JPH0156748B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a continuous manufacturing method for whipped food products, and more specifically, whipped cream products have compressibility derived from high overrun and have large changes in physical properties such as viscosity during the whipping process. The invention relates to a continuous manufacturing method for whipped food, and more specifically, in order to maintain a constant inflow pressure to the whipped rotary stirrer that discharges the whipped food, the discharge of the whipped rotary stirrer is The present invention relates to a continuous manufacturing method for whipped food using a control means for adjusting the flow path resistance of the parts.

Conventionally, as a basic continuous method for producing whipped cream, the method outlined in the flow sheet of FIG. 1 has been known. That is, in this method, gas is continuously blown into the liquid cream line 1 from the compressed gas line 2 to disperse the air bubbles, and if necessary, the air bubbles are made finer by the stationary stirrer 3, and finally, the whip rotating Mold stirrer 4
By continuing to apply shearing force, the fat globules are gradually aggregated around the air bubbles, and are discharged from the whipping rotary stirrer 4 in an optimal whipped state.

However, in the conventional continuous manufacturing method for whipped foods, in order to maintain the overrun of the whipping cream discharged from the whipping rotary stirrer at a desired constant value, the flow rate of the liquid cream and the blowing of gas must be controlled. Even if the amount is adjusted and the dispersed gas is made fine and uniform, the discharge flow rate of the whipped cream fluctuates periodically, and the whipped cream discharged correspondingly may be periodically whipped excessively. Alternatively, a phenomenon of under-whipping occurs (hereinafter referred to as "whipped cream cycling phenomenon"), making it impossible to obtain whipped cream of consistent quality. This excessive or insufficient whipping is related to the amount of shear applied to the whipped cream and the quality of the whipped cream, and this relationship is as follows:
It is explained as follows based on conventionally known knowledge.

When gas is dispersed in liquid cream and shear is applied, it changes from a liquid state to semi-solid whipped cream, and when shear is continued, it undergoes a complete phase transformation (buttering) and separates into butter and buttermilk. In other words, the phase is converted from O/W to W/O, and whipped cream is in an unstable transition region that can be called an intermediate phase. However, if the whipped cream is satisfied as a product, the whipped cream is in a region that can be called the optimum range of a part of this transition range, and if the amount of shear decreases even slightly from this optimum range, the product cannot be obtained. The shape retention of the whipped cream deteriorates, resulting in a so-called "sag" tendency. On the contrary, if the amount of shearing is even slightly excessive, the resulting whipped cream will lose its surface smoothness and tend to have a so-called "rough skin." None of these are satisfactory products.

When whipped cream is manufactured continuously, the above-mentioned excessive whipping or under-whipping poses a particular problem.

In addition, the cycling phenomenon of whipped cream observed in the continuous manufacturing process of whipped cream is similar to the continuous manufacturing process of whipped cream, which has rapid changes in physical properties such as compressibility and viscosity due to high overrun during the whipping process. The same phenomenon occurs to varying degrees in manufacturing processes (hereinafter referred to as the "cycling phenomenon", including the cycling phenomenon of whipped cream); in both cases, non-uniformity in quality occurs in the continuous manufacturing process of whipped foods. It is bringing about this.

The present inventors have quantitatively grasped the optimum range and the associated changes in viscosity in the whipping cream production process, and have used this to clarify the behavior inside the whipped cream rotary stirrer. By discovering that there is a regular correspondence with fluctuations in the inflow pressure to the mold agitator, and by establishing an effective method for controlling that pressure, we were able to solve problems that are unavoidable due to the unique properties of whipped cream. We have completed a continuous manufacturing method for whipped foods that maintains a constant quality by preventing the cycling phenomenon that occurs during the process.

An object of the present invention is to provide a continuous method for producing whipped foods with constant quality by preventing the above-mentioned cycling phenomenon.

The present invention provides a continuous method for manufacturing whipped foods using a rotary stirrer for whipping, by adjusting the flow path resistance of the discharge portion of the rotary stirringr for whipping, which discharges the whipped food. This is a continuous method for producing whipped foods, which is characterized by maintaining constant inflow pressure to a rotary stirrer.

Next, the method of the present invention will be described in detail for the production of whipped cream.

In the method of the present invention, the flow path resistance of the discharge portion of the rotary stirrer for whips is adjusted by attaching a control valve or the like to the discharge portion of the rotary stirrer for whips and adjusting the flow path resistance of this portion. It is done. In other words, in response to an increase in the pressure inside the rotary whip stirrer, or in other words, a decrease in the outlet flow rate, the flow path resistance is reduced by increasing the valve opening and the discharge part in the whip rotary stirrer is increased. The whipped cream in the vicinity of the pump is discharged before it becomes excessively sheared, and in response to the above pressure drop, the valve opening degree is lowered to the contrary.

By this adjustment, the residence time of the cream in the whipping rotary stirrer, ie, the shear time, is controlled to be constant. In other words, the outlet flow rate is maintained constant.
Even if you attempt to control the pressure inside the whip rotary stirrer to a constant value by adjusting the flow path resistance at the inlet to the whip rotary stirrer, this will immediately cause the residence time to become constant. It won't happen.

In other words, when the pressure inside the rotary whipping stirrer increases, if the flow path resistance of the inflow section is increased to reduce the flow rate of cream flowing in, the amount of cream compressed and accumulated inside the whipping rotary stirrer will be reduced. As the amount decreases, the pressure inside the whipping rotary stirrer decreases, but due to this pressure drop, the discharge flow rate of whipped cream from the whipping rotary stirrer decreases, so the cream stays in the whipping rotary stirrer. On the contrary, time increases. This increase in residence time results in an increase in the amount of shearing of the cream, which results in excessively sheared whipped cream being discharged from the whipping rotary stirrer. However, as will be explained later, when the shear amount of the cream exceeds a certain level and exceeds the yield amount of the whipped cream, the viscosity of the cream decreases rapidly, and as a result, the cream in the whipping rotary stirrer is discharged all at once. ,
When this happens, whipped cream that has not been sufficiently sheared will be discharged from the whipped rotary stirrer. This does nothing but encourage the cycling phenomenon.

Therefore, in the present invention, the internal pressure of the whip rotary stirrer must be controlled by adjusting the flow path resistance on the discharge side to keep the residence time of the cream constant and the amount of shearing constant. In addition, when making this adjustment using a control valve, due to sudden contraction and expansion of the flow path, etc.
It is preferable to prevent the formation of fluid stagnation. For example, it is preferable that the piping at the adjustment point be a flexible tube, and that the diameter of the tube be oriented in the flow direction by external pressure and slowly expanded or contracted.

The present inventors increased the amount of shear applied to the liquid cream, observed the resulting changes in quality such as shape retention and surface texture of the whipped food, and simultaneously measured changes in viscosity. The following experiment was conducted to quantitatively understand the existence of an optimal region.

Experiment 1 Put 400 g of each of the same synthetic creams used in Example 1 into a batch-type electric whipper (manufactured by Kenwood Co., Ltd., Kenmix machine), and stir at a rotational speed of 175 r.p.
m., and whipped at a temperature of 8° C. for the respective times shown in FIG. 2 to produce whipped cream.

Taking the stirring time as an indicator of the amount of shear applied,
Sampling was performed as appropriate depending on the stirring time, and the viscosity was measured by a conventional method. Furthermore, the obtained whipped cream is made into artificial flowers by a conventional method, and the condition of the edges of the artificial flowers,
Check the condition of the top of the artificial flower, the condition of the waist of the artificial flower, the condition of the skin of the artificial flower, and the obtained whipped cream at 25℃.
The condition of syneresis was observed with the naked eye after being held for 3 hours, and the suitability of the whip was tested. The results are shown in Figure 2. In the figure, (-〇-) represents viscosity (C・P),
A, b, and c are within the transition region of phase change and represent the regions of excessive shearing, optimal region, and insufficient shearing, respectively, in view of the above-mentioned properties of whipped cream.

The results of Experiment 1 revealed the following. The time it took to complete the whip was 4 minutes 10 seconds (250
However, it takes 3 minutes and 50 seconds (230 seconds) to pass through the O/W type region, accounting for more than 90% of the total stirring time; These are extremely short times of 10 seconds, 5 seconds, and 15 seconds, respectively, and their proportions in the total stirring time are only about 4%, 2%, and 6%, respectively. Also,
Looking at changes in viscosity, the viscosity at the start of stirring
Compared to 300 to 400 C.P., the viscosity has increased to about 300,000 C.P. at the end of the test, and shows a remarkable tendency to increase in viscosity especially near the optimum region b.

Furthermore, the present inventors have found that the results of Experiment 1 are the same in tests using a rotating stirrer for whips in continuous production methods, that is, the optimum range within this rotating stirrer for whips. It was confirmed that the retention width was extremely narrow and the viscosity tended to increase significantly.

Experiment 2 Whipped cream was produced using the same equipment and conditions as in Example 1. The whip rotary stirrer used is shown in Figure 3. In FIG. 3, a gear-shaped rotating plate 5 and surrounding it with a slight interval,
36 and 37 complementary fixing plates 6 are arranged alternately in the axial direction, and the liquid cream with dispersed air bubbles is whipped while being subjected to shear force while passing through the above-mentioned intervals (Fig. 3, illustration). is an axial cross-sectional view, and b is a radial cross-sectional view of the plates 5 and 6). In the continuous production method, unlike in the batch method, whipping of all throughputs is not completed at the same time, so the shearing (stirring) time per unit throughput is short. Therefore, in this experiment, we set the stirring time, that is, the average residence time in the whip rotary stirrer to 30 seconds, and stopped the operation midway through stable production, disassembled the whip rotary stirrer, and observed the inside. did. As a result, the whipped state of the cream in the whipping rotary stirrer can be classified into three types as shown in and in Figure 4A: completely whipped state, semi-fluid state, and almost liquid state, gas-liquid state. It was found that the area is in an unwhipped state where it can be easily separated, and the area of and is a very narrow area compared to the whole area.

From the above results, even in the continuous production method of whipped cream, the state transition to whipped cream as described in the results of Experiment 1 occurs.
and correspond to the optimum region, insufficient shearing region, and O/W region of Experiment 1, respectively. Then, when the stirring time per unit liquid cream is 30 seconds, the elapsed time in the O/W region, the time in the shear shortage region, and the time in the optimal region are respectively
The times are around 27.6 seconds, 1.8 seconds and 0.6 seconds.

From the above experiments 1 and 2, it has become possible to quantitatively understand to a certain extent the optimum range for the continuous manufacturing method of whipped cream, but at the same time, this range is extremely narrow, and at the same time, It was found that the tendency to increase viscosity was particularly marked.

Therefore, in a continuous manufacturing process, a slight change in flow conditions throughout the system can easily change the quality of the product from optimal to degraded. In addition, in the continuous production method, the viscosity increases by more than 1000 times in the flow direction in the whip rotating stirrer, which is less than 0.5 m in length.
Un-whipped cream with low viscosity and high fluidity,
Short passes and back mixing are likely to occur locally within the rotary whip stirrer, making it difficult to maintain a complete piston flow within the whip rotary stirrer. In addition, nearly half of the volume inside the whip rotary stirrer is occupied by gas, and the processing liquid itself has high compressibility, so the extrusion flow is not perfect and the inlet flow rate and outlet flow rate are Balance is often lost. For these reasons, in continuous production methods, the residence time in the whip rotary stirrer is highly likely to be non-uniform.

From the recognition based on the above experiments and considerations, the above cycling phenomenon can be categorized into the observation results of Experiment 2.
If expressed schematically using and, it will be as shown in FIG.

In other words, in A of Fig. 4, the cream flowing in from the right passes through the state of and is discharged to the left in the optimal range. When subjected to shear, the viscosity of the cream in that area increases, which reduces its flowability and further reduces the outlet flow rate, thereby increasing the residence time of the cream. As the residence time of the cream increases, the cream is subjected to even more excessive shearing, which further increases the viscosity of the cream. As a result, the discharge flow rate further decreases, and cream containing compressible gas is accumulated in the whipping rotary stirrer while being compressed under pressure by the cream pump.
It further helps increase residence time and viscosity. In this case, the optimum region moves back to the right side from the discharge port of the whip rotary stirrer, and an excess shear region' is formed instead. This is illustrated in B of the figure. However, when the amount of shear exceeds a certain level and exceeds the yield value of whipped cream (whipped cream is a typical non-Newtonian liquid and has a strong viscoelastic orientation), the viscosity of the cream decreases rapidly, causing Objects are pushed by high internal pressure and are discharged all at once at a higher speed than the discharge port. When this happens, the flow rate in the whipped rotary stirrer increases, and the residence time becomes shorter, contrary to the case B above, and as a result, the whipped cream becomes insufficiently sheared. In this case, an optimal region within the whip rotary stirrer is not formed, and an insufficient shear region occurs in the discharge section, resulting in an increase in the discharge flow rate. This is shown in C in the figure. Then, since the standard flow rate regulated by the cream pump flows into the whipping rotary stirrer, the state shown in A above is restored again.

In this way, the present inventors have discovered that the repetition of the above phenomenon is the mechanism of the cycling phenomenon, but the main cause is the applied shear as described above with reference to FIG. This can be said to be due to its unique properties, as typified by whipped cream, in that the optimal range for the amount is extremely narrow, and the viscosity increases significantly and the yield value exists around this range.

Next, the present inventors discovered that since the cream in the whipping rotary stirrer is a compressible bubbly multiphase fluid, the whipping properties repeatedly fluctuate due to fluctuations in the discharge flow rate and associated excess or deficiency in the amount of shearing. The following experiment was conducted in order to find out what relationship this has with the pressure at the inlet to the rotary whip stirrer, which is subject to back pressure due to flow path resistance within the whip rotary stirrer.

Experiment 3 In the apparatus used in Example 1, the pneumatic converter and control valve were not installed, but an automatic pressure recorder was installed instead, and the synthetic cream transfer flow rate was adjusted to 83.
Whipped cream was produced under the same conditions as in Example 1, except that the whipping cream was adjusted to Kg/hr, and the discharge flow rate from the whipping rotary stirrer and the fluctuation in the pressure at the inlet to the whipping rotary stirrer were measured.

The results are shown in FIG. From this result, the discharge flow rate fluctuates periodically at approximately 1-minute intervals in the range of maximum flow rate of 130 Kg/hr and minimum flow rate of 55 Kg/hr, and at the same time becomes whipped cream with insufficient shearing and excessive shearing, respectively, which is a typical cycling phenomenon. It can be seen that it exhibits Although the overrun was 118 to 120%, which was approximately the target value, the quality of the artificial flowers obtained by the same method as in Experiment 1 was poor. Also, regarding the fluctuation of pressure, it fluctuates in the range of 0.3 to 0.5 Kg/cm ² at a cycle of about 1 minute, similar to the flow rate. In this way, it has been found that the fluctuations in the discharge flow rate and pressure, although having a certain phase difference, both show the same periodic regularity, and therefore, the fluctuations in the discharge flow rate and whippability can be replaced with the above-mentioned pressure fluctuations. The following experiment was conducted based on the prediction that the cycling phenomenon could be prevented if not only the pressure fluctuation could be detected, but also the pressure fluctuation could be controlled to a small value, preferably to a constant pressure value.

Experiment 4 Whipped cream was produced using the same equipment as in Example 1, except that an automatic pressure recorder was added and the synthetic cream transfer flow rate was 87 kg/hr. The quality of the whipped cream was then tested using the same method as in Experiment 1 above. Figure 6 shows the pressure fluctuations at this time. This pressure shows a nearly constant value of 0.37 to 0.38Kg/ ^cm2 , and the discharge flow rate measured at the same time is 85 to 88Kg/hr.
It was hot. In this way, the pressure and discharge flow rate are both controlled to a constant value, and the overrun is 118% to 122%.
The quality of the whipped cream obtained was also constant.

Various methods other than the method of the present invention can be considered as a method for preventing the cycling phenomenon, and the main methods will be shown as comparative examples.

Comparative Example 1 This is a method of adjusting the inflow amount in order to directly control the residence time in the whip rotary stirrer to a constant value. This method increases the amount of cream flowing in when the discharge flow rate from the whipping rotary stirrer decreases and the residence time tends to increase, and the whipping cream is forcibly pumped using the cream pushing pressure. This increases the discharge speed.
However, since cream containing air is compressible, there is a time lag in the increase in the discharge flow rate, and on the other hand, the pressure continues to rise, so at some point the whipped cream is discharged all at once from the whipping rotary stirrer at high speed. As a result, the discharge flow rate increases far more than the standard value. In this case, those with low viscosity and insufficient shearing have been eliminated, and the inside of the whip rotary stirrer is in a state of better fluidity than the standard, so it is necessary to reduce the inflow in order to reduce the discharge flow to the standard value. Then, the flow rate decreases to a value below the standard flow rate, and the residence time becomes longer.

As described above, this method does not result in preventing the cycling phenomenon, but instead forces the cycling phenomenon to occur, and not only shortens the repetition period but also reduces the degree of excess and deficiency of shear. This will increase the range of quality fluctuations. Furthermore, since fluctuations in the pressure within the whip rotary stirrer naturally act as back pressure on the air blowing section, the blowing pressure also needs to be controlled, which complicates the system.

Comparative Example 2 This is a method in which the pressure inside the rotary whip stirrer is controlled to a constant value by adjusting the rotation speed of the stirring blades, that is, the shear strength, without controlling the residence time in the whip rotary stirrer. This method reduces the rotational speed of the stirring blade when the pressure starts to increase, i.e. shows a transition from state A to state B in FIG. It delays the whipping of cream in the areas of and. However, since there is no direct effect of ejecting the cream in the area where excessive whipping has started, there is a delay in the control effect. In addition, when the cream in area ′ is discharged after the rotation speed decreases, the cream in the area and the area is not sheared enough compared to the standard state, so as the cream in the area is discharged, the pressure decreases and the rotation speed is decreased. This is a considerable increase over the standard state. In this case, on the other hand, there is no direct action to control the discharge of cream that is insufficiently sheared, so the control effect is similarly delayed. Then, the cream that newly reaches the area becomes excessively sheared, so that the rotation speed must eventually be reduced. As described above, in this method, there is a delay in the control effect, and even if the fluctuation range of the cycling phenomenon can be suppressed, the phenomenon itself cannot be prevented.

Next, examples of the present invention will be described.

Example 1 A schematic diagram of the apparatus used in this example is shown in FIG. 1 is cream line 3 from cream tank 2
4 is an air dispersion device in which sterilized and purified air at a pressure of 5 kg/cm ² is blown into the air supply line 9 in the form of fine bubbles. Reference numeral 5 is shown in FIG. 3 and is the above-described rotary stirrer for whips, 6 is a control valve installed at the discharge part of the rotary stirrer for whips 5, and pressure detection section 7 (NMB Co., Ltd.)
Sanitary strain gauge pressure gauge, PR/
10S type) and a pneumatic converter 8 (Yamatake Honeywell Co., Ltd., NOX 110 type).

First, the cream used was prepared as follows.

50 parts of commercially available hydrogenated soybean oil (boiling point 35°C) at 65°C
0.3 part of commercially available purified soybean lecithin and 0.3 part of monoglyceride were added, and the mixture was stirred to dissolve and disperse to obtain an oil phase. On the other hand, 0.4 parts of commercially available sugar ester was added to 50 parts of skim milk, and the mixture was stirred to dissolve and disperse to obtain an aqueous phase.

The oil phase and water phase were mixed and emulsified, and the mixture was heated at 70°C for 15 minutes.
Sterilized by heating for a minute, then homogenized twice at pressures of 50 Kg/cm ² and 10 Kg/cm ² , cooled to 8°C, stored in the cream tank 2, and aged overnight at the same temperature to obtain synthetic cream for whipping. Ta.

This synthetic cream for whipping is moved at a flow rate of 150/hr by pump 1, and at the same time air dispersion device 4
5 Kg/cm ² of compressed air was blown into the mixture at 180 N/hr and whipped using a whipping rotary stirrer 5 at a rotational speed of 550 rpm to produce whipped cream. During this time, the discharge flow rate and the pressure of the pressure detection part 7 are 178~181Kg/hr and 0.35~
The overrun of the product was approximately 120%, which maintained a nearly constant value of 0.37 Kg/cm ² and did not cause any cycling phenomenon. is also good and constant,
It was excellent.

Example 2 Using the apparatus used in Example 1, whipped cream was manufactured from a synthetic cream prepared as follows.

40 parts of commercially available hydrogenated rapeseed oil (rising melting point 35℃) at 65℃
0.2 parts of commercially available purified soybean lecithin and 0.25 parts of monoglyceride were added, and the mixture was stirred to dissolve and disperse to obtain an oil phase. On the other hand, 0.3 parts of commercially available sugar ester was added to 60 parts of skim milk and stirred to dissolve and disperse, thereby obtaining an aqueous phase.

The oil phase and water phase were mixed and emulsified, and the mixture was heated at 70°C for 15 minutes.
Heat sterilized for a minute, then homogenized twice at pressures of 50 Kg/cm ² and 10 Kg/cm ² , cooled to 8°C, stored in cream tank 2, and aged overnight at the same temperature to obtain synthetic cream for whipping. .

This synthetic cream for whipping is moved at a flow rate of 100/hr by pump 1, and at the same time air dispersion device 4
5 Kg/cm ² of compressed air was blown into the mixture at 120 N/hr and whipped using a whipping rotary stirrer 5 at a rotational speed of 430 rpm to produce whipped cream. During this period, as in Example 1, the discharge flow rate and pressure were maintained at approximately constant values, no cycling occurred, and the quality of the obtained product was constant and excellent.

[Brief explanation of drawings]

FIG. 1 is a flow sheet of a general continuous production method for whipped cream, and FIG. 2 is a graph showing changes in viscosity and the optimum range of shearing with respect to stirring time of whipped cream. FIG. 3 shows a rotating stirrer for a whip, in which A is an axial cross-sectional view and B is a radial cross-sectional view. Fig. 4 is a schematic diagram for explaining the cycling phenomenon, and Fig. 5 is a graph showing changes over time in the pressure at the inlet part of the whip rotary stirrer and the discharge flow rate when the cycling phenomenon occurs. . FIG. 6 is a graph showing the chronological change in the pressure when the cycling phenomenon is prevented by the method of the present invention;
The figure is a flow sheet showing an example of an apparatus for carrying out the method of the present invention.

Claims (1)

[Scope of Claims] 1. In a continuous method for manufacturing whipped foods using a rotary stirrer for whipping, the pressure in the inflow path to the rotary whipping stirrer is detected, and the rotating whipping type 1. A continuous method for producing whipped foods, which is characterized in that the flow path resistance of the discharge part of a stirrer is adjusted, thereby obtaining whipped foods in a good whipped state. 2. The continuous method for producing whipped food according to claim 1, wherein the flow path resistance is adjusted by adjusting the opening degree of a valve.