Cinnamon milk tea with low glycemic index and preparation method thereof

Abstract

The invention provides cortex cinnamomi milk tea with a low glycemic index and a preparation method of the cortex cinnamomi milk tea, and belongs to the technical field of food processing. The cinnamon milk tea provided by the invention comprises the following raw materials in parts by weight: 0.2-1.0 part of cinnamon active extract, 0.4-1.2 parts of tea powder, 12-20 parts of milk powder, 0-4 parts of white granulated sugar and 100 parts of water. According to the invention, a water extraction and secondary alcohol precipitation method is adopted to extract active substances of cinnamon, and the cinnamon active extract which contains cinnamon polysaccharide and cinnamyl saponin with small polarity and has strong hypoglycemic activity is obtained. The obtained cinnamon milk tea is high in sensory score, belongs to food with a low glycemic index, has a wide application prospect, and is expected to obtain relatively good economic benefits.

Description

Technical Field

[0001] The invention relates to the technical field of food processing, in particular to low-glycemic index cinnamon milk tea and a preparation method thereof. Background Art

[0002] Cinnamon (Cinnamomum cassia Presl.) is a food raw material that is both a medicine and food in my country. It contains volatile oils, polysaccharides, saponins, polyphenols, flavonoids and other ingredients, and has a variety of health benefits. Among them, polysaccharides have the effects of anti-fatigue, lowering blood sugar and delaying aging, and can be used as a type of non-specific immunopotentiator in health foods. Studies have found that cinnamon polysaccharides have an inhibitory effect on α-amylase and α-glucosidase, and have a hypoglycemic effect on diabetic mice. It can be seen that active extracts such as cinnamon polysaccharides have certain application potential in the development of functional foods and nutritional health products.

[0003] Milk tea is a nutritious drink made by mixing tea, milk, sugar, etc. In recent years, functional milk tea has developed rapidly. Wu Xiaoju and others mixed winter melon juice and tea soup at 50%:50% to make refreshing winter melon milk tea; Deng Nuomei and others used tofu chai, black tea, milk powder and white sugar as raw materials to make a milk tea with antioxidant function; Cheng Junqiang and others used walnuts, tea and white sugar as raw materials to develop a health milk tea with multiple functions such as quenching thirst, black hair and brain, relieving greasiness and weight loss. Most of the functional milk teas reported so far are prepared by adding vegetable and fruit juices, nuts, Chinese medicine powder or Chinese medicine liquid as functional ingredients to the milk tea formula. Cinnamon, a plant with medicinal and edible properties, is rich in active ingredients such as polysaccharides and saponins. The technical problem to be solved by this application is to prepare milk tea with cinnamon active extract as a functional ingredient so that milk tea has corresponding health effects. Summary of the invention

[0004] The invention aims to provide a cinnamon milk tea with an active extract of a medicinal and edible plant cinnamon as a functional component and a preparation method thereof.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The invention provides a cinnamon milk tea, comprising the following raw materials in parts by weight: 0.2-1.0 parts of cinnamon active extract, 0.4-1.2 parts of tea powder, 12-20 parts of milk powder, 0-4 parts of white sugar and 100 parts of water.

[0007] Preferably, the milk powder is whole milk powder, skim milk powder or a combination of both.

[0008] Preferably, the preparation method of the cinnamon active extract is:

[0009] (1) After cinnamon bark is extracted with hot water for 1 to 2 times, the filtrates are combined and concentrated, 1 to 3 times the volume of high-concentration ethanol is added and allowed to stand for 24 to 48 hours, and the supernatant is collected;

[0010] (2) After the supernatant is concentrated, 1 to 6 times the volume of high-concentration ethanol is added, and the mixture is allowed to stand for 24 to 48 hours. The precipitate is collected and dried to obtain a cinnamon active extract.

[0011] Preferably, the cinnamon in step (1) is one or a combination of cinnamon bark, cinnamon twigs, and cinnamon leaves.

[0012] Preferably, in step (1), the mass volume ratio of cinnamon and hot water is 1:6-20, the extraction time is 1-3 hours, and the temperature of the hot water is 60-100°C.

[0013] Preferably, the filtrate in step (1) is concentrated to a specific gravity of 1.06 to 1.20 at 80°C.

[0014] Preferably, the high concentration ethanol in step (1) is ethanol with a concentration higher than 95%.

[0015] Preferably, the supernatant in step (2) is concentrated to a specific gravity of 1.08 to 1.20 at 80°C.

[0016] Preferably, the high concentration ethanol in step (2) is ethanol with a concentration higher than 95%.

[0017] The present invention also provides a method for preparing the cinnamon milk tea, comprising the following steps:

[0018] (1) Weigh the raw materials: tea powder, milk powder, and white sugar, and mix well;

[0019] (2) weighing the cinnamon active extract and mixing it with the raw materials of step (1) to obtain a mixed powder;

[0020] (3) Measure water at 75-85° C., pour it into the mixed powder in step (2) and stir evenly to obtain cinnamon milk tea.

[0021] The present invention adopts a water extraction and secondary alcohol precipitation method to extract cinnamon active substances, removes cinnamon polysaccharides with large polarity and water-soluble impurities with weak hypoglycemic activity in the traditional water extraction and alcohol precipitation method, and obtains a cinnamon active extract with strong hypoglycemic activity containing cinnamon polysaccharides with small polarity and cinnamon saponins. As a functional component of milk tea, the cinnamon active extract has better health effects than cinnamon powder or cinnamon water extract, and provides a reference for the development and utilization of extracts from various polar parts of cinnamon in functional foods.

[0022] Compared with milk tea without cinnamon active extract, the product of the present invention has the advantages of having the unique flavor of cinnamon and a lower glycemic index. While not reducing the amount of added white sugar, it not only enriches the flavor of milk tea, but also comprehensively improves the blood sugar lowering health care function of milk tea.

[0023] The optimal preparation process parameters of cinnamon milk tea obtained by the present invention after optimization through single factor and orthogonal test are as follows: 16 parts of milk powder, 2 parts of white sugar, 0.8 parts of tea powder, 0.6 parts of cinnamon active extract, 100 parts of water, and the brewing water temperature is 80 DEG C. The sensory score of cinnamon milk tea obtained under the optimal process is 90.3, and the glycemic index is 20.15. Cinnamon milk tea belongs to low GI food, has broad application prospects, and is expected to obtain good economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a graph showing the effect of the amount of whole milk powder added on the sensory score of cinnamon milk tea in Experimental Example 2;

[0025] Figure 2 This is a graph showing the effect of the amount of added white sugar on the sensory score of cinnamon milk tea in Experimental Example 2;

[0026] Figure 3 This is a graph showing the effect of the amount of black tea powder added on the sensory score of cinnamon milk tea in Experimental Example 2;

[0027] Figure 4 This is a graph showing the effect of the amount of cinnamon active extract added on the sensory score of cinnamon milk tea in Experimental Example 2;

[0028] Figure 5 This is a graph showing the effect of brewing temperature on the sensory score of cinnamon milk tea in Experimental Example 2;

[0029] Figure 6 This is a graph showing the effect of water volume on the sensory score of cinnamon milk tea in Experimental Example 2;

[0030] Figure 7 This is the pathological morphology observation picture in Experimental Example 3 (200x eyepiece);

[0031] Figure 8 The blood glucose response curves of glucose, cinnamon milk tea and reference milk tea in Experimental Example 4;

[0032] Fig. 9 This is the area under the blood glucose response curve of glucose, cinnamon milk tea and reference milk tea in Experimental Example 4. DETAILED DESCRIPTION

[0033] 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.

[0034] Example 1

[0035] A cinnamon milk tea is prepared from the following raw materials by weight: 0.6 parts of cinnamon active extract, 0.8 parts of tea powder, 16 parts of milk powder, 2 parts of white sugar, and 100 parts of water;

[0036] The extraction steps of the cinnamon active extract are:

[0037] (1) Cinnamon bark was extracted with hot water twice and the filtrates were combined. In the first extraction, the mass volume ratio of cinnamon bark to hot water was 1:12, the extraction time was 2 hours, and the temperature of the hot water was 90°C; in the second extraction, the mass volume ratio of cinnamon bark to hot water was 1:8, the extraction time was 2 hours, and the temperature of the hot water was 90°C. The two extracts were combined and concentrated to a specific gravity of 1.10 (measured at 80°C), and then 2 times the amount of anhydrous ethanol was added while stirring and allowed to stand for 36 hours. The upper clear liquid was poured out, and the lower precipitate I obtained mainly contained cinnamon polysaccharides with weak hypoglycemic activity and large polarity and some water-soluble impurities.

[0038] (3) The supernatant collected in step (2) is concentrated to a specific gravity of 1.20 (measured at 80°C), and then 3 times the amount of anhydrous ethanol is added while stirring, and the mixture is allowed to stand for 36 hours. The supernatant is poured out, and the lower precipitate is collected and dried at a temperature of 60°C for 24 hours. After drying, the obtained precipitate II is the active extract of cinnamon. The active extract of cinnamon contains cinnamon polysaccharides and cinnamon saponins with low polarity and strong hypoglycemic activity. It is positive in the Molish reaction and positive in the concentrated sulfuric acid-acetic anhydride reaction.

[0039] The tea powder is black tea powder;

[0040] The milk powder is whole milk powder.

[0041] The cinnamon milk tea is prepared by the following method:

[0042] (1) Premixing: Weigh tea powder, milk powder and white sugar, put them into a clean container and mix well;

[0043] (2) Preparation: Weigh the active extract of cinnamon bark, put it into the container containing the raw materials, mix it thoroughly, and set aside;

[0044] (3) Brewing: Take boiled water cooled to 80° C. and mix it evenly with the above ingredients to obtain cinnamon milk tea.

[0045] Example 2

[0046] A cinnamon milk tea is prepared from the following raw materials by weight: 0.6 parts of cinnamon active extract, 0.8 parts of tea powder, 12 parts of milk powder, 3 parts of white sugar, and 100 parts of water;

[0047] Wherein, the cinnamon active extract is obtained according to the preparation method of Example 1;

[0048] The tea powder is green tea powder;

[0049] The milk powder is skimmed milk powder;

[0050] Preparation method of cinnamon milk tea:

[0051] (1) Premixing: Weigh tea powder, milk powder and white sugar, put them into a clean container and mix well;

[0052] (2) Preparation: Weigh the active extract of cinnamon bark, put it into the container containing the raw materials, mix it thoroughly, and set aside;

[0053] (3) Brewing: Take boiled water cooled to 70° C. and mix it evenly with the above ingredients to obtain cinnamon milk tea.

[0054] Example 3

[0055] A cinnamon milk tea is prepared from the following raw materials by weight: 0.6 parts of cinnamon active extract, 1.2 parts of tea powder, 16 parts of milk powder, 2 parts of white sugar, and 100 parts of water;

[0056] Wherein, the cinnamon active extract is obtained according to the preparation method of Example 1;

[0057] The tea powder is green tea powder;

[0058] The milk powder is skimmed milk powder;

[0059] Preparation method of cinnamon milk tea:

[0060] (1) Premixing: Weigh tea powder, milk powder and white sugar, put them into a clean container and mix well;

[0061] (2) Preparation: Weigh the active extract of cinnamon bark, put it into the container containing the raw materials, mix it thoroughly, and set aside;

[0062] (3) Brewing: Take boiled water cooled to 70° C. and mix it evenly with the above ingredients to obtain cinnamon milk tea.

[0063] Example 4

[0064] A cinnamon milk tea is prepared from the following raw materials by weight: 0.6 parts of cinnamon active extract, 0.8 parts of tea powder, 16 parts of milk powder, 4 parts of white sugar, and 100 parts of water;

[0065] Wherein, the cinnamon active extract is obtained according to the preparation method of Example 1;

[0066] The tea powder is black tea powder;

[0067] The milk powder is whole milk powder;

[0068] Preparation method of cinnamon milk tea:

[0069] (1) Premixing: Weigh tea powder, milk powder and white sugar, put them into a clean container and mix well;

[0070] (2) Preparation: Weigh the active extract of cinnamon bark, put it into the container containing the raw materials, mix it thoroughly, and set aside;

[0071] (3) Brewing: Take boiled water cooled to 70° C. and mix it evenly with the above ingredients to obtain cinnamon milk tea.

[0072] Experimental Example 1

[0073] The sensory evaluation of the cinnamon milk tea of ​​Examples 1 to 4 was carried out, and the specific requirements were as follows:

[0074] Referring to the sensory requirements of NY / T 1713-2018 "Green Food Tea Beverage", a sensory scoring standard table was designed. A sensory evaluation team composed of 12 food quality and safety professionals conducted sensory scoring of cinnamon milk tea from four aspects: color, shape, taste, and smell. The maximum and minimum values ​​were removed from the evaluation results, and the average score was taken, with a total score of 100. The scoring standard is shown in Table 1.

[0075] Table 1 Scoring criteria

[0076]

[0077]

[0078] As a result, the sensory score of Example 1 was 90.3, the sensory score of Example 2 was 84.6, the sensory score of Example 3 was 82.2, and the sensory score of Example 4 was 88.1.

[0079] Experimental Example 2

[0080] Optimization experiment on the ratio of each raw material in the cinnamon milk tea formula of the present invention

[0081] Taking the sensory score as a reference, the effects of the amount of whole milk powder added, the amount of white sugar added, the amount of black tea powder added, the amount of cinnamon active extract added, the brewing temperature and the amount of water on the sensory score of cinnamon milk tea were investigated.

[0082] Add 3 parts of white sugar, 0.8 parts of black tea powder, and 0.6 parts of cinnamon active extract to 5 clean containers, mix thoroughly, then add 12 parts, 14 parts, 16 parts, 18 parts, and 20 parts of whole milk powder, mix well. Add 100 parts of boiled and cooled water to 70°C, mix well. The effect of the amount of whole milk powder added on the quality of cinnamon milk tea is shown in Figure 1 .Depend on Figure 1It can be seen that when the addition amount of whole milk powder is between 12 and 16 parts, the sensory score of milk tea shows an upward trend with the increase of the addition amount of whole milk powder, and the texture of cinnamon milk tea becomes thicker. At 16 parts, the taste is the best, at this time the viscosity of cinnamon milk tea is appropriate, and the milk flavor and tea flavor are coordinated. When the addition amount of whole milk powder is between 16 and 20 parts, the sensory score of cinnamon milk tea shows a downward trend. A higher addition amount of milk powder will cause the milk tea to be too thick and the taste is too mellow, while a lower addition amount of milk powder will cause the milk tea to be relatively thin and the taste is light. Therefore, the optimal addition amount of whole milk powder is determined to be 16 parts.

[0083] Add 16 parts of whole milk powder, 0.8 parts of black tea powder, and 0.6 parts of cinnamon active extract to 5 clean containers, mix thoroughly, then add 0, 1, 2, 3, and 4 parts of whole white sugar, mix well. Add 100 parts of boiled and cooled water to 70°C, mix well. The effect of the amount of white sugar added on the quality of cinnamon milk tea is shown in Figure 2 .Depend on Figure 2 It can be seen that when no white sugar is added, the sensory score is the lowest, and the cinnamon milk tea is astringent and has no sweetness; when it is 0 to 2 parts, the score is getting higher and higher, and the sensory score is the highest when it is 2 parts, and the sweetness of the cinnamon milk tea is appropriate; when the amount of white sugar added is 2 to 4 parts, the sensory score shows a downward trend, and the cinnamon milk tea is too sweet and tastes too greasy. White sugar is the main source of sweetness in cinnamon milk tea. Too much white sugar will make the milk tea too sweet, and insufficient addition will make the milk tea taste not sweet enough. The right amount of white sugar can make the milk tea look more shiny and the color is more attractive. Therefore, the best amount of white sugar is determined to be 2 parts.

[0084] Add 16 parts of whole milk powder, 2 parts of white sugar, and 0.6 parts of cinnamon active extract to 5 clean containers, mix thoroughly, then add 0.4 parts, 0.6 parts, 0.8 parts, 1.0 parts and 1.2 parts of black tea powder, respectively, and mix well. Add 100 parts of boiled and cooled water to 70°C and mix well. The effect of the amount of black tea powder added on the quality of cinnamon milk tea is shown in Figure 3 .Depend on Figure 3 It can be seen that when the amount of black tea powder added is between 0.4 and 0.8 parts, the sensory score of milk tea gradually increases. As the amount of black tea powder added increases, the texture of the milk tea becomes thicker and the taste has a tea flavor. When the amount of black tea powder added is between 0.8 and 1.2 parts, the sensory score shows a downward trend. At this time, there is more black tea powder, and polyphenols cause the taste to be bitter and the color of the milk tea is darker. The tea aroma covers the milk aroma and cinnamon aroma, and the smell is not harmonious. Therefore, the optimal amount of black tea powder added is determined to be 0.8 parts.

[0085] Add 16 parts of whole milk powder, 2 parts of white sugar, and 0.8 parts of black tea powder to 5 clean containers, mix thoroughly, then add 0, 0.2, 0.4, 0.6 and 0.8 parts of cinnamon active extract, respectively, and mix well. Add 100 parts of boiled and cooled water to 70°C and mix well. The effect of the amount of black tea powder added on the quality of cinnamon milk tea is shown in Figure 4 .like Figure 4 As shown. The amount of cinnamon active extract added has an important influence on the taste of milk tea. Adding an appropriate amount of cinnamon active extract can bring a special cinnamon flavor to milk tea and make the taste richer, while excessive addition will mask the tea aroma, and the cinnamon flavor is too strong, affecting the overall taste of the milk tea. When the amount of cinnamon active extract added is between 0 and 0.2 parts, the sensory score rises rapidly, and the cinnamon flavor in the milk tea is lighter at this time; at 0.6 parts, the sensory score is the highest, and the milk flavor, tea flavor and cinnamon flavor are coordinated, and the color is light brown; when the amount added is greater than 0.6 parts, the cinnamon flavor is too strong and the color is darker. Therefore, the optimal amount of cinnamon active extract added is determined to be 0.6 parts.

[0086] Add 16 parts of whole milk powder, 2 parts of white sugar, 0.6 parts of black tea powder, and 0.4 parts of cinnamon active extract to 5 clean containers and mix thoroughly. Add 100 parts of boiled water cooled to 70℃, 75℃, 80℃, 85℃ and 90℃ respectively and mix well. The effect of brewing temperature on the quality of cinnamon milk tea is shown in Figure 5 .Depend on Figure 5 It can be seen that when the brewing temperature is between 70 and 75℃, the sensory score gradually increases with the increase of brewing temperature; at 80℃, the sensory score is the highest, at which time the cinnamon flavor and black tea flavor are suitable and the taste is integrated; when the temperature is lower, the aroma of black tea will weaken and the solubility of cinnamon active extract will also deteriorate. This may be because the lower temperature slows down the thermal motion of aroma molecules in black tea, less pigment leaching, and a slightly lighter taste; when the temperature is higher than 80℃, the sensory score decreases, which may be due to the excessive dissolution of tannins and other substances in black tea, making the taste astringent. Therefore, the optimal brewing temperature of cinnamon milk tea is determined to be 80℃.

[0087] Add 16 parts of whole milk powder, 2 parts of white sugar, 0.6 parts of black tea powder, and 0.4 parts of cinnamon active extract to 5 clean containers and mix thoroughly. Add 60mL, 80mL, 100mL, 120mL, and 140mL of boiled and cooled water to 80℃, respectively, and mix well. The effect of water amount on the quality of cinnamon milk tea is shown in Figure 6 .Depend on Figure 6It can be seen that the amount of water will directly affect the concentration of milk tea. When the amount of water is between 60 and 100 parts, the sensory score of cinnamon milk tea increases with the increase of water. Less water will make the milk tea too thick and the milk powder will clump. When the amount of water is 100 parts, the sensory score of cinnamon milk tea is the highest. At this time, the taste of milk tea is mellower, smoother and has appropriate viscosity. When the amount of water is higher than 100 parts, the sensory score decreases. This is because the increase in water makes the milk tea thinner and the taste is lighter. Therefore, the optimal amount of water for cinnamon milk tea is determined to be 100 parts.

[0088] Experimental Example 3

[0089] Effects of cinnamon active extract on type Ⅱ diabetic mice

[0090] Ten male mice were randomly selected as the blank group and fed with standard feed. The remaining mice were fed with high-sugar and high-fat feed (58.8% high-nutrition basic feed, 20% lard, 1% cholesterol, 0.2% bile salt, 20% sugar, Beijing Keao Xieli Feed Co., Ltd.) for 8 weeks, and then 100 mg / kg alloxan was injected into the tail vein to induce type Ⅱ diabetes mouse model. The mice with successful modeling were randomly divided into model group, positive drug metformin group (350 mg / kg), cinnamon active extract high-dose group (200 mg / kg), and cinnamon active extract low-dose group (100 mg / kg), with 10 mice in each group. Each drug group was gavaged with the corresponding drug (pure water as the drug solvent) at 0.2 mL / 10 g, and the blank group and model group were gavaged with the same amount of pure water for 28 consecutive days. At the same time, the model group continued to be fed with high sugar and high fat, and each drug group was changed from high sugar and high fat feeding to standard feeding, and the blank group remained unchanged. Before the experiment, after 8 weeks of high-sugar and high-fat feeding, after 3 days of alloxan injection, and after 7, 14, 21, and 28 days of drug administration, the fasting blood glucose (FBG) was measured by blood samples collected from the tail vein. The oral glucose tolerance (OGTT) of each group was measured on the 29th day. The next day, blood samples were collected from the eyeballs to measure triglycerides (TG), total cholesterol (TC), high-density lipoprotein (HDL-C), low-density lipoprotein (LDL-C), free fatty acids (FFA), glycosylated serum protein (GSP), and fasting insulin (FINS) content, and the insulin sensitivity index (ISI) and insulin resistance index (IRI) were calculated. The pancreas, liver, and kidney were dissected, and their organ indexes were calculated and their pathological sections were observed. The results are shown in Tables 2 to 7.

[0091] Table 2 Effects of cinnamon active extract on fasting body weight of mice ( n=10)

[0092]

[0093] Note: Compared with the blank group *P<0.05, **P<0.01, compared with the model group ◆P<0.05, ◆◆ P<0.01

[0094] Table 3 Effects of cinnamon active extract on FBG in mice ( n=10)

[0095]

[0096]

[0097] Note: Compared with the blank group *P<0.05, **P<0.01, compared with the model group ◆ P<0.05, ◆◆ P<0.01

[0098] Table 4 Effects of cinnamon active extract on OGTT in mice ( n=10)

[0099]

[0100] Note: Compared with the blank group *P<0.05, **P<0.01, compared with the model group ◆ P<0.05, ◆◆ P<0.01

[0101] Table 5 Effects of cinnamon active extract on five indicators of blood lipids in mice ( n=10)

[0102]

[0103] Note: Compared with the blank group *P<0.05, **P<0.01, compared with the model group ◆ P<0.05, ◆◆ P<0.01

[0104] Table 6 Effects of cinnamon active extract on GSP and FINS in mice ( n=10)

[0105]

[0106]

[0107] Note: Compared with the blank group *P<0.05, **P<0.01, compared with the model group ◆ P<0.05, ◆◆ P<0.01

[0108] Table 7 Results of determination of organ index of mice with cinnamon active extract ( n=10)

[0109]

[0110] Note: Compared with the blank group *P<0.05, **P<0.01, compared with the model group ◆ P<0.05, ◆◆ P<0.01

[0111] Table 7 (Continued)

[0112]

[0113] Note: Compared with the blank group *P<0.05, **P<0.01, compared with the model group ◆ P<0.05, ◆◆ P<0.01

[0114] Through Tables 2 to 7 and Figure 7 It can be seen that compared with the model group, cinnamon active extract can improve the general clinical manifestations of type 2 diabetic mice to a certain extent; the high and low dose groups of cinnamon active extract can increase the weight of mice (P<0.01), reduce FBG and GSP (P<0.01), promote the release of FINS (P<0.01), improve OGTT levels (P<0.01), significantly reduce TG, TC, LDL-C (P<0.0), reduce FFA content (P<0.01), and have no significant effect on the weight and organ index of the pancreas, but have a significant effect on the kidney weight and organ index of mice (P<0.01), and can improve the pathological state of liver, kidney and pancreas tissues in type 2 diabetic mice. The experimental results show that cinnamon active extract can improve the general clinical symptoms of type 2 diabetic mice caused by high sugar and high fat feeding combined with alloxan injection, and has significant effects on lowering blood sugar, lowering blood lipids and repairing organ function.

[0115] Experimental Example 4

[0116] Quality Inspection of Cinnamon Milk Tea

[0117] 4.1 Determination of physical and chemical indicators of cinnamon milk tea

[0118] The cinnamon milk tea was prepared by the best process (Example 1), and the finished product was uniformly yellow in color, sweet and delicious, smooth in taste, and had a strong tea fragrance and cinnamon flavor. The protein content, tea polyphenol content, fat content, total sugar content, solid content, milk tea stability, centrifugal sedimentation rate, and oil precipitation rate of the finished product were measured respectively.

[0119] Determination of protein content: refer to NY / T 1678-2008 "Determination of protein in milk and dairy products - Biuret colorimetric method" to determine the protein content in the finished product;

[0120] Determination of tea polyphenols content: The tea polyphenols content in the finished product was determined by ferrous tartrate colorimetry and calculated according to formula 1:

[0121]

[0122] 1.957 means that when the absorbance is 0.5 using a 1 cm cuvette, the tea polyphenol content in each milliliter of tea soup is equivalent to 1.957 mg;

[0123] Determination of fat content: The fat content of the finished product was determined by the Rothschild-Gottli method and calculated according to formula 2:

[0124]

[0125] m0——total mass of weighing bottle and fat

[0126] m1——the mass of the weighing bottle

[0127] m2——mass of the sample

[0128] V0——Read the total volume of the ether layer

[0129] V1——Total volume of the ether layer released

[0130] Determination of total sugar content: The total sugar content in the finished product was determined by potassium ferrocyanide titration method;

[0131] Determination of solid content: Use a handheld refractometer to determine the solid content in the finished product;

[0132] Determination of stability: The sample was left to stand for 15 hours and the stability was calculated according to Formula 3:

[0133]

[0134] Determination of centrifugal sedimentation rate and oil precipitation rate: Take 25g of the finished product in a centrifuge tube, centrifuge at 3000r / min for 10min, discard the supernatant, turn the centrifuge tube upside down on absorbent paper for 5min, weigh it, repeat 3 times, and use formula 4 to calculate the centrifugal sedimentation rate and formula 5 to calculate the oil precipitation rate:

[0135]

[0136] Where M1 is the mass of the precipitate, g; M2 is the mass of the weighed sample, g.

[0137] Where N1 is the height of the top floating layer, cm; N2 is the height of the sample liquid, cm.

[0138] The results of physical and chemical index determination are shown in Table 8, among which protein and tea polyphenols both meet the corresponding index requirements of GB / T21733-2008 "Tea Beverages".

[0139] Table 8 Physical and chemical indicators of cinnamon milk tea

[0140]

[0141]

[0142] 4.2 Results and analysis of glycemic index of cinnamon milk tea

[0143] Cinnamon milk tea was prepared by the optimal process (Example 1); the reference milk tea preparation process was basically the same as Example (1), the only difference being that 0.6 parts of cinnamon active extract was not added. The glycemic index of cinnamon milk tea and reference milk tea was determined with reference to WS / T652-2019 "Method for Determining the Glycemic Index of Foods". The area under the blood glucose curve (AUC) was plotted with the blood glucose response curve with time t as the horizontal axis and blood glucose concentration c as the vertical axis, and the area under the curve was calculated. The glycemic index was calculated using glucose as the reference food (GI = 100).

[0144]

[0145] SPSS26 software was used to fit the data of blood glucose response curves, and t-test was used to analyze the differences between groups. P < 0.05 indicated that the differences between groups were statistically significant. Origin 2022 was used to draw the blood glucose response curve and calculate the area under the curve.

[0146] (1) Analysis of postprandial blood glucose response levels

[0147] The subjects' postprandial blood glucose levels 2 hours after consuming glucose, cinnamon milk tea, and reference milk tea were as follows: Figure 8As shown. At 0min, the blood glucose levels of the three test substances did not change significantly, which is consistent with the results in Table 9. The difference in postprandial blood glucose among the three was not significant (P>0.05). At 30min, the blood glucose levels of cinnamon milk tea and reference milk tea reached their peaks, and within 0-30min, the postprandial blood glucose level of cinnamon milk tea rose slowly. Within 45-60min, the rate of decline of the blood glucose level of cinnamon milk tea was significantly higher than that of the reference milk tea. Within 60-90min, the rate of decline of the blood glucose level of cinnamon milk tea gradually slowed down and tended to be stable. The rate of decline of the blood glucose level of the reference milk tea was higher than that of cinnamon milk tea. At 90min, the postprandial blood glucose level of the reference milk tea dropped to the lowest, while the cinnamon milk tea reached the lowest level at 120min, which was lower than the level of the reference milk tea. As can be seen from Table 9, at 15min, 30min, 45min, 60min, and 90min, there were statistical differences in the postprandial blood glucose levels of glucose, cinnamon milk tea, and reference milk tea (P<0.05). 0min is the fasting blood sugar, and there is no obvious difference in blood sugar between individuals. At 120min, the individual blood sugar level almost reaches the initial fasting level, so the difference in postprandial blood sugar values ​​among the three is not significant. In addition, the small number of subjects may also be the reason why there is no statistical difference between 0 and 120min.

[0148] Table 9 Multivariate analysis of blood glucose response of glucose, cinnamon milk tea and reference milk tea at each time point

[0149]

[0150] Note: * indicates that there are statistical differences in blood sugar levels among glucose, reference milk tea and cinnamon milk tea in the same time period (P < 0.05).

[0151] (2) Analysis of the area under the postprandial blood glucose curve

[0152] The area under the blood glucose curve can reflect the changes in blood glucose after meals at different time periods. Fig. 9 It can be seen that 15 minutes after eating glucose, the blood sugar level of the subjects showed a sudden upward trend. After eating cinnamon milk tea and reference milk tea, there was no obvious change in blood sugar. Starting from 45 minutes, the blood sugar levels of cinnamon milk tea and reference milk tea rose slowly, and cinnamon milk tea rose more slowly than reference milk tea. The total area under the curve of the reference milk tea obtained was greater than the total area under the curve of cinnamon milk tea.

[0153] As shown in Table 10, both cinnamon milk tea and reference milk tea are low GI foods, and the GI value of cinnamon milk tea is 3.58 lower than that of reference milk tea. (According to the classification standard of GI value, 55 or less is low GI value, 55 to 70 is medium GI value, and 70 or more is high GI value.)

[0154] Table 10 AUC and GI values ​​of glucose, cinnamon milk tea and reference milk tea

[0155]

[0156] 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 low glycemic index cinnamon milk tea, characterized in that: The invention comprises the following raw materials in parts by weight: 0.2-1.0 parts of cinnamon active extract, 0.4-1.2 parts of tea powder, 12-20 parts of milk powder, 0-4 parts of white sugar and 100 parts of water.

2. The cinnamon milk tea according to claim 1, characterized in that The milk powder is one of whole milk powder and skim milk powder or a combination of both.

3. The cinnamon milk tea according to claim 2, characterized in that: The preparation method of the cinnamon active extract is: (1) After cinnamon bark is extracted with hot water for 1 to 2 times, the filtrates are combined and concentrated, 1 to 3 times the volume of high-concentration ethanol is added and allowed to stand for 24 to 48 hours, and the supernatant is collected; (2) After the supernatant is concentrated, 1 to 6 times the volume of high-concentration ethanol is added, and the mixture is allowed to stand for 24 to 48 hours. The precipitate is collected and dried to obtain a cinnamon active extract.

4. The cinnamon milk tea according to claim 3, characterized in that: The cinnamon in step (1) is one or a combination of cinnamon bark, cinnamon twigs and cinnamon leaves.

5. The cinnamon milk tea according to claim 4, characterized in that: In step (1), the mass volume ratio of cinnamon and hot water is 1:6-20, the extraction time is 1-3 hours, and the temperature of the hot water is 60-100°C.

6. The cinnamon milk tea according to claim 5, characterized in that: The filtrate in step (1) is concentrated to a specific gravity of 1.06 to 1.20 at 80°C.

7. The cinnamon milk tea according to claim 6, characterized in that: The high-concentration ethanol in step (1) is ethanol with a concentration higher than 95%.

8. The cinnamon milk tea according to claim 7, characterized in that: The supernatant in step (2) is concentrated to a specific gravity of 1.08 to 1.20 at 80°C.

9. The cinnamon milk tea according to claim 8, characterized in that: The high-concentration ethanol in step (2) is ethanol with a concentration higher than 95%.

10. A method for preparing cinnamon milk tea according to any one of claims 1 to 9, characterized in that: The following steps are involved: (1) Weigh the raw materials: tea powder, milk powder, and white sugar, and mix well; (2) weighing the cinnamon active extract and mixing it with the raw materials of step (1) to obtain a mixed powder; (3) Measure water at 75-85° C., pour it into the mixed powder in step (2) and stir evenly to obtain cinnamon milk tea.

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