Cooking smell substance identification method

Abstract

The invention discloses a cooking smell substance identification method. The method comprises the following steps: S1, building a cooking smell substance collection experiment table; s2, the meal amount and the purging flow are determined; s3, collecting cooking smell substances; and S4, odor substance identification: identifying the odor substances by adopting a method of combining a gas chromatography-olfaction-mass spectrometer (GC-O-MS) and an odor activity value (OAV). According to the meal odor substance collection experiment table, external odor substances can be eliminated, materials making contact with the odor substances are all glass or polytetrafluoroethylene, the adsorption performance on the odor substances is small, and the composition and concentration of the cooking odor substances are reduced as much as possible. According to the smell substance identification method, two different methods are comprehensively adopted, and the cooking smell substances can be comprehensively identified.

Description

Technical Field

[0001] The invention relates to the field of odor substance recognition, and in particular to a cooking odor substance recognition method. Background Art

[0002] Indoor air quality is closely related to people's lives. A large number of studies have been conducted on indoor harmful pollutants to explore their sources, pollution characteristics, control methods, etc. However, indoor air quality not only has a significant impact on the health of residents, but also affects people's comfort and psychological state. Therefore, in recent years, the concept of perceived air quality (PAQ) has gradually attracted people's attention. Odor, as a major factor affecting PAQ, has attracted attention but has not been widely studied. Studies have shown that odors can have adverse effects on people's psychology, physiology and behavior, such as making people irritable and reducing people's productivity. In order to improve people's quality of life, it is imperative to control and purify indoor odors. Cooking is a significant source of indoor odors. A questionnaire survey on household kitchen odors showed that 81% of households still have odors in the kitchen when they are not cooking, and 34% of households think that the odor in the kitchen is unacceptable; 35% of households often smell odors suspected to be from the kitchen in other rooms. Therefore, the odors produced by cooking seriously affect PAQ, trouble people's lives, and need to be solved urgently.

[0003] At present, there have been a lot of studies on pollutants emitted by cooking, such as the emission characteristics and hazards of particulate matter, volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons, and nitrogen oxides, but the odor substances produced by cooking are still unclear. Studies have been conducted to characterize the odor substances emitted by building decoration materials. The main methods used are odor activity value method (OAV) and gas chromatography-olfaction-mass spectrometry (GC-O-MS). Experiments show that the odor substances identified by the two methods are different, so it is necessary to consider the results of the two methods comprehensively. For the collection of odor substances, the cabin method is mainly used (that is, placing the plate in a stainless steel cabin to make it emit odor). Heating in an opaque cabin poses a safety hazard, and operating the cooking process will introduce pollution or lose odor substances (such as hot pot meat, if people operate in the cabin throughout the process, introducing people as a pollution source, and people's clothes will absorb odors). Summary of the invention

[0004] In view of this, the present invention discloses a method for identifying cooking odor substances, which restores the composition and concentration of odor substances generated by cooking as much as possible and can comprehensively identify the odor substances generated by cooking.

[0005] The technical problem to be solved by the present invention is achieved through the following technical solutions:

[0006] A method for identifying cooking odor substances comprises the following steps:

[0007] S1. Construction of a cooking odor substance collection test bench: Select a glass sealed container with a certain volume, a condenser tube of sufficient effective length, and an electric heating furnace that meets the required heating temperature;

[0008] S2. Determination of meal quantity and purge flow rate: The purge flow rate is determined based on the sampling volume required for odor substance identification and meal cooking time. The meal quantity should ensure that the final gas in the gas sampling bag has a distinct odor;

[0009] S3. Collection of cooking odor substances: Add food to a sealed glass container, set the heating temperature of the electric stove, and continuously pass 0°C cold water into the condenser. After reaching the required cooking state, continuously pass clean air into the sealed glass container and collect it into the gas sampling bag. Continue until the set cooking time, and then collect the gas in the gas sampling bag into the DNPH tube and Tenax-TA tube respectively;

[0010] S4. Identification of odor substances: Odor substances were identified by combining gas chromatography-olfactometer-mass spectrometry (GC-O-MS) with odor activity value (OAV), and the odor substances identified by both methods were considered comprehensively.

[0011] Preferably, the glass sealed container is made of high borosilicate glass (GG17 material), has excellent physical and chemical properties, is resistant to high temperatures and is explosion-proof; has an air inlet and outlet, a larger opening for placing food, and good airtightness.

[0012] Preferably, the gas sampling bag material is polyvinyl fluoride (PVF), which has excellent chemical resistance, corrosion resistance, and low adsorption, and can be reused after cleaning.

[0013] Preferably, before performing a cooking operation (such as adding food), close the valve of the gas sampling bag to stop gas collection, and then open the valve after the operation is completed.

[0014] Preferably, the relative humidity of the gas at the outlet of the condenser is not higher than 90%.

[0015] Preferably, the DNPH tube is analyzed by high performance liquid chromatography (HPLC) to obtain the concentration of small molecule aldehydes and ketones and calculate their odor activity values ​​(OAV); the Tenax-TA tube is analyzed by GC-O-MS to obtain the concentration of VOCs and calculate their OAV, and the odor compounds can be identified at the same time.

[0016] Preferably, OAV is defined as the ratio of the concentration of a compound to its odor threshold, the larger the OAV value, the greater the odor contribution.

[0017] Preferably, the odor contribution of all detected compounds is evaluated according to the relative odor activity value (ROAV), and compounds with ROAV ≥ 1 are listed as key odor compounds. ROAV is defined as:

[0018]

[0019] Among them, ROAVi represents the relative odor activity value of compound i, OAVi represents the odor activity value of compound i, and OAVmax represents the largest OAV among the OAVs of all VOCs.

[0020] The above technical solution of the present invention has the following beneficial effects:

[0021] (1) The present invention designs a cooking odor collection system that can effectively collect food odors;

[0022] (2) The odor substance identification method proposed in the present invention can comprehensively identify cooking odor substances and indicate key odor substances, thereby improving the goal of controlling and purifying cooking odors;

[0023] (3) The present invention fills the gap in the field of cooking odor recognition and has the potential for wide application. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0025] Attached Figure 1 This is a schematic diagram of a cooking odor substance collection test bench for the present application.

[0026] Among them: 1-flow meter, 2-electric heating furnace, 3-glass sealed container, 4-condenser, 5-gas sampling bag. DETAILED DESCRIPTION

[0027] Various exemplary embodiments of the present invention will now be described in detail. It should be noted that the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless otherwise specifically stated.

[0028] A cooking smell recognition method comprises the following steps:

[0029] S1. Construction of a cooking odor substance collection test bench: Select a glass sealed container with a certain volume, a condenser with sufficient effective length, and an electric heating furnace that meets the required heating temperature, and connect the air compressor, flow meter, glass sealed container, condenser, and gas sampling bag in sequence;

[0030] S2. Determination of meal quantity and purge flow rate: The purge flow rate is determined based on the sampling volume required for odor substance identification and meal cooking time. The meal quantity should ensure that the final gas in the gas sampling bag has a distinct odor;

[0031] S3. Collection of cooking odor substances: Add food to a sealed glass container, set the heating temperature of the electric stove, and continuously pass 0°C cold water into the condenser. After reaching the required cooking state, continuously pass clean air into the sealed glass container and collect it into the gas sampling bag. Continue until the set cooking time, and then collect the gas in the gas sampling bag into the DNPH tube and Tenax-TA tube respectively;

[0032] S4. Identification of odor substances: Odor substances were identified by combining gas chromatography-olfactometer-mass spectrometry (GC-O-MS) with odor activity value (OAV), and the odor substances identified by both methods were considered comprehensively.

[0033] Furthermore, before performing a cooking operation (such as adding food), close the valve of the gas sampling bag to stop gas collection, and then open the valve after the operation is completed.

[0034] Furthermore, at least 2 parallel samples should be collected from DNPH tubes and at least 3 parallel samples should be collected from Tenax-TA tubes.

[0035] Furthermore, the OAV of all compounds needs to be calculated. OAV is defined as the ratio of the concentration of a compound to its odor threshold. The larger the OAV value, the greater the odor contribution.

[0036] Furthermore, the odor contribution of all detected compounds was evaluated according to the relative odor activity value (ROAV), and compounds with ROAV ≥ 1 were listed as key odor compounds. ROAV is defined as:

[0037]

[0038] Among them, ROAVi represents the relative odor activity value of compound i, OAVi represents the odor activity value of compound i, and OAVmax represents the largest OAV among the OAVs of all VOCs.

[0039] Furthermore, the odor compounds identified by OAV and GC-O-MS should be considered comprehensively.

[0040] The cooking odor substance collection device of the present application has good adsorption of gas components and good air tightness, and is convenient for observing and performing cooking operations, thereby effectively collecting cooking odors.

[0041] The cooking odor identification method of the present invention solves the problem of lack of identification of cooking odor substances in the prior art, overcomes the problem of safety hazards, odor substance contamination or loss in the cooking odor collection process of the cabin method commonly used in the prior art, and at the same time integrates the existing odor identification methods to achieve comprehensive identification of cooking odor substances.

[0042] Although the present invention has been disclosed as above by the embodiments, it is not intended to limit the present invention. Any person skilled in the art may make various choices and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention is limited by the claims and their equivalents.

Claims

1. A method for identifying cooking odor substances, characterized in that: The following steps are involved: S1. Construction of a cooking odor substance collection test bench: Select a glass sealed container with a certain volume, a condenser tube of sufficient effective length, and an electric heating furnace that meets the required heating temperature; S2. Determination of meal quantity and purge flow rate: The purge flow rate is determined based on the sampling volume required for odor substance identification and meal cooking time. The meal quantity should ensure that the final gas in the gas sampling bag has a distinct odor; S3. Collection of cooking odor substances: Add food to a sealed glass container, set the heating temperature of the electric stove, and continuously pass 0°C cold water into the condenser. After reaching the required cooking state, continuously pass clean air into the sealed glass container and collect it into the gas sampling bag. Continue until the set cooking time, and then collect the gas in the gas sampling bag into the DNPH tube and Tenax-TA tube respectively; S4. Identification of odor substances: Odor substances were identified by combining gas chromatography-olfactometer-mass spectrometry (GC-O-MS) with odor activity value (OAV), and the odor substances identified by both methods were considered comprehensively.

2. The food odor substance collection test bench according to claim 1 is characterized in that: include: Air compressor, float flowmeter, glass sealed container, electric heating furnace, condenser, gas sampling bag.

3. The glass sealed container according to claim 1, characterized in that: It is made of high borosilicate glass (GG17 material), has excellent physical and chemical properties, is resistant to high temperatures and explosion-proof; it has air inlets and outlets, a larger opening for placing food, and good airtightness.

4. The gas sampling bag according to claim 1, characterized in that: The material is polyvinyl fluoride (PVF), which has excellent chemical resistance, corrosion resistance, low adsorption, and can be reused after cleaning.

5. The condenser according to claim 1, characterized in that: Ensure that the relative humidity of the gas at the condenser outlet is not higher than 90%.

6. The method for identifying odor substances according to claim 1, characterized in that: The OAV method also analyzed small molecule aldehydes and ketones collected by DNPH tubes.

Images