Use of olfactory receptors in recognizing 3-methylthiopropionaldehyde and method for detecting 3-methylthiopropionaldehyde

Abstract

The present invention relates to the use of an olfactory receptor in recognizing 3-methylthiopropionaldehyde and a method for detecting 3-methylthiopropionaldehyde. The use of the olfactory receptor in recognizing 3-methylthiopropionaldehyde, wherein the olfactory receptor comprises at least one selected from the following: MOR244-3, MOR256-17, and MOR180-1; the method comprises: contacting a sample to be tested with the olfactory receptor, determining the response value of the olfactory receptor, and based on the response value, determining whether 3-methylthiopropionaldehyde is contained in the sample to be tested, wherein the olfactory receptor comprises at least one selected from the following: MOR244-3, MOR256-17, and MOR180-1. The olfactory receptor of the present invention can quickly recognize 3-methylthiopropionaldehyde, and can detect 3-methylthiopropionaldehyde in products such as alcoholic beverages, fruits or fruit products to determine the freshness of the above products or the types of fruits contained therein.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical detection. Specifically, the present invention relates to the use of an olfactory receptor in the recognition of methional and a method for detecting methional. More specifically, the present invention relates to the use of an olfactory receptor in the recognition of methional, the use of methional in activating an olfactory receptor, a method for detecting methional, a method for detecting the freshness of alcoholic beverages, fruits or fruit products, a method for detecting the types of fruits contained in food, a method for distinguishing beer or red wine, and a method for monitoring whether fruit products have been subjected to high-temperature disinfection treatment. Background Art

[0002] Olfactory receptors (ORs), also known as odorant receptors, are chemoreceptors expressed in the cell membranes of olfactory sensory neurons (OSNs). Olfactory receptors activated by odorants trigger nerve impulses that transmit information about the odor to the brain. These receptors are G protein-coupled receptors (GPCRs) located on the cell surface membrane at the tips of the dendrites of olfactory neurons. Olfactory receptors form a multigene family, with approximately 400 genes in humans and approximately 1200 genes in mice.

[0003] Methional (CAS No. 3268-49-3), commonly known as egg yolk aldehyde, is a colorless or light yellow liquid. Its molecular structure contains both a methylthio group and an aldehyde group, presenting odor characteristics such as baked potatoes, onions or potato chips. Methional is widely present in fruits, fruit products and alcoholic products. However, there has been no report on olfactory receptors for detecting methional. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art to some extent. For this purpose, the present invention provides the use of an olfactory receptor in the recognition of methional, the use of methional in activating an olfactory receptor, a method for detecting methional, a method for detecting the freshness of alcoholic beverages, fruits or fruit products, a method for detecting the types of fruits contained in food, a method for distinguishing beer or red wine, and a method for monitoring whether fruit products have been subjected to high-temperature disinfection treatment. The olfactory receptor of the present invention can quickly recognize methional and can detect methional in alcoholic beverages, fruits or fruit products to detect the freshness of alcoholic beverages, fruits or fruit products or the types of fruits contained in food.

[0005] The present invention is completed based on the following discoveries of the inventors:

[0006] 3-Methylthiopropionaldehyde widely exists in foods such as fruits, fruit products, oat flour, sake, wine, beer, and liquor. Research shows that fruits such as durian and mango are rich in 3-methylthiopropionaldehyde, and 3-methylthiopropionaldehyde can also be detected in Beijing roast duck. However, it is difficult to detect 3-methylthiopropionaldehyde in freshly squeezed pineapple juice, while it is one of the substances with the strongest odor in commercially available pasteurized pineapple juice. In addition, fresh liquor (i.e., new liquor) does not contain 3-methylthiopropionaldehyde, but liquor stored for a period of time (i.e., old liquor) contains 3-methylthiopropionaldehyde, and the longer the storage time, the higher the content.

[0007] Based on this, the inventors found through a large number of experiments that the use of four olfactory receptors, MOR244-3, MOR256-17, MOR180-1, and OR2C1, can all detect 3-methylthiopropionaldehyde and have advantages such as high detection sensitivity. Specifically, the inventors selected some olfactory receptors from the human olfactory receptor library and the mouse olfactory receptor library, and then stimulated cells expressing different olfactory receptors with 3-methylthiopropionaldehyde at different concentrations. The results showed that the mouse olfactory receptors MOR244-3, MOR256-17, and MOR180-1, as well as the human olfactory receptor OR2C1, could be activated to varying degrees. Among them, the mouse olfactory receptors MOR244-3 and MOR256-17 could produce a significant response under the stimulation of 30 μM 3-methylthiopropionaldehyde. In addition, the inventors also used cells containing MOR244-3 and MOR256-17 respectively to detect 3-methylthiopropionaldehyde in different fruits, fruit products, and liquors. Among them, the detection results for freshly squeezed orange juice, freshly squeezed grapefruit juice, and freshly squeezed mango juice were consistent with the research reports. In addition, the inventors also used cells containing MOR244-3 and MOR256-17 respectively to detect unpasteurized pineapple juice and pasteurized pineapple juice. The results showed that compared with fresh pineapple juice, the 3-methylthiopropionaldehyde in pasteurized pineapple juice was significantly increased, and the detection results were consistent with the research reports. Therefore, olfactory receptors can be used to detect the high-temperature disinfection situation of fruit products (such as pineapple juice).

[0008] In a first aspect of the present invention, the present invention provides a use of an olfactory receptor in identifying 3-methylthiopropionaldehyde. According to an embodiment of the present invention, the olfactory receptor includes at least one selected from the following: MOR244-3, MOR256-17, MOR180-1, and OR2C1. The inventors found through experiments that after stimulating MOR244-3, MOR256-17, MOR180-1, and OR2C1 with 3-methylthiopropionaldehyde respectively, MOR244-3, MOR256-17, MOR180-1, and OR2C1 can all be activated. Thus, the above olfactory receptors can be used to effectively identify 3-methylthiopropionaldehyde, laying a foundation for the identification of 3-methylthiopropionaldehyde and the detection of samples containing 3-methylthiopropionaldehyde.

[0009] In a second aspect of the present invention, the present invention provides a use of 3-methylthiopropionaldehyde in activating an olfactory receptor, where the olfactory receptor includes at least one selected from the following: MOR244-3, MOR256-17, MOR180-1, and OR2C1. The inventors found through experiments that after stimulating MOR244-3, MOR256-17, MOR180-1, and OR2C1 with 3-methylthiopropionaldehyde respectively, MOR244-3, MOR256-17, MOR180-1, and OR2C1 can all be activated. Thus, the above olfactory receptors can be used to effectively identify 3-methylthiopropionaldehyde, laying a foundation for the identification of 3-methylthiopropionaldehyde and the detection of samples containing 3-methylthiopropionaldehyde.

[0010] In a third aspect of the present invention, the present invention provides a method for detecting 3-methylthiopropionaldehyde. According to an embodiment of the present invention, the method includes: contacting a sample to be tested with an olfactory receptor and determining the response value of the olfactory receptor; based on the response value, determining whether the sample to be tested contains 3-methylthiopropionaldehyde; where the olfactory receptor includes at least one selected from the following: MOR244-3, MOR256-17, MOR180-1, and OR2C1. The inventors found through experiments that 3-methylthiopropionaldehyde can activate the above olfactory receptors. If the sample to be tested contains 3-methylthiopropionaldehyde, when the sample to be tested is contacted with the above olfactory receptor, the above olfactory receptor is activated, and the response value after the activation of the olfactory receptor is obtained. Whether the sample to be tested contains 3-methylthiopropionaldehyde can be determined according to the response value.

[0011] In the fourth aspect of the present invention, a method for detecting the freshness of alcoholic beverages, fruits or fruit products is proposed. According to an embodiment of the present invention, the method includes: contacting a sample to be tested with an olfactory receptor, and determining a response value of the olfactory receptor; based on the response value, determining the freshness of the sample to be tested; wherein the olfactory receptor includes at least one selected from the following: MOR244-3, MOR256-17, MOR180-1, and OR2C1. The inventors found through experiments that 3-methylthiopropionaldehyde can activate the above olfactory receptors. If the sample to be tested contains 3-methylthiopropionaldehyde, when the sample to be tested is contacted with the above olfactory receptors, the above olfactory receptors are activated, and an activated response value can be obtained. According to the response value, the situation of 3-methylthiopropionaldehyde contained in the sample to be tested can be determined, and the freshness of the sample to be tested can be determined based on the situation of 3-methylthiopropionaldehyde contained in different samples to be tested.

[0012] In the fifth aspect of the present invention, a method for detecting the types of fruits contained in food is proposed. According to an embodiment of the present invention, the method includes: contacting a sample to be tested with an olfactory receptor, and determining a response value of the olfactory receptor; based on the response value, determining the types of fruits contained in the sample to be tested; wherein the olfactory receptor includes at least one selected from the following: MOR244-3, MOR256-17, MOR180-1, and OR2C1; the sample to be tested contains only one type of fruit. The inventors found through experiments that foods containing different fruits (such as fruit pulp obtained by grinding, freshly squeezed fruit juice, and beverages containing fruit juice, etc.) contain different concentrations of 3-methylthiopropionaldehyde. By contacting the sample to be tested with the above olfactory receptors, the above olfactory receptors are activated, and an activated response value can be obtained. According to the response value, the situation of 3-methylthiopropionaldehyde contained in the sample to be tested can be determined, thereby determining the types of fruits in the food.

[0013] In a sixth aspect of the present invention, the present invention provides a method for differentiating beer or red wine. According to an embodiment of the present invention, the method includes: contacting a plurality of products to be tested with olfactory receptors, respectively determining the response values of the olfactory receptors corresponding to the plurality of products to be tested, and the plurality of products to be tested are beer and / or red wine; determining the types of the products to be tested based on the response values of the olfactory receptors corresponding to the plurality of products to be tested; wherein, the olfactory receptors include at least one selected from the following: MOR244-3, MOR256-17, MOR180-1, and OR2C1. The inventors found through experiments that compared with red wine, the content of 3-methylthiopropionaldehyde in beer is higher. By contacting the sample to be tested with the above olfactory receptors, 3-methylthiopropionaldehyde in the sample to be tested will activate the above olfactory receptors to obtain corresponding response values. According to the response values, the situation of 3-methylthiopropionaldehyde contained in the sample to be tested can be determined, and based on the situation of 3-methylthiopropionaldehyde contained, it can be determined whether the plurality of samples to be tested are of the same type or determine the types among the plurality of samples to be tested.

[0014] In a seventh aspect of the present invention, the present invention provides a method for monitoring whether fruit products have been subjected to high-temperature disinfection treatment. According to an embodiment of the present invention, the method includes: contacting a sample to be tested with an olfactory receptor, determining the response value of the olfactory receptor; determining whether the sample to be tested has been subjected to high-temperature disinfection treatment based on the response value; wherein, the olfactory receptors include at least one selected from the following: MOR244-3, MOR256-17, MOR180-1, and OR2C1. The inventors conducted experiments and found that after some fruit products (such as pineapple products) are subjected to pasteurization treatment, the content of 3-methylthiopropionaldehyde in the fruit products will increase significantly. When the fruit products are contacted with the above olfactory receptors, if the olfactory receptors are activated, corresponding response values can be obtained. By comparing this response value with the response values of fruit products that have or have not been subjected to high-temperature disinfection treatment, it can be determined whether the fruit products have been subjected to high-temperature disinfection treatment, which is used to monitor the high-temperature disinfection treatment link of fruit products to ensure the processing conditions of fruit products.

[0015] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and / or additional aspects and advantages of the present invention will become apparent and be readily understood from the description of the embodiments in conjunction with the following drawings, wherein:

[0017] Figure 1 It is a dose curve diagram of 4 olfactory receptors responding to 3-methylthiopropionaldehyde in Embodiment 1 of the present invention;

[0018] Figure 2Relative response intensities of MOR244-3 and MOR256-17 to 3-(methylthio)propanal in freshly squeezed orange juice and freshly squeezed mango juice in Example 3 of the present invention;

[0019] Figure 3 Relative response intensities of MOR244-3 and MOR256-17 to 3-(methylthio)propanal in freshly squeezed orange juice, freshly squeezed grapefruit juice and freshly squeezed mango juice in Example 4 of the present invention;

[0020] Figure 4 Relative response intensities of MOR244-3 and MOR256-17 to 3-(methylthio)propanal in freshly squeezed orange juice and three orange juice beverages in Example 5 of the present invention;

[0021] Figure 5 Relative response intensities of MOR244-3 and MOR256-17 to 3-(methylthio)propanal in freshly squeezed mango juice and reconstituted mango juice in Example 6 of the present invention;

[0022] Figure 6 Relative response intensities of MOR244-3 and MOR256-17 to 3-(methylthio)propanal in freshly squeezed pineapple juice and pasteurized processed pineapple juice in Example 7 of the present invention;

[0023] Figure 7 Relative response intensities of MOR244-3 and MOR256-17 to 3-(methylthio)propanal in draft beer, stout and red wine in Example 8 of the present invention. Detailed implementation manners

[0024] The embodiments of the present invention will be described in detail below. The following described embodiments are exemplary and are only used to explain the present invention, and should not be construed as a limitation to the present invention.

[0025] It should be noted that the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. Further, in the description of the present invention, unless otherwise specified, the meaning of "plurality" is two or more than two.

[0026] The endpoints and any values disclosed in this article are not limited to the exact range or value. These ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and a single point value, and between single point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed in this article.

[0027] To facilitate a better understanding of the present invention, certain technical and scientific terms are specifically defined below. Unless otherwise clearly defined elsewhere in this document, all other technical and scientific terms used herein shall have the meanings commonly understood by those of ordinary skill in the art to which the present invention pertains.

[0028] As used herein, the term "comprising" or "including" is an open-ended expression, meaning it includes the content specified in the present invention but does not exclude other aspects.

[0029] As used herein, the terms "optionally", "optional", or "option" generally refer to the subsequent event or condition that may or may not occur, and this description includes the cases where the event or condition occurs and the cases where it does not occur.

[0030] The present invention provides a use of an olfactory receptor in recognizing 3-methylthiopropionaldehyde, a use of 3-methylthiopropionaldehyde in activating an olfactory receptor, a method for detecting 3-methylthiopropionaldehyde, a method for detecting the freshness of alcoholic beverages, fruits or fruit products, a method for detecting the types of fruits contained in foods, a method for distinguishing between beers or red wines, and a method for monitoring whether fruit products have been subjected to high-temperature disinfection treatment. These will be described in detail below respectively.

[0031] Use

[0032] In a first aspect of the present invention, a use of an olfactory receptor in recognizing 3-methylthiopropionaldehyde is provided. According to an embodiment of the present invention, the olfactory receptor includes at least one selected from the following: MOR244-3, MOR256-17, MOR180-1, and OR2C1. The inventors found through experiments that when 3-methylthiopropionaldehyde stimulates MOR244-3, MOR256-17, MOR180-1, and OR2C1 respectively, the above four olfactory receptors can all be activated. Thus, the above olfactory receptors can be used to effectively identify 3-methylthiopropionaldehyde, laying a foundation for the detection of samples containing 3-methylthiopropionaldehyde.

[0033] It should be noted that if the olfactory receptor is activated after being stimulated by 3-methylthiopropionaldehyde, it means that the "olfactory receptor can recognize 3-methylthiopropionaldehyde"; if the olfactory receptor is not activated after being stimulated by 3-methylthiopropionaldehyde, it means that the "olfactory receptor cannot recognize 3-methylthiopropionaldehyde".

[0034] According to an embodiment of the present invention, the recognition or activation is reflected by a change in the activity of the olfactory receptor.

[0035] According to an embodiment of the present invention, the change in activity includes at least one of the following signal changes: cAMP, IP3, calcium ions, current, and pH.

[0036] According to an embodiment of the present invention, the recognition is reflected by an increase in cAMP downstream of the olfactory receptor. The inventors found through experiments that when 3-methylthiopropionaldehyde stimulates cells expressing the olfactory receptor, after the olfactory receptor is activated, the intracellular cAMP concentration increases. By detecting the change in cAMP concentration, it can be determined whether the olfactory receptor can recognize 3-methylthiopropionaldehyde.

[0037] In a second aspect of the present invention, the present invention provides a use of 3-methylthiopropionaldehyde in activating olfactory receptors, where the olfactory receptors include at least one selected from the following: MOR244-3, MOR256-17, MOR180-1, and OR2C1. The inventors found through experiments that after stimulating MOR244-3, MOR256-17, MOR180-1, and OR2C1 with 3-methylthiopropionaldehyde, the above four olfactory receptors can all be activated. Thus, the above olfactory receptors can be used to effectively identify 3-methylthiopropionaldehyde, laying a foundation for the identification of 3-methylthiopropionaldehyde and the detection of samples containing 3-methylthiopropionaldehyde.

[0038] According to an embodiment of the present invention, the activation is reflected by an increase in cAMP downstream of the olfactory receptor. The inventors found through experiments that when 3-methylthiopropionaldehyde stimulates cells expressing the above multiple olfactory receptors, if the olfactory receptor is activated, the intracellular cAMP concentration increases. By detecting the change in cAMP concentration, it is finally determined that 3-methylthiopropionaldehyde can activate the above four olfactory receptors.

[0039] Method

[0040] In a third aspect of the present invention, the present invention provides a method for detecting 3-methylthiopropionaldehyde. According to an embodiment of the present invention, the method includes: contacting a sample to be tested with an olfactory receptor and determining the response value of the olfactory receptor; based on the response value, determining whether the sample to be tested contains 3-methylthiopropionaldehyde; where the olfactory receptor includes at least one selected from the following: MOR244-3, MOR256-17, MOR180-1, and OR2C1. The inventors found through experiments that 3-methylthiopropionaldehyde can activate the above olfactory receptors. If the sample to be tested contains 3-methylthiopropionaldehyde, when the sample to be tested is contacted with the above olfactory receptor, the above olfactory receptor can be activated to obtain the response value after activation. According to the response value, it can be determined whether the sample to be tested contains 3-methylthiopropionaldehyde.

[0041] According to an embodiment of the present invention, the presence of a response value of the olfactory receptor indicates that the sample to be tested contains 3-methylthiopropionaldehyde; or, the absence of a response value of the olfactory receptor indicates that the sample to be tested does not contain 3-methylthiopropionaldehyde.

[0042] It should be noted that the indication of "not containing 3-methylthiopropionaldehyde" means that 3-methylthiopropionaldehyde is completely absent in the sample to be tested; or there is a small amount of 3-methylthiopropionaldehyde in the sample to be tested, but it cannot be detected.

[0043] According to an embodiment of the present invention, the olfactory receptor is selected from MOR244-3 and / or MOR256-17. The presence of a response value of the olfactory receptor is an indication that the sample to be tested contains 3-methylthiopropionaldehyde or contains 3-methylthiopropionaldehyde not less than 30 μM; or, the absence of a response value of the olfactory receptor is an indication that the sample to be tested does not contain 3-methylthiopropionaldehyde or contains 3-methylthiopropionaldehyde less than 30 μM.

[0044] According to an embodiment of the present invention, the olfactory receptor is selected from MOR180-1 and / or OR2C1. The presence of a response value of the olfactory receptor is an indication that the sample to be tested contains 3-methylthiopropionaldehyde or contains 3-methylthiopropionaldehyde not less than 100 μM; or, the absence of a response value of the olfactory receptor is an indication that the sample to be tested does not contain 3-methylthiopropionaldehyde or contains 3-methylthiopropionaldehyde less than 100 μM.

[0045] According to an embodiment of the present invention, the method further includes: determining the content of 3-methylthiopropionaldehyde in the sample to be tested based on a standard curve, where the standard curve is a corresponding curve of a predetermined amount of 3-methylthiopropionaldehyde and the response value of the olfactory receptor. Thus, the content of 3-methylthiopropionaldehyde in the sample to be tested can be detected.

[0046] In the fourth aspect of the present invention, the present invention provides a method for detecting the freshness of alcoholic beverages, fruits or fruit products. According to an embodiment of the present invention, the method includes: contacting the sample to be tested with an olfactory receptor, determining the response value of the olfactory receptor; determining the freshness of the sample to be tested based on the response value; where the olfactory receptor includes at least one selected from the following: MOR244-3, MOR256-17, MOR180-1 and OR2C1. The inventors found through experiments that 3-methylthiopropionaldehyde can activate the above olfactory receptors. If the sample to be tested contains 3-methylthiopropionaldehyde, when the sample to be tested is contacted with the above olfactory receptors, the above olfactory receptors can be activated to obtain an activated response value. According to the response value, the situation of 3-methylthiopropionaldehyde contained in the sample to be tested can be determined, and the freshness of the sample to be tested can be determined based on the situation of 3-methylthiopropionaldehyde contained in different samples to be tested.

[0047] According to an embodiment of the present invention, the method further includes: contacting a control sample with an olfactory receptor to determine a response value of the olfactory receptor, where the control sample is fresh alcoholic beverage, fruit or fruit product; that there is no significant difference between the response value of the test sample and the response value of the control sample is an indication that the test sample is fresh; or, that there is a significant difference between the response value of the test sample and the response value of the control sample is an indication that the test sample is not fresh. The inventor compared the response value of 3-methylthiopropionaldehyde in the alcoholic beverage, fruit or fruit product to be detected (test group) with the response value of 3-methylthiopropionaldehyde in the known fresh alcoholic beverage, fruit or fruit product (control group), and by analyzing the difference in the response values of the test group and the control group, the freshness of the test sample can be quickly detected.

[0048] In a fifth aspect of the present invention, the present invention provides a method for detecting the types of fruits contained in food. According to an embodiment of the present invention, the method includes: contacting a test sample with an olfactory receptor to determine a response value of the olfactory receptor; based on the response value, determining the types of fruits contained in the test sample; where the olfactory receptor includes at least one selected from the following: MOR244-3, MOR256-17, MOR180-1 and OR2C1; the test sample contains only one type of fruit. The inventor found through experiments that foods containing different fruits (such as fruit pulp obtained by grinding, freshly squeezed fruit juice, and beverages containing fruit juice, etc.) contain different concentrations of 3-methylthiopropionaldehyde. By contacting the test sample with the above olfactory receptor, the above olfactory receptor is activated, and the response value after activation can be obtained. According to the response value, the situation of 3-methylthiopropionaldehyde contained in the test sample can be determined, thereby determining the types of fruits in the food.

[0049] According to an embodiment of the present invention, the method further includes: comparing the response value with the response values of multiple known fruits to determine the types of fruits contained in the test sample. The inventor compared the response value of the test sample with the response values of multiple known fruits and found the fruit corresponding to the response value closest to the response value of the test sample, which is the type of fruit contained in the test sample.

[0050] According to an embodiment of the present invention, the food is selected as freshly squeezed fruit juice.

[0051] According to an embodiment of the present invention, the multiple known fruits include orange, grapefruit, mango and pineapple.

[0052] In a sixth aspect of the present invention, the present invention provides a method for differentiating beer or red wine. According to an embodiment of the present invention, the method includes: contacting a plurality of products to be tested with olfactory receptors, respectively determining the response values of the olfactory receptors corresponding to the plurality of products to be tested, and the plurality of products to be tested are beer and / or red wine; based on the response values of the olfactory receptors corresponding to the plurality of products to be tested, determining the types of the products to be tested; wherein, the olfactory receptors include at least one selected from the following: MOR244-3, MOR256-17, MOR180-1, and OR2C1. The inventors found through experiments that compared with red wine, the content of 3-methylthiopropionaldehyde in beer is higher. By contacting the sample to be tested with the above olfactory receptors, 3-methylthiopropionaldehyde in the sample to be tested will activate the above olfactory receptors to obtain corresponding response values. According to the response values, the situation of 3-methylthiopropionaldehyde contained in the sample to be tested can be determined, and whether the plurality of samples to be tested are the same type of product can be determined based on the situation of 3-methylthiopropionaldehyde contained, or the types in the plurality of samples to be tested can be further determined.

[0053] According to an embodiment of the present invention, the lack of significant difference in the response values of the olfactory receptors corresponding to the plurality of products to be tested is an indication that the plurality of products to be tested are beer or red wine. Thus, it can be quickly detected whether the plurality of samples to be tested are the same type of liquor.

[0054] According to an embodiment of the present invention, the response values of the olfactory receptors corresponding to the plurality of products to be tested not being lower than a first preset value is an indication that the plurality of products to be tested are beer; or, the response values of the olfactory receptors corresponding to the plurality of products to be tested being lower than the first preset value is an indication that the plurality of products to be tested are red wine. Thus, it can be further quickly differentiated whether the sample to be tested is beer or red wine.

[0055] It should be noted that the first predetermined value refers to the response value obtained through experiments for differentiating beer and red wine, and it can be determined according to different detection methods. For example, by detecting the change in cAMP concentration, the first preset value can be set to 500.

[0056] According to an embodiment of the present invention, the significant difference in the response values of the olfactory receptors corresponding to the plurality of products to be tested is an indication that the products to be tested are beer and red wine. Thus, it can be quickly differentiated whether the beer or red wine in the sample to be tested.

[0057] According to an embodiment of the present invention, there is a significant difference in the response values of the olfactory receptors corresponding to the plurality of products to be tested. The response value of the olfactory receptor not being lower than the first preset value is an indication that the corresponding product to be tested is beer, and the response value of the olfactory receptor being lower than the first preset value is an indication that the corresponding product to be tested is red wine. Thus, it can be further quickly differentiated whether the beer or red wine in the sample to be tested.

[0058] In the seventh aspect of the present invention, a method for monitoring whether a fruit product has been subjected to high-temperature disinfection treatment is proposed. According to an embodiment of the present invention, the method includes: contacting a sample to be tested with an olfactory receptor, and determining a response value of the olfactory receptor; based on the response value, determining whether the sample to be tested has been subjected to high-temperature disinfection treatment; wherein, the olfactory receptor includes at least one selected from the following: MOR244-3, MOR256-17, MOR180-1, and OR2C1. Through experiments, the inventors found that after some fruit products (such as pineapple products) are subjected to high-temperature disinfection treatment, 3-methylthiopropionaldehyde in the fruit products will increase significantly. When the fruit product is contacted with the above olfactory receptor, if the olfactory receptor is activated, a corresponding response value can be obtained. By comparing this response value with the response value of the fruit product that has or has not been subjected to high-temperature disinfection treatment, it can be determined whether the fruit product has been subjected to high-temperature disinfection treatment, which is used to monitor the disinfection treatment link of the fruit product to ensure the processing situation of the fruit product.

[0059] According to an embodiment of the present invention, that the response values of the olfactory receptors corresponding to multiple samples to be tested are not lower than a second preset value is an indication that the samples to be tested have been subjected to high-temperature disinfection treatment; or, that the response values of the olfactory receptors corresponding to multiple samples to be tested are lower than the second preset value is an indication that the samples to be tested have not been subjected to high-temperature disinfection treatment. Thus, it can be quickly monitored whether the fruit product has been subjected to high-temperature disinfection treatment to ensure the processing link of the fruit product and improve the quality and safety of the fruit product.

[0060] It should be noted that the second predetermined value refers to the response value obtained through experiments for distinguishing between fruit products that have been subjected to high-temperature disinfection treatment and those that have not, and it can be determined according to different detection methods. For example, by detecting the change in cAMP concentration, the first preset value can be set to 200.

[0061] According to an embodiment of the present invention, the sample to be tested is a pineapple product.

[0062] According to an embodiment of the present invention, the pineapple product includes pineapple juice or pineapple cans.

[0063] According to an embodiment of the present invention, the high-temperature disinfection treatment is selected from pasteurization.

[0064] According to an embodiment of the present invention, the pasteurization is carried out at 70-100°C for 20-60 minutes.

[0065] According to an embodiment of the present invention, the methods of the above third aspect, fourth aspect, fifth aspect, sixth aspect, and seventh aspect may further include at least one of the following technical features:

[0066] According to an embodiment of the present invention, the olfactory receptor includes at least one selected from the following: MOR244-3, MOR180-1, and OR2C1. Through experiments, it has been found that the above olfactory receptors can specifically recognize 3-methylthiopropionaldehyde.

[0067] According to an embodiment of the present invention, the olfactory receptor is provided by a cell expressing the olfactory receptor or a transgenic cell.

[0068] According to an embodiment of the present invention, the cell or transgenic cell is a eukaryotic cell or a prokaryotic cell.

[0069] According to an embodiment of the present invention, the eukaryotic cell includes at least one selected from a cell group isolated from the olfactory placode, HEK293 cells, CHO cells, Xenopus oocytes, Hela cells, COS cells, and yeast cells.

[0070] According to an embodiment of the present invention, the prokaryotic cell is selected from bacteria.

[0071] According to an embodiment of the present invention, the response value is obtained by detecting a change in the activity of the olfactory receptor.

[0072] According to an embodiment of the present invention, the change in activity is determined by at least one of the following detection methods: luciferase assay, secreted alkaline phosphatase assay, fluorescent protein assay, fluorescent probe assay, Ca 2+ concentration assay, current assay, isotope labeling assay, antibody assay, and pH assay.

[0073] Exemplarily, in the luciferase assay, when a cell containing an olfactory receptor is stimulated with 3-methylthiopropionaldehyde or a sample containing 3-methylthiopropionaldehyde, if the olfactory receptor is activated, the intracellular cAMP concentration increases. cAMP binds to the promoter region of CRE-luciferase and promotes the transcription and translation of luciferase. Therefore, by detecting the activity of luciferase, the response of the olfactory receptor can be characterized, and it can be determined whether the olfactory receptor can recognize 3-methylthiopropionaldehyde.

[0074] According to an embodiment of the present invention, the response value is obtained by detecting a change in the cAMP concentration in the cell.

[0075] According to an embodiment of the present invention, the change in the cAMP concentration in the cell is obtained by using a GloSensor TM cAMP detection kit. The GloSensor-20F cAMP gene construct can pre-express a luciferase variant. An increase in cAMP concentration can cause a conformational change in the luciferase variant, converting the luciferase from an inactive state to an active state. GloSensorTM The cAMP detection kit provides a substrate for the luciferase variant. This method can measure the concentration change of cAMP in real time and can quickly and sensitively detect the content of 3-methylthiopropionaldehyde in the sample to be tested.

[0076] The solution of the present invention will be explained below in conjunction with embodiments. Those skilled in the art will understand that the following embodiments are only used to illustrate the present invention and should not be regarded as limiting the scope of the present invention. For those not specified in the embodiments, the techniques or conditions described in the literature in the art or according to the product specifications are followed. Those reagents or instruments not specified by the manufacturer can be obtained as conventional products through commercial purchase.

[0077] Example 1: Screening of olfactory receptors

[0078] In this example, the Dual-Glo TM Luciferase Assay System (Promega) was used to measure the activity of olfactory receptors. The inventors selected some olfactory receptors from the human and mouse olfactory receptor libraries, and then prepared gene constructs containing olfactory receptors, Golf, CRE-Luciferase, and pRL-SV40, and transfected the gene constructs into HEK293T cells using the transfection reagent Lipofectamine 2000 (Invitrogen). After culturing for 24 hours, 3-methylthiopropionaldehyde was diluted to a concentration of 500 μM with the culture medium, and the cells were stimulated with the diluted 3-methylthiopropionaldehyde and incubated for 2-4 hours. If the olfactory receptor is activated, the intracellular cAMP concentration increases, and cAMP will bind to the promoter region of CRE-luciferase and promote the transcription and translation of luciferase. By detecting the activity of luciferase, the response of the olfactory receptor can be characterized. Finally, three responsive mouse olfactory receptors, MOR244-3, MOR256-17, and MOR180-1, and one responsive human olfactory receptor, OR2C1, were obtained.

[0079] The inventors also measured the cells containing the above four olfactory receptors stimulated with different concentrations of 3-methylthiopropionaldehyde and observed the dose curves of the four olfactory receptors responding to 3-methylthiopropionaldehyde at different concentrations. The results are as Figure 1 shown, where the horizontal axis is the logarithm of the 3-methylthiopropionaldehyde concentration (M), and the vertical axis is the fold change in response relative to the blank control (without 3-methylthiopropionaldehyde). The results showed that among the above four olfactory receptors, MOR244-3 and MOR256-17 had the strongest response to 3-methylthiopropionaldehyde, and the fold changes in response could reach about 25 times or 10 times respectively, and the sensitivities were both 30 μM.

[0080] Among them, the amino acid sequence of MOR244-3 is as follows:

[0081] MGALNQTRVTEFIFLGLTDNWVLEILFFVPFTVTYMLTLLGNFLIVVTIVFTPRLHNPMYFFLSNLSFIDICHSSVTVPKMLEGLLLERKTISFDNCIAQLFFLHLFACSEIFLLTIMAYDRYVAICIPLHYSNVMNMKVCVQLVFALWLGGTIHSLVQTFLTIRLPYCGPNIIDSYFCDVPPVIKLACTDTYLTGILIVSNSGTISLVCFLALVTSYTVILFSLRKKSAEGRRKALSTCSAHFMVVTLFFGPCIFLYTRPDSSFSIDKVVSVFYTVVTPLLNPLIYTLRNEEVKTAMKHLRQRRICS(SEQ ID NO:1).

[0082] The amino acid sequence of MOR256-17 is as follows:

[0083] MEVDSNSSSGSFILMGVSDHPHLEIIFFAVILASYLLTLVGNLTIILLSRLDARLHTPMYFFLSNLSSLDLAFTTSSVPQMLKNLWGPDKTISYGGCVTQLYVFLWLGATECILLVVMAFDRYVAVCRPLHYMTVMNPRLCWGLAAISWLGGLGNSVIQSTFTLQLPFCGHRKVDNFLCEVPAMIKLACGDTSLNEAVLNGVCTFFTVVPVSVILVSYCFIAQAVMKIRSVEGRRKAFNTCVSHLVVVFLFYGSAIYGYLLPAKSSNQSQGKFISLFYSVVTPMVNPLIYTLRNKEVKGALGRLLGKGRGAS(SEQ ID NO:2).

[0084] The amino acid sequence of MOR180-1 is as follows:

[0085] MDKENHSVVTEFVFMGITQDPQLQIIFFVVFLLVYLVNVIGNVGMIILIITDSQLHTPMYFFLCNLSFVDLGYSSAIAPRMLADFLTKHKVISFSSCATQFAFFVGFVDAECYVLAAMAYDRFVAICRPLHYSTLMSKKVCLVLMLGSYFAGLVSLVAHTSLTFSLSYCGSNIINHFFCEIPPLLALSCSDTYISEILLFSLCGFIEFSTILIIFISYAFILIAIIRIRSAEGRLKAFSTCGSHLTGVTLFYGTVMFMYLRPTSSYSLDQDKWASVFYTIIIPMLNPLIYSLRNKDVKAAFKKLIGKKPQ(SEQ ID NO:3).

[0086] The amino acid sequence of OR2C1 is as follows:

[0087] MDGVNDSSLQGFVLMGISDHPQLEMIFFIAILFSYLLTLLGNSTIILLSRLEARLHTPMYFFLSNLSSLDLAFATSSVPQMLINLWGPGKTISYGGCITQLYVFLWLGATECILLVVMAFDRYVAVCRPLRYTAIMNPQLCWLLAVIACLGGLGNSVIQSTFTLQLPLCGHRRVEGFLCEVPAMIKLACGDTSLNQAVLNGVCTFFTAVPLSIIVISYCLIAQAVLKIRSAEGRRKAFNTCLSHLLVVFLFYGSASYGYLLPAKNSKQDQGKFISLFYSLVTPMVNPLIYTLRNMEVKGALRRLLGKGREVG(SEQ ID NO:4).

[0088] Example 2: Responses of Four Olfactory Receptors to Different Compounds

[0089] In this example, the method of Example 1 was used to detect the responses of MOR244-3, MOR256-17, MOR180-1, and OR2C1 to three structural analogs of 3-methylthiopropionaldehyde (also known as "odor molecules"). The three structural analogs of 3-methylthiopropionaldehyde (methional) are 3-methylthiopropanol (methionol), pentanal, and pentanol, respectively. The specific detection results are shown in Table 1. Among them, the hydroxyl group in 3-methylthiopropanol replaces the aldehyde group of 3-methylthiopropionaldehyde; the carbon atom in pentanal replaces the sulfur atom of 3-methylthiopropionaldehyde; the hydroxyl group and carbon atom in pentanol replace the aldehyde group and sulfur atom of 3-methylthiopropionaldehyde simultaneously. In the table, "+++" indicates that the response change multiple ≥ 10, "++" indicates that the response change multiple 5 < X < 10 (X is the detected response change multiple), "+" indicates that the response change multiple ≤ 5, and "-" indicates no response. The results in Table 1 show that the replacement of the aldehyde group and / or methylthio group will significantly reduce or eliminate the activation effect on the four olfactory receptors.

[0090] Table 1: Response results of four olfactory receptors to different compounds

[0091] MOR256-17 MOR244-3 MOR180-1 OR2C1 methional ++ +++ + + methionol + - - - pentanal - - - - pentanol + - - -

[0092] Example 3: Detection of 3-methylthiopropionaldehyde in different freshly squeezed juices by MOR244-3 and MOR256-17

[0093] The detection method in this example is referred to Example 1, with the only difference being that in this example, a luciferase variant is used instead of the original dual luciferase, and cells expressing the olfactory receptors MOR244-3 and MOR256-17 are used to detect the presence of 3-methylthiopropionaldehyde in freshly squeezed orange juice and freshly squeezed mango juice. The specific detection results are referred to Figure 2 . The results show that the peak is reached at about 15 minutes (min), and both olfactory receptors have strong signals.

[0094] By co-transfecting the pGloSensor-20F cAMP (Promega) construct into the cells, the cells can pre-express a luciferase variant. After the olfactory receptor is activated, the increase in cAMP concentration can cause a conformational change in the luciferase variant, making the luciferase change from an inactive state to an active state. Using the GloSensor TM cAMP detection kit, the concentration change of cAMP can be measured in real time and quickly. Therefore, by combining cells expressing olfactory receptors with the GloSensor TM cAMP detection method, the presence of 3-methylthiopropionaldehyde in foods (such as freshly squeezed juices) can be detected quickly and sensitively.

[0095] Example 4: Detection of 3-(methylthio)propanal in different freshly squeezed fruit juices by MOR244-3 and MOR256-17

[0096] For the detection method in this example, refer to Example 3. Cells expressing the olfactory receptors MOR244-3 and MOR256-17 respectively were used to compare the contents of 3-(methylthio)propanal in three freshly squeezed fruit juices of orange, grapefruit, and mango. The results are as Figure 3 shown. The results show that the content of 3-(methylthio)propanal in the three freshly squeezed fruit juices is mango > orange > grapefruit, which is consistent with the reported research results, and the results of the two olfactory receptors show a consistent trend.

[0097] Example 5: Detection of 3-(methylthio)propanal in four orange-flavored beverages by MOR244-3 and MOR256-17

[0098] For the detection method in this example, refer to Example 3. Cells expressing the olfactory receptors MOR244-3 and MOR256-17 respectively were used to compare the contents of 3-(methylthio)propanal in four orange-flavored beverages, namely freshly squeezed orange juice, Huiyuan concentrated and reconstituted orange juice, Pulpy Orange, and orange-flavored Mirinda soda. The results are as Figure 4 shown. The results show that the contents of 3-(methylthio)propanal in freshly squeezed orange juice and Huiyuan concentrated and reconstituted orange juice are comparable, followed by Pulpy Orange, and there is almost no 3-(methylthio)propanal in orange-flavored Mirinda soda, and the results of the two olfactory receptors show a consistent trend.

[0099] Example 6: Detection of 3-(methylthio)propanal in two mango beverages by MOR244-3 and MOR256-17

[0100] For the detection method in this example, refer to Example 3. Cells expressing the olfactory receptors MOR244-3 and MOR256-17 respectively were used to compare the contents of 3-(methylthio)propanal in freshly squeezed mango juice and concentrated and reconstituted mango juice. The results are as Figure 5 shown. The results show that the contents of freshly squeezed mango juice are relatively high, and the results of the two olfactory receptors show a consistent trend.

[0101] Example 7: Monitoring of the pasteurization process of pineapple juice by MOR244-3 and MOR256-17

[0102] For the detection method in this example, refer to Example 3. Cells expressing the olfactory receptors MOR244-3 and MOR256-17 respectively were used to compare the contents of 3-(methylthio)propanal in two kinds of pineapple juice, namely freshly squeezed pineapple juice and processed pineapple juice obtained by pasteurizing freshly squeezed pineapple juice (pasteurized at 80 °C for 30 min). The results are as Figure 6As shown. The results show that the content of 3-(methylthio)propanal in freshly squeezed pineapple juice increases, and the results of the two olfactory receptors show a consistent trend, which is in line with the reported research results.

[0103] Example 8: Detection of 3-(methylthio)propanal in three alcoholic beverages by MOR244-3 and MOR256-17

[0104] For the detection method in this example, refer to Example 3. Cells expressing the olfactory receptors MOR244-3 and MOR256-17 were used to compare the content of 3-(methylthio)propanal in draft beer, stout, and red wine. The results are as Figure 7 shown. The results show that the content of 3-(methylthio)propanal in beer (draft beer and stout) is relatively high, while the content in red wine is relatively low, and the results of the two olfactory receptors show a consistent trend.

[0105] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0106] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. Use of an olfactory receptor in the recognition of 3-(methylthio)propanal, wherein the olfactory receptor is selected from MOR256-17; Among them, The amino acid sequence of MOR256-17 is as shown in SEQ ID NO:

2.

2. Use of 3-(methylthio)propanal in activating an olfactory receptor, wherein the olfactory receptor is selected from MOR256-17; Among them, The amino acid sequence of MOR256-17 is as shown in SEQ ID NO:

2.

3. The use according to claim 1 or 2, characterized in that, The recognition or activation is reflected by a change in the activity of the olfactory receptor; The change in activity includes at least one of the following signal changes: cAMP, IP3, calcium ions, current, and pH.

4. A method for detecting 3-methylthiopropionaldehyde, characterized in that, Including: Contacting a test sample with an olfactory receptor to determine the response value of the olfactory receptor; Based on the response value, determining whether 3-(methylthio)propanal is contained in the test sample; Wherein, the olfactory receptor is selected from MOR256-17; Wherein, the amino acid sequence of MOR256-17 is as shown in SEQ ID NO:

2.

5. The method according to claim 4, characterized in that, The presence of a response value of the olfactory receptor is an indication that 3-(methylthio)propanal is contained in the test sample; or, the absence of a response value of the olfactory receptor is an indication that 3-(methylthio)propanal is not contained in the test sample; The method further includes: Based on a standard curve, determining the content of 3-(methylthio)propanal in the test sample, and the standard curve is a corresponding curve of a predetermined amount of 3-(methylthio)propanal and the response value of the olfactory receptor.

6. A method for detecting the freshness of a drink containing fruit juice, characterized in that, Including: Contacting a test sample with an olfactory receptor to determine the response value of the olfactory receptor; Based on the response value, determining the freshness of the test sample; Wherein, the olfactory receptor is selected from MOR256-17; Wherein, the amino acid sequence of MOR256-17 is as shown in SEQ ID NO:

2.

7. A method for detecting the types of fruits contained in food, characterized in that, Including: Contacting a test sample with an olfactory receptor to determine the response value of the olfactory receptor; Based on the response value, determining the type of fruit contained in the test sample; Wherein, the olfactory receptor is selected from MOR256-17; Wherein, the amino acid sequence of MOR256-17 is as shown in SEQ ID NO:2; The test sample contains only one kind of fruit.

8. A method for differentiating beer or red wine, characterized in that, Including: Contacting a plurality of test products with an olfactory receptor to respectively determine the response values of the olfactory receptors corresponding to the plurality of test products, and the plurality of test products are beer and / or red wine; Based on the response values of the olfactory receptors corresponding to the plurality of test products, determining the types of the test products; Wherein, the olfactory receptor is selected from MOR256-17; Wherein, the amino acid sequence of MOR256-17 is as shown in SEQ ID NO:

2.

9. A method for monitoring whether a fruit product has been subjected to high-temperature disinfection treatment, characterized in that, Including: Contacting a test sample with an olfactory receptor to determine the response value of the olfactory receptor; Based on the response value, determining whether the test sample has been subjected to high-temperature disinfection treatment; Wherein, the olfactory receptor is selected from MOR256-17; Wherein, the amino acid sequence of MOR256-17 is as shown in SEQ ID NO:

2.

10. The method according to any one of claims 4 to 9, characterized in that, The olfactory receptor is provided by cells expressing the olfactory receptor; alternatively, the response value is obtained by detecting a change in the cAMP concentration in the cells; The cells are eukaryotic cells or prokaryotic cells; The response value is obtained by detecting a change in the activity of the olfactory receptor; The change in activity is determined by at least one of the following detection methods: Luciferase assay, secreted alkaline phosphatase assay, fluorescent protein assay, fluorescent probe assay, Ca 2+ concentration assay, current assay, isotope labeling assay, antibody assay, and pH assay.

11. The method according to claim 10, wherein The olfactory receptor is provided by transgenic cells expressing the olfactory receptor.

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