Containers to be Filled: Clean containers to be filled are conveyed via a conveyor belt into a relatively enclosed filling chamber filled with food-grade CO2 gas. A CO2 gas inlet pipe is then inserted to the bottom of the container, and food-grade CO2 gas with a purity ≥99.9% is introduced at a pressure of 1.3 bar until the oxygen concentration in the headspace of the container is detected to be 0.6% by an oxygen concentration monitor installed on the CO2 gas inlet pipe. At this point, the introduction of food-grade CO2 gas is stopped, and the CO2 gas inlet pipe is quickly withdrawn from the container. Because CO2 gas has a significantly higher specific gravity than air, it is blown out from the bottom of the container. Introducing CO2 gas can more effectively and efficiently expel air from the container opening, and the expelled air enters the filling chamber. Because a small amount of CO2 gas will leak and a small amount of air will enter as the container passes through the conveyor belt into and out of the filling chamber, an oxygen concentration monitor and a CO2 gas inlet pipe are also installed in the filling chamber to monitor the oxygen concentration in the filling chamber in real time and to replenish the filling chamber with food-grade CO2 gas in a timely manner to maintain a high concentration of CO2 gas environment in the filling chamber. The air expelled from the container to be filled will eventually be expelled from the filling chamber by the high concentration of CO2 gas in the filling chamber. b. Rapid Filling and Sealing: After the CO2 gas inlet tube exits the container to be filled, the filling port of the filling equipment located in the filling chamber immediately and rapidly fills the container filled with food-grade CO2 gas. The filling liquid level is 10mm from the container rim, and the resulting headspace volume is 2% of the total container volume. The filled beverage has already undergone membrane filtration and sterilization treatment. After the filling port leaves the container rim, the capping machine located in the filling chamber immediately seals the container rim. During filling, as the beverage liquid level rises continuously, most of the pre-filled food-grade CO2 gas in the container is gradually expelled from the container, eventually forming a "headspace" filled with food-grade CO2 gas at the top of the container. The "CO2 headspace" can play a certain role in oxygen isolation and sealing of the beverage. c. Deep freezing: The capped product is immediately sent to a liquid nitrogen quick-freezing device (available on the market). The liquid nitrogen spray temperature is -80℃. The product temperature drops from 15℃ (filling temperature) to -5℃ within 10 minutes and to -22℃ after 22 minutes. The maximum ice crystal formation zone temperature of the beverage is -1℃ to -5℃. The advantage of allowing the beverage to pass through the maximum ice crystal formation zone quickly is that tiny ice crystals are formed both inside and outside the cells of the beverage, avoiding puncturing the cell structure and thus better protecting the flavor substances in the beverage. d. Frozen storage: Immediately transfer the quick-frozen products to a -25°C freezer for storage.

[0015] Example 2

[0016] A method for long-term preservation of additive-free alcoholic beverages includes the following steps: a. CO2 Oxygen Removal Pretreatment of Containers to be Filled: Clean containers to be filled are conveyed via a conveyor belt into a relatively enclosed filling chamber filled with food-grade CO2 gas. A CO2 gas inlet pipe is then inserted to the bottom of the container, and food-grade CO2 gas with a purity ≥99.9% is introduced at a pressure of 1.5 bar until the oxygen concentration in the headspace of the container is detected by an oxygen concentration monitor installed on the CO2 gas inlet pipe to be below 0.8%. At this point, the introduction of food-grade CO2 gas is stopped, and the CO2 gas inlet pipe is quickly withdrawn from the container. Because CO2 gas has a significantly higher specific gravity than air, oxygen is removed from the bottom of the container. Blowing in CO2 gas can more effectively and efficiently expel air from the container opening, and the expelled air enters the filling chamber. Because a small amount of CO2 gas will leak and a small amount of air will enter as the container passes through the conveyor belt into and out of the filling chamber, an oxygen concentration monitor and a CO2 gas inlet pipe are also installed in the filling chamber to monitor the oxygen concentration in the filling chamber in real time and to replenish the filling chamber with food-grade CO2 gas in a timely manner to maintain a high concentration of CO2 gas environment in the filling chamber. The air expelled from the container to be filled will eventually be expelled from the filling chamber by the high concentration of CO2 gas in the filling chamber. b. Rapid Filling and Sealing: After the CO2 gas inlet tube exits the container to be filled, the filling port of the filling equipment located in the filling chamber immediately and rapidly fills the container filled with food-grade CO2 gas. The filling liquid level is 15mm from the container rim, and the resulting headspace volume is 3.5% of the total container volume. The beverage being filled has already undergone membrane filtration and sterilization. After the filling port leaves the container rim, the capping machine located in the filling chamber immediately seals the container rim. During filling, as the beverage liquid level rises continuously, most of the pre-filled food-grade CO2 gas in the container is gradually expelled from the container, eventually forming a "headspace" filled with food-grade CO2 gas at the top of the container. The "CO2 headspace" can play a certain role in oxygen isolation and sealing of the beverage. c. Deep quick-freezing: The capped product is immediately sent into a high-speed circulating quick-freezing equipment (existing equipment on the market). The product is cooled from 15℃ (filling temperature) to -5℃ within 12 minutes and to -20℃ after 22 minutes. The maximum ice crystal formation zone temperature of the beverage is -1℃ to -5℃. The advantage of allowing the beverage to pass through the maximum ice crystal formation zone quickly is that tiny ice crystals are formed both inside and outside the cells of the beverage, avoiding puncturing the cell structure and thus better protecting the flavor substances in the beverage. d. Frozen storage: Immediately transfer the quick-frozen products to a -25°C freezer for storage.

[0017] Example 3

[0018] A method for long-term preservation of additive-free alcoholic beverages includes the following steps: a. CO2 Oxygen Removal Pretreatment of Containers to be Filled: Clean containers to be filled are conveyed via a conveyor belt into a relatively enclosed filling chamber filled with food-grade CO2 gas. A CO2 gas inlet pipe is then inserted to the bottom of the container, and food-grade CO2 gas with a purity ≥99.9% is introduced at a pressure of 1.8 bar until the oxygen concentration in the headspace of the container is detected by an oxygen concentration monitor installed on the CO2 gas inlet pipe to be below 0.9%. At this point, the introduction of food-grade CO2 gas is stopped, and the CO2 gas inlet pipe is quickly withdrawn from the container. Because CO2 gas has a significantly higher specific gravity than air, oxygen is removed from the bottom of the container. Blowing in CO2 gas can more effectively and efficiently expel air from the container opening, and the expelled air enters the filling chamber. Because a small amount of CO2 gas will leak and a small amount of air will enter as the container passes through the conveyor belt into and out of the filling chamber, an oxygen concentration monitor and a CO2 gas inlet pipe are also installed in the filling chamber to monitor the oxygen concentration in the filling chamber in real time and to replenish the filling chamber with food-grade CO2 gas in a timely manner to maintain a high concentration of CO2 gas environment in the filling chamber. The air expelled from the container to be filled will eventually be expelled from the filling chamber by the high concentration of CO2 gas in the filling chamber. b. Rapid Filling and Sealing: After the CO2 gas inlet tube exits the container to be filled, the filling port of the filling equipment located in the filling chamber immediately and rapidly fills the container filled with food-grade CO2 gas. The filling liquid level is 20mm from the container opening, and the headspace volume formed is 5% of the total container volume. The beverage being filled has already undergone membrane filtration and sterilization treatment. After the filling port leaves the container opening, the capping machine located in the filling chamber immediately seals the container opening. During filling, as the beverage liquid level rises continuously, most of the pre-filled food-grade CO2 gas in the container is gradually expelled from the container, eventually forming a "headspace" filled with food-grade CO2 gas at the top of the container. The "CO2 headspace" can play a certain role in oxygen isolation and sealing of the beverage. c. Deep freezing: The capped product is immediately sent to a plate contact freezer (currently available equipment on the market). The product is cooled from 15°C (filling temperature) to -5°C within 13 minutes and to -20°C after 25 minutes. The maximum ice crystal formation zone temperature of the beverage is -1°C to -5°C. The advantage of allowing the beverage to pass through the maximum ice crystal formation zone quickly is that tiny ice crystals are formed both inside and outside the cells of the beverage, avoiding puncturing the cell structure and thus better protecting the flavor substances in the beverage. d. Frozen storage: Immediately transfer the quick-frozen products to a -25°C freezer for storage.

[0019] The following comparative examples are provided for comparison with the products in the above embodiments.

[0020] Comparative Example 1 A portion of the beverages used in each embodiment was taken out and preserved using the conventional method of "nitrogen filling + refrigeration".

[0021] Comparative Example 2 A portion of the beverages from the same batch used in each embodiment was taken out and preserved using the conventional method of "pasteurization after bottling + refrigeration".

[0022] After 3 months of storage, the products in the above embodiments and the products in the comparative examples were compared in quality, and the following results were found: The beverages in each embodiment retain their aroma and flavor to an extremely high degree, almost like freshly produced beverages, with a very fresh and complex taste. The aroma and flavor of the beverage in Comparative Example 1 were noticeably weak, indicating severe oxidation. The beverage in Comparative Example 2 had a distinct stale taste, lacked freshness, and had a simple, unlayered flavor.

[0023] The alcoholic beverage products produced by the preservation method of the present invention must be transported and sold throughout the entire cold chain (below -18°C) after they are taken out of the cold storage. Consumers can place the products in a refrigerated environment (2°C to 8°C (the temperature of the refrigerator compartment of a typical household refrigerator)) or at room temperature to thaw slowly before drinking.

[0024] The above embodiments are only used to explain the present invention and are not intended to limit the protection of the present invention. Any non-substantial modifications made based on the essential solution of the present invention should fall within the protection scope of the present invention.

Claims

1. A method for long-term preservation of additive-free alcoholic beverages, characterized in that: Includes the following steps: a. CO2 oxygen removal pretreatment of the container to be filled: The clean container to be filled is sent into a relatively closed filling chamber filled with food-grade CO2 gas via a conveyor belt. Then, the CO2 gas inlet pipe is inserted into the bottom of the container to be filled, and food-grade CO2 gas is introduced until the oxygen concentration in the headspace of the container to be filled is detected by the oxygen concentration monitor installed on the CO2 gas inlet pipe as being below 1%. At this time, the introduction of food-grade CO2 gas is stopped, and the CO2 gas inlet pipe is quickly withdrawn from the container to be filled. b. Rapid filling and sealing: After the CO2 gas inlet tube exits the container to be filled, the filling port of the filling equipment located in the filling chamber immediately and quickly fills the container filled with food-grade CO2 gas. The filling liquid level is below the rim of the container, and the beverage being filled has been sterilized by membrane filtration. When the filling port leaves the container, the capping machine located in the filling chamber immediately caps the container. c. Deep freezing: The capped product is immediately sent to the quick-freezing equipment, which cools the beverage from the filling temperature to below -18°C within 30 minutes; d. Frozen storage: Immediately transfer the quick-frozen products to a freezer at -35℃ to -18℃ for storage.

2. The method for long-term preservation of additive-free alcoholic beverages according to claim 1, characterized in that: In step a, by installing an oxygen concentration monitor and a CO2 gas inlet pipe in the filling chamber, the oxygen concentration in the filling chamber is monitored in real time and food-grade CO2 gas is replenished to the filling chamber in a timely manner to maintain a high concentration of CO2 gas environment in the filling chamber. The air that is displaced by the food-grade CO2 gas in the filling container enters the filling chamber and is eventually displaced from the filling chamber by the high concentration of food-grade CO2 gas in the filling chamber.

3. The method for long-term preservation of additive-free alcoholic beverages according to claim 1, characterized in that: The purity of the food-grade CO2 gas mentioned in step a is ≥99.9%.

4. The method for long-term preservation of additive-free alcoholic beverages according to claim 1, characterized in that: In step b, the volume of the headspace from the filling level of the container to the container opening is 2% to 5% of the total volume of the container.

5. The method for long-term preservation of additive-free alcoholic beverages according to claim 1, characterized in that: The quick-freezing equipment described in step c uses liquid nitrogen quick-freezing, strong air circulation quick-freezing, or plate contact quick-freezing; during the quick-freezing process, the beverage takes ≤15 minutes to pass through its maximum ice crystal formation zone.