CN113749150A

CN113749150A - Production method capable of prolonging shelf life of liquid milk

Info

Publication number: CN113749150A
Application number: CN202110748330.9A
Authority: CN
Inventors: 郭俭
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-06-27
Filing date: 2021-06-27
Publication date: 2021-12-07

Abstract

A production method for prolonging shelf life of liquid milk is provided. According to national standards, liquid milk can be classified into pasteurized pure cow (sheep) milk, pasteurized seasoning milk, sterilized pure cow (sheep) milk and sterilized seasoning milk. The killing and sterilizing process comprises the following steps: low temperature long time sterilization (LTLT), high temperature short time sterilization (HTST), ultra high temperature flash sterilization (UHT), and keep sterilization. The milk is sterilized at low temperature for a long time and at high temperature for a short time, only pathogenic bacteria in the milk can be killed, other pathogenic bacteria can be dormant, and the milk is not aseptically filled, so that the milk is stored at the temperature below 6 ℃, and the shelf life is only 7, 15 and 21 days and is up to 40 days. The ultrahigh temperature instant sterilized milk is sterilized at 135 deg.C for 5 seconds, and is packaged in sterile manner with sterile packing material. The shelf life is only 6 months, and the allowable bad package rate is one thousandth. The guarantee period of the liquid milk caused by the reasons is short, and the society generally considers that secondary pollution can be solved by enhancing the control on production management. The sterilized milk can not isolate air, is always mixed with the air, and the bacteria with raised outside temperature, residue and dormancy can revive and propagate in aerobic environment to cause the milk to go bad. In a pasteurization machine and an ultrahigh-temperature instant sterilizer, the sterilized milk is adjusted to about 68 ℃ and then is introduced into a vacuum degasser to remove all gas in the milk, the milk is cooled to about 20 ℃ and then is pumped into an aseptic tank capable of isolating air, and the milk is filled into a product filled in an aseptic filling machine which utilizes high-temperature saturated steam to drive the air in a packaging container away, or the milk is sterilized, pumped into a vacuum aluminum foil bag, an aluminum plastic paper composite bag and then filled in an aseptic manner. The shelf life of the liquid milk can be greatly prolonged.

Description

Production method capable of prolonging shelf life of liquid milk

Technical Field

The liquid milk comprises pasteurized milk, blended milk, ultrahigh-temperature instant sterilized milk, condensed milk, and lactobacillus beverage, soymilk beverage containing milk, fruit and vegetable beverage containing milk, which are prepared by fermenting and blending lactobacillus and then heating to kill bacteria.

Background

At present, the production process and equipment of domestic liquid milk and milk-containing beverage are mostly introduced from foreign countries. The sterilization and disinfection are completed by a pasteurization machine and an ultrahigh temperature instant sterilizer. During the production process, degassers are used at multiple places, but the application is different, for example, when milk is measured by volume, a flow meter is used, a degasser must be installed in front of the flow meter, otherwise, the measurement error is too large to obtain accurate data. Vacuum degassers are also installed in pasteurizing and ultra-high temperature flash sterilizers to reduce the scaling of milk in pipes and influence the heat transfer effect. Avoid the oxidation of milk and the quality reduction. The accuracy of the automatic standardization or production line is improved. But the sterilized milk is mixed with air. Especially, the milk liquid after being sterilized instantaneously at ultrahigh temperature is introduced into a sterile tank for temporary storage. The aseptic tank is introduced by the Swedish Lele company, can be aseptic, but can not isolate air, and the milk in and out of the tank is carried out under high-pressure air. This causes the milk to be always mixed with air, and the external temperature change creates the environment and opportunity for the residual germs and dormant microbes to revive and reproduce in aerobic environment. Making the shelf life of liquid milk difficult to extend.

Disclosure of Invention

In order to overcome the problems of short shelf life, difficult extension and the like of the liquid milk, the invention provides an aseptic tank capable of isolating air, patent No. ZL 201920845235.9 and patent publication No. CN111661501A, and a production method for extending the shelf life of the liquid milk.

The technical scheme adopted by the invention for solving the technical problems is as follows: adding a vacuum degasser in the technological process of a pasteurization machine and an ultrahigh temperature instantaneous sterilizer, adjusting the temperature of the sterilized milk in the pasteurization machine and the ultrahigh temperature instantaneous sterilizer to about 68 ℃, introducing the sterilized milk into the vacuum degasser, removing non-combined gas, dissolved oxygen and all gas in the milk, and then utilizing heat recovery to reduce the temperature to about 20 ℃ and introducing the milk into a sterile tank capable of isolating air for temporary storage. The principle of the sterile tank capable of isolating air is similar to that of an injection syringe for injection, injection is sucked by pumping a sparking plug, the injection is pushed out by pressing the sparking plug, and the injection is not contacted with the air all the time. The sterilized and degassed milk liquid in the aseptic tank is injected into a container made of aseptic packaging materials driven by high-temperature saturated steam, and then is aseptically filled into the container, or is sterilized, pumped into a vacuum aluminum foil bag and an aluminum plastic paper composite bag and then is aseptically filled into the product.

The invention has the beneficial effects that: touches the benefits of foreign milk enterprises and treasures groups, breaks through the mystery that foreign technologies cannot surpass, and subverts the unmovable position of the tetra Pak aseptic tank in the dairy industry. No reviving and breeding environment and opportunity are left for residual germs and dormant microorganisms. Greatly prolongs the shelf life of the liquid milk, and particularly expands the service range of the pasteurized milk while preserving the full nutrition of the milk.

Detailed description of the invention

The conventional production process flow (1) of pasteurized milk in the society at present is accepted in GB 19645-2010- -metering- -filtering- -pure milk- -cooling- -milk bin preheating- -degassing- -standardization- -homogenization- -pasteurization- -heat recovery- -cooling- -filling 68- -C- -65- -75-65-95- -20 ℃.

(2) Ultra-high temperature instant sterilized milk (UHT) (GB 25190-2010) acceptance- -metering- -filtering- -purified milk- -cooling- -milk preheating- -degassing- -standardization- -homogenization- -UHT sterilization- -heat recovery- -cooling- -aseptic filling 68- -65- -75- -135- -142- -20 ℃ - -

(3) Adding a vacuum degasser and a sterile tank capable of isolating air in the pasteurization system, adjusting the temperature of pasteurized milk from 65-95 ℃ to 68 ℃, and pumping the pasteurized milk into the vacuum degasser to remove all gases in the milk. The mixture is recovered and cooled to 20 ℃ and then pumped into a sterile tank capable of isolating air for temporary storage. The air injected into a container made of the aseptic packaging material driven away by high-temperature saturated steam is filled into the container again in an aseptic mode through temporary storage and regulation of an aseptic tank, or the container is sterilized, vacuumized and filled into an aluminum foil bag or an aluminum plastic paper composite bag again in an aseptic mode.

(4) Adding a vacuum degasser and an aseptic tank capable of isolating air in the (2) ultrahigh-temperature instantaneous sterilization system, adjusting the temperature of milk subjected to ultrahigh-temperature instantaneous sterilization from 135 ℃ to-142 ℃ to 68 ℃ through heat recovery, pumping the milk into the vacuum degasser, removing all gases in the milk, cooling to 20 ℃, and entering the aseptic tank capable of isolating air for temporary storage. The air injected into a container made of the aseptic packaging material driven away by high-temperature saturated steam is filled into the container again in an aseptic mode through temporary storage and regulation of an aseptic tank, or the container is sterilized, vacuumized and then filled into a product of a multi-layer aluminum foil bag, an aluminum plastic paper composite bag and the like again in an aseptic mode.

Claims

1. A production method for prolonging the quality guarantee period of liquid milk comprises pasteurized milk, sterilized milk, modified milk, condensed milk, lactobacillus beverage prepared by fermenting and blending lactobacillus and then heating for sterilization, soymilk beverage containing milk, fruit and vegetable beverage containing milk, and plant beverage containing milk.

2. The production method of claim 1, wherein a vacuum degasser is connected to the pasteurizer or the ultra-high temperature instant sterilizer, and the sterilized milk is heated to about 68 ℃ and fed into the vacuum degasser to remove all gases in the milk, then heated to about 20 ℃ for recycling, and fed into a sterile tank capable of isolating air for temporary storage.

3. The method as claimed in claim 1, wherein the milk liquid is injected into an air-tight aseptic tank of patent number ZL 201920845235.9 (publication No. CN 111661501A), and the air is removed by saturated steam at high temperature to form a container, and the air is filled into the container, or sterilized and vacuumized aluminum foil bag or aluminum plastic paper composite bag is filled into the container.