JP4739123B2 - Oil sterilization method - Google Patents

Description

The present invention relates to a method of sterilizing an oil edible oil.

  In general, microorganisms such as koji, yeast, and bacteria adhere to and mix with food, and when there is a lot of water, it causes spoilage. Therefore, food is stored after being sterilized in advance and placed in the distribution process.

  For example, a whipped cream composition, which is a mixed food such as edible fats and oils, is also stored and transported after being sterilized. However, when trying to sterilize the whipped cream composition at ultra high temperature (UHT), the whipped cream composition is thickened due to the ultra high temperature and solidifies. Therefore, high temperature short time sterilization (HTST) is performed to prevent this. Therefore, microorganisms remain and long-term storage is difficult (see, for example, Patent Document 1).

  On the other hand, foods containing acids such as salad dressing can suppress the growth of microorganisms by keeping the pH low or storing it in a cool and dark place even if it contains oil, water, etc. Both can be stored for a long time.

Japanese Examined Patent Publication No. 7-108201

  In recent years, there has been a demand for packaging, storing, using, or distributing almost neutral oil / water mixtures in which oil is mixed with water such as soup in ramen soup such as ramen soup. . The present inventor initially purchased a commercially available edible oil and tried to preserve it by adding a sterilized water to the oil, but it was difficult to preserve for a long period of time due to the growth of bacteria. The present inventor examined this point, the edible oil itself does not rot if it does not contain moisture even if bacteria are present, it can be stored for a long time without sterilization, When it is injected after sterilizing the water in the freshly opened oil, it does not seem to spoil at first glance, but there may be bacteria in the oil, and these bacteria will propagate due to the presence of water, It became clear that the oil / water mixture may rot. Then, when this inventor mixed the water and oil after heat-sterilizing separately, long-term preservation | save was possible.

  The present invention has been made based on such knowledge, and an object thereof is to provide a method and an apparatus capable of efficiently performing sterilization of oil which has not been conventionally performed.

  In order to solve the above problems, the present invention employs the following configuration.

That is, in the invention according to claim 1, while flowing the oil in a pressurized state of atmospheric pressure or higher , steam or hot water is injected into the oil so that the temperature of the oil is 120 to 160 ° C., and the heating time is 2 to 3 seconds. It is characterized by heating directly and then cooling the oil.

  Examples of oils include soybean oil, cottonseed oil, rapeseed oil, corn oil, rice bran oil, safflower oil, sunflower seed oil, coconut oil, corn oil, cocoa butter, peanut oil, olive oil, sesame oil, kapok oil, evening primrose oil, and shea fat Vegetable oils such as monkey fat, coconut oil and palm kernel oil, or animal fats such as milk fat, beef tallow, lard, fish oil, whale oil and the like can be targeted for sterilization. The temperature during direct heating of the oil is preferably 120 ° C to 160 ° C, more preferably 135 ° C to 150 ° C. The temperature of the oil during cooling is preferably room temperature to 60 ° C, more preferably 30 ° C to 50 ° C.

In the oil sterilization method according to claim 1, steam or hot water is injected into the oil so that the temperature of the oil is 120 to 160 ° C., and the heating time is indirect heating before direct heating for 2 to 3 seconds. By increasing the oil temperature from 40 ° C. to 80 ° C. , the sterilization effect of direct heating can be enhanced.

Further, in the oil sterilization method according to claim 1, the oil may be stored in the tank after the oil is cooled, and water injected as steam or hot water into the oil may be removed, or the oil may be cooled. You may make it remove the water mixed by direct heating by performing by vacuum cooling.

Sterilization method of the above oil, and direct heating means (5) for heating the oil directly by injecting steam or hot water directly heated oil cooling means for cooling the (6), but the oil of above atmospheric pressure It can be implemented by an oil sterilization device provided in an oil flow path (1) that flows under pressure.

According to the present invention, while flowing oil at a pressure higher than atmospheric pressure, steam or hot water is injected, the temperature of the oil is 120 to 160 ° C., and the heating time is directly heated for 2 to 3 seconds. Since the oil is cooled, it is possible to appropriately sterilize the oil such as edible oil, and therefore, it is possible to produce an oil that does not rot even when mixed with water.

  Next, embodiments of the present invention will be described with reference to the drawings.

<Embodiment 1>
This oil sterilization method is, for example, to sterilize oil extracted from a plant, and primary heat (I), secondary heat (II) while flowing oil in a pressurized state by a sterilizer as shown in FIG. ), Primary cooling (III), secondary cooling (IV), draining (V), and packaging (VI) are sequentially performed.

  This sterilizer is provided with a flow path 1 for flowing oil in one direction, and on this flow path 1 from the upstream side toward the downstream side, the container tank 2, the pump 3, and the primary for primary heating (I). Heater 4, secondary heater 5 for secondary heating (II), primary cooler 6 for primary cooling (III), secondary cooler 7 for secondary cooling (IV), control valve 8 , A surge tank 9 for draining (V) and the like, a pump 35, and a filling machine 11 for packaging (VI).

  The container tank 2 stores oil before sterilization. The oil in the container tank 2 is sent out to the flow path 1 by the pump 3. On the downstream side of the flow path 1, the control valve 8 throttles the opening of the flow path 1, so that the oil flows between the pump 3 and the control valve 8 while being pressurized to atmospheric pressure or higher.

  The primary heater 4 for primary heating (I) raises oil temperature to 40 to 80 degreeC by heating the oil of room temperature. The heating time is about 45 seconds, for example.

  The primary heater 4 has a sealed pot 12 as shown in FIG. Inside the kettle 12, an oil flow path 13 and a steam flow path 14 are stretched in a mesh shape by pipes or the like, and the flow paths 13 and 14 are blocked by a wall such as a pipe. The shuttle 12 is provided with inlets 13a and 14a and outlets 13b and 14b for the oil passage 13 and the steam passage 14 in the shuttle 12, respectively. As oil and steam flow through the flow paths 13 and 14, respectively, the heat of the steam is transmitted to the oil through a wall such as a pipe to heat and sterilize the oil. The sterilization by the primary heater 4 is performed as indirect heating in which the oil and the steam do not come into contact with each other, thereby preliminarily heating the oil. Of course, hot water may be used instead of steam.

  The primary heating is provided to make up for the shortage of the heating capacity in the next secondary heater 5, and therefore can be omitted if the heating capacity and sterilization capacity of the secondary heater 5 are sufficient.

  This primary heating can also be performed by a heater 4a as shown in FIG.

  4, reference numerals 15a and 15b denote an oil feed pipe and a return pipe, respectively, reference numerals 16a and 16b denote a steam feed pipe and a return pipe, respectively, and reference numeral 17... Flows oil and steam, respectively. Indicates a shell. In each shell 17, a flat oil chamber P and a steam chamber Q partitioned by a central partition wall 17a are formed back to back. A large number of fins (not shown) for heat exchange are formed on the partition wall 17a. These shells 17 are overlapped in one direction so that the oil chambers P coincide with each other and the steam chambers Q coincide with each other. Further, on the oil chamber P side of each shell 17, a steam pipe q communicating with the steam feed pipe 16a and the return pipe 16b for allowing steam to pass therethrough is attached so as to penetrate the partition wall 17a. The steam pipes q in the oil chamber P of the matching shell 17 are connected to each other. Similarly, an oil pipe p communicating with an oil feed pipe 15a and a return pipe 15b for allowing oil to pass through is attached to the side of the steam chamber Q of each shell 17, and the inside of the steam chamber Q of the adjacent shell 17 is attached. Are connected to each other.

  In the primary heater 4a, oil flows from the feed pipe 15a to the return pipe 15b through the oil chamber P between the shells 17, while steam also flows from the feed pipe 16a to the return pipe 16b in the steam chamber Q between the shells 17. In the meantime, the heat of the steam is transmitted to the oil through the partition walls 17a of the shells 17 and 18. Thereby, oil temperature rises to the said temperature and oil is indirectly heated.

  The secondary heater 5 for the secondary heating (II) further raises the oil temperature by further heating the oil, preferably from 120 ° C to 160 ° C, more preferably from 135 ° C to 150 ° C. If the temperature is lower than 120 ° C, sterilization failure may occur, and if the temperature is higher than 160 ° C, the oil may be burnt or deteriorated. The heating time is desirably about 2 to 3 seconds.

  As the secondary heater 5, a steam injection heater as shown in FIG. 3 can be used. In the heater 5, first, second, and third cylinders 19, 20, and 21 are provided in a nested manner from the outside to the inside, and a valve rod 22 is inserted into the cavity of the third cylinder 21. It is constituted by. The first, second, and third cylinders 19, 20, and 21 and the valve rod 22 are coupled to each other by screws 23, 24, and 25 so that they can be screwed back and forth in the same direction. The first, second and third cylinders 19, 20, 21 and the tip of the valve stem 22 are formed with annular gaps 26, 27, 28 between them. The sizes of the gaps 26, 27, and 28 can be finely adjusted by rotating the third cylinders 20, 21 and the valve rod 22 to relatively advance and retract. An inlet 5a for introducing oil into the heater 5 is provided in the first cylinder 19, and a through hole 20a is formed in the second cylinder 20 corresponding to the inlet 5a. An outlet 5 b for taking oil out of the heater 5 is formed at the tip of the cylindrical body 19. Further, an inlet 5c for introducing steam into the heater 5 is provided in the first cylinder 19, and this inlet 5c is electrically connected to the oil outlet 5b. It is also possible to use hot water instead of steam.

  The oil flows through the flow path 1 by the pump 3 as described above, flows into the secondary heater 5 from the inlet 5a in the pressurized state, travels toward the outlet 5b, and passes through the annular gaps 27 and 28. When the steam is blown from the gap 26, it is heated in direct contact with the steam. Since the oil is pressurized above the atmospheric pressure between the pump 3 and the control valve 8, the boiling point increases and the oil is heated to the high temperature as described above and sterilized. This sterilization is direct heating, and as a result of supplying a large amount of heat from steam to the oil in a short time, it is sterilized in a relatively short time.

  This secondary heating can also be performed by a steam infusion type heater 5d as shown in FIG. The heater 5d includes a cylindrical body 29 extending in the vertical direction, and an oil inlet 30 formed by a collection of many small holes is provided at the upper end of the cylindrical body 29, and is tapered at the lower end of the cylindrical body 29. An oil outlet 31 is provided. A steam inlet 32 a and an outlet 32 b are provided in the middle of the cylinder 29 in the vertical direction. Oil is injected in a streak shape into each cylinder 29 from each small hole 30a of the inlet 30 in a pressurized state, and steam is injected into the cylinder 29 from its inlet 32a. Oil comes in direct contact with steam and gives a large amount of heat from the steam in a short time and is sterilized quickly and reliably. The sterilized oil is taken out of the cylinder 29 from the outlet 31 in a state of containing moisture of the steam, and after the heat is deprived of heat by the oil, the steam is discharged out of the cylinder 29 from the outlet 32b.

  The primary cooler 6 for primary cooling (III) has the same structure as the heater 4 shown in FIG. 2, and oil is injected in the same manner as the heater 4, but cooling water is used instead of steam. It is injected into the place where steam is injected. By this primary cooling, the oil is cooled from the secondary heating temperature to about 40 ° C. to 60 ° C. and taken out from the primary cooler 6 through the outlet 13b (see FIG. 2).

  The secondary cooler 7 for the secondary cooling (IV) has the same structure as the primary cooler 6, and oil that has flowed out of the primary cooler 6 is injected into the secondary cooler 7, and the secondary cooler 7 is preferably cooled to room temperature to 60 ° C., more preferably 30 ° C. to 50 ° C., and is taken out from the secondary cooler 7 through the outlet 13b (see FIG. 2). If the temperature is higher than 60 ° C., the heat sealability of the bag or the like may be impaired when the bag is filled with oil and heat sealed later.

  In addition, when the cooling performance of the primary cooler 6 is high and the oil can be cooled to the above temperature only by the primary cooler 6, the secondary cooler 7 can be omitted. Further, when the cooling performance of the primary and secondary coolers 6 and 7 is low, a tertiary or higher cooler may be provided.

  The surge tank 9 stores the sterilized oil that has exited the secondary cooler 7 and passed through the control valve 8. A drain pipe 34 provided with an opening / closing valve 33 is connected to the surge tank 9. The water mixed in the secondary heater 5 accumulates at the bottom of the surge tank 9, but this water is removed from the drain tank 34 to the outside of the surge tank 9. The surge tank 9 also functions to adjust the oil sterilization speed and the filling speed of the next filling machine.

  A flow path 1 extends from the surge tank 9 to a filling machine 11 for packaging (VI), and oil in the surge tank 9 is sent to the filling machine 11 by a pump 35 provided in the flow path 1. The filling machine 11 includes a chamber 11a, and a bag making machine (not shown) is provided in the chamber 11a. The inside of the chamber 11a is sterilized by a sterilizing agent such as hydrogen peroxide and is in a sterile state. The bag making machine closes the mouth of the bag 36 by heat sealing when a fixed amount of oil is filled in each bag 36 while making the bag 36 by heat sealing the resin film. A nozzle (not shown) is attached to the tip of the flow path 1 extending from the surge tank 9, and this nozzle faces the mouth of the bag 36 made by the bag making machine, and sterilized oil is injected into the bag 36 from the nozzle. . Since the oil has been sterilized, it will not rot during storage even if water mixed in during heating remains.

  In addition, since a well-known thing is used for a filling machine and a bag making machine, those detailed description is abbreviate | omitted.

  As shown in FIG. 1, a water sterilizer can be provided alongside the oil sterilizer, and the water can be packaged together with the oil by the filling machine.

  The water sterilization apparatus is intended to sterilize water such as soup stock, so that heating (A), cooling (B), and storage (C) are sequentially performed while flowing the water under pressure. It has become.

  The water sterilizer includes a flow path 37 for flowing water in one direction, and the container tank 38, the pump 39, and the heating (A) on the flow path 37 from the upstream side toward the downstream side. A heater 40 for cooling, a cooler 41 for cooling (B), a control valve 42, a surge tank 43 for storage (C), and a pump 44 are provided in this order.

  The container tank 38 stores water before sterilization. The water in the container tank 38 is sent out to the flow path 37 by the pump 39. On the downstream side of the flow path 37, the control valve 42 throttles the flow path 37, so that water flows between the pump 39 and the control valve 42 while being pressurized to atmospheric pressure or higher.

  The heater 40 for heating (A) heats the water at room temperature, and raises the temperature to 120 ° C. to 160 ° C. when the water is dashi stock, for example. The heating time is desirably about 2 to 3 seconds.

  As the heater 40, one having the same structure as the oil heater 4 shown in FIG. 2 can be used, and water can be sterilized by indirect heating using steam or hot water.

  The cooler 41 for cooling (B) has the same structure as the heater 4 shown in FIG. 2, and water is injected into the cooler 41 in the same manner as the heater 4. Cooling water is injected instead of the steam. By this cooling, the water is cooled from the sterilization temperature to about 30 ° C. to 50 ° C. after cooling and taken out of the cooler 41 from the outlet 13b (see FIG. 2).

  The surge tank 43 for storage (C) stores the sterilized water that has exited the cooler 41 and passed through the control valve 42. The surge tank 43 functions to adjust the water sterilization speed and the filling speed of the next filling machine 11.

  As shown in FIG. 1, a flow path 37 extends from the surge tank 43 to the filling machine 11 for packaging (VI), and water in the surge tank 43 is transferred by a pump 44 provided in the flow path 37. It is sent to the filling machine 11 described above. A nozzle (not shown) is attached to the tip of the flow path 37 extending from the surge tank 43, and this nozzle faces the mouth of the bag 36 made by the bag making machine 11, and sterilized water is put into the bag 36 from the nozzle. inject. Since the oil already injected into the bag 36 or later injected is sterilized, it does not rot during storage even if water is added.

<Embodiment 2>
As shown in FIG. 6, in the second embodiment, a vacuum cooler 45 is used as the primary cooler in the first embodiment. When the oil sterilized by the secondary heater 5 reaches the vacuum cooler 45, the water mixed in the secondary heater 5 evaporates out of the oil due to the reduced pressure, and heats the vaporization from the oil to cool the oil. . Moreover, unnecessary odor of oil is removed by evaporation of moisture.

  Since the water in the oil is removed by this primary cooling, the drain pipe 34 and the like (see FIG. 1) from the surge tank 9 are omitted.

  In FIG. 6, the same parts as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

  Although the present invention is configured as described above, it is not limited to the first and second embodiments. For example, in the first and second embodiments, only one secondary heater is provided. Two or more groups can be provided as necessary. Of course, a drain pipe may be used in combination.

It is a block diagram which shows the sterilization method of the oil which concerns on Embodiment 1 of this invention. It is a vertical sectional view of a primary heater. It is a vertical sectional view of a secondary heater. It is a perspective view of the modification of a primary heater. It is a vertical sectional view of a modification of the secondary heater. It is a block diagram which shows the sterilization method of the oil which concerns on Embodiment 2 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Oil flow path 5 ... Heater 6 ... Cooler 9 ... Storage tank 34 ... Drain pipe 45 ... Vacuum cooler

Claims (4)

  While flowing the oil at a pressure higher than atmospheric pressure, injecting steam or hot water into the oil, the oil temperature is 120-160 ° C., the heating time is directly heated for 2 to 3 seconds, and then the oil is cooled. An oil sterilization method characterized by the above.   The oil sterilization method according to claim 1, wherein the oil temperature is increased to 40 ° C. to 80 ° C. by indirect heating before the direct heating.   The oil sterilization method according to claim 1, wherein the oil is stored in a tank after the oil is cooled, and water injected into the oil as steam or hot water is removed.   The oil sterilization method according to claim 1, wherein water injected as steam or hot water into the oil is removed by cooling the oil by vacuum cooling.

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