Yoghourt capable of reducing blood sugar and preparation method thereof

Abstract

The invention belongs to the field of food, and particularly relates to yoghourt capable of reducing blood sugar and a preparation method of the yoghourt. The preparation method comprises the following steps: adding mulberry leaf powder and / or a mulberry leaf water extract, mulberry powder, mogroside and radix puerariae powder into milk, uniformly stirring, and adding yoghourt zymophyte powder; according to the preparation method disclosed by the invention, monosaccharides such as fructose and glucose in the mulberry powder and the mogroside are removed by utilizing the growth of microorganisms such as lactic acid bacteria, so that the final yoghourt almost does not contain free monosaccharides, the alpha-glucosidase inhibitory activity of the final yoghourt is not influenced, and the yoghourt is suitable for being taken by people with hyperglycemia.

Description

Technical Field

[0001] The invention belongs to the field of food, and in particular relates to yogurt for lowering blood sugar and a preparation method thereof. Background Art

[0002] Early prevention of people with high blood sugar is the key to preventing diabetes and its complications. Many people with high blood sugar have elevated blood sugar after meals in the early stages, and the main reason for the elevated blood sugar after meals is insufficient insulin secretion. The intense blood sugar reaction after a meal means that blood sugar rises rapidly and sharply, and at this time the body needs to quickly secrete a large amount of insulin to help lower blood sugar. Insulin is the only hormone in the body that can lower blood sugar. When insulin secretion is insufficient, blood sugar cannot be effectively controlled, resulting in blood sugar levels higher than normal. However, due to dietary restrictions, such people often have insufficient nutrient intake, which further increases the difficulty of insulin synthesis and secretion. α-glucosidase inhibitors such as acarbose and miglitol can inhibit the activity of α-glucosidase in the intestine and delay the production and absorption of glucose from carbohydrate sources. By taking the above drugs with meals, the increase in blood sugar after meals can be effectively delayed and reduced, which is very suitable for Chinese people who mainly eat carbohydrates. In addition, this type of inhibitor can also be used in combination with diet, exercise and other hypoglycemic drugs. Therefore, developing a functional food that has both nutritional supplements and assists in lowering postprandial blood sugar, and taking it with meals in daily diet, will show great application value.

[0003] Mulberry leaves are the tender leaves of the mulberry tree, a plant of the silkworm family. They are widely used in traditional Chinese medicine to clear away heat and detoxify, lower blood pressure, and promote diuresis and reduce swelling. There are records about mulberry leaves in the Compendium of Materia Medica, which calls them "medicines for clearing heat and detoxifying, promoting diuresis and reducing swelling." In addition, mulberry leaves can be used as medicines, as well as health foods or food additives. In 2002, mulberry leaves were confirmed as "medicine and food homologous" plants and are new green food resources for humans. Modern research shows that mulberry leaves are rich in 1-deoxynojirimycin (DNJ), which has good α-glucosidase inhibitory activity (DNJ is a miglitol analog), making mulberry leaves one of the natural auxiliary therapeutic drugs for lowering postprandial blood sugar.

[0004] Mulberries are the fruits of the mulberry tree, a plant of the Silkworm family. They are green when immature, gradually grow into white and red, and are mostly purple or purple-black when mature. They are sweet and juicy. Mulberries contain a variety of functional ingredients, such as vitamins, anthocyanins, polyphenols (rutin, resveratrol), etc., which have the effects of delaying aging, anti-inflammatory, increasing vascular elasticity, and also have the benefits of protecting the eyes, aiding digestion, and preventing gray hair. Compared with mulberry leaves, the content of DNJ in mulberries is lower, or even almost non-existent. In addition, mulberries are low in calories (only about 43 calories per 100 grams), and the glycemic index (GI value is about 25) is not high, which is relatively friendly to people with high blood sugar.

[0005] Yogurt is a dairy product made from high-quality milk or milk powder and fermented by lactic acid bacteria. After microbial fermentation, biological macromolecules such as proteins are further degraded into polypeptides or free amino acids, making them easier to digest and absorb. Yogurt also has a unique flavor. The accumulation of probiotics during the fermentation process and the beneficial substances produced by physiological metabolism make yogurt both nutritious and health-care. In recent years, various flavored yogurts and fruit yogurts have been continuously introduced on the market, but functional yogurts for specific groups of people are relatively scarce.

[0006] CN102475144A discloses a method for processing mulberry yogurt, and the technical scheme is as follows: mulberries are rinsed, peeled, pulped, heated and concentrated, and sugar, sodium alginate and potassium sorbate are added to make mulberry jam, and then yogurt, sodium alginate, white sugar, citric acid and potassium sorbate are added and mixed by a stirrer to make mulberry yogurt. The yogurt is mainly made by mixing mulberry jam.

[0007] CN104170970A discloses a mulberry leaf yogurt, which is prepared from the following raw materials: fresh milk, mulberry leaf-lotus leaf juice, mulberry pulp, 60% fructose syrup, 80% maltose syrup, lactic acid bacteria, plant lactobacillus, and Bulgarian thermophilic lactic acid bacteria. Among them, mulberry leaf-lotus leaf juice and mulberry pulp are prepared by hot water extraction, filtration, concentration, blending, fermentation, homogenization and other processes. The mulberry leaf yogurt of the invention contains multiple nutritional components and physiologically active substances of mulberry leaves, lotus leaves and mulberries; however, the formula contains fructose syrup and maltose syrup, which is not conducive to people with high blood sugar.

[0008] CN106578049A discloses a mulberry yogurt and a preparation method thereof. The formula contains 30% fresh milk, 7% white sugar, 16% mulberry pulp, and 47% drinking water, and the mulberry pulp contains a color-protecting liquid processed from pineapple. The product of the invention is a solidified yogurt containing mulberry pulp, which belongs to a fruit-flavored yogurt. The preparation process is relatively complicated, and it does not have the aforementioned health-care effect of assisting in lowering blood sugar.

[0009] Mulberry leaves are rich in 1-deoxynojirimycin (DNJ), which is an excellent natural α-glucosidase inhibitor with definite efficacy in the treatment of diabetes. One of the active ingredients in the total alkaloids of mulberry branches, my country's first original natural hypoglycemic drug, is DNJ. Therefore, taking mulberry leaf products with meals in daily diet can effectively control the peak blood sugar after meals, especially for the subtype of hyperglycemia in the early stage of hyperglycemia. However, mulberry leaf products are taken directly, and the taste is poor, and the dosage is difficult to control. In addition, dietary control of hyperglycemic people is not conducive to the recovery of insulin function, especially insulin secretion. Therefore, hyperglycemic people should pay more attention to protein supplementation and intake, and yogurt is a good form of nutritional supplement. However, in order to pursue taste, most commercially available yogurts contain sweeteners such as sucrose, which are not suitable for hyperglycemic people, and there are few yogurt products that take into account both nutrition and functionality for the above-mentioned people to choose.

[0010] At present, there are still few types of blood sugar-lowering yogurts truly developed for people with high blood sugar on the market, especially functional yogurt products that clearly contain mulberry leaves, a medicinal and edible component, and its efficacy (clearly defining its α-glucosidase inhibitory activity and the correct way of taking it with meals), and do not contain sucrose in the formula. Summary of the invention

[0011] In view of the above problems, the present invention starts from the actual application, and develops a functional yogurt containing mulberry leaves for the nutritional supplement and auxiliary hypoglycemic needs of people with high blood sugar. In the yogurt formula, combined with clinical medication experience, a formula yogurt is designed with mulberry leaves containing 1-deoxynojirimycin (DNJ) as the main active ingredient, and mulberries, kudzu root and other (modulation) Chinese medicines suitable for people with high blood sugar as medicine and food as compatibility.

[0012] Specifically, the present invention provides a yogurt for lowering blood sugar and a preparation method thereof. The yogurt contains components such as mulberry leaves, and utilizes the growth of microorganisms such as lactic acid bacteria to remove monosaccharides such as fructose and glucose in mulberry powder and mogroside, so that the final yogurt contains almost no free monosaccharides, and the α-glucosidase inhibitory activity of the final yogurt is not affected, and the yogurt is suitable for people with high blood sugar.

[0013] The preparation method of yogurt of the present invention is as follows:

[0014] (1) adding mulberry leaf powder and / or mulberry leaf water extract, mulberry powder, mogroside, and kudzu root powder to milk and stirring evenly, and then adding yogurt fermentation bacteria powder;

[0015] (2) fermenting and maturing the material prepared in step (1).

[0016] Preferably, in step (1), the raw materials are fermented with the following weight parts: 100 milk, 1-2 mulberry leaf powder and / or mulberry leaf water extract, 1-2 mulberry powder, 1-7 kudzu root powder, 0.1-0.2 mogroside, 0.1 yogurt fermentation bacteria powder; preferably, 100 milk, 1 mulberry leaf, 1 mulberry powder, 1-3 kudzu root powder, 0.15 mogroside, 0.05-0.15 yogurt fermentation bacteria powder; mulberry leaf water extract is a mulberry leaf water extract with different DNJ contents. Specifically, the mulberry leaf powder and / or mulberry leaf water extract contains 0.2% to 5% DNJ, such as 0.4%, 1%, 2%, 3%, 4% or 5% DNJ.

[0017] Among the above-mentioned yogurt components, the active substance DNJ in mulberry leaves has a good effect on controlling postprandial blood sugar; mulberries can adjust the color of yogurt and supplement nutrients such as vitamins and anthocyanins; the combination of kudzu root powder, combined with the theory of compatibility in traditional Chinese medicine, makes the yogurt formula more suitable for people of all constitutions; mogroside is a natural sweetener with high sweetness, no calories, and adjusts the taste of yogurt.

[0018] Preferably, the milk used is commercially available pure milk, fresh milk, etc.

[0019] Preferably, the yogurt fermentation bacteria powder can be a commercially available product containing lactic acid bacteria, Lactobacillus plantarum and Streptococcus thermophilus.

[0020] In order to ensure the universality of the yogurt formula, no special requirements are made for the yogurt fermentation powder. Basically, as long as the commercially available yogurt fermentation powder contains lactic acid bacteria, Lactobacillus plantarum and Streptococcus thermophilus, it can basically ensure the formation of the final yogurt, and will not affect the active substance components in the formula. All materials are added before fermentation. The purpose is to use the growth of microorganisms such as lactic acid bacteria to remove monosaccharides such as fructose and glucose in mulberry powder and mogroside, so that the final yogurt contains almost no free monosaccharides, further ensuring that the yogurt is absolutely 0 sugar added.

[0021] Preferably, in step (2), the fermentation process is performed at 40-45°C for 10-12 hours, preferably, at a constant temperature of 42°C for 12 hours.

[0022] Preferably, in step (2), the aging process is aging at 4° C. for 10-12 hours, preferably, aging at 4° C. for 12 hours.

[0023] Preferably, fermentation is carried out in a fermentation container, and the fermentation container is sterilized at high temperature; preferably, boiling water is first used for high temperature sterilization, and the boiled water is poured out after cooling to about 70 degrees; and sterilized pure milk is added to the fermentation container.

[0024] After ripening, the tasters will evaluate the taste and color of the yogurt through oral tasting. At the same time, the physical and chemical indicators of the yogurt will be measured, mainly including: acidity (pH value), colony count (refer to GB 4789.18-2010), α-glucosidase inhibition activity and other physical and chemical indicators.

[0025] The present invention has the following advantages:

[0026] (1) Mulberry leaves are on the list of medicines and foods, so they are safe and reliable. Mulberry leaves are rich in DNJ, which is an α-glucosidase inhibitor with proven efficacy. It is particularly suitable for patients with elevated blood sugar after meals who mainly consume carbohydrates. There is solid evidence for DNJ's α-glucosidase inhibitory activity, and its mechanism in lowering postprandial blood sugar is clear. The main active ingredient in the total alkaloids of mulberry branches, China's first original natural drug for lowering blood sugar, is DNJ.

[0027] (2) Biomacromolecules such as proteins in dairy products are degraded into peptides and free amino acids after microbial fermentation, and polysaccharides are consumed by microorganisms as carbon sources. Therefore, yogurt is beneficial for the supplementation of nutrients such as protein;

[0028] (3) Mulberries in the formula can adjust the color of yogurt and supplement vitamins, anthocyanins and other nutrients; the combination of kudzu root powder and the theory of compatibility in traditional Chinese medicine make the yogurt formula more suitable for people of all physical conditions; mogroside is a natural sweetener with high sweetness, no calories, and can adjust the taste of yogurt;

[0029] (4) All materials are added before fermentation. The purpose is to use the growth of microorganisms such as lactic acid bacteria to remove monosaccharides such as fructose and glucose in mulberry powder and mogroside, so that the final yogurt contains almost no free monosaccharides, further ensuring that the yogurt is absolutely sugar-free. DETAILED DESCRIPTION

[0030] The technical solution of the present invention is described in detail below in conjunction with specific embodiments. Unless otherwise specified, the reagents and instruments used in the following embodiments are all commercially available products.

[0031] The following examples involve the following main instruments and materials:

[0032] Pure milk (Mengniu pure milk), yogurt fermentation bacteria powder (commercially available Eubit fermentation bacteria with 50 bacterial specifications, purchased from Taobao), mulberry leaf fragments (purchased from Guang'anmen Hospital of China Academy of Chinese Medical Sciences), mulberry leaf water extract with different DNJ contents (0.4% DNJ (purchased from Shanghai Yuanye Biology, this is a conventional mulberry leaf water extract); 1% DNJ, 2% DNJ, 5% DNJ (purchased from Zhejiang Huisong Pharmaceutical Co., Ltd., this is a mulberry leaf water extract concentrated with DNJ)), mulberry powder (purchased from Shanghai Yuanye Biology), mogroside (purchased from Shanghai Yuanye Biology), kudzu root powder (Nanjing Tongrentang), yogurt fermentation machine, pH meter, incubator, MRS solid culture medium, microplate reader, etc.

[0033] The specific implementation cases are as follows:

[0034] Example 1: Effects of different specifications of mulberry leaf raw materials on yogurt

[0035] (1) The fermentation container is sterilized by high temperature sterilization with boiling water, and the boiling water is poured out after cooling to about 70 degrees, and the fermentation container is dried and set aside;

[0036] (2) adding 100 parts by weight of sterilized pure milk into the fermentation container;

[0037] (3) Add 1 part by weight of mulberry leaf products of various specifications (mulberry leaf powder (mulberry leaf fragments powdered and sieved through a 200-mesh sieve), mulberry leaf fragments, mulberry leaf water extract with a DNJ content of 0.4%, mulberry leaf water extract with a DNJ content of 1%, mulberry leaf water extract with a DNJ content of 2%, mulberry leaf water extract with a DNJ content of 5%), 1 part by weight of mulberry powder, and 0.1 part by weight of yogurt fermentation bacteria powder) to the milk and stir evenly;

[0038] (4) Fermentation and maturation: the prepared materials are placed in a fermentation reactor, fermented at a constant temperature of 42° C. for 12 hours, and then matured at 4° C. for 12 hours;

[0039] (5) After ripening, the taste and color of the yogurt were evaluated by oral tasting. At the same time, the yogurt's acidity (pH value), colony count (refer to GB 4789.18-2010), α-glucosidase inhibition activity and other physical and chemical indicators were measured.

[0040] The sensory evaluation scores were given according to Table 1. The number of participants in the tasting was no less than 10, and the final result was the average.

[0041] Table 1. Yogurt sensory evaluation rules

[0042]

[0043]

[0044] The test results are shown in Table 2 below:

[0045] Table 2. Effects of different specifications of mulberry leaves on yogurt

[0046]

[0047] The above results show that after fermentation, the conventional physical and chemical indicators such as the number of live bacteria and acidity of yogurt meet the relevant national standards, and the fermented yogurt has good sensory perception. The appearance observation found that except for the mulberry leaf fragment group with obvious mulberry leaf solids, the rest were homogeneous. In terms of taste, the yogurt of this group tasted sour, and the mulberry leaf water extract containing 0.4% DNJ scored the highest in terms of comprehensive taste, because its water extract was not concentrated by DNJ and had relatively less odor. The results of in vitro enzyme inhibition activity showed that yogurt containing mulberry leaves showed good inhibitory activity, and the inhibitory activity increased with the increase of DNJ content, which was reflected in the α-GA inhibitory activity. It was not a linear relationship, that is, the yogurt contained different amounts of DNJ and its efficacy was also different. The yogurt of the mulberry leaf water extract group with 0.4% DNJ in comprehensive taste was more easily accepted by everyone. Therefore, for different blood sugar conditions, such as mild hyperglycemia, people can eat yogurt with a lower DNJ content, while people with severe hyperglycemia are recommended to eat yogurt with a higher DNJ content.

[0048] Example 2: Effect of mogroside on the taste of yogurt

[0049] The difference from Example 1 is that 0.15 parts by weight of mogroside was also added. The results are shown in Table 3 below:

[0050] Table 3. Effects of mogrosides on yogurt.

[0051]

[0052]

[0053] The above results show that after fermentation, the conventional physical and chemical indicators such as the number of live bacteria and acidity of yogurt all meet the relevant national standards. After the introduction of mogroside, the taste was significantly improved, the overall score of the flavor evaluation was improved, and the overall taste was sweet and sour. In addition, the introduction of mogroside slightly increased the in vitro enzyme inhibition activity of α-glucosidase to a certain extent. In terms of comprehensive taste, the score of mulberry leaf water extract containing 0.4% DNJ is still the highest, because it has not been concentrated by DNJ and has less odor.

[0054] Example 3: Effect of Pueraria powder on mulberry leaf yogurt

[0055] Based on the mulberry leaf water extract of 0.4% DNJ selected in Example 2, 1-7 parts by weight of kudzu root powder was added. The results are shown in Table 4 below:

[0056] Table 4. Effect of kudzu root powder on the taste of mulberry leaf yogurt

[0057]

[0058] The results in Table 4 above show that when the amount of kudzu root powder added is 1 or 3 parts by weight, the tasters have a higher acceptance and the kudzu root powder has a better solubility. When the amount added is 5 and 7 parts by weight, the kudzu root powder has obvious precipitation and affects the taste, with a starch granular feel.

Claims

1. A method for preparing a yogurt for lowering blood sugar, characterized in that: The steps include: (1) Add mulberry leaf powder and / or mulberry leaf water extract, mulberry powder, mogroside, and kudzu root powder to milk, stir evenly, and then add yogurt fermentation bacteria powder; (2) Fermenting and maturing the materials prepared in step (1).

2. The preparation method according to claim 1, characterized in that In step (1), the raw materials comprising the following parts by weight are fermented: 100 parts of milk, 1-2 parts of mulberry leaf powder and / or mulberry leaf water extract, 1-2 parts of mulberry powder, 1-7 parts of kudzu root powder, 0.1-0.2 parts of mogroside, and 0.05-0.15 parts of yogurt fermentation bacteria powder; the mulberry leaf powder and / or mulberry leaf water extract contains 0.2% to 5% DNJ, for example, 0.4%, 1%, 2%, 3%, 4% or 5% DNJ.

3. The preparation method according to claim 2, characterized in that: The invention is fermented from the following raw materials in parts by weight: 100 parts of milk, 1 part of mulberry leaf powder and / or mulberry leaf water extract, 1 part of mulberry powder, 1 part of kudzu root powder, 0.15 parts of mogroside and 0.1 part of yogurt fermentation bacteria powder.

4. The preparation method according to claim 1, characterized in that: In step (2), the fermentation process is 40-45° C. for 10-12 hours.

5. The preparation method according to claim 1, characterized in that: The fermentation process is constant temperature fermentation at 42°C for 12 hours.

6. The preparation method according to claim 1, characterized in that: The aging process is 10-12 hours at 4°C.

7. The preparation method according to claim 1, characterized in that: The aging process is 12 hours at 4°C.

8. The preparation method according to claim 1, characterized in that: Yogurt fermentation powder contains lactic acid bacteria, Lactobacillus plantarum and Streptococcus thermophilus.

9. The preparation method according to claim 1, characterized in that: The milk is pure milk and fresh milk.

10. The blood sugar lowering yogurt obtained by any one of the preparation methods of claims 1 to 9.

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