JPS6259838A - Measuring method for flowability of raw food material under high pressure - Google Patents

Abstract

PURPOSE:To measure viscosity accurately by arranging two cylinders and plungers in a line vertically opposite each other and coupling respective end parts of both cylinders through a capillary. CONSTITUTION:A push-in cylinder 5 equipped with a push-in plunger 1 and a receiving cylinder 19 equipped with a receiving plunger 13, and the plungers 1 and 13 are arranged in a line vertically opposite each other, and the facing end parts of both cylinders 5 and 19 are coupled together through a thin capillary 10. In this case, the plunger load W0 or plunger speed V of the plunger 1 is optionally settable and the load W1 of the plunger 13 is held at an optional constant value. The raw food material to be measured is charged in a push-in reserver 8, the capillary 10, and a receiving reserver 17 formed on the sides of both cylinders 5 and 19 through the plungers 1 and 13. Then, the viscosity of the raw food material is measured by measuring the flow rate of the raw food material in the capillary 10 by giving a difference in pressure between the plungers or measuring the pressure by setting the speed of the upstream-side plunger.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to the provision of a new measuring means for measuring the fluidity (viscosity) of food materials when present under high pressure.

(Prior Art) As is well known, it is a material that has been processed into food products for a long time, and its most significant feature is that its composition changes when heat is applied. From the initial stage of processing, in which materials are left in a certain place for a certain period of time, like cooking rice, recently processing methods have been developed that aim at mass production by making these processes continuous. In addition, many food materials exhibit fluidity during the processing process, so when making continuous processing,
This is often done by using the characteristics of the fluid. For example, a food extruder is a suitable example, and is a machine that takes advantage of the fluidity of food. When trying to apply the fluidity of foods in processing methods, there are various points to consider, such as the following. First, the temperature range for processing is 100° C. or higher or lower than 100° C.

The reason why 100° C. is set as a limit depends on whether or not the water contained in the food material is vaporized. For example, the temperature is 100° C. or lower before the sausage is placed in a cylindrical container, and the temperature of the molten product before the corn grits is heated to expand and expand into a gooey for extrusion is 100° C. or higher. When the temperature is over 100°C, there is a problem that steam is generated. The next issue is whether or not the material contains a lot of water. Normally, there are few processing methods that allow the moisture in the food to turn into steam. The food must be mixed in liquid form.The reasons why steam generation is not good are: firstly, the food is dehydrated and only dry food is obtained;
Second, the processability may become extremely unstable, but when manufacturing puffed confectionery, etc., water is contained as a liquid up to the die that requires fluidity, and it evaporates at the same time as it puffs. It goes without saying that this is different from the above explanation because the main focus is on Therefore, in order to prevent moisture from evaporating, it is necessary to apply pressure to the material even when the temperature is rising to prevent moisture from evaporating, and normally from this state processed foods are obtained by the above-mentioned swelling or cooling. There are two purposes for applying pressure to food materials; one is to prevent water evaporation as mentioned above, and the other is to prevent compositional changes by exposing food materials to high pressure. Or, conversely, to intentionally cause a compositional change. In any case, in order to analyze the processing technology or understand the phenomena when food materials exist under high pressure, it is necessary to measure their fluidity (viscosity) regardless of whether they are heated or not. occurs. It can also be understood that the fluidity of food materials changes once the water content evaporates, but this is a case that involves an extreme change in physical properties. Its viscosity is different.

Conventionally, it is known that a capillary rheometer, flat plate rheometer, cylindrical rheometer, etc. are used to measure the fluidity, or viscosity, of a fluid, but this method is not suitable for measuring the flow of food materials under high pressure. is not appropriate for the following reasons.

(Problems to be Solved by the Invention) The cabillary rheometer shown in FIG. The fluidity of the polymer material is measured by filling it with a polymer material, and the pressure distribution is as shown in the figure. However, W
When is the plunger load, W=A−P. In this case, if the water content turns into vapor at pressure P0, the fluid becomes a vapor-containing fluid in section 7 of the plot, so it does not mean that the viscosity of the food material is measured as a pure liquid.

Furthermore, the material put into the reservoir 8 is heated to the measured temperature by heating the cylinder 5.
Water separation occurs because the capillary 10 portion is open, and as the push-in plunger 1 is lowered, a phenomenon in which water is initially squeezed out occurs. Therefore, in the initial stage, it is necessary to maintain the pressure even when the temperature of the material filled in the reservoir 8 is raised, and a sealed space is also required for this purpose.

Generally used polymer materials do not undergo phenomena such as water separation or dehydration when heated, and their composition does not change even when exposed to atmospheric pressure near the capillary outlet. Although it is considered possible to use it, it is not suitable for measuring the fluidity (viscosity) of materials in the food industry.

(Means for Solving the Problems) The present invention provides a method for measuring the fluidity (viscosity) of materials containing high moisture content such as food materials under high pressure without generating steam. Various measurements related to this can be obtained. Specifically, two cylinders and plungers are arranged in a straight line and vertically facing each other, and each end of both cylinders is connected with a thin capillary. Fill the food material into two reservoirs and a capillary formed by connecting the two plungers, and measure the flow rate at which the food material flows through the capillary by setting a difference in the two plunger pressures, or by setting the upstream plunger speed. By measuring the pressure, the viscosity of the food material can be measured. Furthermore, by arbitrarily setting the pressure inside the reservoir on the downstream side where the food material flows through the capillary, it is possible to measure the viscosity of the food material under high pressure. The purpose of this technology is to measure the viscosity of the liquid without evaporating its volatile content, and furthermore, it is possible to adjust the temperature of each of the two zones of the high-pressure side cylinder and capillary section and the low-pressure side cylinder section. In addition, the low-pressure side cylinder section, where the temperature is adjusted, is separately filled with a low-viscosity fluid different from that of the food material to be measured, and the extrudate extruded from the high-pressure side cylinder section via the capillary is cooled to volatilization conditions. In addition, when extruding the same food material, the two zones of the high-pressure side cylinder and capillary section and the low-pressure side cylinder section are kept at the same temperature, and the internal pressures of the upper and lower reservoirs are alternately adjusted to the high pressure - By measuring the viscosity of the food material passing through the capillary by changing the pressure from low pressure to low pressure to high pressure, and measuring the viscosity of the food material through the capillary, changes in composition can be interpreted as changes in viscosity with respect to the shear history of the food material under shear. It is in.

(Function) According to the technical means of the present invention, as shown in FIG. , 19. In the present invention, a measuring device is used in which the plungers 1 and 13 are arranged in a straight line and vertically facing each other, and the opposing ends of both cylinders 5 and 19 are connected by a narrow cavity 5. Yes, in this case, the plunger load W or plunger speed V of the push-in plunger 1 can be set arbitrarily, and the receiver is the plunger 1.
The load W at 3 (indicated by reference numeral 22) can also be maintained at any constant value by keeping the air pressure of the air cylinder 15 constant. The air cylinder 15 is shown as an example of a constant load generating device that ensures that the load -1 set for measurement is always constant during operation, and is not limited to the air cylinder, and other mechanisms may be used. I can do it. The present invention provides the above-mentioned pressing,
The receiver connects each end of the cylinder 5.19 with a capillary 10, and has plungers 1, 13 on the 5°19 side of both cylinders.
A forced reservoir 8 formed through a capillary 10,
The receiver fills the food material to be measured into the reservoir 17 and performs the measurement, but the temperature is adjusted by installing the temperature control device 20 with the push-in cylinder 5 facing the push-in reservoir 8 and capillary 10 as one zone. In addition, the cylinder 19 facing the receiving reservoir 17 can be installed with a temperature control device 20 to adjust the temperature, and the push cylinder 5 and the cylinder 19 have the same temperature setting value. However, generally by taking different values, a heat insulating material 18 is interposed between these two cylinders 5 and 19 to thermally isolate them.

Further, the push-in plunger 1 and the receiver have the plunger 13, and the push-in cylinder 5 and the receiver have the respective reservoirs 8. To prevent the material to be measured from leaking to the outside even if the inside of the F is under high pressure, sealing parts 2.
4 will be provided. These seal portions 2 and 14 are connected to the plungers 1 and 1.
It is impossible to resist the movement of step 3. For example, use an O-ring made of Teflon resin (tetrafluoroethylene),
It was assumed that it could be used up to an inner diameter of 1000 kg/cal. In addition, 21 is the installation frame, the other 3 indicates the pushing plunger load -〇, and 4 indicates the plunger speed V
, 6 indicates the diameter 2Ro of the pushing cylinder 5, 9 indicates the internal pressure Pit of the pushing reservoir 8, 11 indicates the length of the capillary 10, and 12 indicates the diameter 21? of the capillary 10.
, 16 indicates the internal pressure PIz of the plunger 13, 22 indicates the plunge load edge, and 23 indicates the diameter 2R+ of the cylinder 19. The principle of measuring food materials under high pressure according to the present invention using the above-mentioned measuring device is as follows.

Assuming that the internal pressure of the push-in reservoir 8 is PIl, and the internal pressure of the receiving reservoir 16 is PI2, the fluid flows through the capillary 10 due to the differential pressure between PI and PI. The flow rate of the material at this time is Q
(CJJ/5ec), the apparent shear rate r generated on the wall surface of the capillary 10 is expressed by the following equation.

and=40/πR3 On the other hand, the shear stress τ generated on the wall surface of the capillary 10 is expressed by the following equation.

τ = R (PII Ph) / 2L Therefore, Newton's apparent viscosity μ is generally the following formula.The viscosity of the material can be found using the above formula, but as for the shape of the cavity, L/R should be 40 or more. It is assumed that the influence of the entrance effect is almost negligible.

If the plunger load -〇 can be given arbitrarily, it is given as PI, = -0/πR0Z. On the other hand, if the air pressure in the air cylinder 15 is Po, and the effective pressure receiving area of the air cylinder 15 is 8, then W, = P0
・A Plz = Wr/πR1” = PO−A , /πR,Z
Therefore, if the plunger speed -■ of the push-in plunger is measured, the flow rate Q becomes Q=πR,''V, so PI.

, Pl2, and Q, then τ and μ can be determined. In particular, by measuring μ by changing the following, it is also possible to measure non-Newtonian viscosity.

In addition, if the plunger speed V can be given arbitrarily, by measuring the equations such as Q=πR, ``V, and the pushing plunger load -〇 at this time, Pl, , prz, mouth can be found, and the door, It is possible to determine τ and μ, and by changing the door, it is also possible to measure non-Newtonian viscosity.

The above is the method for measuring viscosity in the present invention.
When the pressure is such that the water in the food material does not evaporate,
The pressure Ph can be arbitrarily set by adjusting the air pressure.

As already mentioned, the viscosity of food materials differs depending on the pressure to which they are exposed, and by bringing the PII (>PIz) value closer to the Pl2 value, the material viscosity near the pH value can be measured. In this case, the plunger speed V needs to be set to a very small value. In this way, the viscosity of the food material can be measured without evaporating the moisture contained inside the food material.

(Example) When performing measurements according to the present invention, after each of the upper and lower cylinders 5, 19 is brought to a predetermined temperature by the temperature control device 7, 20, each reservoir 8. The food material to be measured is filled inside I7 and the capillary 10, and the plunger 1 is inserted so as to prevent air from entering. Then each reservoir 8.7
The internal pressure is kept constant at a pressure PI2 above the limit at which water in the food material evaporates and is maintained for a predetermined period of time. This holding time is the time required for the heated material to melt, and varies depending on the food material.

The viscosity is measured as described above in the section on action, and the indentation granger load is used. Alternatively, it can be measured by changing the pushing speed V.

According to the present invention, it is also possible to obtain a capillary extrudate in the following manner. That is, the materials put into the push-in reservoir 8 and capillary 10 and the material put into the reservoir 17 are changed, and the set temperature on the push-in cylinder 5 side and the set temperature on the cylinder 19 side are different, and generally The cylinder 19 side of the receiver is kept at a low temperature, and the material in the receiver server 1f is, for example, water or a low-viscosity liquid, so that the material extruded from the capillary 10 enters the reservoir 17. However, it should be placed in such a way as to minimize deformation resistance. In these conditions p
As the pressure relationship H>PI2, capillary 1 due to the differential pressure
By collecting the material extruded from the container 17 from the reservoir 17, it is possible to obtain an extrudate extruded from a narrow nozzle under high pressure. However, in this case, the temperature of the low-temperature side reservoir 17 is desirably 100° C. or lower, and the extrudate is cooled to volatilization conditions before being taken out.

In addition, the temperature of the upper and lower cylinders 5, 19 is kept the same,
And for the same food material, PII > prz(Δ
After measuring its viscosity under the condition of P = PI + Pig), PI2 (= the above PI,) > pH (the above PI
If the viscosity is measured in the same way when pushing back in the state of It is also possible to capture the process of movement, and these can also be used effectively as part of measurement.

(Effects of the Invention) According to the present invention, it is possible to accurately measure the viscosity of a food material that contains a large amount of volatile matter such as moisture without containing evaporated gas generated in the material. ,
Generally, if food materials are heated to high temperatures, evaporated gas is likely to be generated, but the viscosity can be measured even at such high temperatures. Furthermore, although the fluidity of food materials differs under high pressure, it is possible to accurately measure the viscosity even under high pressure (between the inlet pressure and outlet pressure of the capillary 10). By keeping the inlet pressure and outlet pressure in step 10 at a pressure difference as small as possible, it is possible not only to easily measure viscosity under a nearly constant pressure, but also to A capillary extrudate can be obtained, and the composition change (mixing,
Changes in viscosity due to deterioration (indicating deterioration, etc.) can now be measured reliably and easily. Fluidity (viscosity) is essential for analyzing food processing technology and understanding phenomena when food materials are placed under high pressure. It has an excellent effect as it allows accurate measurement of the temperature to be easily obtained regardless of heating or non-heating.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional front view of an embodiment of an apparatus for carrying out the measuring method of the present invention, and FIG. 2 is an explanatory diagram of a conventional capillary rheometer. 1-Push plunger, 5-Push cylinder, 7, 20-Temperature control device, 8-Push reservoir, 10-Capillary, 1
3 - The receiver is a plunger, 5 - The air cylinder, 17 - The receiver is the reservoir, 1 - Thermal insulation material, 19 - The receiver is the cylinder. Patent applicant: Kobe Steel, Ltd. 7th floor, Figure 2

Claims (1)

[Claims] 1. Two reservoirs constituted by arranging two cylinders and plungers in a straight line and vertically facing each other, and connecting each end of both cylinders with a thin capillary, and food in the capillary. Measure the viscosity of the food material by filling the material and measuring the flow rate of the food material through the capillary by setting a difference between the two plunger pressures, or by setting the upstream plunger speed and measuring the pressure. A method for measuring the flow of food materials under high pressure. 2. By arbitrarily setting the pressure inside the reservoir on the downstream side where the food material flows through the capillary, the viscosity of the food material or the volatile matter in the food material under high pressure can be measured without volatilizing it. A method for measuring the flow of food materials under high pressure according to claim 1. 3. The method for measuring the flow of food material under high pressure according to claim 1, wherein the two zones of the high-pressure side cylinder and capillary section and the low-pressure side cylinder section each perform temperature adjustment. 4. The low-pressure side cylinder section where the temperature is adjusted is separately filled with a low-viscosity fluid different from the food material to be measured, and the extrudate extruded from the high-pressure side cylinder section via the capillary is cooled to volatilization conditions. 2. A method for measuring the flow of food material under high pressure according to claim 1, wherein the food material flow is taken out under high pressure. 5. The two zones of the high-pressure side cylinder and capillary part and the low-pressure side cylinder part are kept at the same temperature, and when extruding the same food material, the pressure inside the upper and lower reservoirs is alternately changed from high pressure to low pressure, and from low pressure to high pressure. The food material passing through the capillary is caused to flow forward and backward, and its viscosity is measured, thereby detecting changes in composition as changes in viscosity with respect to the shear history of the food material under shear. A method for measuring the flow of food materials under high pressure according to scope 1.