CN112167337B - Ultraviolet sterilization method and sterilization machine for producing high-activity liquid milk - Google Patents
Ultraviolet sterilization method and sterilization machine for producing high-activity liquid milk Download PDFInfo
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Classifications
-
- A—HUMAN NECESSITIES
- A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
- A23C—DAIRY PRODUCTS, e.g. MILK, BUTTER OR CHEESE; MILK OR CHEESE SUBSTITUTES; MAKING THEREOF
- A23C3/00—Preservation of milk or milk preparations
- A23C3/02—Preservation of milk or milk preparations by heating
- A23C3/03—Preservation of milk or milk preparations by heating the materials being loose unpacked
- A23C3/033—Preservation of milk or milk preparations by heating the materials being loose unpacked and progressively transported through the apparatus
-
- A—HUMAN NECESSITIES
- A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
- A23C—DAIRY PRODUCTS, e.g. MILK, BUTTER OR CHEESE; MILK OR CHEESE SUBSTITUTES; MAKING THEREOF
- A23C3/00—Preservation of milk or milk preparations
- A23C3/07—Preservation of milk or milk preparations by irradiation, e.g. by microwaves ; by sonic or ultrasonic waves
- A23C3/076—Preservation of milk or milk preparations by irradiation, e.g. by microwaves ; by sonic or ultrasonic waves by ultraviolet or infrared radiation
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- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Food Science & Technology (AREA)
- Polymers & Plastics (AREA)
- Health & Medical Sciences (AREA)
- Toxicology (AREA)
- Apparatus For Disinfection Or Sterilisation (AREA)
- Dairy Products (AREA)
Abstract
The invention discloses an ultraviolet sterilization method and a sterilization machine for producing high-activity liquid milk, and belongs to the technical field of food processing. The ultraviolet sterilization component 15 of the ultraviolet sterilization machine, the feed pump 8, the control console 9, the lamp tube fixer 10, the ultraviolet lamp bracket 11, the shell bracket 12, the stainless steel shell 13, the partition 14, the shunt 16 and the heating tube 17, wherein the ultraviolet sterilization component 15 comprises a gasket 1, an ultraviolet intensity monitor 2, a three-way valve 3, a lamp tube 4, the ultraviolet lamp tube 5, a quartz sleeve 6 and a PFA tube fixing clamp 7. The invention adopts the form of spirally encircling the PFA tube 4, controls the D/Dc range to be 0.03-0.1, changes the processing capacity of the cow milk by changing the flow rate of liquid milk or the running length of the cow milk in the PFA tube 4 and changing the number of parallel ultraviolet tubes, has convenient operation and less time consumption, can meet various processing requirements and has wide application.
Description
Technical Field
The invention relates to an ultraviolet sterilization method and a sterilization machine for producing high-activity liquid milk, and belongs to the technical field of food processing.
Background
Ultraviolet sterilization is a novel non-thermal sterilization mode. The ultraviolet (UV-C) band for sterilization is generally 200-280nm, with 253.7nm being the most preferred. Ultraviolet light inhibits the proliferation of bacteria, viruses, fungi and other microorganisms by destroying their DNA, thereby killing the microorganisms. Ultraviolet sterilization is mainly applied to three fields: air sterilization, liquid sterilization and surface sterilization. In the food industry, clarified liquids such as water, egg liquid, fruit juice, and alcoholic beverages have been used for sterilization of liquids. Because ultraviolet light has weak penetrability to turbid liquid, materials currently available for ultraviolet sterilization are mainly limited to clear liquid.
The cow milk has rich nutrition and plays an important role in human growth and health. Cow milk contains abundant proteins, vitamins, minerals, etc., and besides, contains abundant bioactive proteins including immunity proteins and antibacterial enzymes, etc. These active proteins protect the human intestinal health and immune system. Most of the bioactive proteins are thermosensitive proteins, and are easy to inactivate in the heat sterilization process of cow milk. Therefore, the ultraviolet sterilization is used as a mature non-thermal sterilization technology, and has good application prospect in the aspect of cow milk sterilization. Although the ultraviolet sterilization temperature is low and the efficiency is high, the ultraviolet transmittance is reduced due to the high turbidity of the milk, and the sterilization effect is greatly reduced.
Several methods and devices for ultraviolet sterilization of different liquid foods have been invented by current researchers. Sun Yijun (201811149112.8) discloses a water ultraviolet sterilization method, which adopts the irradiation sterilization inside a water pipe and uses a ladder-shaped sterilization channel, thereby increasing the ultraviolet treatment time of water flow and improving the ultraviolet sterilization efficiency; however, as the cow milk is turbid liquid, although the ladder-shaped channel can play a certain shunting effect, the ultraviolet lamps are respectively arranged at two ends of the device, and the sterilizing effect cannot be ensured due to uneven contact of the cow milk with ultraviolet rays. Lin Daxiong (201680016968.0) discloses a UV-C water purification device, which improves a UV-C LED module, reduces the loss of ultraviolet light in transmission, and improves the light extraction efficiency; but the material container is a water tank, the UV-C module is arranged in the water tank, the material depth is large, the material container is in a static state, and the sterilization process is discontinuous. Sun Fukuan (201220341807.8) discloses an ultraviolet beverage sterilizing device, which mainly comprises a container for containing beverage and an ultraviolet lamp tube inside, wherein materials enter from the top of the container and flow out from the bottom; the microwave generator is adopted to generate microwave to excite ultraviolet rays, so that the ultraviolet intensity and the sterilization effect are improved, and the service life of the ultraviolet lamp is prolonged; however, as the peripheral space of the ultraviolet lamp tube in the container is larger, the liquid layer is thicker when the material flows in the container, and ultraviolet rays are difficult to completely penetrate through the turbid liquid; the material flows in and out perpendicular to the ultraviolet lamp tube, the direction is perpendicular to the direction of the ultraviolet lamp tube, and the flowing mode of liquid is difficult to control during flowing; therefore, the device cannot ensure that the turbid materials are uniformly irradiated by ultraviolet rays. Yin Quanquan (201720671599.0) discloses an ultraviolet sterilizer for beverage production, wherein a plurality of ultraviolet lamps are arranged in a long cylinder body and are vertical to the direction of a cavity, and a material inlet and a material outlet are arranged at the top of the cavity; because the inner space of the cylinder body is larger and a drainage device is not arranged, the material flow state is difficult to control; the cylinder body is internally provided with a plurality of ultraviolet lamp tubes, and the actual ultraviolet dose received by the materials is difficult to calculate. Ma Xuewu (201710865815. X) discloses an ultraviolet sterilization device for donkey milk processing, comprising a sterilization box and a storage box. The sterilizing box adopts heat sterilization, and the ultraviolet lamp tube is arranged in the storage box. When in heat sterilization, if the temperature of the sterilization box exceeds a set value, namely, when the sterilization box fails, donkey milk in the sterilization box can be automatically discharged into a storage box, and the donkey milk is continuously sterilized by ultraviolet rays; the ultraviolet light in the device only plays roles in standby and auxiliary sterilization, and the materials are in uneven contact with the ultraviolet light in the storage box, so that the sterilization efficiency is very low.
From the above, the conventional ultraviolet sterilization method and apparatus for liquid food are not suitable for sterilizing cow milk. Therefore, there is a need for an ultraviolet sterilization method capable of sterilizing a turbid liquid such as cow's milk and retaining active ingredients, and which is excellent in sterilization effect, and which can continuously process, and which is adjustable in ultraviolet dose, yield, and processing temperature.
Disclosure of Invention
In order to solve at least one of the problems described above, the present invention provides an ultraviolet sterilization method and a sterilizer for producing high-activity liquid milk.
The first object of the present invention is to provide an ultraviolet sterilizer for producing high-activity liquid milk, the ultraviolet sterilizer comprising an ultraviolet sterilizer 15, the ultraviolet sterilizer 15 comprising a gasket 1, an ultraviolet intensity monitor 2, a three-way valve 3, a PFA tube 4, an ultraviolet lamp tube 5, a quartz sleeve 6 and a PFA tube fixing clamp 7, wherein the quartz sleeve 6 is covered on the surface of the ultraviolet lamp tube 5, the PFA tube 4 is tightly wound around the quartz sleeve 6, the PFA tube is fixed by the PFA tube fixing clamp 7, no gap exists between the PFA tube 4 and the quartz sleeve 6, each 1m (10-30 circles) of the PFA tube 4 is wound as a sterilization area, and the PFA tubes 4 of adjacent sterilization areas are connected by the three-way valve 3; a gasket 1 is arranged between the ultraviolet lamp tube 5 and the quartz sleeve 6; the ultraviolet intensity detector 2 is closely attached to the outside of the quartz sleeve 6 where the PFA tube is not wound.
In one embodiment of the invention, one or more ultraviolet intensity detectors 2 are included between adjacent sterilization areas in the ultraviolet sterilizer.
In one embodiment of the invention, one side of the ultraviolet sterilizer is provided with a feed pump 8, one end of the PFA pipe 4 passes through the feed pump 8, and liquid milk is fed into a pipeline through the feed pump 8.
In one embodiment of the invention, one side of the ultraviolet sterilization machine is provided with a feed pump 8, and the other side is provided with a control console 9.
In one embodiment of the present invention, the ultraviolet sterilizer further comprises a lamp holder 10 and an ultraviolet lamp bracket 11, wherein the lamp holder 10 and the ultraviolet lamp bracket 11 are used for fixing the ultraviolet lamp 5.
In one embodiment of the invention, the ultraviolet sterilization machine also comprises a shell bracket 12 and a stainless steel shell 13; the stainless steel housing 13 is supported by the housing bracket 12; the stainless steel housing 13 contains a plurality of ultraviolet lamps 5.
In one embodiment of the present invention, the ultraviolet sterilizer further includes a partition 14, where the partition 14 separates each ultraviolet lamp 5, so as to ensure that ultraviolet lights emitted by different lamps do not interfere with each other.
In one embodiment of the invention, the ultraviolet sterilization machine further comprises a flow divider 16, wherein the flow divider 16 is arranged between the feed pump 8 and the stainless steel shell 13; the flow divider 16 evenly distributes the raw material into each PFA tube 4 according to the flow rate.
In one embodiment of the present invention, the ultraviolet sterilizer further comprises a heating pipe 17, wherein the heating pipe 17 is arranged around the PFA tube 4 between the feed pump 8 and the stainless steel housing 13, and is used for heating the material to a certain temperature and then performing subsequent ultraviolet sterilization.
In one embodiment of the present invention, the number of the ultraviolet sterilizing components 15 in the ultraviolet sterilizing device may be 1-100, and correspondingly, the number of the heating pipes 17 and the flow splitters 16 may be 1-10; when the number of the ultraviolet sterilization components is multiple, the ultraviolet sterilization components are placed in parallel, and the treatment capacity of the ultraviolet sterilization machine can be 3-1200L/h.
In one embodiment of the present invention, the ultraviolet sterilizer further comprises a control console 9, wherein the control console 9 can control the temperatures in the ultraviolet lamp tube 5, the ultraviolet intensity monitor 2, the feed pump 8, the heating pipe 17 and the stainless steel housing 13, and display the ultraviolet intensity monitored by each ultraviolet intensity monitor.
In one embodiment of the invention, the ultraviolet sterilization machine comprises an ultraviolet sterilization component 15, a feed pump 8, a control console 9, a lamp tube fixer 10, an ultraviolet lamp bracket 11, a shell bracket 12, a stainless steel shell 13, a baffle 14, a flow divider 16 and a heating tube 17, wherein the ultraviolet sterilization component 15 comprises a gasket 1, an ultraviolet intensity monitor 2, a three-way valve 3, a PFA tube 4, an ultraviolet lamp tube 5, a quartz sleeve 6 and a PFA tube fixing clamp 7; wherein the stainless steel housing 13 is supported by the housing bracket 12; the stainless steel shell 13 contains a plurality of ultraviolet lamp tubes 5, the ultraviolet lamp tubes 5 are separated by a baffle 14, and the ultraviolet lamp tubes 5 are fixed by a lamp tube fixer 10 and an ultraviolet lamp bracket 11; the surface of the ultraviolet lamp tube 5 is covered with a quartz sleeve 6, a layer of gasket 1 is arranged between the ultraviolet lamp tube 5 and the quartz sleeve 6, the PFA tube 4 is tightly wound around the quartz sleeve 6, no gap exists between the PFA tube 4 and the quartz sleeve 6, the PFA tube 4 is wound for 10-30 circles to serve as a sterilization area, the whole sterilization area is fixed by a PFA tube fixing clamp 7, and the PFA tubes 4 of adjacent sterilization areas are connected by a three-way valve 3; the ultraviolet intensity detector 2 is tightly attached to the outer side of the quartz sleeve 6 where the PFA tube is not wound; one side of the ultraviolet sterilization machine is provided with a feed pump 8, and the other side is provided with a control console 9; a heating pipe 17 is arranged around the PFA pipe 4 between the feed pump 8 and the stainless steel shell 13; a flow divider 16 is between the feed pump 8 and the stainless steel housing 13.
In one embodiment of the present invention, the outer diameter of the quartz sleeve 6 is 2-3cm, and may be more preferably 2.3cm, and the quartz sleeve is supported and fixed by two stainless steel brackets, so as to ensure that the ultraviolet lamp tube and the quartz sleeve are coaxial.
In one embodiment of the present invention, during operation, the liquid milk enters one end of the PFA tube 4 through the feed pump 8, flows around the tube for several weeks, flows out from the other end of the PFA tube 4 after being irradiated by ultraviolet light, and can change the flow direction of the liquid milk in the PFA tube 4 by controlling the opening and closing of the three-way valve 3, so that the liquid milk enters the next area to continue ultraviolet sterilization or end sterilization and directly flows out.
In one embodiment of the invention, the stainless steel shell 13 is tightly sealed, a temperature control system is arranged inside the stainless steel shell, and the temperature of the ultraviolet sterilization module can be controlled between 0 ℃ and 80 ℃ through a water bath.
In one embodiment of the present invention, the stainless steel housing 13 has a plurality of metal clamping grooves therein for fixing the PFA tube 4 wound around the outside of the quartz tube.
In one embodiment of the present invention, the PFA tube 4 is of the specification: the inner diameter is 1-2mm, and the outer diameter is 2-3mm; further preferred are: 1mm x 2mm, 1.5mm x 2mm or 2mm x 3mm (inner diameter x outer diameter).
In one embodiment of the invention, the ratio of the surrounding inner diameter Dc of the PFA tube 4 to the inner diameter D of the PFA tube 4 in the ultraviolet sterilization device is between 0.03 and 0.1, so that the liquid milk can be uniformly mixed in the tube at different flow rates, and the liquid milk has good ultraviolet sterilization effect at different treatment capacities.
The second object of the invention is to provide a method for producing high-activity liquid milk by adopting the sterilizing machine.
In one embodiment of the present invention, the PFA tube 4 in the sterilizer has the following specifications: the inner diameter is 1-2mm, and the outer diameter is 2-3mm; further preferred are: 1mm x 2mm, 1.5mm x 2mm or 2mm x 3mm (inner diameter x outer diameter).
In one embodiment of the present invention, the liquid milk is cow milk or sheep milk.
In one embodiment of the invention, the ratio of the surrounding inner diameter Dc of the PFA tube 4 to the inner diameter D of the PFA tube 4 in the ultraviolet sterilization device is between 0.03 and 0.1, so that the liquid milk can be uniformly mixed in the tube at different flow rates, and the liquid milk has good ultraviolet sterilization effect at different treatment capacities; the Reynolds number (R) is calculated according to the following formulas (1) and (2) e ) And dean number (D) e )：
Wherein ρ is the density of liquid milk, 1021.46kg/m 2 The method comprises the steps of carrying out a first treatment on the surface of the Mu is dynamic viscosity of liquid milk, 1.941 ×10 3 Ns/m 2 The method comprises the steps of carrying out a first treatment on the surface of the v is the flow rate of the liquid milk in the tube; d is the inner diameter of the PFA tube 4; dc is the surrounding inner diameter of the PFA tube 4.
Re < 2100 indicates that the liquid flow state is laminar, re > 4000 indicates that the liquid flow state is turbulent, and Re is interposed between the two, indicating a mixed flow state. De is a representation of how the fluid flows in the coil, and when 0.03 < D/Dc < 0.1, the fluid in the coil creates a secondary flow pocket that enhances the degree of fluid mixing.
In one embodiment of the invention, the ultraviolet dose of the liquid milk is changed by changing the flow rate of the liquid milk or the length of the PFA tube 4 actually used, so that microorganisms in the liquid milk meet the pasteurization requirement and the bioactive protein in the liquid milk is ensured not to be significantly reduced; the throughput can be changed by changing the number of parallel ultraviolet lamps.
In one embodiment of the invention, the high-activity liquid milk refers to liquid milk with a certain sterilization mode, the microbial limit in the liquid milk meets the national standard of pasteurized milk (GB 19645-2010 and GB 19301-2010), the liquid milk can be sold as pasteurized milk, and the content of bioactive proteins such as immune-active proteins and antibacterial enzymes is higher.
In one embodiment of the invention, the ultraviolet sterilization intensity can be controlled by changing the liquid milk flow rate; the flow rate of the selected liquid milk is 50-200mL/min; the method comprises collecting fresh liquid milk, maintaining the temperature of the liquid milk at 25deg.C, and passing through 5 sterilization areas, wherein the flow rate of the liquid milk in the tube is controlled to 50-200mL/min, and the corresponding ultraviolet dose is 65-16mJ/cm 2 。
In one embodiment of the present invention, the sterilization intensity can be controlled by changing the length of the PFA tube 4; selecting 2-6 sterilization areas, wherein the winding number of each area is 12 (the length of each PFA4 is 1 m); in particular to a method for preparing fresh liquid milk,the temperature of the liquid milk is kept at 25 ℃, and the liquid milk passes through 2-6 sterilization areas by controlling the opening and closing of the three-way valve 3, and the corresponding ultraviolet dose is 16-47mJ/cm 2 。
In one embodiment of the present invention, the throughput of the highly active liquid milk can be adjusted by changing the number of ultraviolet sterilizing members 15 connected in parallel; because the proper treatment capacity of each ultraviolet lamp tube is 50-200mL/min, the number of the ultraviolet sterilization components 15 can be 1-100, and correspondingly, the number of the heating pipes 17 and the shunts 16 can be 1-10; when the number of the ultraviolet sterilization components 15 is more, the ultraviolet sterilization components are placed in parallel, and the treatment capacity of the ultraviolet sterilization machine can be 3-1200L/h.
In one embodiment of the invention, the flow rate of the liquid milk in the PFA tube 4 of the ultraviolet sterilizer is 50-200mL/min.
In one embodiment of the invention, the number of sterilization areas through which the liquid milk passes is 2 to 6, the number of windings of the PFA tube in each sterilization area is 12, and the length of each PFA tube is 1m.
In one embodiment of the invention, the liquid milk may be heated to a certain temperature by a heating tube before being subjected to ultraviolet irradiation; during ultraviolet sterilization, the liquid milk can be kept at a certain temperature by a temperature control system, and the adjustable temperature range is 0-80 ℃.
The third object of the present invention is the highly active liquid milk produced by the process of the present invention.
In one embodiment of the present invention, the high-activity liquid milk is one of skim cow's milk, whole cow's milk, skim sheep milk, and whole sheep milk.
The invention has the beneficial effects that:
(1) The invention provides an ultraviolet sterilizer for producing high-activity liquid milk, which realizes sterilization of turbid liquid such as liquid milk by ultraviolet rays. The invention adopts the form of spiral surrounding of the PFA tube 4 and controls the range of D/Dc to be 0.03-0.1, so that the liquid milk is fully mixed when running in the tube, and the sterilization efficiency of the liquid milk is improved; according to the invention, the ultraviolet dose received by the cow milk is changed by changing the flow rate of the liquid milk or the running length of the liquid milk in the PFA tube 4, so that the sterilization intensity of the liquid milk is controlled; the invention changes the processing capacity of the liquid milk by changing the number of the ultraviolet lamp tubes connected in parallel, has convenient operation and less time consumption, can meet various processing requirements, and has wide application.
(2) The invention provides an ultraviolet sterilization method for producing high-activity liquid milk, which is various in ultraviolet dosage changing method, convenient and quick. The ultraviolet sterilization method can lead the microbial quantity of the liquid milk to meet the requirements of national standards, and simultaneously, the damage to the active protein in the liquid milk is obviously lower than that of pasteurization (15 s at 72 ℃) with the weakest heat treatment intensity, and almost no obvious active protein loss is caused.
(3) The invention provides high-activity liquid milk. Compared with pasteurization (15 s at 72 ℃), the high-activity liquid milk produced by the method has the same safety, but has more immune active proteins and antibacterial proteins, and is high-activity pasteurized liquid milk.
(4) IgG, igM, igA and lactoferrin in cow milk are collectively called immunocompetent proteins, and have antibacterial, defensive, anti-inflammatory, antioxidant, anticancer and immunoregulatory functions. In addition, both LPO and XO enzymes also have antibacterial activity and are beneficial enzymes in cow milk. The retention of these bioactive proteins has important promoting effects on human intestinal health and immune function. The ultraviolet dose is changed by changing the liquid milk flow rate or the actual use length of the PFA tube 4, so as to obtain the high-activity liquid milk. After ultraviolet sterilization, the total colony count of the liquid milk is 0-40000CFU/mL, the coliform colony count is 0CFU/mL, and the liquid milk is in the range of national standards (GB 19645-2010 and GB 19301-2010). The content or activity of bioactive protein and antibacterial enzyme in cow milk after sterilization, including IgG, igM, igA, lactoferrin, peroxidase and xanthine oxidase, is not obviously reduced (but is reduced by 20-60% by pasteurization) compared with that before sterilization, and is high-activity liquid milk. The ultraviolet sterilization intensity can be adjusted according to the sanitary quality of the raw milk.
Drawings
Fig. 1 shows a structure of an ultraviolet sterilizing member 15 inside an ultraviolet sterilizer;
FIG. 2 is a front view (perspective) of the ultraviolet sterilizer;
FIG. 3 is a left side view (perspective) of the ultraviolet sterilizer;
FIG. 4 is a top view (perspective) of the ultraviolet sterilizer;
in fig. 1 to 4, a gasket 1, an ultraviolet intensity monitor 2, a three-way valve 3, a PFA tube 4, an ultraviolet lamp tube 5, a quartz sleeve 6, a PFA tube fixing clip 7, a feed pump 8, a console 9, a lamp tube holder 10, an ultraviolet lamp holder 11, a housing holder 12, a stainless steel housing 13, a partition 14, an ultraviolet sterilization member 15, a shunt 16, and a heating tube 17.
FIG. 5 is a graph showing the effect of two UV doses on milk immunoreactive protein content in example 6; wherein A is the effect on IgG content; b is the effect on lactoferrin content; c is the effect on IgM content; d is the effect on IgA content.
FIG. 6 is a graph showing the effect of two UV doses on bovine Lactoperoxidase (LPO) and Xanthine Oxidase (XO) levels in example 6.
Detailed Description
The following description of the preferred embodiments of the present invention is provided for better illustration of the invention, and should not be construed as limiting the invention.
Colony count determination: 1mL of diluted sample is taken by adopting a 3M company colony total number test piece (6406), the diluted sample is dripped in the center of the test piece, then the upper layer film is pressed, the sample is stood for 1 minute, after the culture medium is solidified, the sample is placed in a 32 ℃ incubator for culturing for 24 hours, and the test piece with the colony number of 25-250 is taken for counting.
Coliform group determination: 1mL of diluted sample is taken by adopting a 3M company colony total number test piece (6416), the diluted sample is dripped in the center of the test piece, then the upper layer film is pressed, the sample is stood for 1 minute, after the culture medium is solidified, the sample is placed in a 32 ℃ incubator for 12 hours, and the test piece with the colony number of 15-150 is taken for counting.
Measurement of total number of spores: taking a certain amount of treated cow milk into a sterile centrifuge tube, and placing the cow milk into a water bath kettle at 80 ℃ for heat preservation for 10min. Immediately placing the mixture into crushed ice for cooling after the heat preservation is finished, taking a proper amount of cow milk, diluting the cow milk by a certain multiple, and carrying out subsequent measurement according to a colony total number measurement method.
Determination of the content of immunocompetent proteins (IgG, igM, igA, lactoferrin): the Elisa kit (Cat. No. E10-118, E10-131, E10-101 and E10-126;Bethyl Laboratories,USA) was used to determine IgG, igM, igA and lactoferrin content in cow milk. And (3) diluting cow milk by 500-1000 times, determining, and carrying out fitting quantification on standard curves by using a 4-parameter equation.
Lactoperoxidase (LPO) activity assay: the activity was determined by measuring the rate of Red fluorescent oxidation product (9-hydroxy-3-isophenoxazolone) produced by the oxidation of the Amplex Red dye (AR) by lactoperoxidase. 23.1. Mu.L of AR, 4.6. Mu.L of potassium thiocyanate solution and 972.3. Mu.L of 100mM phosphate buffer (pH 7.4) are mixed to prepare a reaction reagent, 30. Mu.L of diluted cow milk is mixed with 195. Mu.L of the reaction reagent, 50. Mu.L of the mixture is added to a 96-well plate, after incubation at 37 ℃ for 20min, 50. Mu.L of 110. Mu.M hydrogen peroxide solution (blank 50. Mu.L of deionized water is used instead of hydrogen peroxide solution) is automatically added by an enzyme-labeled instrument, and the fluorescence intensity is measured at excitation/emission wavelength of 544/590nm every 10 s. Standard curves were prepared with hydrogen peroxide solutions of different concentration gradients. Lactoperoxidase activity was calculated by the following formula (3):
note that F1 and F2 are differences in fluorescence intensity at two ends in time T, and K is the slope of the standard curve.
Xanthine Oxidase (XO) activity assay: xanthine oxidase catalyzes the production of hydrogen peroxide from hypoxanthine, which is catalyzed by horseradish peroxidase (HRP) to produce a fluorescent product. The reaction reagent was prepared by mixing 10. Mu.L of 10mM AR, 4. Mu.L of 200U/mL HRP, 40. Mu.L of 10mM hypoxanthine, 946. Mu.L of phosphate buffer (pH 7.4). 50 mu L of diluted cow milk is added into a 96-well plate, 50 mu L of xanthine oxidase reaction reagent is added for mixing, and fluorescence intensity is measured at the excitation/emission wavelength of 544/590nm by an enzyme-labeling instrument every 30 seconds. Standard curves were prepared with hydrogen peroxide solutions of different concentration gradients. Xanthine oxidase activity was calculated by the following formula (4):
note that F1 and F2 are differences in fluorescence intensity at two ends in time T, and K is the slope of the standard curve.
Example 1 ultraviolet sterilizer (ultraviolet sterilizing Member 15)
The ultraviolet sterilization machine comprises an ultraviolet sterilization component 15, a feed pump 8, a control console 9, a lamp tube fixer 10, an ultraviolet lamp bracket 11, a shell bracket 12 and a stainless steel shell 13, wherein the ultraviolet sterilization component 15 comprises a gasket 1, an ultraviolet intensity monitor 2, a three-way valve 3, a PFA tube 4, an ultraviolet lamp tube 5, a quartz sleeve 6 and a PFA tube fixing clamp 7; wherein the stainless steel housing 13 is supported by the housing bracket 12; the stainless steel shell 13 contains 1 ultraviolet lamp tube 5, and the ultraviolet lamp tube 5 is fixed by a lamp tube fixer 10 and an ultraviolet lamp bracket 11; the surface of the ultraviolet lamp tube 5 is covered with a quartz sleeve 6, a layer of gasket 1 is arranged between the ultraviolet lamp tube 5 and the quartz sleeve 6, the PFA tube 4 is tightly wound around the quartz sleeve 6, no gap exists between the PFA tube 4 and the quartz sleeve 6, the PFA tube 4 is wound for 10-30 circles to serve as a sterilization area, the whole sterilization area is fixed by a PFA tube fixing clamp 7, and the PFA tubes 4 of adjacent sterilization areas are connected by a three-way valve 3; the ultraviolet intensity detector 2 is tightly attached to the outer side of the quartz sleeve 6 where the PFA tube is not wound; one side of the ultraviolet sterilizer is provided with a feed pump 8, and the other side is provided with a control console 9.
In the operation process, the liquid milk enters one end of the PFA tube 4 through the feed pump 8, flows around the tube for a plurality of weeks, flows out from the other end of the PFA tube 4 after being irradiated by ultraviolet light, and can change the flow direction of the liquid milk in the PFA tube 4 by controlling the opening and closing of the three-way valve 3, so that the liquid milk enters the next area to continue ultraviolet sterilization or end sterilization and directly flows out. The ultraviolet intensity detector 2 is tightly attached to the outer side of the quartz sleeve, so that the ultraviolet intensity of the outer measurement of the quartz sleeve can be accurately monitored. The stainless steel shell 13 is tightly sealed, a temperature control system is arranged in the stainless steel shell, and the temperature (0-80 ℃) of the ultraviolet sterilization module can be controlled through a water bath. The console 9 may control the temperature within the ultraviolet lamp, ultraviolet intensity monitor, and stainless steel housing 13. The number of ultraviolet lamp tubes connected in parallel can be selected by controlling the feed pump 8, so that the treatment capacity of ultraviolet sterilization is changed.
Example 2 ultraviolet sterilizer (multiple parallel ultraviolet sterilizing members 15)
Schematic diagrams of the ultraviolet sterilization machine are shown in fig. 1, 2, 3 and 4, respectively. The ultraviolet sterilization device comprises an ultraviolet sterilization component 15 of the ultraviolet sterilization machine, a feed pump 8, a control console 9, a lamp tube fixer 10, an ultraviolet lamp bracket 11, a shell bracket 12, a stainless steel shell 13, a baffle 14, a shunt 16 and a heating tube 17, wherein the ultraviolet sterilization component 15 comprises a gasket 1, an ultraviolet intensity monitor 2, a three-way valve 3, a PFA tube 4, an ultraviolet lamp tube 5, a quartz sleeve 6 and a PFA tube fixing clamp 7; wherein the stainless steel housing 13 is supported by the housing bracket 12; the stainless steel shell 13 contains a plurality of ultraviolet lamp tubes 5, the ultraviolet lamp tubes 5 are separated by a baffle 14, and the ultraviolet lamp tubes 5 are fixed by a lamp tube fixer 10 and an ultraviolet lamp bracket 11; the surface of the ultraviolet lamp tube 5 is covered with a quartz sleeve 6, a layer of gasket 1 is arranged between the ultraviolet lamp tube 5 and the quartz sleeve 6, the PFA tube 4 is tightly wound around the quartz sleeve 6, no gap exists between the PFA tube 4 and the quartz sleeve 6, the PFA tube 4 is wound for 10-30 circles to serve as a sterilization area, the whole sterilization area is fixed by a PFA tube fixing clamp 7, and the PFA tubes 4 of adjacent sterilization areas are connected by a three-way valve 3; the ultraviolet intensity detector 2 is tightly attached to the outer side of the quartz sleeve 6 where the PFA tube is not wound; one side of the ultraviolet sterilization machine is provided with a feed pump 8, and the other side is provided with a control console 9; a heating pipe 17 is arranged around the PFA pipe 4 between the feed pump 8 and the stainless steel shell 13; a flow divider 16 is between the feed pump 8 and the stainless steel housing 13.
In the operation process, after passing through the feed pump 8, the liquid milk enters one end of the PFA tube 4 through the heating pipe 17 and the shunt 16, flows around the tube for a plurality of weeks, flows out from the other end of the PFA tube 4 after being irradiated by ultraviolet light, and can change the flow direction of the liquid milk in the PFA tube 4 by controlling the opening and closing of the three-way valve 3, so that the liquid milk enters the next area to continue ultraviolet sterilization or end sterilization and directly flows out. The ultraviolet intensity detector 2 is tightly attached to the outer side of the quartz sleeve, so that the ultraviolet intensity of the outer measurement of the quartz sleeve can be accurately monitored. The stainless steel shell 13 is tightly sealed, a temperature control system is arranged in the stainless steel shell, and the temperature (0-80 ℃) of the ultraviolet sterilization module can be controlled through a water bath. The control console 9 can control the temperature in the ultraviolet lamp tube 5, the ultraviolet intensity monitor 2, the feed pump 8, the heating tube 17 and the stainless steel housing 13. The shunt 16 can be connected with ten PFA tubes 4 in parallel at most, and the number of parallel ultraviolet lamp tubes can be selected by controlling the shunt 16, so that the treatment capacity of ultraviolet sterilization is changed.
Example 3 the sterilizer of example 1 was used for sterilizing milk
To ensure adequate mixing of the cow's milk as it moves in the PFA tube 4, the Reynolds number (Re) and the dean number (De) are calculated according to formulas (1) and (2):
wherein ρ is the density of cow milk, 1021.46kg/m 2 The method comprises the steps of carrying out a first treatment on the surface of the Mu is dynamic viscosity of cow milk, is 1.941 multiplied by 103Ns/m 2 The method comprises the steps of carrying out a first treatment on the surface of the v is the flow rate of cow's milk in the tube; d is the inner diameter of the PFA tube 4; dc is the surrounding inner diameter of the PFA tube 4.
Re < 2100 indicates that the liquid flow state is laminar, re > 4000 indicates that the liquid flow state is turbulent, and Re is interposed between the two, indicating a mixed flow state. De is a representation of how the fluid flows in the coil, and when 0.03 < D/Dc < 0.1, the fluid in the coil creates a secondary flow pocket that enhances the degree of fluid mixing.
The ultraviolet sterilizer was set up according to the combination of PFA tubes of different specifications and quartz sleeves of different outer diameters in table 1 so that the sterilization of the cow's milk was completed through two areas, re and D/Dc were calculated, and the ultraviolet dose received by the cow's milk was calculated by the following formulas (5) and (6):
UV-C dose (mJ/cm) 2 ) =uv-C intensity (mW/cm 2 ) X treatment time(s) X PFA tube 4UV-C transmittance (%) (6)
As can be seen from table 1: because the outer diameter of a section of the ultraviolet lamp tube is 19mm, the possible inner diameter of the quartz sleeve is 20mm at minimum. It can be seen that the main factor determining the ratio is the PFA tube specification. Therefore, when the outer diameter of the quartz sleeve is 20-30mm, 1 x 2mm, 1.5 x 2.5mm, 1.5 x 3mm, 2 x 3mm and 2 x 4mm PFA tubes are selected; when the outer diameter of the quartz sleeve is 20-30mm, 1 x 2mm, 1.5 x 2.5mm, 1.5 x 3mm, 2 x 3mm and 2 x 4mm PFA tubes are selected.
TABLE 1D/Dc values for different PFA tube specifications and different outer diameter quartz sleeves in combination
The cow milk after sterilization was subjected to performance test, and the test results are shown in table 2. As can be seen from Table 2, although the D/Dc values of the 2X 4mm PFA tubes are satisfactory, the total number of bacteria does not meet the criteria for pasteurization. The ultraviolet transmittance is low probably due to the too thick pipe wall, so that the sterilization effect is affected. Therefore, PFA tube specifications that can be selected are 1mm by 2mm, 1.5mm by 2.5mm, 2mm by 3mm.
TABLE 2 Sterilization Effect under different PFA tube specifications
Note that: "-" indicates that fewer than 1 colony was on the plate, and was regarded as undetectable.
Comparative example 1 sterilizing Effect of different ultraviolet sterilizing apparatuses
Cow milk is sterilized by commercial direct current type and stationary type ultraviolet sterilizing equipment, direct current type (Ster)New York, NY, USA) mainly comprises an ultraviolet lamp tube, a quartz sleeve wrapped outside the lamp tube and a metal sleeve with a distance of 1.5mm from the quartz sleeve. During sterilization, cow milk flows in the axial direction between the quartz sleeve and the metal sleeve. Stationary equipment (cf. Custom made: malekAmiali et al, inactivation of Staphylo)The bacterium aureus (ATCC 6538), escherichia coli (ATCC 25922) and Pseudomonas aeruginosa (ATCC 9027) in Skimmed Bovine Milk using UltraViolet-C Irradication, international Journal of Advanced Research (2015), volume 3, issue 5, 387-395) is composed of a metal box, and the ultraviolet lamp tube is arranged at the top part of the box. The sample is placed at the bottom of the box body and evenly spread in the round sample cell, and the height of the sample is 1.5mm.
Controlling the flow speed of cow milk in the direct-current type equipment and the irradiation time of an ultraviolet lamp in the static type equipment, and controlling the surface ultraviolet dose of the cow milk in three ultraviolet sterilization modes in contact with ultraviolet light to be 31mJ/cm 2 The total number of bacteria was determined.
The test results of the sterilized cow milk obtained in example 3 and comparative example 1 are shown in table 3. As can be seen from Table 3, the total number of milk bacteria after sterilization with the spiral tube type apparatus (example 1) was the least and the sterilization intensity was the highest at the same ultraviolet dose. Therefore, the spiral tube type ultraviolet sterilizer has high sterilization strength and high efficiency.
Table 3 test results of sterilized cow milk obtained in example 3 and comparative example 1
EXAMPLE 4 modification of cow milk flow (Q) to vary UV dose
PFA tube with an inner diameter of 1.5mm and an outer diameter of 2.5mm is selected.
Fresh cow milk is taken, the temperature of the cow milk is kept at 25 ℃, and the cow milk passes through 5 sterilization areas, and the flow of the cow milk in a tube is respectively controlled to be 50, 100 and 200mL/min, and the corresponding ultraviolet dose is respectively 65mJ/cm 2 、33mJ/cm 2 、16mJ/cm 2 The method comprises the steps of carrying out a first treatment on the surface of the Cow milk is sterilized by ultraviolet rays and then is connected into a sterile bottle, and then is immediately put into crushed ice.
Meanwhile, pasteurization (15 s at 72 ℃) was performed with the same batch of fresh cow milk (total colony count of 5.48.+ -. 0.03log (CFU/mL), coliform count of 2.77.+ -. 0.01log (CFU/mL)), and total colony count of cow milk pasteurized (15 s at 72 ℃) of 2.45.+ -. 0.05log (CFU/mL) was performed without coliform count.
The colony count and coliform group of cow milk before and after sterilization were measured, and the test results are shown in table 4:
the limit standard of microorganisms on raw milk in China is 2 multiplied by 10 6 (CFU/mL); the total colony count for pasteurized milk was 50000 (CFU/mL) and the coliform limit was 5 (CFU/mL). The data in table 4 shows that the raw milk, pasteurized milk and three doses of uv sterilized milk all meet the requirements of the national standards (GB 19645-2010, GB 19301-2010). Wherein the milk flow rate is 100mL/min (ultraviolet dose is 33 mJ/cm) 2 ) When the sterilizing effect is best, the flow rate is increased, the time for receiving ultraviolet irradiation of cow milk in the tube is shortened, and the sterilizing effect is weakened; the flow rate is reduced, the flow rate of cow's milk in the tube is reduced, the irradiation time of ultraviolet is prolonged, but the flow rate is too low, and the degree of mixing of cow's milk in the tube is not as severe as when the flow rate is large, so that the sterilization effect is weak.
Table 4 test results of example 4
Note that: "-" indicates that fewer than 1 colony was on the plate, and was regarded as undetectable.
Example 5 variation of UV dose by varying PFA tube 4 length
Selecting PFA tube 4 with inner diameter of 1.5mm and outer diameter of 2.5mm, controlling flow rate of cow milk in the tube to 150mL/min, and respectively passing cow milk through 2, 3, 4, 5 and 6 sterilization areas (each sterilization area has length of 1m and is wound for 12 circles) by opening and closing a three-way valve 3, wherein ultraviolet doses of 5 treatment modes are 16, 23, 31, 39 and 47mJ/cm respectively 2 . Cow milk is sterilized by ultraviolet rays and then is connected into a sterile bottle, and then is immediately put into crushed ice.
Meanwhile, pasteurization (15 s at 72 ℃) was performed using the same batch of fresh cow milk (total colony count of 5.02.+ -. 0.02log (CFU/mL), coliform count of 2.02.+ -. 0.02log (CFU/mL)), and total colony count of cow milk pasteurized (15 s at 72 ℃) was 1.18.+ -. 0.00log (CFU/mL), without coliform count.
The colony count and coliform group of cow milk before and after sterilization were measured, and the test results are shown in table 5:
as can be seen from the data in Table 5 in combination with the national standards (GB 19645-2010 and GB 19301-2010), the total number of bacterial colonies of the ultraviolet sterilized cow milk and the number of coliform bacteria of 5 parameters all meet the national standard requirements. The PFA tube 4 is wound for more than 3m, and the ultraviolet sterilization effect of the cow milk is equal to pasteurization (15 s at 72 ℃).
Table 5 test results of example 5
Note that: "-" indicates that fewer than 1 colony was on the plate, and was regarded as undetectable.
EXAMPLE 6 Effect of ultraviolet Sterilization on cow milk active protein
The cow milk flows 100mL/min and passes through 4 sterilization areas (the ultraviolet dose is 26 mJ/cm) 2 Recorded as UV 4-100), cow milk flow rate was 150mL/min, passed through 6 sterilization zones (UV dose 47 mJ/cm) 2 For example, UV 6-150), the content of bovine milk immunoglobulin (IgG, igA, igM) and lactoferrin, lactoperoxidase LPO and xanthine oxidase XO activities before and after ultraviolet sterilization were measured, with raw milk (R) and pasteurized milk (72 ℃ for 15 seconds) (H) as controls.
The test results are shown in table 6, table 7, fig. 5 and fig. 6: as can be seen from table 6, the milk sterilized with both uv doses meets the national standard requirements for pasteurized milk. After ultraviolet sterilization, the bacterial nutrition in cow milk can only be killed by pasteurization, but not the spores in cow milk can be killed by pasteurization, and besides the bacterial nutrition, part of spores can also be killed by ultraviolet sterilization. As can be seen from table 7, fig. 5 and fig. 6, pasteurization resulted in a significant reduction of 4 immunologically active proteins, LPO and XO in cow's milk, whereas both uv sterilizations had no significant effect on these 6 biologically active substances, so that high activity cow's milk could be produced using the uv sterilization method of the present invention.
TABLE 6 Sterilization test results for example 6
Note that: "-" indicates that fewer than 1 colony was on the plate, and was regarded as undetectable.
TABLE 7 Activity test results for example 6
While the invention has been described with reference to the preferred embodiments, it is not limited thereto, and various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.
Claims (4)
1. The method for producing the high-activity liquid milk by adopting the ultraviolet sterilization machine is characterized in that the ultraviolet sterilization machine comprises an ultraviolet sterilization component 15, a feed pump 8, a control console 9, a lamp tube fixer 10, an ultraviolet lamp bracket 11, a shell bracket 12 and a stainless steel shell 13, wherein the ultraviolet sterilization component 15 comprises a gasket 1, an ultraviolet intensity monitor 2, a three-way valve 3, a PFA tube 4, an ultraviolet lamp tube 5, a quartz sleeve 6 and a PFA tube fixing clamp 7; wherein the stainless steel housing 13 is supported by the housing bracket 12; the stainless steel shell 13 contains 1 ultraviolet lamp tube 5, and the ultraviolet lamp tube 5 is fixed by a lamp tube fixer 10 and an ultraviolet lamp bracket 11; the surface of the ultraviolet lamp tube 5 is covered with a quartz sleeve 6, a layer of gasket 1 is arranged between the ultraviolet lamp tube 5 and the quartz sleeve 6, the PFA tube 4 is tightly wound around the quartz sleeve 6, no gap exists between the PFA tube 4 and the quartz sleeve 6, the PFA tube 4 is wound for 10-30 circles to serve as a sterilization area, the length of each sterilization area is 1m, the whole sterilization area is fixed by a PFA tube fixing clamp 7, and the PFA tubes 4 of adjacent sterilization areas are connected by a three-way valve 3; the ultraviolet intensity detector 2 is tightly attached to the outer side of the quartz sleeve 6 where the PFA tube is not wound; one side of the ultraviolet sterilization machine is provided with a feed pump 8, and the other side is provided with a control console 9;
in the operation process, the liquid milk enters one end of the PFA tube 4 through the feed pump 8, flows around the tube for a plurality of weeks, flows out from the other end of the PFA tube 4 after being irradiated by ultraviolet light, and can change the flow direction of the liquid milk in the PFA tube 4 by controlling the opening and closing of the three-way valve 3, so that the liquid milk enters the next area to continue ultraviolet sterilization or end sterilization and directly flows out; the ultraviolet intensity detector 2 is tightly attached to the outer side of the quartz sleeve, so that the ultraviolet intensity of the outer measurement of the quartz sleeve can be accurately monitored; the stainless steel shell 13 is tightly sealed, a temperature control system is arranged in the stainless steel shell, and the temperature of the ultraviolet sterilization module can be controlled to be 0-80 ℃ through water bath; the control console 9 can control the temperature inside the ultraviolet lamp, the ultraviolet intensity monitor and the stainless steel housing 13;
wherein the use specification of the PFA tube 4 is that the inner diameter is 1-2mm, and the outer diameter is 2-3mm; the ratio of the surrounding inner diameter Dc of the PFA tube 4 to the inner diameter D of the PFA tube 4 is between 0.03 and 0.1;
the flow rate of the liquid milk in the PFA tube 4 of the ultraviolet sterilizer is 100-150 mL/min;
the liquid milk passes through 4-6 sterilization areas with corresponding ultraviolet dose of 26-47 mJ/cm 2 。
2. A method for producing high-activity liquid milk by adopting an ultraviolet sterilizer is characterized in that an ultraviolet sterilization component 15 of the ultraviolet sterilizer, a feed pump 8, a control console 9, a lamp tube fixer 10, an ultraviolet lamp bracket 11, a shell bracket 12, a stainless steel shell 13, a baffle 14, a shunt 16 and a heating pipe 17, wherein the ultraviolet sterilization component 15 comprises a gasket 1, an ultraviolet intensity monitor 2, a three-way valve 3, a PFA tube 4, an ultraviolet lamp tube 5, a quartz sleeve 6 and a PFA tube fixing clamp 7; wherein the stainless steel housing 13 is supported by the housing bracket 12; the stainless steel shell 13 contains a plurality of ultraviolet lamp tubes 5, the ultraviolet lamp tubes 5 are separated by a baffle 14, and the ultraviolet lamp tubes 5 are fixed by a lamp tube fixer 10 and an ultraviolet lamp bracket 11; the surface of the ultraviolet lamp tube 5 is covered with a quartz sleeve 6, a layer of gasket 1 is arranged between the ultraviolet lamp tube 5 and the quartz sleeve 6, the PFA tube 4 is tightly wound around the quartz sleeve 6, no gap exists between the PFA tube 4 and the quartz sleeve 6, the PFA tube 4 is wound for 10-30 circles to serve as a sterilization area, the length of each sterilization area is 1m, the whole sterilization area is fixed by a PFA tube fixing clamp 7, and the PFA tubes 4 of adjacent sterilization areas are connected by a three-way valve 3; the ultraviolet intensity detector 2 is tightly attached to the outer side of the quartz sleeve 6 where the PFA tube is not wound; one side of the ultraviolet sterilization machine is provided with a feed pump 8, and the other side is provided with a control console 9; a heating pipe 17 is arranged around the PFA pipe 4 between the feed pump 8 and the stainless steel shell 13; the flow divider 16 is between the feed pump 8 and the stainless steel housing 13;
in the operation process, after passing through the feed pump 8, the liquid milk enters one end of the PFA tube 4 through the heating pipe 17 and the shunt 16, flows around the tube for a plurality of weeks, flows out from the other end of the PFA tube 4 after being irradiated by ultraviolet light, and can change the flow direction of the liquid milk in the PFA tube 4 by controlling the opening and closing of the three-way valve 3, so that the liquid milk enters the next area to continue ultraviolet sterilization or end sterilization and directly flows out; the ultraviolet intensity detector 2 is tightly attached to the outer side of the quartz sleeve, so that the ultraviolet intensity of the outer measurement of the quartz sleeve can be accurately monitored; the stainless steel shell 13 is tightly sealed, a temperature control system is arranged in the stainless steel shell, and the temperature of the ultraviolet sterilization module can be controlled to be 0-80 ℃ through water bath; the control console 9 can control and control the temperatures in the ultraviolet lamp tube 5, the ultraviolet intensity monitor 2, the feeding pump 8, the heating pipe 17 and the stainless steel shell 13; the shunt 16 can be connected with ten PFA tubes 4 in parallel at most, and the number of parallel ultraviolet lamp tubes can be selected by controlling the shunt 16, so that the treatment capacity of ultraviolet sterilization is changed;
wherein the use specification of the PFA tube 4 is that the inner diameter is 1-2mm, and the outer diameter is 2-3mm; the ratio of the surrounding inner diameter Dc of the PFA tube 4 to the inner diameter D of the PFA tube 4 is between 0.03 and 0.1;
the flow rate of the liquid milk in the PFA tube 4 of the ultraviolet sterilizer is 100-150 mL/min;
the liquid milk passes through 4-6 sterilization areas with corresponding ultraviolet dose of 26-47 mJ/cm 2 。
3. The method according to claim 2, wherein the number of ultraviolet sterilizing members 15 in the ultraviolet sterilizing device is 1-100, and the number of heating pipes 17 and shunts 16 is 1-10; when the number of the ultraviolet sterilization components is multiple, the ultraviolet sterilization components are placed in parallel, and the treatment capacity of the ultraviolet sterilization machine can be 3-1200L/h.
4. A high activity liquid milk produced by the method of any one of claims 1-3.
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Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2143499Y (en) * | 1992-11-03 | 1993-10-13 | 陈政统 | Ultra-violet sterilizer |
| CN200949062Y (en) * | 2006-09-19 | 2007-09-19 | 石有信 | Microwave ultraviolet disinfection decontaminating apparatus |
| CN204273101U (en) * | 2014-10-14 | 2015-04-22 | 荣成炭谷有限公司 | A kind of equipment for sterilization of milk sterilization |
| CN206108974U (en) * | 2016-08-25 | 2017-04-19 | 厦门水务水处理科技有限公司 | High -efficient STREAMING ultraviolet disinfection equipment of crossing |
| CN209322516U (en) * | 2018-09-21 | 2019-08-30 | 青岛海尔施特劳斯水设备有限公司 | A kind of circulating water sterilizing unit |
| CN208883539U (en) * | 2018-09-30 | 2019-05-21 | 四川金澜科技有限公司 | A kind of ultraviolet sterilizer |
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| CN112167337A (en) | 2021-01-05 |
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