Purple corn composite tea and preparation method thereof

Abstract

The invention discloses purple corn composite tea and a preparation method thereof. The purple corn flour is prepared from the following raw materials in parts by weight: 50-80 parts of purple corn, 15-35 parts of broom corn millet peel, 1-5 parts of a sweetening agent and 0.1-0.5 part of vitamin C. The purple corn is treated in a repeated freezing and thawing mode, the prepared tea drink is high in anthocyanin release speed and high in anthocyanin release proportion, the broom corn millet peel is added, anthocyanin release is better promoted, and meanwhile the content of active iron and active selenium in the tea drink is increased.

Description

Technical Field

[0001] The invention belongs to the technical field of food engineering, and particularly relates to purple corn compound tea and a preparation method thereof. Background Art

[0002] Purple corn, both cobs and kernels, are purple. Plants grow about 1.5 meters tall and mature in about 100 days. When newly formed, the kernels are a translucent ivory color, gradually turning light red as they mature, then purple as they mature, and finally purplish-black when dry. The cobs are about 10 cm long, and 1,000 kernels weigh about 120 grams. Purple corn is rich in anthocyanins, which are responsible for its red, purple, purplish-red, and blue colors. They have antioxidant and antimutagenic properties, making them potent antioxidants.

[0003] In order to make full use of the anthocyanins in purple corn, people make purple corn into tea beverages. For example, Patent 200910010934.2 discloses a purple corn tea bag and its production method, which uses purple corn husks, cobs, and silks harvested in the mature stage or purple corn male flowers harvested in the flowering stage as raw materials, which are crushed, sieved through 30-100 mesh, sterilized at high temperature, and packaged. Patent 202110970339.4 discloses a preparation method for purple corn substitute tea, which uses corn meat, corn cobs, corn leaves, and corn silk of anthocyanin-rich purple corn as raw materials; the raw materials are respectively withered using microwave equipment; after withering, they are quickly moderately rolled and pre-frozen in a cold storage; then low-temperature dried or freeze-dried; the corn meat, corn cobs, corn leaves, and corn silk are processed into substitute tea according to proportion; the microwave withering is performed with a controlled temperature of 85 degrees Celsius and a withering time of 80-120 seconds; the pre-freezing is performed at -1 to -5 degrees Celsius for 2-10 hours. Although the corn tea product prepared by the above method has a high content of anthocyanins, it is not easily released during the tea brewing process. Other nutrients in purple corn, such as active iron and active selenium, are also locked in the purple corn and are difficult to release into the tea solution. Summary of the Invention

[0004] The purpose of the present invention is to provide a purple corn compound tea and a preparation method thereof.

[0005] A purple corn compound tea is prepared from the following raw materials in weight fractions: 50-80 parts of purple corn, 15-35 parts of millet husks, 1-5 parts of sweetener, and 0.1-0.5 parts of vitamin C.

[0006] The purple corn comprises purple corn cobs, purple corn kernels and purple corn kernel husks.

[0007] The mass ratio of the purple corn cobs, purple corn kernels and purple corn kernel husks is 8:1:1.

[0008] The purple corn cobs, purple corn kernels and purple corn kernel husks are crushed, frozen at -20 to -10°C for 1 to 3 hours, restored to room temperature, and then repeatedly frozen and thawed 2 to 5 times.

[0009] The millet peel is processed as follows:

[0010] (1) Take millet husk, freeze it at -20 to -10°C for 1-3 hours, return it to room temperature, and repeat freezing and thawing 2-5 times;

[0011] (2) Immersing the millet husks treated in step (1) in a 1-3% malic acid solution for 8-24 hours;

[0012] (3) The millet husks processed in step (2) are fished out and dried.

[0013] The sweetener is one or a combination of white sugar, brown sugar, aspartame and glucose.

[0014] The preparation method of the purple corn compound tea is carried out according to the following steps:

[0015] (1) Take 50-80 parts of purple corn and 15-35 parts of broomcorn millet husk according to weight, crush the purple corn and mix them evenly with the broomcorn millet husk;

[0016] (2) sterilize instantaneously at 115° C. for 10-20 seconds in a high-pressure container, take out and dry, add 1-5 parts of sweetener and 0.1-0.5 parts of vitamin C, and mix well.

[0017] The purple corn comprises purple corn cobs, purple corn kernels and purple corn kernel husks, with the usage mass ratio being 8:1:1.

[0018] Beneficial effects of the present invention: The present invention uses a repeated freeze-thaw method to process purple corn, and the prepared tea beverage has a fast release speed and a high release ratio of anthocyanins. The addition of millet husk further promotes the release of anthocyanins and, at the same time, increases the content of active iron and active selenium in the tea beverage. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is the standard curve of cyanidin.

[0020] Figure 2 The anthocyanin content in different parts of purple corn and purple corn tea products. DETAILED DESCRIPTION

[0021] To facilitate understanding of the present invention, the present invention will be described more fully below. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0022] Example 1

[0023] A purple corn compound tea is prepared from the following raw materials in weight fractions: 65 parts of purple corn, 25 parts of millet husks, 3 parts of white sugar, and 0.3 parts of vitamin C; the purple corn comprises purple corn cobs, purple corn kernels, and purple corn husks; the mass ratio of the raw materials is 8:1:1; the purple corn cobs, purple corn kernels, and purple corn husks are crushed, frozen at -15°C for 2 hours, restored to room temperature, and repeatedly frozen and thawed three times.

[0024] The millet peel is processed as follows:

[0025] (1) Take millet peel, freeze it at -18°C for 2 h, return it to room temperature, and repeat freeze-thaw three times;

[0026] (2) The millet husks treated in step (1) were immersed in a 2% malic acid solution for 16 hours;

[0027] (3) The millet husks processed in step (2) are fished out and dried.

[0028] The preparation method of the purple corn compound tea is carried out according to the following steps:

[0029] (1) Taking 65 parts of purple corn and 25 parts of millet husks by weight, crushing the purple corn and mixing them evenly with the millet husks; the purple corn includes dried purple corn cobs, purple corn husks and purple corn silks, and the mass ratio of the purple corn cobs is 3:1:1;

[0030] (2) Sterilize instantaneously at 115°C for 15 seconds in a high-pressure container, take out and dry, add 3 parts of white sugar and 0.3 parts of vitamin C, and mix well.

[0031] Example 2

[0032] A purple corn compound tea is prepared from the following raw materials in weight fractions: 50 parts of purple corn, 15 parts of millet husks, 1 part of brown sugar, and 0.1 part of vitamin C; the purple corn comprises purple corn cobs, purple corn kernels, and purple corn husks; the mass ratio of the raw materials is 8:1:1; the purple corn cobs, purple corn kernels, and purple corn husks are crushed, frozen at -20°C for 1 hour, restored to room temperature, and repeatedly frozen and thawed twice.

[0033] The millet peel is processed as follows:

[0034] (1) Take millet husk, freeze it at -20℃ for 1 hour, return it to room temperature, and freeze-thaw it twice;

[0035] (2) The millet husks treated in step (1) were immersed in a 1% malic acid solution for 24 hours;

[0036] (3) The millet husks processed in step (2) are fished out and dried.

[0037] The preparation method of the purple corn compound tea is carried out according to the following steps:

[0038] (1) Taking 50 parts of purple corn and 15 parts of millet husks by weight, crushing the purple corn and mixing them evenly with the millet husks; the purple corn includes purple corn cobs, purple corn kernels and purple corn kernel husks, and the mass ratio of the purple corn cobs is 8:1:1;

[0039] (2) Sterilize instantaneously at 115°C for 10 seconds in a high-pressure container, take out and dry, add 1 part of brown sugar and 0.1 part of vitamin C, and mix well.

[0040] Example 3

[0041] A purple corn compound tea is prepared from the following raw materials in weight fractions: 80 parts of purple corn, 35 parts of millet husks, 1 part of aspartame, and 0.5 part of vitamin C; the purple corn comprises purple corn cobs, purple corn kernels, and purple corn husks; the usage mass ratio is 8:1:1; the purple corn cobs, purple corn kernels, and purple corn husks are crushed, frozen at -10°C for 3 hours, restored to room temperature, and repeatedly frozen and thawed 5 times.

[0042] The millet peel is processed as follows:

[0043] (1) Take millet husk, freeze it at -10°C for 3 h, return it to room temperature, and repeat freeze-thaw 4 times;

[0044] (2) The millet husks treated in step (1) were immersed in a 3% malic acid solution for 10 h;

[0045] (3) The millet husks processed in step (2) are fished out and dried.

[0046] The preparation method of the purple corn compound tea is carried out according to the following steps:

[0047] (1) Taking 80 parts of purple corn and 35 parts of millet husks by weight, crushing the purple corn and mixing them evenly with the millet husks; the purple corn includes purple corn cobs, purple corn kernels and purple corn kernel husks, and the mass ratio of the purple corn cobs is 8:1:1;

[0048] (2) Sterilize instantaneously at 115°C for 20 seconds in a high-pressure container, take out and dry, add 1 part of aspartame and 0.5 part of vitamin C, and mix well.

[0049] Comparative Example 1

[0050] A purple corn tea is prepared from the following raw materials in weight fractions: 90 parts of purple corn, 3 parts of white granulated sugar, and 0.3 parts of vitamin C; the purple corn comprises purple corn cobs, purple corn kernels, and purple corn kernel husks; the usage mass ratio is 8:1:1; the purple corn cobs, purple corn kernels, and purple corn kernel husks are crushed, frozen at -15°C for 2 hours, restored to room temperature, and repeatedly frozen and thawed three times.

[0051] The preparation method of the purple corn tea is carried out according to the following steps:

[0052] (1) Taking 90 parts by weight of purple corn; the purple corn includes purple corn cobs, purple corn kernels and purple corn kernel husks, and the mass ratio of the purple corn cobs is 3:1:1;

[0053] (2) Sterilize instantaneously at 115°C for 15 seconds in a high-pressure container, take out and dry, add 3 parts of white sugar and 0.3 parts of vitamin C, and mix well.

[0054] Comparative Example 2

[0055] The invention discloses broomcorn millet peel tea, which is prepared from the following raw materials in weight fractions: 90 parts of broomcorn millet peel, 3 parts of white granulated sugar and 0.3 part of vitamin C.

[0056] The millet peel is processed as follows:

[0057] (1) Take millet husk, freeze it at -18°C for 2 h, return it to room temperature, and repeat freeze-thaw three times;

[0058] (2) The millet husks treated in step (1) were immersed in a 2% malic acid solution for 16 hours;

[0059] (3) The millet husks processed in step (2) are fished out and dried.

[0060] The preparation method of the millet bark tea is carried out according to the following steps:

[0061] (1) Take 90 parts of millet peels according to weight;

[0062] (2) Sterilize instantaneously at 115°C for 15 seconds in a high-pressure container, take out and dry, add 3 parts of white sugar and 0.3 parts of vitamin C, and mix well.

[0063] Comparative Example 3

[0064] A purple corn compound tea is prepared from the following raw materials in weight fractions: 65 parts of purple corn, 25 parts of millet husks, 3 parts of white sugar, and 0.3 parts of vitamin C; the purple corn comprises purple corn cobs, purple corn kernels, and purple corn kernel husks; and the usage mass ratio is 8:1:1.

[0065] The purple corn cobs, purple corn kernels and purple corn kernel husks are crushed, frozen at -15°C for 2 hours, restored to room temperature, and then repeatedly frozen and thawed three times.

[0066] The millet husks were processed as follows: the millet husks were taken and frozen at -18°C for 2 hours, the temperature was restored to room temperature, and then the millet husks were repeatedly frozen and thawed for 3 times.

[0067] The preparation method of the purple corn compound tea is carried out according to the following steps:

[0068] (1) Taking 65 parts of purple corn and 25 parts of millet husks by weight, crushing the purple corn and mixing them evenly with the millet husks; the purple corn includes dried purple corn cobs, purple corn husks and purple corn silks, and the mass ratio of the purple corn cobs is 3:1:1;

[0069] (2) Sterilize instantaneously at 115°C for 15 seconds in a high-pressure container, take out and dry, add 3 parts of white sugar and 0.3 parts of vitamin C, and mix well.

[0070] Experimental Example 1:

[0071] Take 0.1g each of purple corn kernels, purple corn kernel skins, purple corn cobs, and the purple corn tea product prepared in Comparative Example 1 (take 3 samples for each sample), grind all samples into fine powder, add 2ml of 95% ethanol and 2ml of 0.1mol / L HCL, temperature: 40°C, ultrasonic for 75min, centrifuge at 8000r / min for 5min, take the supernatant into a 10ml centrifuge tube, redissolve the precipitate, extract once, and then take the supernatant into a 10ml centrifuge tube. Using cyanidin as the standard, use a microplate reader to determine the anthocyanin content of each experimental group of purple corn ( Figure 1 ).

[0072] The results are shown in Figure 2 The results showed that purple corn kernels are rich in anthocyanins, but the anthocyanin content in other parts of the plant was higher than that in the kernels. The highest content was found in the cob, at 33.63±0.517 mg / g. Purple corn tea is also quite rich in anthocyanins, even about four times higher than in some fresh blueberries.

[0073] 1 g of each tea product prepared in Examples 1-3 and Comparative Examples 1-2 (3 samples for each sample) was soaked in 20 ml of water at a constant temperature of 85°C for 8 minutes, centrifuged at 8000 rpm for 5 minutes, and the supernatant was transferred to a 50 ml centrifuge tube. The anthocyanin content of each experimental group of purple corn was determined using a microplate reader using cyanidin as a standard. The results are shown in Table 1:

[0074] Table 1

[0075]

[0076] Note: * indicates p<0.05 compared with the control group

[0077] Experimental Example 2:

[0078] 1 g of each of the tea products prepared in Examples 1-3 and Comparative Examples 1-3 (3 samples were taken for each sample), and the selenium and iron contents in the samples were detected according to the methods specified in GB5009.93-2017 and GB 5009.90-2016. The test results are shown in Table 2:

[0079] Table 2

[0080]

[0081] Note: * indicates p<0.05 compared with the control group

[0082] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A purple corn compound tea, characterized in that: The invention is prepared from the following raw materials in weight fractions: 50-80 parts of purple corn, 15-35 parts of millet husk, 1-5 parts of sweetener and 0.1-0.5 parts of vitamin C.

2. The purple corn compound tea according to claim 1, characterized in that The purple corn comprises purple corn cobs, purple corn kernels and purple corn kernel husks.

3. The purple corn compound tea according to claim 2, characterized in that The mass ratio of the purple corn cobs, purple corn kernels and purple corn kernel husks is 8:1:

1.

4. The purple corn compound tea according to claim 2, characterized in that The purple corn cobs, purple corn kernels and purple corn kernel husks are crushed, frozen at -20 to -10°C for 1 to 3 hours, restored to room temperature, and then repeatedly frozen and thawed 2 to 5 times.

5. The purple corn compound tea according to claim 1, characterized in that The millet peel is processed as follows: (1) Take millet husk, freeze it at -20 to -10°C for 1-3 hours, return it to room temperature, and repeat freezing and thawing 2-5 times; (2) Immersing the millet husks treated in step (1) in a 1-3% malic acid solution for 8-24 hours; (3) The millet husks processed in step (2) are fished out and dried.

6. The purple corn compound tea according to claim 1, characterized in that The sweetener is one or a combination of white sugar, brown sugar, aspartame and glucose.

7. The method for preparing the purple corn compound tea according to claim 1, characterized in that: Follow these steps: (1) Take 50-80 parts of purple corn and 15-35 parts of broomcorn millet husk according to weight, crush the purple corn and mix them evenly with the broomcorn millet husk; (2) sterilize instantaneously at 115° C. for 10-20 seconds in a high-pressure container, take out and dry, add 1-5 parts of sweetener and 0.1-0.5 parts of vitamin C, and mix well.

8. The method for preparing the purple corn compound tea according to claim 7, characterized in that: The purple corn comprises purple corn cobs, purple corn kernels and purple corn kernel husks, with the usage mass ratio being 8:1:1.

Images