JP5118717B2 - Liquid egg heat treatment method and heat treatment apparatus - Google Patents

Description

  The present invention relates to a heat treatment technique for liquid eggs for continuous heat sterilization while conveying the liquid eggs.

  In the restaurant business that provides customers with egg dishes and the food processing industry that manufactures foods made from eggs, liquid eggs that have been preliminarily heat-sterilized at the factory and packed in containers are used. Liquid eggs used as such foods for cooking include liquid egg yolk with only egg yolk, liquid egg white with only egg white, and liquid whole egg in which egg white and egg yolk are mixed. In order to mass-produce liquid whole eggs for cooking, as described in Patent Document 1, a shelled egg is divided by a cracking machine, and calaza and liquid egg are separated by a strainer. The separated liquid egg is stored in a container and stored in a refrigerator, and the stored liquid egg is conveyed to a heating device when sterilized by heating.

  In order to heat sterilize a liquid egg, the liquid egg stored in a container and refrigerated at about 5 ° C. is heated to a sterilization temperature of 60 ° C. with a heating device, and then at least 3.5 at 60 ° C. with a heat retaining device. It is necessary to hold the minute. By holding at this sterilization temperature for 3.5 minutes, harmful bacteria contained in the liquid egg can be killed. The sterilized liquid egg is cooled to 5 ° C., which is a storage temperature, by a cooling device, packed in a container, and transported to a restaurant or food processor.

  In order to heat sterilize liquid eggs, conventionally, as described in Patent Document 1, a method of heating liquid eggs at 58 ° C. for 10 minutes using a batch-type sterilization tank has been proposed. Moreover, as described in Patent Document 2, the heating process is divided into two stages, and the first heating process is heated at 57 to 60 ° C. for 1 to 60 seconds, and after cooling, the heating process is 55 to 58 ° C. in the second heating process. A method of heating for 3.5 to 10 minutes has been proposed, and a plate heat exchanger is used for each heating step.

JP 10-248532 A Japanese Patent Laid-Open No. 2002-165583

  For example, when cooking egg soup, if you put an unsterilized liquid egg that has been split and taken out of the shell into boiling water, you can cook egg soup that has become hardened, whereas in the past It has been found that when a liquid egg sterilized by this technique is put into hot water, the liquid egg does not become solidified. This phenomenon is not limited to cooking egg soup, but also occurs when cooking other egg dishes such as omelets and teacups, and heat-sterilized liquid eggs are hard to harden even when heated. There was a point. In this way, the phenomenon that sterilization liquid eggs are less coagulated than non-sterilized liquid eggs, especially in order to mass-produce sterilized liquid eggs, using a plate-type or tube-type heat exchange device This was remarkable in the liquid eggs that were heat-treated while continuously transporting the liquid eggs to the flow path.

  As a result of repeating various experiments in order to improve the coagulation characteristics of the sterilized liquid egg, when the liquid egg is heated while being conveyed in the flow path, the time during which the liquid egg is at a temperature exceeding 20 ° C. becomes longer. It was found to reduce the coagulation properties of liquid eggs. In order to sterilize the liquid egg, the liquid egg is held for 210 seconds (3.5 minutes) or more under a state where the liquid egg is heated to a sterilization temperature of about 60 ° C., and then cooled to the storage temperature.

  The heat treatment apparatus using a conventional heat exchanger has a structure shown in FIG. 9 and heats to exchange heat between the liquid egg to be heated and the liquid egg to be cooled, as will be described later. The energy required for heating and cooling is reduced using a recovery unit and a heating recovery unit that exchanges heat between the liquid egg to be cooled and the liquid egg to be heated. The time for which the temperature of the liquid egg exceeded 20 ° C. could not be shortened within 600 seconds.

  Conventionally, the liquid egg is heated to the sterilization temperature, held at the sterilization temperature for a certain period of time, and further the liquid egg moving time in the apparatus until the liquid egg is cooled to the storage temperature and the coagulation characteristics of the sterilization liquid egg. The relationship was not noted, but it was found that shortening the time when the liquid egg was 20 ° C. increased the coagulation characteristics of the liquid egg. Further, it was found that when the liquid egg flows in the flow path of the heating device, it receives a shearing force, and when this shearing force increases, the solidification characteristics of the liquid egg deteriorate. In particular, it is considered that the coagulation characteristics of the sterilized liquid egg are greatly influenced by the time until the sterilization temperature is reached. The reason for this is that when the temperature of the liquid egg is raised to a sterilization temperature of 60 ° C., the transformation of the liquid egg proceeds at a temperature of 20 ° C. or more, and the time during which the transformation proceeds is a short time. Then, even if it maintains at the sterilization temperature of 60 degreeC for 3.5 minutes or more, the coagulation | solidification characteristic of a sterilization liquid egg can be brought close to an unsterilized egg. When the liquid egg sterilized in this way is poured into hot water, the liquid egg becomes hardened and can be cooked at the same time as an unsterilized liquid egg.

  An object of the present invention is to make the coagulation characteristic of a sterilized liquid egg a coagulation characteristic close to that of an unsterilized liquid egg.

The liquid egg heat treatment method of the present invention is a liquid egg heat treatment method in which the liquid egg is continuously sterilized while being conveyed, and the sterilization temperature while flowing the liquid egg at the storage temperature through the tube-type heating channel. A heating process in which the heated liquid egg is flown into the heat retaining channel, a holding process in which the heated egg is kept at the sterilization temperature for a certain holding time, and the liquid egg after the temperature is maintained is flowed into the cooling channel. And the cooling process of cooling from the sterilization temperature to the storage temperature, and the movement time in the flow path within the time when the liquid egg has exceeded 20 ° C. from the start of heating to the end of cooling is within 600 seconds. And the total shearing amount of the liquid egg from the start of heating to the end of cooling is 50000 or less.

  In the liquid egg heat treatment method of the present invention, the heating step is a Joule heating step in which the liquid egg flowing in the heating channel is heated by Joule heat to heat from the storage temperature to the sterilization temperature. To do.

  In the liquid egg heat treatment method according to the present invention, the heating step includes heat that heats the liquid egg from a storage temperature to a temperature lower than the sterilization temperature by exchanging heat with a heating medium while flowing the liquid egg in the heating channel. It has an exchange heating process, and a Joule heating process for heating the liquid egg to the sterilization temperature by generating heat by Joule heat while flowing the liquid egg heated in the heat exchange heating process into the heating channel. And

  In the heat treatment method for liquid eggs of the present invention, the heating step includes a Joule heating step of heating the liquid eggs from a storage temperature to a temperature lower than the sterilization temperature by generating heat by Joule heat while flowing in the heating flow path. And a heat exchange heating step in which the liquid egg heated in the Joule heating step is heated to the sterilization temperature by exchanging heat with a heating medium while flowing into the heating flow path.

  In the liquid egg heat treatment method of the present invention, the heating step is a heat exchange heating step in which the liquid egg flowing in the heating flow path is heat-exchanged with a heating medium and heated from a storage temperature to a sterilization temperature. Features.

The liquid egg heat treatment apparatus of the present invention is a liquid egg heat treatment apparatus that sterilizes by heating while continuously transporting the liquid egg, and has a tube-type heating flow path for flowing the liquid egg at a storage temperature, There is a heating means for heating the liquid egg to the sterilization temperature while flowing the liquid egg through the heating channel, and a heat retaining channel communicating with the heating channel, and the heated liquid egg is sterilized while flowing into the heat retaining channel. It has a temperature holding means that holds the temperature for a certain holding time and a cooling channel that communicates with the heat holding channel, and from the sterilization temperature to the storage temperature while flowing the liquid egg after the temperature is maintained in the cooling channel a cooling means for cooling, and a transit time setting means for setting the travel time in the flow path of the liquid egg in the heating start to the end of cooling is a state exceeding the 20 ° C. time within 600 seconds possess the total amount of shear of the liquid egg in the heating start to the end of cooling 50,000 or more Characterized by a.

  In the liquid egg heat treatment apparatus of the present invention, the heating means is a Joule heating unit that heats the liquid egg flowing in the heating flow path from Joule heat to heat it from a storage temperature to a sterilization temperature. To do.

  In the liquid egg heat treatment apparatus of the present invention, the heating means heats the liquid egg from a storage temperature to a temperature lower than the sterilization temperature by exchanging heat with the heating medium while flowing the liquid egg in the heating flow path. A replaceable heating unit, and a Joule heating unit that heats the liquid egg to a sterilization temperature by generating heat by Joule heat while flowing the liquid egg heated in the heat exchange heating unit into the heating flow path. And

  In the liquid egg heat treatment apparatus according to the present invention, the heating means includes a Joule heating unit that heats the liquid egg from the storage temperature to a temperature lower than the sterilization temperature by causing the liquid egg to flow through the heating flow path and generating heat by Joule heat. And a heat exchange heating unit that heats the liquid egg heated in the Joule heating unit to a sterilization temperature by exchanging heat with a heating medium while flowing into the heating flow path.

  In the liquid egg heat treatment apparatus of the present invention, the heating means is a heat exchange heating unit that heats the liquid egg flowing in the heating flow path with a heating medium and heats it from a storage temperature to a sterilization temperature. Features.

  According to the present invention, it is possible to improve the coagulation characteristics of a sterilized liquid egg, and it is possible to produce a liquid egg having a coagulation characteristic close to that of an unsterilized liquid egg. Thereby, even if an egg and egg soup are cooked using the sterilized liquid egg, the liquid egg can be hardened.

It is the schematic which shows the heat processing apparatus which is one embodiment of this invention. It is sectional drawing which shows the heat exchange type heating unit shown in FIG . It is sectional drawing which shows the Joule type heating unit shown in FIG. It is a characteristic diagram which shows the temperature change of a liquid egg when a liquid egg is heat-processed with the heat processing apparatus shown in FIG. It is the schematic which shows the heat processing apparatus which is other embodiment of this invention. It is a characteristic diagram which shows the temperature change of a liquid egg when a liquid egg is heat-processed with the heat processing apparatus shown in FIG. It is a characteristic diagram which shows the temperature change of a liquid egg when the liquid egg is heat-processed by other embodiment of this invention. It is a characteristic diagram which shows the temperature change of a liquid egg when the liquid egg is heat-processed by further another embodiment of this invention. (A), (B) is the schematic which shows the conventional heat processing apparatus, respectively.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. A heat treatment apparatus 10 shown in FIG. 1 has a hopper 11 that houses a liquid egg. The liquid egg accommodated in the hopper 11 is obtained by dividing a shell egg with a cracking machine and separating the calaza and the liquid egg with a strainer. The separated liquid egg is stored in a container and maintained at a storage temperature of, for example, about 5 ° C., and the liquid egg is put into the hopper 11 from the container.

  The hopper 11 is connected to a heat exchange type heating unit 13 as a heating means by a pipe 12a. The pipe 12 a is provided with a pump P for supplying the liquid egg in the hopper 11 toward the heat exchange type heating unit 13, and this pump P is driven by the electric motor 14. The heat exchange type heating unit 13 as a heating means has a heating channel that communicates with the pipe 12a and guides the liquid egg. The liquid egg that flows through the heating channel by a heating medium applied from outside is about 40 ° C. The temperature is raised by the heat exchange type heating unit 13.

  The heat exchange heating unit 13 is connected to a Joule heating unit 15 as a heating means by a pipe 12b. The Joule heating unit 15 has a heating flow path that communicates with the pipe 12b and guides the liquid egg, and heats the liquid egg by Joule heat by supplying power to the electrodes provided in the Joule heating unit 15. Let The liquid egg heated to 40 ° C. in the heat exchange type heating unit 13 by the Joule type heating unit 15 is heated to 60 ° C. which is a sterilization temperature at a stretch.

  The joule heating unit 15 is connected to a temperature holding unit 16 as temperature holding means by a pipe 12c. The temperature holding unit 16 has a heat retaining channel for holding the liquid egg at 60 ° C. which is a sterilization temperature for a certain holding time while communicating with the pipe 12c and guiding the liquid egg. This holding time is set to 3.5 minutes or more, for example. The temperature holding unit 16 is connected to a cooling unit 17 as a cooling means by a pipe 12d. The cooling unit 17 has a cooling flow path communicating with the pipe 12d, and the liquid egg flowing through the cooling flow path is cooled from a sterilization temperature of 60 ° C. to a storage temperature. The liquid egg cooled by the cooling unit 17 is supplied to the collection container 18.

Of the time until the liquid egg flows into the heat exchange type heating unit 13 and flows out of the cooling unit 17, the processing time for the liquid egg to exceed 20 ° C. and flow through the flow path is within 600 seconds. This processing time is set by a controller 19 that sets the rotation speed of the electric motor 14. The liquid egg receives a shearing force when flowing in the flow path, and the total shear amount that the liquid egg receives before flowing into the heat exchange heating unit 13 and out of the cooling unit 17, that is, the total shear amount is 50,000. It is set as follows. This total shearing amount is determined by the product of the shear rate and the processing time when the liquid egg is conveyed, and is set by the shape and dimensions of the flow path cross section.
In a heating unit having a tube-type heating channel, the shear rate is a value obtained by dividing twice the average flow rate of the liquid egg by the radius of the heating channel.

Figure 2 is Ru sectional view showing a heat exchanger type heating unit 13 shown in FIG. 1 in detail.

As shown in FIG. 2, the heat exchange heating unit 13 has an inner tube 21 for guiding the liquid egg. One end of the inner tube 21 is formed with an inlet 22a communicating with the flow path in the pipe 12a, and the other end is provided with an outlet 22b communicating with the flow path in the pipe 12b. A heating channel 23 is provided between 22a and the outlet 22b. As shown by the arrow 24a, the liquid egg flows into the heating channel 23 of the inner tube 21 from the inlet 22a and flows out of the outlet 22b as shown by the arrow 24b. An outer tube 25 is attached to the outer side of the inner tube 21, and a medium flow path 26 through which a heating medium is supplied is formed between the inner tube 21 and the outer tube 25. As shown by an arrow 27a, hot water as a heating medium flows into the medium flow path 26 from an inflow port 28a provided at one end of the outer tube 25 and from an outflow port 28b provided at the other end. As shown in the figure, it flows out. Thereby, the liquid egg is heated to a predetermined temperature by the heating medium. As described above, the heat exchange type heating unit 13 shown in FIG. 2 is a tube type heat exchanger that heats the liquid egg while flowing the liquid egg through the heating flow path 23 formed in the inner tube 21.

  FIG. 3 is an enlarged cross-sectional view of the joule heating unit 15 shown in FIG. 1. This joule heating unit 15 is a heating pipe or tubular member 31 having a circular cross section in which a heating channel 23 for guiding the liquid egg is formed. have. The tubular member 31 is composed of seven ring-shaped electrodes 32 and six cylindrical bodies 33 arranged therebetween. As described above, the Joule heating unit 15 includes the tubular member 31 including the plurality of electrodes 32 and the plurality of cylindrical bodies 33, and the adjacent electrodes 32 are provided in pairs on the tubular member 31. . Each electrode 32 is formed of a conductor such as titanium, and each cylindrical body 33 is formed of an insulator such as resin. At both end portions of the tubular member 31, inflow side and outflow side joint portions 34 and 35 made of an insulator are attached. A power supply unit 36 is connected to each electrode 32 via a cable, and a high frequency current is supplied from the power supply unit 36 so that the electrodes 32 adjacent to each other in the flowing direction of the liquid egg have opposite polarities. Is done. In addition, the number of the electrodes 32 provided in the joule type heating unit 15 is arbitrarily set according to the heating temperature or the like.

  The temperature holding unit 16 is provided with a flow path inside as with the heat exchange type heating unit 13 and the joule type heating unit 15, and by providing a heat insulating material outside the temperature holding unit 16, the internal holding flow path can be reduced. The flowing liquid egg is kept at the sterilization temperature. However, a heating medium may be allowed to flow outside in order to prevent a decrease in temperature.

The cooling unit 17 is formed by the heat exchanger type heating unit 13 and tube heat exchanger of the same structure, the heating channel in the heat exchanger type heating unit 13 shown in FIG. 2 is a cooling channel, medium By flowing a refrigerant, that is, a cooling medium through the flow path 26, the liquid egg is cooled to the storage temperature. The storage temperature is room temperature or about 5 ° C., which is lower than this.

  FIG. 4 is a characteristic diagram showing the temperature change of the liquid egg when the liquid egg is heat sterilized by the heat treatment apparatus 10 shown in FIG. 1 in comparison with the conventional example. In FIG. 4, the temperature change of the liquid egg when sterilized by the conventional heat treatment apparatus is shown by a broken line, and the temperature change of the liquid egg when sterilized by the heat treatment apparatus shown in FIG. 1 is shown by a solid line. ing.

  FIG. 9A is a schematic view showing a conventional heat treatment apparatus 40 a, and this heat treatment apparatus 40 a has a heat recovery unit 41, a heating unit 42, and a cooling unit 43. The liquid egg supplied from the hopper 44 is guided to the temperature holding unit 46 by the heating side channel 45, and the liquid egg flowing out from the temperature holding unit 46 is guided to the recovery container 48 by the cooling side channel 47. The heat recovery unit 41 performs heat exchange between the heated liquid egg and the cooled liquid egg, and the liquid egg flowing out of the heat recovery unit 41 is cooled in the cooling unit 43 by cooling water as a cooling medium. On the other hand, the liquid egg heated by the heat recovery unit 41 is heated to the sterilization temperature by the hot water as the heating medium in the heating unit 42.

  FIG. 9B is a schematic diagram showing another conventional heat treatment apparatus 40b. This heat treatment apparatus 40b includes first and second heat recovery units 41a and 41b, and includes a first heat recovery unit. A heat medium is circulated by the pump Pa in the unit 41a and the second heat recovery unit 41b. In this heat treatment apparatus 40b, the liquid egg that has flowed out of the temperature holding unit 46 is heat-exchanged with the heat medium of the second heat recovery unit 41b to cool the liquid egg. On the other hand, in the first heat recovery unit 41a, heat exchange is performed between the heated liquid egg and the heat medium of the second heat recovery unit 41b to heat the liquid egg.

In the conventional heat treatment apparatus 40a shown in FIG. 9A, a heat recovery unit 41 is provided to assist heating by the heating unit 42 that heats the liquid egg with hot water. In addition, in the conventional heat treatment apparatus 40b shown in FIG. 9B, a heat recovery unit 41a is provided to assist the heating of the liquid egg, and a heat recovery unit 41b is provided to assist the cooling of the liquid egg. The heat medium is circulated through both the heat recovery units 41a and 41b. For this reason, the temperature difference effective for heat transfer is reduced, and furthermore, the heat exchanger capacity is prepared excessively so that sterilization can be continued even when the heat transfer performance decreases due to the adhesion of egg protein, The passage time of the part exceeding 20 ° C. had to be 600 seconds or more.

  Therefore, as shown by a broken line in FIG. 4, the conventional heat treatment apparatus raises the temperature of the liquid egg to the sterilization temperature 60 ° C. by the heating unit 42, holds the liquid egg at the sterilization temperature by the temperature holding unit 46, and The liquid egg is cooled to the storage temperature by 43, the heating time Se0 by the heating unit 42 is 300 seconds (5 minutes) including the heat recovery unit, and the temperature holding time Sh0 is 210 seconds (3.5 minutes). The cooling time Sc0 is 276 seconds (4.6 minutes). Therefore, the total time from the start of heating to the end of cooling is 786 seconds (13.1 minutes), and the flow path at the time when the liquid egg has exceeded 20 ° C. from the start of heating to the end of cooling. The travel time St0 was 630 seconds (10.5 minutes).

  Thus, liquid eggs that have been sterilized by a conventional heat treatment device whose travel time St0 will exceed 600 seconds will have poor coagulation characteristics when used to cook eggs and egg soup, and liquid eggs It does not become a solid state.

  On the other hand, in the heat treatment apparatus 10 shown in FIG. 1, the liquid egg is heated to about 50 ° C. by heating for 240 seconds as the heating time Se1 by the heat exchange type heating unit 13, and then sterilized by the Joule type heating unit 15. Heat the liquid egg to temperature. The Joule heating unit 15 raised the temperature of the liquid egg by 10 ° C. with a heating time Sj of 10 seconds. The holding time Sh1 by the temperature holding unit 16 of this heat treatment apparatus 10 is 210 seconds which is the same as the conventional holding time Sh0, and the cooling time Sc1 by the cooling unit 17 is 276 seconds which is the same as the conventional one. Therefore, the total time from the start of heating to the end of cooling is 736 seconds (12.2 minutes), and the liquid egg is in a state where the temperature exceeds 20 ° C. from the start of heating to the end of cooling. The travel time St1 was 594 seconds (9.9 minutes). The liquid egg sterilized in this way has improved coagulation characteristics, and when the egg or egg soup is cooked using the liquid egg, the liquid egg hardened in the same manner as the unsterilized liquid egg.

  FIG. 5 is a schematic view showing a liquid egg heat treatment apparatus 10 according to another embodiment of the present invention. In FIG. 5, members common to those shown in FIG. Has been.

The liquid egg heat treatment apparatus 10 shown in FIG. 5 heats the liquid egg from the storage temperature to the sterilization temperature by the Joule type heating unit 15, and the heat exchange type heating unit 13 shown in FIG. 1 is used. Not. Also in the heat treatment apparatus 10 for the liquid egg, the liquid egg exceeds 20 ° C. in the passage time until the liquid egg flows into the Joule heating unit 15 and flows out of the cooling unit 17. Is set within 600 seconds, and this processing time is set by the controller 19 that sets the rotation speed of the electric motor 14. The liquid egg receives a shearing force when it flows in the flow path, and the total shear amount that the liquid egg receives before flowing into the Joule heating unit 15 and out of the cooling unit 17, that is, the total shear amount , Depending on the cross-sectional shape and dimensions, it is set to 50000 or less as in the case described above .

  FIG. 6 is a characteristic diagram showing a temperature change of the liquid egg when the liquid egg is heat sterilized by the heat treatment apparatus 10 shown in FIG. 5 in comparison with the conventional example. Also in FIG. 6, the temperature change of the liquid egg when sterilized by the conventional heat treatment apparatus is shown by a broken line, and the temperature change of the liquid egg when sterilized by the heat treatment apparatus shown in FIG. 5 is shown by a solid line. ing.

  When the liquid egg is sterilized using the heat treatment apparatus 10 shown in FIG. 5, the liquid egg at the storage temperature is heated to the sterilization temperature in 30 seconds (0.5 minutes) by the Joule heating unit 15. The holding time Sh1 by the temperature holding unit 16 is 210 seconds which is the same as the conventional holding time Sh0, and the cooling time Sc1 by the cooling unit 17 is 276 seconds which is the same as the conventional one. Therefore, the total time from the start of heating to the end of cooling is 516 seconds (8.6 minutes), and in the flow path at the time when the liquid egg has exceeded 20 ° C. from the start of heating to the end of cooling. The travel time St1 was 432 seconds (7.2 minutes). The liquid egg sterilized in this way has improved coagulation characteristics, and when the egg or egg soup is cooked using the liquid egg, the liquid egg hardened in the same manner as the unsterilized liquid egg.

In each of the liquid egg heat treatment apparatuses 10 described above, the movement time St1 in the flow path at the time when the liquid egg has exceeded 20 ° C. from the start of heating to the end of cooling is 600 seconds. It is set as follows. When the moving time exceeds 600 seconds as in the past, the coagulation characteristics of the liquid egg deteriorated, whereas when the moving time is shortened, the liquid egg having a coagulation characteristic close to that of an unsterilized liquid egg is heat-treated. Can do. In any of the liquid egg heat treatment apparatuses of the present invention, the total shear amount received by the liquid egg flowing in the flow channel from the start of heating to the end of cooling is set to 50000 or less, as in the case described above . Further, when the liquid egg is heated from the storage temperature to the sterilization temperature, the time until the liquid egg reaches the sterilization temperature through the temperature in the metamorphic temperature zone is shortened.

  FIG. 7 is a characteristic diagram showing a temperature change of the liquid egg when the liquid egg is heat sterilized by the liquid egg heat treatment apparatus according to another embodiment of the present invention, as compared with the conventional example. The liquid egg heat treatment apparatus shown in the characteristic diagram first heats the liquid egg at the storage temperature to about 40 ° C. with a heating time Sj of about 10 seconds by the Joule type heating unit 15, and then heat exchange type heating unit. 13 is heated to the sterilization temperature in 122 seconds (2.03 minutes). That is, the positions of the heat exchange type heating unit 13 and the Joule type heating unit 15 in the heat treatment apparatus 10 shown in FIG. 1 are reversed, and it takes 618 seconds (10.3 minutes) from the start of heating to the end of cooling. The moving time St1 in the flow path at the time when the liquid egg was in a state exceeding 20 ° C. from the start to the end of cooling was 534 seconds (8.9 minutes).

  FIG. 8 is a characteristic diagram showing a temperature change of the liquid egg when the liquid egg is heat sterilized by the liquid egg heating apparatus according to still another embodiment of the present invention, as compared with the conventional example. The liquid egg heat treatment apparatus shown in the characteristic diagram is configured to heat the liquid egg at the storage temperature to the sterilization temperature by the heat exchange heating unit 13 shown in FIG. Conventionally, the time Se0 for heating to the sterilization temperature is 300 seconds, whereas the heating time Se1 is set to 210 seconds, which is shorter than the conventional time. Thereby, the moving time St1 in the flow path in the time when the liquid egg exceeded 20 ° C. from the start of heating to the end of cooling was 552 seconds (9.2 minutes). When liquid eggs are sterilized in this manner, liquid eggs with improved coagulation characteristics can be produced.

  7 and 8, the temperature change of the liquid egg when sterilized by the conventional heat treatment apparatus is indicated by a broken line, and the temperature change of the liquid egg when sterilized by the respective heat treatment apparatus is indicated by a solid line. ing.

  In each heat treatment apparatus, the temperature increase rate per unit time is higher than that in the conventional case at 40 to 50 ° C., which is the protein denaturation temperature zone of the liquid egg. Can be increased.

  In each heat treatment apparatus, the cooling time Sc1 by the cooling unit 17 is set to be the same as the conventional time. However, by setting the cooling time Sc1 to be shorter than the conventional time, the liquid egg is produced from the start of heating to the end of cooling. The moving time in the flow path when the temperature exceeds 20 ° C. can be set within 600 seconds, and the coagulation characteristics of the liquid egg can be enhanced.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, in the liquid egg heat treatment apparatus described above, the case where the liquid whole egg is sterilized has been described. Similarly, when only liquid egg yolk or only liquid egg white is heat-treated, the respective coagulation characteristics are improved. Can do.

DESCRIPTION OF SYMBOLS 10 Liquid egg heat processing apparatus 11 Hopper 13 Heat exchange type heating unit 14 Electric motor 15 Joule type heating unit 16 Temperature holding unit 17 Cooling unit 19 Controller

Claims (10)

A heat treatment method for liquid eggs that is heat sterilized while continuously conveying the liquid eggs,
A heating process for heating the liquid egg at the storage temperature to the sterilization temperature while flowing through the tube-shaped heating channel;
A holding step of holding the heated liquid egg in the heat-retaining channel and holding at a sterilization temperature for a certain holding time;
A cooling step of cooling from the sterilization temperature to the storage temperature while flowing the liquid egg after being held in the cooling flow path,
Set the movement time in the flow path within 600 seconds at the time when the liquid egg exceeded 20 ° C from the start of heating to the end of cooling ,
A liquid egg heat treatment method, wherein the total shearing amount of the liquid egg from the start of heating to the end of cooling is 50000 or less .   2. The liquid egg heat treatment method according to claim 1, wherein the heating step is a Joule heating step in which the liquid egg flowing in the heating channel is heated by Joule heat to be heated from a storage temperature to a sterilization temperature. Heat treatment method for liquid eggs.   3. The liquid egg heat treatment method according to claim 1 or 2, wherein in the heating step, the liquid egg is heated from the storage temperature to a temperature lower than the sterilization temperature by flowing the liquid egg through the heating flow path while being heated. A heat exchange heating step for heating, and a Joule heating step for heating the liquid egg to the sterilization temperature by generating heat by Joule heat while flowing the liquid egg heated in the heat exchange heating step into the heating channel. A method for heat-treating a liquid egg.   3. The liquid egg heat treatment method according to claim 1 or 2, wherein the heating step generates Joule heat while flowing the liquid egg through the heating flow path and heats the egg from a storage temperature to a temperature lower than the sterilization temperature. A liquid egg comprising: a heating process; and a heat exchange heating process in which the liquid egg heated in the Joule heating process is heated to a sterilization temperature by exchanging heat with a heating medium while flowing into the heating channel. Heat treatment method.   3. The heat treatment method for liquid eggs according to claim 1, wherein the heating step is a heat exchange heating step in which the liquid eggs flowing in the heating flow path are heat-exchanged with a heating medium and heated from a storage temperature to a sterilization temperature. A method for heat-treating a liquid egg, comprising: A liquid egg heat treatment device for heat sterilization while continuously transporting liquid eggs,
A heating means for heating the liquid egg to the sterilization temperature while flowing the liquid egg through the heating flow path, having a tube-type heating flow path for flowing the liquid egg at the storage temperature;
A temperature holding means that has a heat retaining channel communicating with the heating channel, and holds the heated liquid egg in the heat retaining channel while maintaining the sterilization temperature for a certain holding time;
A cooling means that has a cooling flow path that communicates with the heat retention flow path, and that cools the liquid egg after the temperature is maintained from the sterilization temperature to the storage temperature while flowing into the cooling flow path;
Passing time setting means for setting the moving time in the flow path within 600 seconds at the time when the liquid egg has exceeded 20 ° C. from the start of heating to the end of cooling,
A liquid egg heat treatment apparatus, wherein the total shearing amount of the liquid egg from the start of heating to the end of cooling is 50000 or less . 7. The liquid egg heat treatment apparatus according to claim 6 , wherein the heating means is a Joule heating unit that heats the liquid egg flowing in the heating flow path from Joule heat to heat from a storage temperature to a sterilization temperature. A heat treatment apparatus for liquid eggs. 8. The liquid egg heat treatment apparatus according to claim 6 or 7 , wherein the heating means heat-exchanges the liquid egg with a heating medium while flowing the liquid egg in the heating flow path, so that the liquid egg is cooled to a temperature lower than the sterilization temperature. A heat exchange heating unit for heating, and a Joule heating unit for heating the liquid egg to a sterilization temperature by generating heat by Joule heat while flowing the liquid egg heated in the heat exchange heating unit into the heating channel. A liquid egg heat treatment apparatus characterized by the above. The liquid egg heat treatment apparatus according to claim 6 or 7 , wherein the heating means generates Joule heat while flowing the liquid egg in the heating flow path and heats the egg from a storage temperature to a temperature lower than the sterilization temperature. A liquid egg comprising: a heating unit; and a heat exchange type heating unit that heats the liquid egg heated in the Joule type heating unit to a sterilization temperature by exchanging heat with a heating medium while flowing into the heating channel. Heat treatment equipment. The liquid egg heat treatment apparatus according to claim 6 or 7 , wherein the heating means is a heat exchange type heating unit that heats the liquid egg flowing in the heating flow path from a storage temperature to a sterilization temperature by heat exchange using a heating medium. An apparatus for heat-treating a liquid egg, comprising:

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