JPH0433385B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for accurately measuring the coagulation state of cheese curd in order to determine the appropriate time for cutting the cheese curd, and a measuring device therefor.

Conventional technical background In the production of natural cheese, the coagulation (curd formation) process of the natural cheese raw material after adding rennet or starter to the raw milk varies depending on the quality of the milk used as the raw material, the activity of the starter or rennet, the temperature, etc. Therefore, it is not easy to judge when to cut the curd produced by coagulation, and conventionally cutting has been carried out by sensory judgment by a skilled person. However, in sensory evaluation, it is inevitable that the hardness of the cards will vary to some extent.

In recent years, as manufacturing equipment has become larger, it has become necessary to form curds with stable structures and improve manufacturing yields. Establishment and provision of measurement equipment for this purpose are important issues in the production of natural cheese.

Measurement devices that apply optical means and acoustic means have been proposed in the past in response to the above-mentioned problems, but all of them are laboratory scale and have not yet been able to be used on factory production lines. Not yet.

Recently, a method of measuring mechanical vibration has been proposed to measure gel hardness, which involves placing a sample between vibrating disks placed opposite each other.
How to measure vibration transmission in a sample (Dairy & Ice
Cream Field, 161(8)68F-68H, 1978), a method of vibrating a cylindrical container containing gel food and measuring its attenuation rate (J.Food Sci., 45(2) 204~
207, 1980: Journal of Japan Food Industry Association, 27(5) 227~
233, 1980), but they have not yet been put into practical use on production lines.

Problems to be Solved by the Invention In view of the above-mentioned situation, the inventor of the present invention investigated the measurement of the coagulation state of cheese curd, and found that a sample of natural cheese raw material to which rennet or starter had been added was subjected to constant vibration using an oscillator. When detecting this with a highly sensitive diaphragm, when the sample is still in liquid state, the vibration is diffused upward and is not directly transmitted to the diaphragm.
As the sample gels, the upward diffusion of vibrations becomes smaller and is transmitted directly to the diaphragm; that is, changes in the solidification of the sample can be determined by the course of increase in the amplitude transmitted directly to the diaphragm. The present invention was made based on this knowledge.

Therefore, an object of the present invention is to arrange a sensing unit for injecting a sample of natural cheese raw material between a vibration-generating side disc and a pressure-receiving side diaphragm, and apply a constant vibration to the sample to inject the diaphragm. To provide a method for accurately measuring the coagulation state of cheese curd by converting the pressure change due to the amplitude into an electric signal and recording it, and a measuring device for the same that can be directly applied to a factory line. be.

The present invention will be explained in detail below.

Structure of the Invention (1) A sample of natural cheese raw material is injected into the sensing unit, and while its temperature and liquid level are kept constant, the vibration generating side disc attached to the sensing unit and the vibration generating side disc attached to the sensing unit are placed in contact with the disc. A constant vibration was applied from an oscillator and transmitted to the sample in the unit through a thin elastic plate such as silicone rubber that was in contact with the sample, and the transmitted vibration was attached to the unit opposite to the vibration-generating disk. It is sensed by a diaphragm, the pressure change resulting from this sensing is converted into an electrical signal by a transducer, this converted signal is then amplified and recorded, the solidification state of the cheese curd is determined from the amplitude of the liquid curve, and then the sample is sensed. A method for measuring the coagulation state of cheese curd, characterized by discharging it from a discharge valve at the bottom of the unit.

(2) A sensing unit for injecting a sample of natural cheese raw material; a vibration-generating disk attached to the sensing unit via a thin elastic plate such as silicone rubber, and an oscillator connected to the vibration-side disk; A diaphragm attached to the sensing unit to face the vibration-generating disk; a converter connected to the diaphragm; an amplifier connected to the converter; and a recorder and sensing connected to the amplifier. It consists of a discharge valve installed at the bottom of the unit, which transmits a certain amount of vibration generated from the oscillator to the sample in the sensing unit via the vibration-generating disk and a thin elastic plate such as silicone rubber. Detected by a diaphragm, this sensed pressure change is converted into an electrical signal by a transducer, amplified by an amplifier, and recorded by a recorder. The sample is then discharged from the discharge valve at the bottom of the sensing unit to measure the coagulation state of the cheese curd. device to do.

The term "natural cheese raw material" as used herein means a milky raw material prepared for the production of cheese by adding rennet, starter, and other blended raw materials.

Means for Solving the Problems The measuring device used in the present invention will be explained based on the accompanying drawings illustrating the measuring device, and the measuring method according to the present invention will also be explained.

FIG. 1 is an explanatory diagram of the present device, in which numeral 1 is a sensing unit for injecting a sample of natural cheese raw material, and an oscillating side circle is connected to one side of the sensing unit through a thin silicone rubber 3. A plate 2 is attached, and a diaphragm 6 is attached to the other side facing the disk 2 with a gap of 13 mm from the disk 2.

An oscillator 4 is connected to the oscillation side disk 2. Note that 5 is a motor for operating the oscillator 4. The diaphragm 6 is connected to a converter 7, the converter 7 is connected to an amplifier 8, and the amplifier is connected to a recorder 9.

In the sensing unit 1 of this device, the vibration-generating side disc 2 and the pressure-receiving side diaphragm as described above are attached so as to be placed on the outside of each. This has the advantage that there is no need to remove the diaphragm and clean the inside of the unit each time a measurement is made, unlike the conventional sensing unit. Furthermore, the sensing unit in this apparatus has a top and a bottom formed so that the sample can be smoothly injected from the cheese raw material tank and the gelled cheese can be smoothly discharged.

Note that if the top of the sensing unit is widened as shown in the figure, the rise in the liquid level before gelation of the sample due to the vibration of the vibration generating side disk 2 will be reduced, and the amplitude value due to the vibration accompanying gelation will be reduced. This is convenient for observing the change process. Note that a temperature sensor and a heater are installed on the outer wall of the sensing unit (not shown).

In addition, in the apparatus according to the present invention, the vibration to be applied to the sample is performed via the disk 2 by operating the oscillator 4 composed of a low-speed motor 5, an eccentric cam, etc., so that stable low-frequency vibration is generated. and
In addition, since a constant change can be achieved over the entire surface of the disk 2, the stroke is relatively small, and there is no fear that the gel formed by solidification of the sample will be destroyed.

In addition, the disc is equipped with a thin plate of elastic material such as silicone rubber, and the disc gently pushes this to transmit the test motion to the sample, so this vibration is not directly transmitted to the sensing unit body. , the generation of noise can be prevented.

Conventionally, low-frequency vibrations are generated by using a pump to send liquid to and return from a diaphragm, but this method not only complicates the equipment but also reduces the The disadvantage is that the liquid level tends to be uneven, and therefore the displacement of the diaphragm lacks stability.

In this device, the oscillator 4
The vibrations transmitted to the sensing unit are sensed by a diaphragm 6 attached to the sample in the unit. This diaphragm 6 is designed so that it can directly sense vibrations that do not destroy the gel formed by solidification of the sample.
It is preferable that a waveform designed to have a diameter of 110 mm is arranged so that the distance from the vibration generating side disc is 13 mm.

In this device, a converter 7 is arranged in series with the diaphragm, and the converter converts the pressure change (slight differential pressure) caused by the vibration detected by the diaphragm into an electrical signal, which is then connected to the converter. The sample is amplified by an amplifier 8 and recorded by a recorder 9 connected to the amplifier 8, and the coagulation state of the sample can be determined from the amplitude of the wavy curve. In the figure, reference numeral 10 is a valve attached to the converter 7, which is closed after the liquid level of the sample in the unit becomes stable to keep the negative side pressure of the converter 7 constant. .

Next, a method of measuring the coagulation state of cheese curd using this device will be explained.

First, a sample was injected into the sensing unit 1 from a cheese tank (not shown) containing natural cheese raw materials, and after the liquid level in the unit was kept constant by an overflow method, the sensor was attached to the converter 7. Close the above valve.

A temperature sensor and a heater installed on the outer wall of the sample unit in the above unit control the temperature to be maintained at the same temperature as the natural cheese raw material in the cheese tank.

Next, the motor 5 is rotated at a low speed of 2 rpm, and the eccentric cam converts it into a reciprocating motion, causing the vibration generating side disc 2 to vibrate twice per minute with a stroke of 0.25 mm. This vibration is caused by thin elastic silicone rubber 3
The signal is transmitted to the sample within the sensing unit 1 via the sensor. Due to this vibration transmission to the sample, when the sample is in a liquid state that has not yet gelled, the vibration is diffused above the sample, causing only a slight rise in the liquid level, and is not directly transmitted to the diaphragm, but when the sample gels. As the vibration increases, the upward diffusion of the vibration becomes smaller and is directly transmitted to the diaphragm 6, where it is sensed as a pressure change. The pressure change sensed by the diaphragm is converted into an electrical signal by the transducer 7 (slight differential pressure), so this is amplified by the amplifier 8 and recorded by the recorder 9. From the amplitude of the recorded sinusoidal curve, cheese is determined. Determine the coagulation state of the curd. Note that the recorder 9 is equipped with an alarm device so that it can sense the output from the diaphragm. The cheese curd formed by coagulation is removed from the bottom of the sensing unit. There is a discharge valve at the bottom of the sensing unit, which is closed during measurement.
After the measurement is completed, discharge the sample by opening the valve, etc.
By doing so, it is possible to repeatedly measure samples industrially in the production line.

Incidentally, FIG. 2 shows the relationship between the coagulation time of the cheese raw material and the amplitude of vibrations received by the diaphragm. Figure 2 shows the above relationship as a change in the output voltage amplitude value. In the figure, A1 represents the amplitude due to the rise in the liquid level of the sample in the sensing unit.
A2 indicates the amplitude due to vibrations directly applied to the diaphragm, and A1+A2 indicates their combined value. Further, FIG. 3 shows the transition of the amplitude due to the rise in the liquid level of the sample to the increase in amplitude due to solidification.

Effects of the Invention As described above, the sensing unit in the apparatus according to the present invention is installed in series with the preparation tank for natural cheese raw materials, a sample of the cheese raw material is taken out and injected into the sensing unit, and the above-mentioned procedure is followed. The coagulation state of the sample can thus be recorded and measured. Therefore, based on the amplitude value of the pressure change (output voltage) sensed by the diaphragm as the sample collected from the cheese raw material tank solidifies, the amplitude value of the output voltage at the appropriate time for cutting cheese curds can be determined in advance. By setting this value in advance, it becomes possible to determine the appropriate cheese curd cutting time by comparing with the above recorded value. As described above, according to the present invention, it is possible to incorporate the present device into the cheese manufacturing process and automatically determine the timing of curd production and cutting.

EXAMPLES The present invention and its effects will be explained in more detail with reference to Examples below.

Example 1 Preparation of natural cheese raw material: Adding glucono-δ-lactone (starter) to reduced skim milk with a total solid content of 10 wt% and milk fat of 0.1 wt%.
0.1wt%, CaCl ₂ 0.05wt% and rennet 0.01wt%
A mixture of the following was used.

Measurement of coagulation state: The above cheese raw material is placed in a cheese tank, and a sample of the cheese raw material is injected into the sensing unit of this device connected to the tank through the openable opening of the tank, and the cheese raw material sample is poured into the above unit using an overflow method. After making the liquid level of the sample constant in the chamber, the valve attached to the transducer is closed, the oscillator is activated, and the eccentric cam converts it into reciprocating motion, and the vibration generating side disc is moved twice per minute with a stroke of 0.25 mm. vibrated. The temperature of the sample inside the unit was maintained at the same temperature (30°C) as the cheese material inside the tank during the operation period by an electric heater and a temperature sensor installed on the outer wall of the unit.

Vibration from the oscillator is transmitted to the sample in the sensing unit via the vibration-generating disk, and this vibration is then directly sensed by the diaphragm as the sample solidifies, so the resulting pressure change is transferred to the transducer. This was converted into an electrical signal, amplified by an amplifier, and recorded. As a result, the output voltage increased almost linearly for about 30 minutes from the start of solidification of the sample (so-called rise).

Next, the above operation was repeated five times, and the elapsed time was examined using the rise point of each sample and the output voltage values of 1.5 V and 3 V as check points. The results are shown in FIG. As seen in FIG. 4, there is no essential difference in the elapsed time at each of the above check points, which indicates that the method according to the present invention has good reproducibility.

In addition, it was confirmed that the appropriate cutting time for the cheese curd produced by coagulation is around 1.5V.

Example 2 Preparation of natural cheese raw material: Raw milk with a total solid content of 11 wt% and milk fat of 2.8 wt% was mixed with 1 wt% of lactic acid bacteria starter, 0.01 wt% of CaCl ₂ and 0.003 wt% of rennet.

Measurement of coagulation state: Using the above cheese raw material, the coagulation state was measured in the same manner as described in Example 1. This measurement is 5
I did it repeatedly. The cutting timing of cheese curd determined by this method was determined by a conventional sensory method, and the results are shown in FIG. As shown in FIG. 5, the cutting timing based on the sensual method is determined by the pressure voltage amplitude value between 1.3 and 1.5V when using the method of the present invention. It can be seen that the voltage amplitude value almost coincides with the cutting time when it is 1.5V.
Incidentally, the difference between 1.3V and 1.5V (0.2V) is only a difference of about 2 minutes when converted to elapsed time.

The reason why the coagulation progress of the samples in FIG. 5 is different each time is because the activity of the starter in the samples used each time is not constant.

After the measurements have been completed as described above, the sample is taken out by opening the pot provided at the bottom of the sensing unit, washed with hot water, and used for the next production line.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram illustrating the apparatus according to the present invention, Fig. 2 shows the relationship between the solidification time of a sample of cheese raw material and the output voltage amplitude value, and Fig. 3 shows the relationship between the liquid level rise due to vibration of the sample. The transition from the accompanying amplitude to an increase in amplitude as the sample solidifies is shown, respectively. Fourth
The figure shows the reproducibility of the method of the present invention shown in Examples based on the measurement of elapsed solidification time at specific check points, and Figure 5 shows the cutting of cheese curd determined by the method of the present invention. It shows the results of comparing time with that of the sensual method.

Claims (1)

[Scope of Claims] 1. A sample of natural cheese raw material is injected into the sensing unit, and while its temperature and liquid level are kept constant, the vibration generating side disk attached to the sensing unit and the disk are connected to the sensing unit. A constant vibration is applied from an oscillator to the sample in the unit through a thin elastic plate such as silicone rubber that is in contact with the specimen, and the transmitted vibration is attached to the unit opposite to the vibration-generating disk. The pressure change caused by this sensing is converted into an electrical signal by a transducer. This converted signal is then amplified and recorded. The coagulation state of the cheese curd is determined from the amplitude of the wavy curve, and then the sample is A method for measuring the coagulation state of cheese curd, characterized by discharging it from a discharge valve at the bottom of a sensing unit. 2. A sensing unit for injecting a sample of natural cheese raw material; A vibration generating side disk attached to the sensing unit via a thin elastic plate such as silicone rubber; an oscillator connected to the vibration side disk; A diaphragm attached to the unit facing the vibration generating side disc, a transducer disposed in series with the diaphragm; an amplifier coupled with the transducer; a recorder and sensing unit coupled with the amplifier; It consists of a discharge valve installed in the sensor, which transmits constant vibrations generated by the oscillator to the sample in the sensing unit via the vibration-generating disk and a thin elastic plate such as silicone rubber, and the transmitted vibrations are sensed by the diaphragm. A device that measures the coagulation state of cheese curd by converting this sensed pressure change into an electrical signal with a transducer, amplifying it with an amplifier, and recording it with a recorder, and then discharging the sample from the discharge valve.