JP2020016443A - Umami intensity determination method - Google Patents

Abstract

To provide a method for experimentally calculating and comparing correlation with a sensory test of umami intensity of a sample.SOLUTION: A component giving umami is picked, a five-stage concentration sample of the umami component is produced, and intensity of an umami property of the component is recorded by ten panelists. The component of the sample is quantified, the resultant is introduced into an umami intensity calculation formula, and consistency is determined. The calculation formula is of a calculation approach of multiplying an inverse of a threshold value of the umami component by an umami component concentration. Calculation is thus performed with the calculation formula of the approach involving multiplication by the concentration of the umami component with the threshold value of the umami component as a conversion factor. A flash chromatograph for fractionation is effective when taste synergy has a significant effect, where a target component part is fractionated and the resultant is suitably utilized in the approach.SELECTED DRAWING: Figure 1

Description

The present invention is the development of a method for determining the strength of the taste power over the entire taste of food,
As a feature, a method and an apparatus that can use an analytical instrument to quantify the components and obtain the same judgment by instrumental analysis without relying on human taste, based on numerical values calculated using the calculation formula in this patent About.

Sensory tests are conducted by taste panelists in the prototype rooms of each food manufacturer. The results of sensory tests by dozens of people are statistically processed to evaluate the taste of the product.
The judgment of the taste greatly contributes to the value of the product. Elaborate sensory test methods and equipment analyzers by humans have been developed. One of them uses a sensor chip for umami tasted by Professor Toko of Kyushu University, and has been producing data close to human sensory tests (the device itself is expensive).
Such a technique is different from the taste intensity determination method of the present invention in the following points.
1. This is a determination method that focuses on the intensity of taste rather than the evaluation of the overall taste. 2. The taste intensity can be determined by a calculation formula utilizing the threshold value of the component. Inexpensive measuring device can be assembled by combining calculation formula and quantitative device

JP 2014-119350 A

The present invention is a measuring method for judging the strength of the taste of a food, not for judging the taste of human sensory tests. However, unlike the sensory test up to the present, it is a method for measuring the intensity of taste with high accuracy, so that the sensory test by a taste panel of personnel and the result of the present invention must match. For that purpose, the following issues were raised and a proof experiment was conducted.
1. It is an issue whether the technique for determining the taste intensity matches the result of the sensory test currently performed in each quality control room. For that purpose, we investigated the umami component and the sour component of the fruit juice, and searched the taste threshold of each component.
・ The concentration at which the sensory test panelists can determine the concentrations of the umami component and the sour component has been determined through sharp research.
3. If the concentration of each component in the sample cannot be measured accurately, the calculation method and the judgment method of the present invention are meaningless to use, so that the accuracy of data from various analyzers, especially liquid chromatography, is important.
・ We prepared an experiment to determine the strength of taste by panelists and to confirm the consistency between the results of the chromatography developed by us and the calculated values. Then, the density is sequentially changed, and the intensity of the umami and the sourness is recorded on the panel and the order is assigned.
5. The sample was subjected to chromatography to obtain quantitative values of each component, and compared with the data values obtained by applying the calculation formula. The challenge was to obtain the consistency and reliability.

The following measures were taken to prove that the taste intensity determination technique of the present invention was consistent with the determination of the taste strength by the sensory test paneler.
・ Check the umami components of the yeast extract and the sour components of the fruit juice, and create a table of threshold values.
・ A taste test is first conducted to a sensory test paneler according to the threshold value. The concentration actually used is determined based on the result.
• Find a way to accurately quantify the concentrations determined in the tests described above.
In practice, the measurement method is determined by comparison with various analyzers, mainly for liquid chromatography.
・ The same sample was subjected to chromatography to obtain quantitative values of each component, and the data values obtained by applying the developed formulas were recorded.
5. The concentration of the sample is sequentially changed in parallel, and the intensity of umami and sourness by a sensory test panel is recorded on paper and the order is determined.
5. The consistency between the taste intensity result using the operation detector and the sensory test is compared.

By combining the panelist's sensory test and the result of taste evaluation by the instrumental analysis of the present invention, more accurate objective data can be obtained. This can be used in the quality control room of the food manufacturer to judge the taste quality of products manufactured on that day. Specifically, in the manufacturing process of noodle soup, the determination of the taste strength of the intermediate product at the end of the blending is automated by the sensory test according to the present invention without relying on the sensory test of the panelists. As another example, coffee is being imported and exported in large quantities worldwide. The quality judgment method has a very high industrial value. The determination of the degree of taste is included in the quality determination. The taste of coffee is very important in terms of bitterness. To judge the taste of the bitterness, it is separated by chromatography, separated and quantified, and the numerical values are applied to the formula of the present invention.As a result, an enormous amount of raw material bitterness is not accompanied by enormous labor costs by panelists. , It can be determined quickly.
As a specific use method, even food materials that cannot be tasted by humans can be measured because it is a technique for determining the taste power by instrumental analysis. For example, the first taste of deep-sea fish and the taste of new tropical mushrooms.

Means for solving the problem are shown as a flowchart. Means for solving the problem using the arithmetic unit are shown. Example chromatogram

 This is as shown in FIGS. 1, 2, and 3.

1. Judgment Method of Umami Intensity of Yeast Extract Seasoning The umami components of the yeast seasoning are 5 'IMP, 5'-GMP, 5'-UMP which are taste substances of nucleic acid and sodium glutamate (GLU) of amino acid. An analytical method was established so that the quantification of these four components could be measured by liquid chromatography. The aim was to develop a simple technique that can determine the strength of umami, so we started with the development of an analytical method that can simultaneously measure umami components with a single column. Particular emphasis was placed on column selection experiments. The developed technique and the conditions of liquid chromatography are shown below.
A standard curve was prepared using standard 5'-IMP, 5'-GMP, 5'-UMP and 5'-XMP. As a result, components of 2 to 20 ppm could be measured. The test was performed based on a commercially available yeast extract seasoning as a sample.
(1) HPLC condition column (Nacalai Tesque) (4.6Φ × 150mm)
Eluent: 0.025 mol phosphate buffer (pH 7.2), 20% CH ₃ OH solution Detector: UV260 nm
Sample volume: 10 μl
Column temperature 25 ° C
Flow rate 0.5ml / min
(2) Umami Component Concentration Measurement Method The threshold values of the four components, which are the center of umami, were examined using reference materials, and the amount was determined to be 5 to 10 times the threshold value, and a calibration curve was created. As reference materials, I used several books, mainly I and II revised food and nutrition handbook (author, former Ehime University professor Norio Tashiro, published in March 1997).
(3) Quantitative calibration curve
The threshold value of L-glutamic acid is 0.005 g in 100 g. The threshold value of inosinic acid is 0.004 g in 100 g. Since the other two components also fall in the range of 0.002 to 0.010 g, the concentration was adjusted to 5 to 10 times the concentration, and a calibration curve was prepared at a concentration within a range where humans can sense.
・ Sensory test (by 10 panelists)
For comparison with this determination method, a sensory test was conducted by 10 men and women in total. Samples were prepared according to the threshold value of the four component taste nucleotides so that the taste was felt. Ten panelists reduced the effects of conversations in the individual room for sensory tests. The solution was finished in almost the same manner with respect to the temperature and color of the solution. 2 g of the commercially available yeast extract seasoning used in the preparation of the sample was dissolved in 100 ml to prepare a base solution.
In the calculation formula, the 5′-GMP threshold, the 5′-IMP threshold, the Glu threshold, and the 5′-UMP threshold are searched or obtained by own experiments.
This judgment method is consistent with the human sensory test because the order of the magnitude of the numerical value of the sum total (Σ) of the taste intensity judgment formula matched the umami intensity rank given by the 10 panelists. It proves that umami can be used as a strength ranking method. Table 1 shows the results.

2. Judgment of the sourness of the fruit juice The sour component in the fruit juice and its threshold are grasped. The conversion factors for the threshold were 1.0 citric acid, 1.1 acetic acid, and 0.45 ascorbic acid. When the thresholds of the three components are grasped in this way, the taste intensity can be calculated only by multiplying the component concentration and the conversion coefficient. Performed quantitative analysis and measurement of citric acid, acetic acid, and ascorbic acid. The concentration in the concentration calculation of each sample was set to 0.005 to 0.012% in accordance with the threshold.
Extraction of fruit juice from 100 g of four kinds of fruits was squeezed with a squeezer. Specifically, fresh fruits of Unshu mandarin orange, summer citrus, lemon and Iyo citrus were used. No. 2 filter paper was used for filtration of the extract. Thereafter, the supernatant separated by a precision centrifugal separator was treated with an HPLC filtration membrane to obtain an analysis sample. (Dilution is about 10 to 25 times)
(1) HPLC condition column STR-ODS column (4.6Φ × 150mm)
Eluent: 0.025 mol phosphate buffer (pH 2.4)
Detector: UV210nm (0.04 AUFS)
Sample volume: 10 μl
Column temperature 25 ° C
Flow rate 0.5ml / min
(2) Method for measuring the concentration of sour components Check the threshold values of the three components that are the center of sourness in reference materials, determine the amount of the threshold value 2 to 5 times,
A calibration curve was created. As reference materials, I used the tables of several books, mainly I and II revised food and nutrition handbook (author, former Ehime University professor Norio Tashiro, published in March 1997).
(3) Quantification and calibration curve of each component The threshold value is 0.0010 g for citric acid and 0.0020 g for ascorbic acid in 100 g. Since the threshold value of acetic acid is 0.0014 g in 100 g, the concentration was adjusted to 5 to 20 times that of the threshold, and a calibration curve was prepared at a concentration within a range where human beings can sense.
・ Sensory test (by 10 panelists)
For comparison with this determination method, a sensory test was conducted by 10 men and women in total. Samples were prepared based on the sourness of the organic acid component according to the threshold so that the taste was felt. Ten panelists reduced the effects of conversations, etc., in individual rooms for sensory tests. The solution was finished in almost the same manner with respect to the temperature and color of the solution. For the calculation method of the taste intensity, a conversion coefficient was created using a threshold value. That is, citric acid is 2, ascorbic acid is 1, and acetic acid is 1.4.
The sour components in the fruit juice were measured, and the numerical values applied to the mathematical formula of the present patent method were consistent with the results of the sourness of the sensory panelists. This fact proves that this determination method is consistent with the result of the human sensory test, and shows that it is excellent as a sourness intensity ranking method. Table 2 shows the results.

The following can be considered as an application of the new method for determining the intensity of umami. The following method can be used for determining the purchase amount of the yeast extract seasoning. That is, the intensity of umami is proportional to the unit price of the extract.
-It can be used for quality control in the production of food flavor extract seasonings.-It can be used for research and development of food seasonings, for example, it can be used to judge the quality of enzymatic decomposition method and separation treatment.
・ It can be used to change the taste of processed food over time, and the range of quality control is expanded. Until now, it could be a new quality control decision item that could not have been considered.
・ It can be used to determine the taste of natural products with novelty. This method can be used even if it is impossible to find food materials that are not understood healthy by human sensory tests. For example, a calculation method such as a sensory test for an extract that may have toxicity may be (reciprocal of the threshold value of taste component a) × ( Concentration of the component a) = A
(Reciprocal of the threshold value of taste component b) x (concentration of that component b) = B
(Reciprocal of the threshold value of taste component c) x (concentration of that component c) = C
A + B + C = Σ
It is determined whether or not the magnitude of the value of Σ matches the ranking of umami intensity conducted by panelists of ten sensory tests.

A: Eluent-1 for separating components
B: Eluent for component separation-2
C: Pump for controlling eluent speed
D: Column for separating components
E: detector to convert to taste intensity

Claims (1)

In the examples, the measurement is performed by liquid chromatography using the yeast extract seasoning and fruit juice as samples, and the calculation is performed. However, since the taste intensity can be obtained by a total sum of (reciprocal of the threshold value) × (concentration of the component), The scope covers the method and the equipment for its measurement.