Method for removing pesticide and heavy metal lead residues in black tea liquid

Abstract

The invention discloses a method for removing pesticide and heavy metal lead residues in black tea liquid, and belongs to the technical field of food safety. According to the method, the black tea liquid with pesticide residues is treated by using microorganisms, the pesticide residues are reduced and the heavy metal lead is removed by combining the absorption and transformation capabilities of lactobacillus plantarum JYLP-002 and pseudomonas with enzymolysis, and then the black tea liquid is separated by using a centrifugal method, so that the safe and reliable black tea liquid without pesticide residues and heavy metal lead is obtained; according to the method for removing the pesticide residues in the black tea liquid, the heavy metal lead can be effectively removed, and meanwhile active ingredients in the black tea liquid are not damaged. Meanwhile, the method has the advantages of no toxicity, no residue, no secondary pollution and the like, and is low in cost, high in safety and suitable for industrial large-scale application.

Description

Technical Field

[0001] The invention relates to the technical field of food safety and the field of cosmetics, and in particular to a method for removing pesticide and heavy metal lead residues in black tea liquid. Background Art

[0002] Pesticide residues are mainly caused by factors such as artificial spraying, soil residues, and water residues. Pesticides applied through soil or water generally remain in natural products. Black tea is a fully fermented tea. Fresh leaves may still contain pesticides and heavy metal residues after a series of complex processing techniques. Among them, organophosphorus pesticides, pyrethroid pesticides, and imidacloprid are more common, and lead is the most representative heavy metal residue in black tea.

[0003] Tea (extract) liquid can be used as one of the important raw materials for cosmetics. Its pesticide residues will affect its subsequent processing. Even if it contains a large amount of pesticides or heavy metal residues, it may cause chemical reactions, resulting in adverse effects. Therefore, it is very necessary to remove pesticide residues and heavy metal residues in cosmetics.

[0004] The main method reported so far to remove pesticide residues from tea is to wash the fresh leaves and then to use O 3 However, there are still some defects such as taste retention, and there is basically no method to remove pesticide residues in tea liquid. In order to use black tea liquid as a raw material for the cosmetics industry more safely, it is necessary to remove pesticide residues and other harmful factors as much as possible. Therefore, a method that can effectively remove residual pesticides and lead in tea liquid is urgently needed. Summary of the invention

[0005] The purpose of the present invention is to solve the problem of pesticide residues in black tea liquid in the prior art and to provide a method for removing pesticide and heavy metal lead residues in black tea liquid.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows: a method for removing pesticide and heavy metal lead residues in black tea liquid, comprising the following steps:

[0007] S1, enzymatic hydrolysis: under the condition of pH 6.5-7.5, add enzyme to black tea liquid, the mass ratio of enzyme to black tea liquid is 1:1000-1:20000, react at 30-60°C for 2-12 hours, and obtain enzymatic hydrolysis product of black tea liquid;

[0008] S2, enzyme inactivation: the enzymatic hydrolyzate of the black tea liquid is inactivated and sterilized at 80°C to 90°C for 30 to 120 minutes;

[0009] S3. Strain treatment: add the strain to the sterilized black tea liquid enzymatic hydrolysate, the mass ratio of the strain to the black tea liquid enzymatic hydrolysate is 1:50-1:1000, the action temperature is 28°C-32°C, the rotation speed is 120-180rpm, the time is 24-72 hours, and then the obtained liquid is centrifuged and filtered to obtain clarified black tea liquid.

[0010] Preferably, the preparation method of the black tea liquid in S1 is: add deionized water to black tea and then perform ultrasonic treatment, the mass ratio of black tea to deionized water is 1:30, react in a shaker at 30°C and 180rpm for 48 hours, and centrifuge or filter to obtain the black tea liquid.

[0011] Preferably, the enzyme in S1 is one or both of organophosphorus hydrolase and pyrazine.

[0012] Preferably, the enzymes are organophosphorus hydrolase and pyrazine in a mass ratio of 1:1.

[0013] Preferably, the strain in S3 is one or both of Lactobacillus plantarum JYLP-002 and Pseudomonas.

[0014] More preferably, the strains are Lactobacillus plantarum JYLP-002 and Pseudomonas, with a mass ratio of 1:1.

[0015] The beneficial effects of the present invention are:

[0016] 1. The present invention uses microorganisms to treat black tea liquid with pesticide residues, utilizes the absorption and conversion capabilities of Lactobacillus plantarum JYLP-002 and Pseudomonas aeruginosa combined with enzymatic hydrolysis to reduce pesticide residues and remove heavy metal lead, and then separates them by centrifugation to obtain safe and reliable black tea liquid without pesticide residues and heavy metal lead; and the method for removing pesticide residues and effectively removing heavy metal lead in black tea liquid provided by the invention does not destroy the active ingredients in the black tea liquid.

[0017] 2. The present invention removes pesticide and heavy metal lead residues in black tea liquid through the combined action of enzymolysis and microorganisms. This method has the advantages of being non-toxic, residue-free, and free of secondary pollution. It is low-cost, highly safe, and suitable for large-scale industrial applications. DETAILED DESCRIPTION

[0018] The present invention will be further described below in conjunction with specific embodiments.

[0019] In Examples 1-3 of the present invention, the detection of pesticide, heavy metal lead residue content and tea polyphenol content in black tea liquid is specifically referred to the following method:

[0020] With reference to NY / T 761-2008 “Determination of organophosphorus, organochlorine, pyrethroid and carbamate pesticide residues in vegetables and fruits”, the gas chromatography was used to determine the residues of isocarbophos, chlorcyhalothrin and bifenthrin in black tea liquid; with reference to GB 23200.13-2016 “National Food Safety Standard - Determination of 448 Pesticides and Related Chemical Residues in Tea - Liquid Chromatography-Mass Spectrometry”, the liquid chromatography-mass spectrometry was used to determine the content of indoxacarb in black tea liquid.

[0021] The lead content was determined by referring to the inductively coupled plasma optical emission spectrometry method in accordance with DB37 / T 4494-2022 "Determination of major heavy metal elements in marine organisms by inductively coupled plasma optical emission spectrometry".

[0022] The content of tea polyphenols was determined by referring to the spectrophotometer method in GB / T8313-2018 "Determination of Tea Polyphenols and Catechins in Tea".

[0023] Lactobacillus plantarum JYLP-002 was purchased from Shandong Zhongke Jiayi Bioengineering Co., Ltd.; Pseudomonas was purchased from Ningbo Testo Biotechnology Co., Ltd.

[0024] Example 1 Preparation of black tea liquid

[0025] After adding deionized water to black tea, ultrasonic treatment was performed. The mass ratio of black tea to deionized water was 1:30. The mixture was reacted in a shaker at 30°C and 180 rpm for 48 hours. The black tea liquid was retained by centrifugation or filtration and then filtered through a membrane for storage. The pesticide, heavy metal lead residue and tea polyphenol content in the black tea liquid were tested. The results are shown in Table 1.

[0026] Table 1 Detection results of pesticide residues and tea polyphenols content in black tea liquid

[0027]

[0028] Example 2 Effect of enzyme selection during comprehensive treatment on pesticide and heavy metal lead residues in black tea liquid

[0029] 1. At pH 7.0 and 40°C, different enzymes were added to the black tea liquid prepared in Example 1 (the types of enzymes added are detailed in Table 2, including the addition of organophosphatase, pyrazine, and the combination of organophosphatase and pyrazine; and no enzyme was set as a control), the mass ratio of the added enzyme to the black tea liquid was 1:10000, and the mixture was stirred and hydrolyzed for 5 hours;

[0030] 2. Inactivate enzyme: Treat the enzymatic hydrolyzate of black tea at 80°C for 60 minutes;

[0031] 3. Strain treatment: After the black tea liquid is cooled, add Lactobacillus plantarum JYLP-002, the mass ratio of the strain to the black tea liquid is 1:1000, and culture at 30°C and 180rpm for 48 hours;

[0032] 4. Post-treatment: The obtained liquid is centrifuged and filtered through a membrane to obtain clarified black tea liquid.

[0033] 5. The obtained clear black tea liquid was tested for pesticide, heavy metal lead residue content and tea polyphenol content. The results are shown in Table 2.

[0034] Table 2 Effect of enzyme selection on pesticide residues and tea polyphenols content in comprehensive treatment process

[0035]

[0036] Note: “ND” means the concentration is lower than the minimum detection concentration of 0.001 μg / mL

[0037] Combining the results of Table 1 and Table 2, it can be clearly seen that the two enzymes effectively remove pesticide residues in black tea liquid, and have no destructive effect on the active ingredients in black tea liquid. Among them, the best removal effect of pesticides can be achieved when organic phosphatase and pyrazolase (1:1) are used in combination.

[0038] Example 3 Effect of bacteria selection in comprehensive treatment process on pesticide and heavy metal lead residues in black tea liquid

[0039] 1. Enzymatic hydrolysis: under the conditions of pH 7.0 and 40° C., add organophosphatase and pyrazine (1:1) to the black tea liquid prepared in Example 1, with the mass ratio of enzyme to black tea liquid being 1:10000, stir and hydrolyze for 5 hours;

[0040] 2. Inactivate enzyme: Treat the enzymatic hydrolyzate of black tea at 80°C for 60 minutes;

[0041] 3. Strain treatment: After the black tea liquid was cooled, different strains were added (see Table 3 for the strain types, including the addition of Lactobacillus plantarum JYLP-002, Pseudomonas, and the combination of Lactobacillus plantarum JYLP-002 and Pseudomonas; and a control without strain was set at the same time), the mass volume ratio of the strain to the black tea liquid was 1:1000, and the culture was carried out at 30°C and 180rpm for 48 hours;

[0042] 4. Post-treatment: centrifuge the liquid obtained after strain treatment and filter it through a membrane to obtain clarified black tea liquid;

[0043] 5. The obtained clear black tea liquid was tested for pesticide, heavy metal lead residue content and tea polyphenol content. The results are shown in Table 3.

[0044] Table 3 Detection results of pesticide, lead residue and tea polyphenol content in black tea liquid by strain selection during comprehensive treatment

[0045]

[0046] Note: “ND” means the concentration is lower than the minimum detection concentration of 0.001 μg / mL

[0047] The results of Table 1 and Table 3 show that adding strains can significantly reduce the pesticide residues in black tea liquid, and it can be seen that Pseudomonas has a stronger ability to remove isocarbophos, indoxacarb, cyhalothrin, and bifenthrin, but has no obvious effect on heavy metal lead; while Lactobacillus plantarum JYLP-002 has a significant removal effect on heavy metal lead. Adding strains has no destructive effect on the active ingredients of black tea liquid.

[0048] Based on the results of Example 1, Example 2 and Example 3, it can be obtained that after enzymatic treatment with organophosphatase and pyrimethamine (1:1), adding Lactobacillus plantarum JYLP-002 and Pseudomonas (1:1) to treat the black tea liquid, the optimal method of the present invention is obtained. The method provided by the present invention can efficiently remove organophosphorus pesticides and pyrethroid pesticides in black tea liquid, and can effectively remove heavy metal lead, and has no obvious effect on the content of the main functional active ingredients of the black tea liquid.

[0049] The description of the present invention is considered to be illustrative rather than restrictive. Based on the present invention, those skilled in the art can make some substitutions and modifications to some of the technical features according to the disclosed technical content without creative labor, all of which are within the protection scope of the present invention.

Claims

1. A method for removing pesticide and heavy metal lead residues in black tea liquid, characterized in that: The following steps are involved: S1, enzymatic hydrolysis: under the condition of pH 6.5-7.5, add enzyme to black tea liquid, the mass ratio of enzyme to black tea liquid is 1:1000-1:20000, react at 30-60°C for 2-12 hours, and obtain enzymatic hydrolysis product of black tea liquid; S2, enzyme inactivation: the enzymatic hydrolyzate of the black tea liquid is inactivated and sterilized at 80°C to 90°C for 30 to 120 minutes; S3. Strain treatment: add the strain to the sterilized black tea liquid enzymatic hydrolysate, the mass ratio of the strain to the black tea liquid enzymatic hydrolysate is 1:50-1:1000, the action temperature is 28°C-32°C, the rotation speed is 120-180rpm, the time is 24-72 hours, and then the obtained liquid is centrifuged and filtered to obtain clarified black tea liquid.

2. The method according to claim 1, characterized in that The preparation method of the black tea liquid in S1 is: add deionized water to black tea and then perform ultrasonic treatment, the mass ratio of black tea to deionized water is 1:30, react in a shaker at 30°C and 180rpm for 48 hours, and centrifuge or filter to obtain the black tea liquid.

3. The method according to claim 1, characterized in that The enzyme in S1 is one or two of organophosphorus hydrolase and pyrazine.

4. The method according to claim 3, characterized in that The enzymes are organophosphorus hydrolase and pyrazine, with a mass ratio of 1:

1.

5. The method according to claim 1, characterized in that The strain in S3 is one or both of Lactobacillus plantarum JYLP-002 and Pseudomonas.

6. The method according to claim 5, characterized in that The strains are Lactobacillus plantarum JYLP-002 and Pseudomonas, with a mass ratio of 1:1.

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