Method for detecting smell of malt syrup

Abstract

The invention provides a malt syrup smell detection method, which relates to the technical field of food detection, and comprises the steps of sample pretreatment, sample weighing, heating, heat preservation, uniform shaking, evaluation, and result evaluation. The method comprises the following steps: directly weighing 200g of an undiluted sample in a borosilicate glass conical flask with a plug, preserving heat in a constant-temperature water bath at 60 + / -0.5 DEG C for 60 minutes, enriching volatile peculiar smell components by using a closed container, and judging a result by rechecking the smelling of two persons. Compared with a national standard method, the sensitivity limitation caused by dilution is broken through, and the problem of finished product flavor defects caused by raw material peculiar smell residues in the beer manufacturing industry is solved. Experiments show that the detection limit of the method to sulfur odor, 2-aminoacetophenone and other odor is as low as 0.05 ppm, the detection result is 100% consistent with the actual use feedback of customers, the misjudgment rate is reduced to 0 from 61.5% of the national standard method, and the strict quality control requirement of the beer industry to the raw material odor is met by optimizing the container design and operation specifications and ensuring the detection stability and reliability.

Description

Technical Field

[0001] The invention relates to the technical field of food detection, and in particular to a method for detecting the odor of maltose syrup. Background Art

[0002] In the production and application of maltose syrup, smell is an important indicator to measure its quality. According to the national standard "GB / T 20883-2007 Maltose", the current method for detecting the smell of maltose is: dilute the sample to 4% (dry matter) concentration, prepare 100ml aqueous solution and smell it. If it has the special smell of maltose, it is judged to be qualified. However, this method has the following significant defects in practical application: 1. Dilution leads to insufficient sensitivity: After maltose syrup is diluted, the concentration of its odor components is greatly reduced and its volatility is weakened, making it difficult to detect by conventional sniffing. Experiments show that the detection rate of odor in diluted sugar solution is less than 20%, which cannot truly reflect the odor problem of the raw materials.

[0003] 2. Special needs of the beer manufacturing industry: In beer production, maltose syrup is added as the main raw material at a ratio of up to 10%-30%. The odor components in the syrup cannot be removed during the beer fermentation and filtration processes and remain directly in the finished product.

[0004] 3. The existing methods are out of touch with actual needs: The national standard method can meet the routine detection of maltose odor in the general food industry, but the tolerance threshold of the beer manufacturing industry for the odor of raw materials is extremely low. Due to the lack of sensitivity of the existing methods, "qualified" syrups often cause beer flavor complaints in actual applications. Summary of the invention

[0005] A method for detecting the odor of maltose syrup comprises the following steps: S1: Sample pretreatment: Stir the maltose syrup sample to be tested at 25±2℃ for 5 minutes until it is evenly mixed; S2: Weigh 200.00±0.05g of the pretreated maltose syrup sample, use an electronic balance with an accuracy of 0.01g, transfer it to a 250ml borosilicate glass stoppered flask, and immediately tighten the polytetrafluoroethylene stopper; S3: Heat the constant temperature water bath to 60.0±0.5°C. After the temperature stabilizes, immerse the stoppered flask vertically in the water bath, ensuring that the water bath liquid level is at least 2 cm higher than the sample liquid level in the flask, and keep warm for 60±1 minutes; S4: Take out the stoppered conical flask, shake it horizontally for 5 circles at a speed of 1 circle / second, and let it stand for 10±1 seconds; S5: In a closed environment with a temperature of 20-25°C and a relative humidity of 40-60%, an activated carbon air purification system is used to maintain air cleanliness. Two or more operators with normal sense of smell who have passed the standard tests for sulfide, 2-aminoacetophenone and burnt odors are required to smell the volatile odors in the bottle at a distance of 5 cm from the bottle mouth within 5 seconds after opening the bottle stopper; S6: If the smell result is odorless or has the sweet smell unique to maltose syrup, it is judged to be qualified; if any one of the following smells is detected: sulfur smell, 2-aminoacetophenone smell, burnt smell, ink smell, pickle smell, soy sauce smell or indole smell, it is judged to be unqualified.

[0006] Furthermore, in S3, the temperature fluctuation of the constant temperature water bath does not exceed ±0.2°C / hour, and the distance between the stoppered conical flasks immersed in the water bath is ≥5cm.

[0007] Furthermore, in S5, the operator needs to avoid contact with perfume, tobacco, spices and irritating foods within 1 hour before the test, and the sniffing time each time should not exceed 3 seconds. The continuous testing of no more than 3 samples must be followed by a 10-minute interval.

[0008] Furthermore, the activated carbon air purification system in S5 needs to be run for 30 minutes before testing, and the iodine adsorption value of the activated carbon filter element is ≥1000 mg / g, and the replacement cycle is every 100 tests or 200 hours of cumulative operation.

[0009] Furthermore, the inner diameter of the mouth of the stoppered triangular flask in S3 is 28±1 mm, the tightening torque of the stopper is 0.5-1.0 N·m, and it needs to be dried in an oven at 150° C. for 2 hours before use to eliminate residual odor.

[0010] Furthermore, in S4, the horizontal shaking trajectory is a circular motion with a diameter of 10 cm, and touching the bottle body is prohibited during the static process after shaking.

[0011] Furthermore, the samples judged as unqualified in S6 need to be rechecked for the second time: another group of independent operators repeat steps S1-S6, and if the two results are consistent, the samples are finally judged as unqualified.

[0012] Compared with the prior art, the present invention has the following advantages: Advantages of the Invention 1. The present invention directly uses undiluted maltose syrup stock solution and combines it with 60°C constant temperature enrichment technology to fully volatilize and enrich the odor components in the closed space of the stoppered triangular flask. Experimental data show that the detection sensitivity of this method for sulfur odor reaches 0.05ppm, which is more than 50 times higher than the national standard method, and can effectively identify trace odor pollution in beer raw materials.

[0013] 2. The present invention simulates the actual scenario of syrup volatilization under heat during beer production through the design of 60±1 minute heat preservation and 5 second sniffing operation, ensuring that the detection results are highly correlated with the odor of finished beer. As shown in Table 1, the 8 groups of "unqualified" samples detected by this method all caused abnormal flavors in beer customer applications, verifying the applicability of this method to the beer industry.

[0014] 3. The present invention reduces the misjudgment rate of odor determination from more than 30% of the national standard method to less than 5% through a two-person independent sniffing review mechanism, activated carbon purification environment control, and operator odor identification training. At the same time, the weighing standard accurate to 0.01g and the temperature control accuracy of ±0.5℃ ensure the repeatability and reliability of the test results, meeting the quality control requirements of industrial production. DETAILED DESCRIPTION

[0015] The subject matter described herein will now be discussed with reference to example embodiments. It should be understood that the discussion of these embodiments is only to enable those skilled in the art to better understand and implement the subject matter described herein, and is not a limitation of the scope of protection, applicability or examples set forth in the claims. The functions and arrangements of the elements discussed can be changed without departing from the scope of protection of the contents of this specification. Various examples can omit, replace or add various processes or components as needed. For example, the described method can be performed in an order different from the described order, and various steps can be added, omitted or combined. In addition, the features described relative to some examples can also be combined in other examples.

[0016] As used herein, the term "including" and its variations represent open terms, meaning "including but not limited to". The term "based on" means "based at least in part on". The terms "one embodiment" and "an embodiment" mean "at least one embodiment". The term "another embodiment" means "at least one other embodiment". The terms "first", "second", etc. may refer to different or the same objects. Other definitions may be included below, whether explicit or implicit. Unless the context clearly indicates otherwise, the definition of a term is consistent throughout the specification.

[0017] Example 1 A method for detecting the odor of maltose syrup comprises the following steps: S1: Sample pretreatment: Stir the maltose syrup sample to be tested at 25±2℃ for 5 minutes until it is evenly mixed; S2: Weigh 200.00±0.05g of the pretreated maltose syrup sample, use an electronic balance with an accuracy of 0.01g, transfer it to a 250ml borosilicate glass stoppered flask, and immediately tighten the polytetrafluoroethylene stopper; S3: Heat the constant temperature water bath to 60.0±0.5°C. After the temperature stabilizes, immerse the stoppered flask vertically in the water bath, ensuring that the water bath liquid level is at least 2 cm higher than the sample liquid level in the flask, and keep warm for 60±1 minutes; S4: Take out the stoppered conical flask, shake it horizontally for 5 circles at a speed of 1 circle / second, and let it stand for 10±1 seconds; S5: In a closed environment with a temperature of 20-25°C and a relative humidity of 40-60%, an activated carbon air purification system is used to maintain air cleanliness. Two or more operators with normal sense of smell who have passed the standard tests for sulfide, 2-aminoacetophenone and burnt odors are required to smell the volatile odors in the bottle at a distance of 5 cm from the bottle mouth within 5 seconds after opening the bottle stopper; S6: If the smell result is odorless or has the sweet smell unique to maltose syrup, it is judged to be qualified; if any one of the following smells is detected: sulfur smell, 2-aminoacetophenone smell, burnt smell, ink smell, pickle smell, soy sauce smell or indole smell, it is judged to be unqualified.

[0018] Furthermore, in S3, the temperature fluctuation of the constant temperature water bath does not exceed ±0.2°C / hour, and the distance between the stoppered conical flasks immersed in the water bath is ≥5cm.

[0019] Furthermore, in S5, the operator needs to avoid contact with perfume, tobacco, spices and irritating foods within 1 hour before the test, and the sniffing time each time should not exceed 3 seconds. The continuous testing of no more than 3 samples must be followed by a 10-minute interval.

[0020] Furthermore, the activated carbon air purification system in S5 needs to be run for 30 minutes before testing, and the iodine adsorption value of the activated carbon filter element is ≥1000 mg / g, and the replacement cycle is every 100 tests or 200 hours of cumulative operation.

[0021] Furthermore, the inner diameter of the mouth of the stoppered triangular flask in S3 is 28±1 mm, the tightening torque of the stopper is 0.5-1.0 N·m, and it needs to be dried in an oven at 150° C. for 2 hours before use to eliminate residual odor.

[0022] Furthermore, in S4, the horizontal shaking trajectory is a circular motion with a diameter of 10 cm, and touching the bottle body is prohibited during the static process after shaking.

[0023] Furthermore, the samples judged as unqualified in S6 need to be rechecked for the second time: another group of independent operators repeat steps S1-S6, and if the two results are consistent, the samples are finally judged as unqualified.

[0024] The standard operating procedures and detection results of the method of the present invention were verified, and its feasibility and performance difference with the national standard method were proved.

[0025] 1 The device consists of the following: 1.1 Constant temperature water bath: temperature control accuracy ±0.5℃, equipped with liquid level scale; 1.2250ml stoppered triangular flask: made of borosilicate glass, inner diameter of bottle mouth 28±1mm, polytetrafluoroethylene stopper; 1.3 Electronic balance: range 0-500g, accuracy 0.01g; 1.4 Horizontal shaking platform: shaking speed is adjustable (1 circle / second), shaking track diameter is 10cm; 1.5 Activated carbon air purification system: particle filtration efficiency ≥99%, VOCs adsorption value ≥1000mg / g.

[0026] 2. Sample pretreatment: 2.1 Place the maltose syrup sample in a constant temperature room at 25±2℃ and stir it at 60rpm with a glass rod for 5 minutes to ensure that there is no precipitation or stratification.

[0027] 3. Weighing and loading samples: 3.1 Accurately weigh 200.00±0.05g of sample using an electronic balance, transfer to a 250ml stoppered conical flask, and tighten the stopper (torque 0.8N·m).

[0028] 4. Constant temperature enrichment: 4.1 Heat the water bath to 60.0±0.5℃. When the temperature stabilizes, immerse the stoppered flask vertically, ensuring that the water bath liquid level is at least 2cm higher than the sample liquid level in the flask. Keep warm for 60±1 minutes.

[0029] 5. Shake well and let stand: 5.1 Take out the conical flask, place it on a horizontal shaking platform, shake it horizontally for 5 circles at a speed of 1 circle / second, and then let it stand for 10±1 seconds.

[0030] 6. Olfactory detection: 6.1 In a closed room (temperature 20-25℃, humidity 40-60%) purified with activated carbon, two operators who have passed the olfactory tests for sulfide (1ppm), 2-aminoacetophenone (0.5ppm) and burnt odor (10ppm) are to smell the odor at a distance of 5cm from the bottle mouth within 5 seconds after opening the bottle stopper.

[0031] 7. Result determination: 7.1 If both operators judge that it is tasteless or has the unique sweet smell of maltose syrup, it is considered qualified; if sulfur smell, burnt smell, ink smell or other foreign smells are detected, it is considered unqualified.

[0032] The experimental results are shown in Table 1: Table 1 The method of the present invention has a 100% odor detection rate for samples 1 to 9, while the national standard method only detects samples 5 and 9, with an under-detection rate of 84.6%. The detection results of the present invention are completely consistent with the actual use effect of customers.

[0033] Example 2 Verify the effect of constant temperature water bath on odor detection and clarify the rationality of "60±0.5℃" in the claims.

[0034] The experimental design parameters are as follows: 1. Temperature gradient: 55℃, 58℃, 60℃, 62℃, 65℃; 2. Samples: Sample 1, Sample 5; 3. Other conditions: Same as Example 1.

[0035] The experimental results are shown in Table 2: Table 2 The odor detection rate is the highest (100%) at 60°C, and there is no interference from the caramel flavor; "60±0.5°C" in claim 2 covers the effective range of 58-62°C, and exceeding this range will lead to decreased sensitivity or misjudgment.

[0036] Example 3 Verify the influence of the stoppered conical flask material (borosilicate glass) and its sealing performance on the test results.

[0037] Compare containers: Borosilicate glass flask with stopper; Ordinary soda-lime glass triangular flask; PET plastic bottle.

[0038] Test samples: Sample 2 and Sample 6.

[0039] The experimental results are shown in Table 3. Table 3 "Borosilicate glass" and "polytetrafluoroethylene bottle stopper" in claim 6 are necessary technical features, and other materials cannot meet the testing requirements.

[0040] Example 4 Determine the minimum effective threshold of sample weight to support the expandable range of "m=200g" in the claim.

[0041] Sample volume gradient: 50g, 100g, 150g, 200g, 300g; Test samples: Sample 3 and Sample 7.

[0042] The experimental results are shown in Table 4. Table 4 When the sample amount is ≥100g, the odor can be stably detected (detection rate ≥80%); "m=200g" in claim 1 can be extended to 100-300g, preferably 200g.

[0043] Those skilled in the art should understand that the various embodiments disclosed above can be changed and modified in various ways without departing from the essence of the invention. Therefore, the protection scope of the present invention should be defined by the appended claims.

[0044] It should be noted that not all steps and units in the above processes are necessary, and some steps or units can be ignored according to actual needs. The execution order of each step is not fixed and can be determined as needed. The device structure described in the above embodiments can be a physical structure or a logical structure, that is, some units may be implemented by the same physical entity, or some units may be implemented by multiple physical entities, or some components in multiple independent devices may be implemented together.

[0045] The specific embodiments set forth above describe exemplary embodiments, but do not represent all embodiments that may be implemented or fall within the scope of protection of the claims. The term "exemplary" used throughout this specification means "used as an example, instance, or illustration" and does not mean "preferred" or "having advantages" over other embodiments. For the purpose of providing an understanding of the described techniques, the specific embodiments include specific details. However, these techniques may be implemented without these specific details. In some instances, in order to avoid obscuring the concepts of the described embodiments, well-known structures and devices are shown in block diagram form.

[0046] The above description of the present disclosure is provided to enable any person of ordinary skill in the art to implement or use the present disclosure. Various modifications to the present disclosure will be apparent to those of ordinary skill in the art, and the general principles defined herein may be applied to other variations without departing from the scope of protection of the present disclosure. Therefore, the present disclosure is not limited to the examples and designs described herein, but is consistent with the widest range of principles and novel features disclosed herein.

Claims

1. A method for detecting the odor of maltose syrup, characterized in that: The following steps are involved: S1: Sample pretreatment: Stir the maltose syrup sample to be tested at 25±2℃ for 5 minutes until it is evenly mixed; S2: Weigh 200.00±0.05g of the pretreated maltose syrup sample, use an electronic balance with an accuracy of 0.01g, transfer it to a 250ml borosilicate glass stoppered flask, and immediately tighten the polytetrafluoroethylene stopper; S3: Heat the constant temperature water bath to 60.0±0.5°C. After the temperature stabilizes, immerse the stoppered flask vertically in the water bath, ensuring that the water bath liquid level is at least 2 cm higher than the sample liquid level in the flask, and keep warm for 60±1 minutes; S4: Take out the stoppered conical flask, shake it horizontally for 5 circles at a speed of 1 circle / second, and let it stand for 10±1 seconds; S5: In a closed environment with a temperature of 20-25°C and a relative humidity of 40-60%, an activated carbon air purification system is used to maintain air cleanliness. Two or more operators with normal sense of smell who have passed the standard tests for sulfide, 2-aminoacetophenone and burnt odors are required to smell the volatile odors in the bottle at a distance of 5 cm from the bottle mouth within 5 seconds after opening the bottle stopper; S6: If the smell result is odorless or has the sweet smell unique to maltose syrup, it is judged to be qualified; if any one of the following smells is detected: sulfur smell, 2-aminoacetophenone smell, burnt smell, ink smell, pickle smell, soy sauce smell or indole smell, it is judged to be unqualified.

2. A method for detecting the odor of maltose syrup according to claim 1, characterized in that: In S3, the temperature fluctuation of the constant temperature water bath does not exceed ±0.2°C / hour, and the distance between the stoppered flasks immersed in the water bath is ≥5cm.

3. A method for detecting the odor of maltose syrup according to claim 1, characterized in that: In S5, the operator must avoid contact with perfume, tobacco, spices and irritating foods within 1 hour before the test, and each sniffing time must not exceed 3 seconds. Continuous testing must not exceed 3 samples and must be separated by 10 minutes.

4. The method for detecting the odor of maltose syrup according to claim 1, characterized in that: The activated carbon air purification system in S5 needs to run for 30 minutes before testing, and the iodine adsorption value of the activated carbon filter element must be ≥1000 mg / g. The replacement cycle is every 100 tests or 200 hours of cumulative running.

5. The method for detecting the odor of maltose syrup according to claim 1, characterized in that: The inner diameter of the stoppered triangular flask in S3 is 28±1 mm, the tightening torque of the stopper is 0.5-1.0 N·m, and it needs to be dried in an oven at 150° C. for 2 hours before use to eliminate residual odor.

6. The method for detecting the odor of maltose syrup according to claim 1, characterized in that: In S4, the horizontal shaking trajectory is a circular motion with a diameter of 10 cm, and the bottle body is prohibited from being touched during the static process after shaking.

7. A method for detecting the odor of maltose syrup according to claim 1, characterized in that: The samples judged as unqualified in S6 need to be re-checked: another group of independent operators repeat steps S1-S6, and if the two results are consistent, they are finally judged as unqualified.

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