JP3107499B2 - How to detect the degree of deterioration of frying oil - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting the degree of deterioration of frying oil during the operation of frying such as tempura and fry.

[0002]

2. Description of the Related Art Conventionally, the degree of deterioration of cooking oil used for tempura and frying (hereinafter sometimes referred to as frying oil) is determined by a method relying on the sense of appearance, smell, color tone, etc. Empirically, or by a period of time, after the frying operation or the like has been completed, sampling after the frying oil has cooled, and analyzing the physical properties such as the acid value and the refractive index.

Of these methods, methods based on appearance, smell, color, and the like, and methods of judging based on the period of use of frying oil can quickly identify whether or not frying oil has deteriorated, and require replacement of frying oil or lubrication. Although the judgment and the response can easily be made, since the former relies on the senses, the evaluation varies depending on the judge and the evaluation differs depending on the physical condition of the judge, and the accuracy is lacking. Also, when judging from the use time of the frying oil, it is not considered that the degree of deterioration of the frying oil differs depending on the type of frying, and when oil is oiled,
The accuracy of that decision is even more questionable.

On the other hand, the method of analyzing the physical properties by sampling the frying oil after cooling it can obtain accurate physical property values, but it takes too much time for it, and it is necessary to determine whether the frying oil has reached the limit of use or whether the oil is oiled. It was not immediately possible to decide. In fact, there are cases where a large number of defective products are generated because this method is employed and the fly operation is continued as it is.

For this reason, Japanese Patent Application Laid-Open No. Hei 6-141984 proposes a fryer which integrates the energizing time of a heater of a fryer and issues an alarm when a predetermined value is reached. Japanese Patent Application Laid-Open No. Hei 6-178731 discloses that an edible oil to be measured is guided into a predetermined cell, irradiated with transmitted ultraviolet light generated from a light emitting element, the degree of absorption is measured and converted into an electric signal. An apparatus for detecting a change in the property of an edible oil is disclosed. However, regarding the former, there is no difference from the above-described method based on the period in which the frying oil is used, and there remains a question about the accuracy in determining the degree of deterioration of the frying oil for the same reason as the above method. In the case of the latter, it is difficult to measure the degree of deterioration of frying oil during frying from a structural point of view.

[0006]

As described above, the fact that the degree of deterioration of the frying oil can be quickly, objectively and accurately detected during the frying operation is not limited to the case where a large amount of frying is performed for business use. This was also an important issue when frying at home. However, there is still no way to satisfy this. In view of such circumstances, an object of the present invention is to solve the above-mentioned problems.

[0007]

Means for Solving the Problems The present inventors have paid attention to the fact that the degree of change in the amount of foam generated during the operation of fried foods such as tempura and fries has a correlation with the degree of deterioration of frying oil.
The inventors have found that there is a correlation between the amount of foam and the illuminance on the surface of the frying oil, and have completed the present invention. That is, the gist of the present invention is a method of detecting the degree of deterioration of frying oil, which is characterized by detecting the amount of foam generated on the surface of frying oil during the operation of frying using edible oil, more preferably The degree of change in the amount of foam is used as an index, and the amount of foam is detected by illuminance.

In the present invention, the amount of foam generated during the operation of the frying is actually measured, and the degree of deterioration of the quality of the frying oil is determined based on the degree of the change. The degree of deterioration of the frying oil can be known based on the degree of change in the amount of foam generated by obtaining the correlation with physical properties such as quality, for example, acid value, refractive index, and carbonyl value.

In the present invention, the amount of foaming is detected, for example, as follows. That is, the illuminance on the surface of the frying oil is measured by an illuminometer provided above the fryer. It is preferable to illuminate the surface of the frying oil using a spotlight in order to easily catch the change in foaming. In order to keep the initial illuminance constant, the intensity of light applied to the surface of the frying oil may be adjusted to, for example, 5 to 15 lux. Note that an image recognition device or the like can be used instead of the illuminometer as a means for detecting the amount of bubbles.

Immediately after the introduction of the deep-fried seeds, the evaporation of water is intense and the generation of bubbles is remarkable, and the illuminance at that time shows the maximum value. However, as the frying time elapses, foaming decreases,
As a result, the illuminance on the surface of the frying oil also becomes low, and the illuminance eventually stops almost, and maintains a constant value.

In such a frying operation involving a change in the state of the frying oil, the illuminance is measured with time from the start of use of the frying oil to continuous use of the frying oil and from the time when it deteriorates to the limit of use. The degree of change to a constant value (the value when the illuminance is constant), that is, the degree of decrease in illuminance for each number of times of frying and the degree of increase of the constant value of illuminance due to the number of times of frying, and the quality of frying oil (for example, Acid value, refractive index, etc.) and the quality of fried food, etc.
Alternatively, it is stored as an output signal via a microprocessor or the like, and by comparing with this data, the deterioration degree of the frying oil newly used can be known. Also,
By setting the predetermined use limit condition, it is possible to easily determine whether or not the frying oil can be used continuously.
At that time, the set value can be notified by a lamp, a buzzer, or the like.

According to the method of the present invention described above, when the type of frying oil is different, for example, soybean oil, rapeseed oil, palm oil, corn oil, safflower oil, sunflower oil, cottonseed oil, sesame oil and the like, and a mixed oil thereof However, it shows the same tendency. Also, if the fried seeds are different, if the fried seeds are mixed, for example, if croquettes and shrimp are fried alternately,
Compared with the case where one kind of fried seed is fried continuously, it is necessary to compare and examine the change of foam when each is fried alone. The above-mentioned tendency was clearly shown irrespective of whether it was shrimp, croquette, or potato.

[0013]

EXAMPLE 1 Soybean oil was used as frying oil, heated to 180 ° C., and potatoes were fried as potato seeds (1 cm × 1 cm × 4 cm).
cm), and 50 g of the product cut into pieces were fed. At the point of time when the frying was completed (fry time: 4 minutes), the frying was finished, and the fried seeds were taken out. This operation was repeated 20 times every 20 minutes. The measurement of the illuminance on the surface of the frying oil is right above the fryer.
An illuminometer was attached to 5 cm, and the surface of the frying oil was illuminated at 8 lux using a spotlight. First, third, sixth, ninth, twelfth,
The measurement was performed at the 15th, 18th, and 20th measurements, respectively. At the same time, the acid value and the refractive index were also measured to determine the degree of deterioration of the frying oil. FIG. 1 shows the change in the illuminance of the surface of the frying oil at the first, twelfth, and twentieth frying times, and Table 1 shows the acid value and refractive index of the frying oil used at that time.

[0014]

[Table 1]

From the data shown in FIG. 1 and Table 1, it can be seen that the maximum value and the constant value of the illuminance change as the number of frying times increases, that is, as the frying oil deteriorates, and in particular, the constant value of the illuminance gradually increases. Recognize. Then, from the maximum value and the constant value of the illuminance on the surface of the frying oil and the degree of change thereof, the degree of deterioration of the frying oil newly used can be estimated by illuminance measurement during the frying operation.

Example 2 Soybean oil as frying oil and peeled raw shrimp (20 g) as fried seeds (together with clothing liquid and bread crumbs)
Fried in the same manner as in Example 1, and the illuminance of the surface of the frying oil at that time (see FIG. 2), the acid value and the refractive index of the frying oil (Table 2)
) Was measured over time. As a result, even if the frying species are different, the change in illuminance due to bubbles generated on the surface of the frying oil is
It was recognized that it could respond to changes in the quality of frying oil. Therefore, when a similar frying operation is separately performed, the frying operation can be continued while measuring the illuminance on the surface of the frying oil until the quality of the frying oil is set in advance.

[0017]

[Table 2]

Example 3 Soybean oil as fried oil and chicken pieces (26 g) as fried seed
Using three pieces (with fried flour attached), fry in the same manner as in Example 1, and at that time, the illuminance of the surface of the fried oil (see FIG. 3), the acid value of the fried oil and the refractive index (see Table 3) Measured over time. As a result, it was recognized that the change in the illuminance due to the bubbles generated on the surface of the frying oil corresponded to the change in the quality of the frying oil, even if the frying types were different.

[0019]

[Table 3]

Example 4 Using rapeseed oil as the frying oil and the same potato (50 g) as in the example 1 as the frying seed, frying was carried out in the same manner as in the example 1, and the illuminance of the surface of the frying oil (see FIG. 4), The acid value and the refractive index (see Table 4) were measured over time. As a result,
It was recognized that even if the frying oil was different, the change in illuminance due to the foam generated on the surface of the frying oil corresponded to the change in the quality of the frying oil.

[0021]

[Table 4]

Example 5 Sesame salad oil was used as the frying oil, and the same potato (50 g) as in Example 1 was used as the frying seed. Frying was carried out in the same manner as in Example 1, and the illuminance of the surface of the frying oil (see FIG. 5) was used. The acid value and the refractive index (see Table 5) were measured over time. As a result, it was recognized that, even if the frying oil was different, the change in the illuminance due to the foam generated on the surface of the frying oil corresponded to the change in the quality of the frying oil.

[0023]

[Table 5]

Example 6 Soybean oil was used as the frying oil, and the same potato (50 g) as in Example 1 was used as the frying seed.
25% by weight of the first soybean oil after finishing the 0th frying operation
And then fried the potatoes (21st time), and measured the illuminance of the surface of the fried oil (see FIG. 6), the acid value of the fried oil and the refractive index (see Table 6) over time. . As a result, it was recognized that even if the oil was immersed in the frying oil, the change in the illuminance caused by the bubbles generated on the surface of the frying oil corresponded to the change in the quality of the frying oil.

[0025]

[Table 6]

In Examples 1 to 6, there is a certain correlation between the illuminance and the AV (acid value) at the specific number of flies. That is, a. The illuminance at the time of putting the deep-fried seeds is larger than after 200 seconds (in a steady state). b. As the number of fly increases, the illuminance increases,
At the same time, the degree of oil deterioration measured by AV increases. This tendency is also observed at the time of putting the deep-fried seeds and in a steady state after 200 seconds. c. It can be seen that the above tendency is observed within a certain range regardless of the type of the frying oil or the type of the frying oil. d. By measuring and recording the above correlation for specific frying oils and specific frying types, it is possible to measure and detect the degree of deterioration of the frying oil in use every time the illuminance is measured without stopping the fire and sampling. it can.

[0027]

According to the method of the present invention, the following effects can be obtained. (1) Without depending on the appearance, smell, color tone, etc. of the frying oil,
Determining the degree of deterioration of frying oil on an objective basis and accurately,
And high reliability. (2) It can be applied to the difference in the degree of deterioration of frying oil due to the type of frying, and the change in the degree of deterioration due to oil filling, and can flexibly cope with frying work under various conditions. (3) The measurement can be performed continuously without stopping the operation during the frying operation. (4) Since the detection method is simple, anyone can easily perform the measurement. (5) In the measurement, since the cooling process, time and analysis time of the frying oil are not required, the degree of deterioration of the frying oil can be immediately known, and the necessity of oiling and the necessity of replacement of the frying oil can be immediately determined on the spot. (6) Since the required combination and structure of the devices are simple, they can be easily integrated and reduced in size, and can be used alone or by being attached to a fryer.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a relationship between fly time and illuminance in a first embodiment.

FIG. 2 is a diagram illustrating a relationship between fly time and illuminance in a second embodiment.

FIG. 3 is a diagram illustrating a relationship between fly time and illuminance in a third embodiment.

FIG. 4 is a diagram illustrating a relationship between fly time and illuminance in a fourth embodiment.

FIG. 5 is a diagram illustrating the relationship between fly time and illuminance in a fifth embodiment.

FIG. 6 is a diagram illustrating a relationship between fly time and illuminance in a sixth embodiment.

[Explanation of symbols]

1 to 5, reference numeral 1 denotes a temporal change of the illuminance at the first fly number, 2 denotes a temporal change of the illuminance at the 12th fly number, and 3 denotes a temporal change of the illuminance at the 20th fly number. In FIG. 6, 1 is a temporal change of illuminance at the first fly number, 2 is a temporal change of illuminance at the 12th fly number, 3 is a temporal change of illuminance at the 20th fly number, and 4 is a temporal change of illuminance at the 21st fly number. It is a change.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-50-116070 (JP, A) JP-A-2-61557 (JP, A) JP-A-64-39748 (JP, U) Koichi Sugita “ Science of Kotsu-Answering Cooking Questions-"Shibata Shoten (1971-4-5), pp. 146-148 (58) Fields surveyed (Int. Cl. ⁷ , DB name) A47J 37/12

Claims (1)

(57) [Claims] 1. A method for detecting the degree of deterioration of frying oil, wherein the amount of foam generated on the surface of the frying oil is detected by illuminance during the operation of frying using edible oil.