Selenium-rich lactobacillus plantarum embedded particles and organic selenium-rich and high-antioxidant herb tea containing particles

Abstract

The invention relates to the technical field of herb tea processing. The invention provides selenium-rich lactobacillus plantarum embedded particles and organic selenium-rich and high-antioxidant herb tea containing the particles. The lactobacillus plantarum is lactobacillus plantarum with the preservation number of CGMCC (China General Microbiological Culture Collection Center) NO.23908. The invention further provides a preparation method of the selenium-rich lactobacillus plantarum embedded particles. According to the selenium-rich lactobacillus plantarum embedded particles obtained by the embedding technology, the survival rate of lactobacillus plantarum at a relatively high temperature can be improved; in addition, the organic selenium can play a role together with the dried tea in the tea brewing treatment, so that the nutritional ingredients of the scented tea are improved, the combination of the organic selenium and the high oxidation resistance is realized, and the health-care effect is effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of herbal tea processing, and in particular to selenium-enriched plant lactobacillus embedded particles and organic selenium-rich, high-antioxidant herbal tea containing the particles. Background Art

[0002] Herbal tea is rich in protein, vitamin A, vitamin E, vitamin B and various minerals. The characteristics and medicinal value of herbal tea are recorded in the Compendium of Materia Medica. It has the effects of clearing away heat and promoting diuresis, detoxifying and reducing swelling, soothing the liver and improving eyesight, promoting blood circulation and removing blood stasis, and regulating menstruation. Its aromatic oil has the effect of calming and regulating the nervous system.

[0003] Selenium is an indispensable trace element for the human body. It plays an important role in regulating various physiological functions of the human body. It can enhance the body's immune function, and play an anti-oxidation and free radical scavenging role. In addition, it is also an antidote for some toxic substances and can promote the discharge of toxic substances. For example, for patients with heavy metal poisoning, selenium can play a detoxifying effect.

[0004] As a probiotic closely related to humans, Lactobacillus plantarum has made a huge contribution to human health. It has a wide range of applications in food fermentation, lactic acid fermentation and medical care. Lactobacillus plantarum has the functions of inhibiting the growth of pathogens, reducing serum cholesterol levels, enhancing the body's immunity and inhibiting the formation of tumor cells.

[0005] In recent years, various herbal tea products have developed rapidly, and incorporating probiotics and trace elements into herbal tea has become a new choice for people's health food. However, due to the low content of selenium in daily diet, probiotics are highly sensitive to the external environment and often have low survival rates during use and production. Therefore, it is very necessary to obtain a herbal tea that can effectively solve the above problems. Summary of the invention

[0006] The object of the present invention is to provide a herbal tea rich in organic selenium and high in antioxidant activity. The herbal tea contains selenium-rich plant lactobacillus embedded particles obtained by the embedding technology of the present invention, and the embedded particles improve the survival rate of plant lactobacillus at a relatively high temperature; and can work together with dried tea in the process of brewing tea leaves, thereby improving the nutritional content of the herbal tea, realizing the combination of organic selenium and high antioxidant activity, and effectively improving the health care effect.

[0007] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0008] The present invention provides a method for preparing selenium-enriched plant lactobacillus embedded particles, comprising the following steps:

[0009] (1) inoculating the pre-cultured Lactobacillus plantarum with a preservation number of CGMCC NO.23908 into a selenium-enriched MRS culture medium for culture, collecting the bacterial mud after centrifugation and diluting it to obtain a selenium-enriched Lactobacillus plantarum suspension;

[0010] (2) mixing the microporous starch with the selenium-enriched plant lactobacillus suspension, and then performing an oscillation embedding treatment to obtain primary embedding particles;

[0011] (3) mixing the chitosan solution with the primary embedding particles described in step (2), stirring and then allowing to stand to obtain selenium-enriched plant lactobacillus embedding particles.

[0012] Preferably, the selenium-enriched MRS culture medium in step (1) uses water as a solvent and includes components in the following concentrations: 12-17 g / L beef extract, 13-17 g / L yeast powder, 18-22 g / L lactose, 0.7-1.2 mL / L Tween 80, 1.5-2.5 g / L anhydrous dipotassium hydrogen phosphate, 1.8-2.3 g / L anhydrous sodium acetate, 1.8-2.2 g / L diammonium hydrogen citrate, 0.1-0.3 g / L anhydrous magnesium sulfate, 0.18-0.3 g / L manganese sulfate, and 0.02-0.08 g / L sodium selenite.

[0013] Preferably, the inoculation amount of Lactobacillus plantarum in step (1) is 1-3%.

[0014] Preferably, the cell concentration of the selenium-enriched plant lactobacillus suspension is (0.8-1.2)×10 9 CFU / mL.

[0015] Preferably, the mass volume ratio of the microporous starch and the selenium-enriched plant lactobacillus suspension mixed in step (2) is (3-5) g: (90-110) mL.

[0016] Preferably, the speed of the oscillating embedding is 130-180 r / min, and the time of the oscillating embedding is 30-50 min.

[0017] Preferably, the volume-to-mass ratio of the chitosan solution mixed with the primary embedding particles in step (3) is (18-22) mL: (3-5) g.

[0018] Preferably, the stirring speed is 80-120 rpm, and the stirring time is 15-25 min.

[0019] The invention provides selenium-enriched plant lactobacillus embedded particles prepared by the preparation method.

[0020] The present invention also provides a herbal tea rich in organic selenium and high in antioxidant properties, comprising the selenium-rich plant lactobacillus embedded particles and dried tea in a mass ratio of 1:(2-4); the dried tea comprises gardenia, green tea, kudzu root and honey in a mass ratio of (2.1-2.7):(1.2-1.8):(0.2-0.8):(2.5-3.4).

[0021] The present invention also provides a method for preparing the organic selenium-rich, high antioxidant herbal tea, comprising the following steps:

[0022] The dried tea is mixed with the selenium-enriched plant lactobacillus embedded particles, and then water is added according to the material-liquid ratio of the mixture to water 1g: (40-60)mL, and the mixture is soaked to obtain the product.

[0023] Preferably, the temperature of the water is 85-95° C., and the soaking time is 3-8 min.

[0024] By adopting the above technical solution, the present invention has the following beneficial effects:

[0025] The selenium-enriched plant lactobacillus embedded particles obtained by the embedding technology of the present invention can improve the survival rate of plant lactobacillus at a relatively high temperature; and can work together with dried tea in the process of brewing tea leaves, improve the nutritional ingredients of scented tea, realize the combination of organic selenium and high antioxidant properties, and effectively improve the health care effect. The materials used in the present invention are all food grade materials, non-toxic and harmless, avoid edible dangers, and the process is relatively simple, the cost is relatively low, and industrialized production is easily realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Inoculate Lactobacillus plantarum into selenium-enriched MRS culture medium for cultivation;

[0027] Figure 2 It is a selenium-enriched Lactobacillus plantarum suspension.

[0028] Biological Deposit Description

[0029] The present invention relates to Lactobacillus plantarum HBSD09, whose taxonomic name is Lactobacillus plantarum, which was deposited in the General Microbiology Center of China Culture Collection of Microorganisms on November 15, 2021. The deposit address is the Institute of Microbiology, Chinese Academy of Sciences, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, and the deposit number is CGMCC No. 23908. DETAILED DESCRIPTION

[0030] The present invention provides a method for preparing selenium-enriched plant lactobacillus embedded particles, comprising the following steps:

[0031] (1) inoculating the pre-cultured Lactobacillus plantarum with a preservation number of CGMCC NO.23908 into a selenium-enriched MRS culture medium for culture, collecting the bacterial mud after centrifugation and diluting it to obtain a selenium-enriched Lactobacillus plantarum suspension;

[0032] (2) mixing the microporous starch with the selenium-enriched plant lactobacillus suspension, and then performing an oscillation embedding treatment to obtain primary embedding particles;

[0033] (3) mixing the chitosan solution with the primary embedding particles described in step (2), stirring and then allowing to stand to obtain selenium-enriched plant lactobacillus embedding particles.

[0034] In the present invention, first, plant lactobacillus with a deposit number of CGMCC NO.23908 is inoculated into an MRS medium for pre-culture. The MRS medium in the present invention uses water as a solvent, and preferably includes the following components in concentrations: 8-12 g / L peptone, 8-12 g / L beef extract, 3-7 g yeast extract, 18-22 g glucose, 0.8-1.1 mL / L Tween 80, 1.5-2.5 g / L anhydrous dipotassium hydrogen phosphate, 1.5-2.5 g / L anhydrous sodium acetate, 1.6-2.3 g / L diammonium hydrogen citrate, 0.1-0.4 g / L anhydrous magnesium sulfate, 0.2-0.3 g / L manganese sulfate, and 12-18 g / L agar; further preferably includes 9-11 g / L peptone, 9-11 g / L beef extract, 4-6 g / L yeast extract, 19-21 g / L glucose, 0.85-1.05mL / L Tween 80, 1.7-2.2g / L anhydrous dipotassium hydrogen phosphate, 1.8-2.1g / L anhydrous sodium acetate, 1.8-2.2g / L diammonium hydrogen citrate, 0.15-0.3g / L anhydrous magnesium sulfate, 0.22-0.27g / L manganese sulfate and 13-17g / L agar; further preferably including 10g / L peptone, 10g / L beef extract, 5g / L yeast extract, 20g / L glucose, 1mL / L Tween 80, 2g / L anhydrous dipotassium hydrogen phosphate, 2g / L anhydrous sodium acetate, 2g / L diammonium hydrogen citrate, 0.2g / L anhydrous magnesium sulfate, 0.25g / L manganese sulfate and 15g / L agar. The pH value of the MRS medium in the present invention is preferably 6.0-6.6, further preferably 6.1-6.5, further preferably 6.2-6.4. In the present invention, the pre-culture time is preferably 20-30h, further preferably 22-26h, further preferably 24h; the pre-culture temperature is preferably 25-32°C, further preferably 27-31°C, further preferably 30°C.

[0035] In the present invention, after pre-culture, plant lactobacillus with good growth potential is selected and inoculated into selenium-enriched MRS culture medium for culture. The selenium-enriched MRS culture medium in the present invention uses water as a solvent, and preferably includes the following components in concentrations: 12-17g / L beef extract, 13-17g / L yeast powder, 18-22g / L lactose, 0.7-1.2mL / L Tween 80, 1.5-2.5g / L anhydrous dipotassium hydrogen phosphate, 1.8-2.3g / L anhydrous sodium acetate, 1.8-2.2g / L diammonium hydrogen citrate, 0.1-0.3g / L anhydrous magnesium sulfate, 0.18-0.3g / L manganese sulfate, 0.02-0.08g / L sodium selenite; further preferably includes 13-16g / L beef extract, 14-16g / L yeast powder, 19-21g / L lactose, 0. 9-1.1mL / L Tween 80, 1.8-2.2g / L anhydrous dipotassium hydrogen phosphate, 1.9-2.1g / L anhydrous sodium acetate, 1.9-2.1g / L diammonium hydrogen citrate, 0.15-0.25g / L anhydrous magnesium sulfate, 0.22-0.27g / L manganese sulfate, 0.04-0.07g / L sodium selenite; further preferably including 15g / L beef extract, 15g / L yeast powder, 20g / L lactose, 1mL / L Tween 80, 2g / L anhydrous dipotassium hydrogen phosphate, 2g / L anhydrous sodium acetate, 2g / L diammonium hydrogen citrate, 0.2g / L anhydrous magnesium sulfate, 0.25g / L manganese sulfate, 0.06g / L sodium selenite. In the present invention, the inoculation amount of the plant lactobacillus is preferably 1-3%, further preferably 1.5-2.5%, and further preferably 2%; the culture time is preferably 32-38h, further preferably 34-37h, and further preferably 36h; the culture temperature is preferably 28-32°C, further preferably 29-31°C, and further preferably 30°C.

[0036] In the present invention, after the cultivation is completed, the supernatant is centrifuged and decanted, and then washed with physiological saline and the bacterial mud is collected, and then diluted to obtain a selenium-enriched plant lactobacillus suspension. The centrifugal speed in the present invention is preferably 3500-4300rpm, further preferably 3800-4100rpm, and further preferably 4000rpm; the centrifugal time is preferably 15-25min, further preferably 18-22min, and further preferably 20min; the centrifugal temperature is preferably 2-6°C, further preferably 3-5°C, and further preferably 4°C. The cell concentration of the selenium-enriched plant lactobacillus suspension in the present invention is preferably (0.8-1.2)×10 9 CFU / mL, further preferably (0.9-1.1)×10 9 CFU / mL, and more preferably 1.0×10 9 CFU / mL.

[0037] In the present invention, microporous starch is mixed with a selenium-enriched plant lactobacillus suspension, and then subjected to an oscillation embedding treatment to obtain primary embedded particles. The mass volume ratio of the microporous starch and the selenium-enriched plant lactobacillus suspension mixed in the present invention is preferably (3-5) g: (90-110) mL, further preferably (3.5-4.5) g: (95-105) mL, and further preferably 4 g: 100 mL; the speed of the oscillation embedding is preferably 130-180 r / min, further preferably 140-160 r / min, and further preferably 150 r / min; the time of the oscillation embedding is preferably 30-50 min, further preferably 35-45 min, and further preferably 40 min; the temperature of the oscillation embedding is preferably 18-25 ° C, further preferably 19-22 ° C, and further preferably 20 ° C. The pH value of the microporous starch in the present invention is preferably 5.7-6.2, further preferably 5.8-6.1, and further preferably 6.0. In the present invention, the primary embedded particles are obtained by standing for a period of time after the shaking embedding treatment, and the standing time is preferably 8-13 minutes, more preferably 9-12 minutes, and even more preferably 10 minutes.

[0038] In the present invention, the chitosan solution is mixed with the primary embedding particles, stirred and then allowed to stand to obtain selenium-enriched plant lactobacillus embedded particles. The volume mass ratio of the chitosan solution mixed with the primary embedding particles in the present invention is preferably (18-22) mL: (3-5) g, further preferably (19-21) mL: (3.5-4.5) g, and further preferably 20 mL: 4 g. The stirring speed in the present invention is preferably 80-120 rpm, further preferably 90-110 rpm, and further preferably 100 rpm; the stirring time is preferably 15-25 min, further preferably 18-22 min, and further preferably 20 min; the standing time is preferably 50-70 min, further preferably 55-65 min, and further preferably 60 min.

[0039] The invention also provides selenium-enriched plant lactobacillus embedded particles prepared by the preparation method.

[0040] The present invention also provides an organic selenium-rich, high antioxidant herbal tea, comprising the selenium-rich plant lactobacillus embedded particles and dried tea. The mass ratio of the selenium-rich plant lactobacillus embedded particles to the dried tea in the present invention is preferably 1:(2-4), further preferably 1:(2.5-3.5), and further preferably 1:3.

[0041] In the present invention, the dried tea comprises gardenia, green tea, kudzu root and honey, and the mass ratio of gardenia, green tea, kudzu root and honey is preferably (2.1-2.7):(1.2-1.8):(0.2-0.8):(2.5-3.4), further preferably (2.3-2.6):(1.4-1.6):(0.3-0.7):(2.7-3.2), and further preferably 2.5:1.5:0.5:3.

[0042] The present invention also provides a method for preparing the organic selenium-rich, high antioxidant herbal tea, comprising the following steps: mixing dried tea with selenium-rich plant lactobacillus embedded particles, then adding water according to a material-liquid ratio of 1 g: (40-60) mL of the mixture to water, and soaking to obtain the tea.

[0043] In the present invention, firstly, dried tea and selenium-enriched plant lactobacillus embedded particles are mixed to obtain a mixture, and then water is added to the mixture, wherein the solid-liquid ratio of the mixture to water is preferably 1 g:(40-60) mL, further preferably 1 g:(45-55) mL, and further preferably 1 g:50 mL. The temperature of the water in the present invention is preferably 85-95° C., further preferably 88-92° C., and further preferably 90° C.; the soaking time is preferably 3-8 min, further preferably 4-6 min, and further preferably 5 min.

[0044] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0045] Example 1

[0046] A selenium-enriched Lactobacillus plantarum embedded particle, the preparation method is as follows:

[0047] (1) 1 mL of Lactobacillus plantarum stock solution with a preservation number of CGMCC NO.23908 was inoculated into 100 mL of MRS medium (with distilled water as solvent, 10 g / L peptone, 10 g / L beef extract, 5 g / L yeast extract, 20 g / L glucose, 1 mL / L Tween 80, 2 g / L anhydrous dipotassium hydrogen phosphate, 2 g / L anhydrous sodium acetate, 2 g / L diammonium hydrogen citrate, 0.2 g / L anhydrous magnesium sulfate, 0.25 g / L manganese sulfate and 15 g / L agar; pH 6.2), and cultured at 30° C. for 24 hours. Then, a bacterial colony with good growth potential was selected and inoculated into selenium-enriched MRS culture solution (with distilled water as solvent, 15 g / L agar) at an inoculum size of 2%. / L beef extract, 15g / L yeast powder, 20g / L lactose, 1mL / L Tween 80, 2g / L anhydrous dipotassium hydrogen phosphate, 2g / L anhydrous sodium acetate, 2g / L diammonium hydrogen citrate, 0.2g / L anhydrous magnesium sulfate, 0.25g / L manganese sulfate, 0.06g / L sodium selenite; pH 6.2), cultured at 30°C for 36 hours, then centrifuged at 4°C, 4000rpm for 20min, the supernatant was poured off, and then washed three times with 0.85% saline, the bacterial sludge was collected and diluted to obtain a cell concentration of 1.0×10 9 CFU / mL of selenium-enriched Lactobacillus plantarum suspension;

[0048] (2) mixing microporous starch with a pH value of 6 with a selenium-enriched plant lactobacillus suspension in a mass volume ratio of 4 g:100 mL, performing an embedding treatment at 20° C. and 150 r / min for 40 min, then collecting the particles after standing for 10 min, and washing them with sterile water with a pH value of 4 to obtain primary embedded particles;

[0049] (3) Weigh 0.4 g of chitosan solid and add it to 90 mL of distilled water, add 0.4 mL of glacial acetic acid to assist dissolution, then add distilled water to make the volume 100 mL, and add 1 mol / L sodium hydroxide solution to adjust the pH of the solution to 5.4 to obtain a chitosan solution;

[0050] (4) The chitosan solution was mixed with the primary encapsulation particles at a volume mass ratio of 20 mL:4 g, stirred at 100 rpm for 20 min, and then allowed to stand for 60 min for full coating, thereby obtaining selenium-enriched plant lactobacillus encapsulation particles.

[0051] Example 2

[0052] A selenium-enriched Lactobacillus plantarum embedded particle, the preparation method is as follows:

[0053] (1) 1 mL of Lactobacillus plantarum stock solution with a preservation number of CGMCC NO.23908 was inoculated into 100 mL of MRS medium (with distilled water as solvent, 8 g / L peptone, 12 g / L beef extract, 3 g / L yeast extract, 18 g / L glucose, 0.8 mL / L Tween 80, 1.5 g / L anhydrous dipotassium hydrogen phosphate, 1.5 g / L anhydrous sodium acetate, 1.6 g / L diammonium hydrogen citrate, 0.1 g / L anhydrous magnesium sulfate, 0.2 g / L manganese sulfate and 12 g / L agar; pH 6.2), and cultured at 28° C. for 20 hours. Then, a bacterial colony with good growth potential was selected and inoculated into selenium-enriched MRS culture solution (with distilled water as solvent, 12 g / L The cells were incubated at 28°C for 32 hours, then centrifuged at 3°C ​​and 3500 rpm for 25 minutes, the supernatant was removed, and the cells were washed three times with 0.85% saline solution. The bacterial sludge was collected and diluted to obtain a cell concentration of 0.8×10 9 CFU / mL of selenium-enriched Lactobacillus plantarum suspension;

[0054] (2) mixing microporous starch with a pH value of 6 with a selenium-enriched plant lactobacillus suspension in a mass volume ratio of 5 g:90 mL, and performing an embedding treatment at 18° C. and 130 r / min for 50 min, then collecting the particles after standing for 8 min, and washing them with sterile water at pH=4 to obtain primary embedded particles;

[0055] (3) Weigh 0.4 g of chitosan solid and add it to 90 mL of distilled water, add 0.4 mL of glacial acetic acid to assist dissolution, then add distilled water to make the volume 100 mL, and add 1 mol / L sodium hydroxide solution to adjust the pH of the solution to 5.4 to obtain a chitosan solution;

[0056] (4) The chitosan solution and the primary encapsulation particles were mixed in a volume mass ratio of 18 mL:3 g, stirred at 120 rpm for 15 min, and then allowed to stand for 50 min for full coating, thereby obtaining selenium-enriched plant lactobacillus encapsulation particles.

[0057] Example 3

[0058] A selenium-enriched Lactobacillus plantarum embedded particle, the preparation method is as follows:

[0059] (1) 1 mL of Lactobacillus plantarum stock solution with a preservation number of CGMCC NO.23908 was inoculated into 100 mL of MRS medium (with distilled water as solvent, 12 g / L peptone, 8 g / L beef extract, 7 g / L yeast extract, 22 g / L glucose, 1.1 mL / L Tween 80, 2.5 g / L anhydrous dipotassium hydrogen phosphate, 2.5 g / L anhydrous sodium acetate, 2.3 g / L diammonium hydrogen citrate, 0.4 g / L anhydrous magnesium sulfate, 0.3 g / L manganese sulfate and 18 g / L agar; pH 6.2), and cultured at 30° C. for 30 hours. Then, a bacterial colony with good growth potential was selected and inoculated into selenium-enriched MRS culture solution (with distilled water as solvent, 17 g / L The cells were incubated at 32°C for 38 hours, then centrifuged at 6°C and 4300 rpm for 15 min, the supernatant was removed, and the cells were washed three times with 0.85% saline solution. The bacterial sludge was collected and diluted to obtain a cell concentration of 1.2×10 9 CFU / mL of selenium-enriched Lactobacillus plantarum suspension;

[0060] (2) mixing microporous starch with a pH value of 6 with a selenium-enriched plant lactobacillus suspension in a mass volume ratio of 3 g:110 mL, and performing an embedding treatment at 25° C. and 180 r / min for 30 min, then collecting the particles after standing for 13 min, and washing them with sterile water with a pH value of 4 to obtain primary embedded particles;

[0061] (3) Weigh 0.4 g of chitosan solid and add it to 90 mL of distilled water, add 0.4 mL of glacial acetic acid to assist dissolution, then add distilled water to make the volume 100 mL, and add 1 mol / L sodium hydroxide solution to adjust the pH of the solution to 5.4 to obtain a chitosan solution;

[0062] (4) The chitosan solution was mixed with the primary encapsulation particles at a volume mass ratio of 22 mL:3 g, stirred at 80 rpm for 25 min, and then allowed to stand for 70 min for full coating, thereby obtaining selenium-enriched plant lactobacillus encapsulation particles.

[0063] Example 4

[0064] A herbal tea rich in organic selenium and high in antioxidant properties, the preparation method of which is as follows:

[0065] Dried gardenia, green tea, dried kudzu root and honey were mixed in a mass ratio of 2.5:1.5:0.5:3 to obtain dried tea, and the dried tea was mixed with the selenium-enriched plant lactobacillus embedded particles prepared in Example 1 in a mass ratio of 1:3, and then 90°C hot water was added in a solid-liquid ratio of the mixture to hot water of 1 g:50 mL, and the mixture was soaked for 5 minutes.

[0066] Example 5

[0067] A herbal tea rich in organic selenium and high in antioxidant properties, the preparation method of which is as follows:

[0068] Dried gardenia, green tea, dried kudzu root and honey were mixed in a mass ratio of 2.1:1.2:0.2:2.5 to obtain dried tea, and the dried tea was mixed with the selenium-enriched plant lactobacillus embedded particles prepared in Example 2 in a mass ratio of 1:2, and then 95°C hot water was added in a solid-liquid ratio of the mixture to hot water of 1 g:40 mL, and the mixture was soaked for 3 minutes.

[0069] Example 6

[0070] A herbal tea rich in organic selenium and high in antioxidant properties, the preparation method of which is as follows:

[0071] Dried gardenia, green tea, dried kudzu root and honey were mixed in a mass ratio of 2.7:1.8:0.2:3.4 to obtain dried tea, and the dried tea was mixed with the selenium-enriched plant lactobacillus embedded particles prepared in Example 3 in a mass ratio of 1:4, and then 85°C hot water was added in a solid-liquid ratio of the mixture to hot water of 1 g:60 mL, and the mixture was soaked for 8 minutes.

[0072] Test Example 1

[0073] Take 1mL of the mesh plant lactobacillus stock solution with the deposit number of CGMCC No.23908 and inoculate it into 100mL of MRS medium (MRS medium: peptone 10g, beef extract 10g, yeast extract 5g, glucose 20g, Tween 80 1.0mL, dipotassium hydrogen phosphate (anhydrous) 2g, sodium acetate (anhydrous) 2g, diammonium hydrogen citrate 2g, magnesium sulfate (anhydrous) 0.2g, manganese sulfate 0.25g, agar 15g, distilled water 1000mL, pH 6.2-6.4), and culture at 30°C for 24 hours. Pick the bacteria with better growth and inoculate them into 100mL of improved selenium-enriched MRS culture medium (15g beef extract, 15g yeast powder, 20g lactose, 1.0mL Tween 80, 2g dipotassium hydrogen phosphate (anhydrous), 2g sodium acetate (anhydrous), 2g diammonium hydrogen citrate, 0.2g magnesium sulfate (anhydrous), 0.25g manganese sulfate, 0.06g sodium selenite, 1000mL distilled water, ph6.2-6.4), and culture at 30℃ for 36 hours. Centrifuge at 4℃ and 4000rpm for 20 minutes, pour off the supernatant, and then wash repeatedly with 0.85% saline three times to obtain selenium-enriched bacterial mud. Use the concentration gradient dilution method to dilute the bacterial mud into a bacterial suspension, and the cell concentration of the bacterial suspension is 10 9 CFU / mL, for future use.

[0074] Microporous starch primary embedding: According to the ratio of 4g microporous starch to 100mL of Lactobacillus plantarum suspension, add microporous starch to a triangular flask containing Lactobacillus plantarum suspension and place it in a shaking incubator. Shake and embed the sample for 40 minutes at 20°C and 150r / min. After standing for 10 minutes, collect the microparticles and wash them several times with sterile water at pH=4 to obtain primary embedding particles.

[0075] Chitosan secondary embedding: weigh 0.4g chitosan solid and add it to 90ml distilled water, add 0.4ml glacial acetic acid to assist dissolution, then add distilled water to make up to 100ml, add 1mol / l sodium hydroxide solution to adjust the solution pH to 5.0-6.0; take 20mL chitosan solution and mix it thoroughly with 4g primary embedding particles, stir at 100rmp for 20min, let it stand for 60min to allow the small particles to be fully coated, filter and collect the microparticles after secondary embedding, which are selenium-enriched plant lactobacillus embedded particles.

[0076] The obtained selenium-enriched Lactobacillus plantarum embedded particles were placed in a constant temperature drying oven, dried at 60°C for three hours, then the product was taken out and ground into powder for later use.

[0077] (I) Embedding survival rate

[0078] The Lactobacillus plantarum suspension was used as the control group, and the selenium-enriched Lactobacillus plantarum embedded particles were used as the experimental group. The suspensions were diluted and spread, and after culturing for 48 hours under the same conditions, the colony numbers on the control group and experimental group plates were counted, and the embedding rate was calculated.

[0079] Embedding survival rate = number of colonies in the experimental group / number of colonies in the control group

[0080] The results showed that the survival rate of microporous starch was 49.4% after one embedding, and the survival rate of chitosan was 65.2% after two embedding. The survival rate of Lactobacillus plantarum was increased by 15.8%.

[0081] (II) Determination of embedding rate

[0082] The powdered selenium-enriched plant lactobacillus embedded particles were prepared into a suspension, centrifuged at a speed of 1500 r / min for 5 minutes, and the supernatant was recovered. The precipitate was washed twice with sterile physiological saline, and the supernatant was mixed and spread for counting.

[0083] Embedding rate = (cell concentration of original solution - cell concentration of centrifuged supernatant) / cell density of original solution × 100%.

[0084] The results showed that the embedding efficiency was 89.4%.

[0085] (III) Thermal stability test

[0086] The selenium-enriched plant lactobacillus suspension was used as the control group, and the powdered selenium-enriched plant lactobacillus embedded particles were used as the experimental group. They were immersed in 90°C hot water for 20 minutes respectively, and the viable bacterial count and survival rate of the selenium-enriched plant lactobacillus in the powder were detected.

[0087] The results showed that the live bacterial rate of selenium-enriched plant lactobacillus in the powder was 65.2%.

[0088] (IV) Gastric juice simulation experiment

[0089] With selenium-enriched plant lactobacillus suspension as the control group, 3g pepsin was dissolved in 1000mL sterile water, and the pH was adjusted to 2.0 with 1M HCI to prepare SGF (simulated gastric juice). Weigh 4g sample (powdered selenium-enriched plant lactobacillus embedded particles) and add it to 36mL SGF, place it in an incubator at 35°C and 100rpm for shaking. The number of viable plant lactobacillus was measured at 0, 10, 20, 30, and 40min respectively. The survival rate was calculated using the following formula:

[0090] Survival rate (%) = EE (%) = N / N0 × 100%

[0091] Where N is the number of cells after treatment (Log CFU / g), and N0 is the number of cells before treatment (Log CFU / g).

[0092] The results showed that the survival rate at 40 minutes was 59.8%.

[0093] (V) Intestinal fluid simulation experiment

[0094] The selenium-enriched plant lactobacillus suspension was used as the control group. After being treated in simulated gastric fluid for 60 minutes, the mixture was converted into simulated intestinal fluid, 1 mg / mL pancreatic enzyme and 4.5 mg / mL bile salts suspended in phosphate buffer were added to 36 mL of the mixture, and then the pH was adjusted to 7.4 with 0.1 M NaOH. The mixture was then periodically shaken and incubated at 35°C for 4 hours, and finally the number of viable Lactobacillus plantarum was diluted and spread to determine the final survival rate of 56.2%.

[0095] In summary, it can be seen that the technical solution of the present invention can achieve effective embedding of selenium-enriched Lactobacillus plantarum and improve the survival rate of Lactobacillus plantarum at higher temperatures.

[0096] Experimental Example 2: Sensory Effects of Herbal Tea

[0097] (I) Effects of Encapsulation on the Sensory Properties of Herbal Tea

[0098] The filter residue obtained based on Example 4 was divided into two parts, one part was normally added with selenium-enriched plant lactobacillus embedded particles as an experimental group, and the other part was not added with any substance as a control group, and then soaked in 90°C hot water for 5 minutes at a liquid-to-solid ratio of 1:50, and filtered to obtain a herbal tea extract. The herbal tea extracts of the experimental group and the control group were subjected to sensory evaluation.

[0099] The results showed that there was no difference in the color and aroma of the two extracts. Both were uniform light yellow, transparent and clear, without flocculent precipitation and stratification, without impurities and odor. The two herbal teas were tasted separately and both had a mellow taste and moderate sweetness, with very little difference.

[0100] (II) Determination of high temperature resistant phenol content and sensory evaluation

[0101] The total phenol content was tested by Folin-phenol colorimetry (FC). Draw a standard curve: accurately weigh 0.005g of gallic acid, dissolve it in pure water and dilute it to 1000mL as the standard solution for determining total phenol. Take 1, 2, 3, 4, 5, and 6mL of the standard solution respectively and dilute it to 100mL with deionized water, which is the standard solution of different concentrations of gallic acid. Accurately measure 0.5mL of gallic acid standard solution of each concentration, add 2.5mL of Folin-phenol (0.1mol / L) reagent and mix well, then add 2mL of Na2CO3 (7.5%) solution and react for 120min at 25ssd2. Pure water can be used as a blank control to measure the light absorption value of gallic acid standard solution of each concentration at a wavelength of 765nm. Each parallel is repeated 3 times to calculate the average value. The absorbance values ​​were measured to be 0.141, 0.181, 0.219, 0.265, 0.335, and 0.384, respectively. Then, a standard curve was drawn with the concentration of the gallic acid standard solution as the abscissa and the absorbance value A765 as the ordinate. The equation can be obtained from the curve: y = 0.001x + 0.0817 (R 2 =0.9886).

[0102] 1. Take green tea as a single factor: Take 1.5g of gardenia and kudzu root respectively, set five groups of green tea at 1.0g, 1.5g, 2.0g, 2.5g, and 3.0g, and brew with 300mL, 80℃ hot water for 5min. Perform sensory evaluation based on the color, aroma and taste of the tea soup and accurately measure 0.5mL of the sample solution respectively, and dilute it with the fermentation liquid: pure water = 1:4 according to the above operation. Measure the absorbance at a wavelength of 765nm, and calculate the total phenol content of the sample solution based on the standard curve of gallic acid. The results are shown in Table 1.

[0103] Table 1 Effects of different green tea dosages on total phenol content and sensory evaluation

[0104]

[0105] 2. Determination with Pueraria root as single factor: Take 1.5g of green tea and gardenia respectively, and set five groups of Pueraria root at 0.5g, 1g, 1.5g, 2g, and 2.5g. Perform sensory evaluation and determination of total phenolic content according to the above operation.

[0106] Table 2 Effects of different kudzu root dosages on total phenol content and sensory evaluation

[0107]

[0108] 3. Take gardenia as the single factor for determination: take 1.5g of green tea, 1g of kudzu root respectively, and set five groups of gardenia: 1g, 1.5g, 2g, 2.5g, and 3g. Perform sensory evaluation and determine the total phenolic content according to the above operation.

[0109] Table 3 Effects of different kudzu root dosages on total phenol content and sensory evaluation

[0110]

[0111] According to the comprehensive analysis of total phenol content and sensory evaluation, 1.5g is the optimal value in the single factor determination of green tea, 1.0g is the optimal value in the single factor determination of kudzu root, and 2.0g is the optimal value in the single factor determination of gardenia. The taste, color, and aroma of the tea soup are better and the total phenol content is higher.

[0112] Test Example 3 Evaluation of the Antioxidant Activity of Herbal Tea in Vitro

[0113] According to the comprehensive analysis of the single factor total phenol content determination and sensory evaluation, the taste, color and aroma of the tea soup were better and the total phenol content was higher when 1.5g, 2g, and 2.5g of green tea, 1g, 2g, and 2.5g of gardenia and 0.5g, 1g, and 1.5g of kudzu root were taken. Therefore, 1.5g, 2g, and 2.5g of green tea, 1g, 2g, and 2.5g of gardenia and 0.5g, 1g, and 1.5g of kudzu root were used for orthogonal experiments to determine their DPPH clearance rates.

[0114] Accurately weigh a certain amount of DPPH, and prepare a 0.04 mg / mL DPPH solution with anhydrous ethanol. Prepare and use it now. Accurately pipette 2 mL of the solution to be tested, add 2 mL of DPPH solution, mix well, and place for 30 minutes. Then, use a cuvette to measure the light absorption value at 517 nm on a spectrophotometer, and add 2 mL of anhydrous ethanol to 2 mL of the solution to be tested as a blank control. Each concentration group is measured in parallel 3 times to calculate the average value. The total DPPH light absorption value is determined as 2 mL of DPPH solution adding 2 mL of anhydrous ethanol. The blank control uses 2 mL of pure water instead of DPPH solution to measure the light absorption value A517, and VC is used as a positive control. Finally, the scavenging ability of the sample solution for DPPH free radicals is calculated according to the clearance calculation formula. VC is used as a positive control. The results are shown in Table 4.

[0115] The DPPH clearance formula is: K(%) = [1-A1 / A0] × 100%

[0116] In the formula: A1 represents the absorbance value of 2.0mL sample solution + 2.0mL DPPH solution; A0 represents the absorbance value of 2.0mL anhydrous ethanol + 2.0mL DPPH solution;

[0117] Table 4 Effects of different factors on DPPH removal rate in herbal tea

[0118]

[0119]

[0120] According to the extreme differences of the factors, the content of gardenia has the greatest impact on the DPPH clearance rate, followed by the content of green tea, and the content of kudzu root has the least impact. Analysis of the K value shows that the best combination is 2.5g of gardenia, 1.5g of green tea, and 0.5g of kudzu root. Based on the above analysis, the best experimental combination is: 2.5g of gardenia, 1.5g of green tea, and 0.5g of kudzu root. Under the best conditions, the DPPH clearance rate is 88.5%.

[0121] In summary, it can be seen that the technical solution of the present invention can be used to obtain herbal tea rich in organic selenium and high in antioxidant properties, which can achieve the combination of organic selenium and high antioxidant properties, improve the nutritional content of herbal tea, and effectively improve the health care effect.

[0122] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing selenium-enriched plant lactobacillus embedded particles, characterized in that: The steps include: (1) inoculating the pre-cultured Lactobacillus plantarum with a preservation number of CGMCC NO.23908 into a selenium-enriched MRS culture medium for culture, collecting the bacterial mud after centrifugation and diluting it to obtain a selenium-enriched Lactobacillus plantarum suspension; (2) mixing the microporous starch with the selenium-enriched plant lactobacillus suspension, and then performing an oscillation embedding treatment to obtain primary embedding particles; (3) mixing the chitosan solution with the primary embedding particles described in step (2), stirring and then allowing to stand to obtain selenium-enriched plant lactobacillus embedding particles.

2. The preparation method according to claim 1, characterized in that: The selenium-enriched MRS culture medium in step (1) uses water as a solvent and includes the following components in concentrations: 12-17 g / L beef extract, 13-17 g / L yeast powder, 18-22 g / L lactose, 0.7-1.2 mL / L Tween 80, 1.5-2.5 g / L anhydrous dipotassium hydrogen phosphate, 1.8-2.3 g / L anhydrous sodium acetate, 1.8-2.2 g / L diammonium hydrogen citrate, 0.1-0.3 g / L anhydrous magnesium sulfate, 0.18-0.3 g / L manganese sulfate, and 0.02-0.08 g / L sodium selenite.

3. The preparation method according to claim 1, characterized in that: The inoculation amount of the plant lactobacillus in step (1) is 1-3%; The cell concentration of the selenium-enriched plant lactobacillus suspension is (0.8-1.2)×10 9 CFU / mL.

4. The preparation method according to claim 1, characterized in that: The mass volume ratio of the microporous starch and the selenium-enriched plant lactobacillus suspension in step (2) is (3-5) g: (90-110) mL; The speed of the shaking embedding is 130-180 r / min, and the time of the shaking embedding is 30-50 min.

5. The preparation method according to claim 1, characterized in that: The volume mass ratio of the chitosan solution and the primary embedding particles in step (3) is (18-22) mL: (3-5) g; The stirring speed is 80-120 rpm, and the stirring time is 15-25 min.

6. Selenium-enriched Lactobacillus plantarum embedded particles obtained by the preparation method according to any one of claims 1 to 5.

7. A herbal tea rich in organic selenium and high in antioxidant properties, characterized in that: Comprising the selenium-enriched plant lactobacillus embedded particles of claim 6 and dried tea in a mass ratio of 1:(2-4); The dried tea comprises gardenia, green tea, kudzu root and honey in a mass ratio of (2.1-2.7):(1.2-1.8):(0.2-0.8):(2.5-3.4).

8. The method for preparing the organic selenium-rich, high antioxidant herbal tea according to claim 7, characterized in that: The steps include: The dried tea is mixed with the selenium-enriched plant lactobacillus embedded particles, and then water is added according to the material-liquid ratio of the mixture to water 1g: (40-60)mL, and the mixture is soaked to obtain the product.

9. The preparation method according to claim 8, characterized in that: The temperature of the water is 85-95° C., and the soaking time is 3-8 minutes.

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