Instant nutritious rice flour containing rice protein extract

Abstract

The application discloses instant nutritional rice flour containing rice protein extract and belongs to the technical field of solid beverage. The instant nutritional rice flour with coffee flavor is prepared from the following raw materials in parts by mass: rice flour 55-72 parts, coffee powder 23-35 parts, coconut powder 3-7 parts, yam powder 2-5 parts, milk powder 2-5 parts and emulsifier 0.2-1.5 parts. The instant coffee-flavored rice flour has a strong coffee aroma, moderate bitterness and acidity, rich taste, and the taste and mouthfeel of the rice flour, and the combination degree of the taste and the mouthfeel is good. Moreover, the product has a lower glycemic index and is less likely to cause health problems to the human body, and has a good application prospect.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of solid beverage, in particular to a ready-to-eat nutritional rice flour containing rice protein extract. BACKGROUND

[0002] At present, with the expansion of the coffee consumption market, more types of coffee have emerged; for example, coffee and rice flour are mixed together to form a mixed food, which can not only meet the energy needs of consumers, but also provide the flavor and refreshing effect of coffee, which is a good development direction.

[0003] However, although there are food products containing both coffee and rice flour in the prior art, the brewing difficulty of rice flour is obviously higher than that of coffee because rice flour usually needs a long time to soften and dissolve, and further improvement is still needed. Moreover, the undissolved rice flour will float to the upper part of the liquid and form a foam-like froth with stirring, which not only affects the uniformity of the beverage, causes color difference, but also reduces the eating experience. Therefore, the brewing process of such products is usually difficult, and only products that have been prepared in coffee shops are usually purchased. At present, there is no mature product on the market that can be simply brewed.

[0004] After investigation and research, it was found that consumers are generally accustomed to consuming coffee products in the morning, but at this time, the secretion of various hormones in the human body is prone to imbalance, especially the secretion of hormones such as growth hormone, cortisol, glucagon and catecholamine, which antagonize insulin, increases, and the level of insulin decreases relatively, so it is difficult to control blood sugar. The problem of rice flour not being easily dissolved is mainly caused by the starch components in it. Pre-gelatinization is a common method of modifying rice flour. After treatment, the starch in the prepared rice flour is partially or completely gelatinized, which can further improve the dissolution rate and solubility of the rice flour. However, this treatment also causes the starch molecular chain to break, rearrange and hydrate, increases the glycemic index (GI), and makes the starch more easily decomposed by digestive enzymes, thereby accelerating the release and absorption of glucose into the blood, which affects human health. Moreover, although rice flour contains a certain amount of protein (about 6-8%), its content is not as high as that of high-protein foods such as meat and beans, and it is not suitable as the only source of protein. Therefore, it is usually necessary to eat other foods to supplement enough protein and other nutrients.

[0005] Therefore, with the increasing emphasis on healthy eating concepts, researchers in this field need to design a coffee-flavored brewing rice flour product that has a low glycemic index and can be quickly and simply brewed. SUMMARY

[0006] The present application aims to provide instant nutritional rice flour containing rice protein extract to solve the above problems in the background art. The instant nutritional rice flour with coffee flavor has rich coffee aroma, moderate bitterness and acidity, rich taste, and also has the sticky and tender taste of rice flour, and the combination of taste and mouthfeel is good. Moreover, the product has a lower glycemic index and is less likely to affect human health, and has a good application prospect.

[0007] To achieve the above-mentioned object, the present application provides the following technical solutions.

[0008] One of the technical solutions of the present application provides instant nutritional rice flour with coffee flavor, and the raw materials include, by mass fraction:

[0009] Rice flour 55-72 parts, coffee powder 23-35 parts, coconut powder 3-7 parts, yam powder 2-5 parts, milk powder 2-5 parts, and emulsifier 0.2-1.5 parts.

[0010] Preferably, the preparation method of the coconut powder is as follows: taking coconut meat, crushing, adding coconut juice and glycerol monostearate, high-pressure homogenization, spray drying to obtain the coconut powder.

[0011] More preferably, the mass ratio of the coconut meat, coconut juice and glycerol monostearate is 5-10:20-30:0.1-0.3; and the average particle size of the coconut powder is 100-200 μm.

[0012] Preferably, the emulsifier is sodium trimetaphosphate.

[0013] Preferably, the instant nutritional rice flour with coffee flavor is composed of the following raw materials by mass fraction:

[0014] Rice flour 67 parts, coffee powder 31 parts, coconut powder 4 parts, yam powder 2.5 parts, milk powder 4 parts, and emulsifier 1.1 parts.

[0015] The second technical solution of the present application provides a preparation method of the instant nutritional rice flour with coffee flavor, comprising the following steps:

[0016] adding rice flour into water, adding α-amylase for enzymolysis, sterilizing, pre-gelatinizing, cooling, collecting solid phase components to obtain rice protein extract;

[0017] adding coffee powder, yam powder, milk powder and water into the rice protein extract to obtain a liquid mixture, spray drying to obtain a precursor powder, and then mixing with coconut powder and emulsifier to obtain the instant nutritional rice flour with coffee flavor.

[0018] Preferably, the enzymatic hydrolysis temperature is 50-70 DEG C, and the time is 8-15 min; the sterilization is heating at 95-100 DEG C for 1-3 min; the pregelatinization temperature is 65-70 DEG C, and the time is 15-20 min.

[0019] Preferably, the proportion of water in the liquid phase mixture is 50-60 wt%; the inlet air temperature of the spray drying is 110-150 DEG C; the average particle size of the precursor powder is 100-200 mu m.

[0020] The particle size of the precursor powder is limited to 100-200 mu m after the test. When the particle size of the precursor powder is larger, the solubility of the product system increases significantly, and the taste becomes worse; when the particle size of the rice powder is smaller, the preparation cost increases.

[0021] The beneficial technical effects of the present application are as follows:

[0022] The present application realizes synergistic modification by enzymatic hydrolysis and pregelatinization of rice powder. The enzymatic hydrolysis operation defined in the present application does not completely decompose the starch in the rice powder, and a part of the starch remains; in the subsequent pregelatinization process, the microcrystalline structure of part of the starch is destroyed, the intermolecular hydrogen bond is broken, the starch molecules are converted from an ordered crystalline state to a disordered non-crystalline state, the long-chain starch molecules are decomposed into relatively loose and disordered short chains, and the tendency of macromolecular re-polymerization is reduced; this operation helps to improve the viscosity during the later brewing, so that the product has a soft and smooth taste, reduces the taste gap with conventional rice powder, and improves the audience acceptance.

[0023] After the enzymatic hydrolysis and pregelatinization treatment of the present application, the product can provide satiety while having a lower glycemic index and a slower digestion and decomposition speed. This is mainly because the protein content in the product is relatively high, and it is more difficult to be decomposed and converted into blood sugar than conventional rice powder with high starch and low protein content; and the remaining starch has more and tighter binding sites with the protein, and the protein uniformly surrounds part of the remaining starch molecules, playing a protective role.

[0024] After the spray drying treatment, the release effect of the coffee-flavored instant nutritional rice powder prepared by the present application is more ideal, and the simultaneous release of different raw material components can be achieved as much as possible, so that the flavor controllability of the product is better.

[0025] The coffee-flavored rice powder of the present application only needs to be simply brewed and heated for consumption, without long-time stirring or waiting. The added coconut powder can provide suitable nutty and milky flavors to the system. The yam powder is rich in nutrients and has health care functions such as lowering blood lipids and regulating the stomach and intestines, and can also improve the taste. A large proportion of coffee powder is added in the rice powder scheme designed in the present application, which has a refreshing effect.

[0026] The related modification operation of the present application can effectively improve the taste and texture of the product after brewing, making it more smooth and delicate. The present application can significantly improve the flavor of the beverage by mixing and blending various raw materials, making it more acceptable to the buyers, and having higher nutritional value. The instant nutritional rice flour with coffee flavor of the present application has a rich coffee aroma after brewing, moderate bitterness and acidity, rich taste, and also has the sticky and tender taste of rice flour, and the combination of taste and texture is good. Moreover, the product has a lower glycemic index and is less likely to affect human health, and has good application prospect. DETAILED DESCRIPTION

[0027] The various exemplary embodiments of the present application will now be described in detail, which should not be considered as limiting the present application, but should be understood as a more detailed description of certain aspects, characteristics and embodiments of the present application. It should be understood that the terms described in the present application are only for the description of the particular embodiments, and are not intended to limit the present application.

[0028] In addition, for the numerical range in the present application, it should be understood that each intermediate value between the upper limit and the lower limit of the range is also specifically disclosed. Each smaller range between any stated value or intermediate value in the stated range, and any other stated value or intermediate value in the stated range, is also included in the present application. The upper limit and the lower limit of these smaller ranges can be independently included or excluded from the range.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application pertains. Although preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present application.

[0030] As used herein in connection with the present application, the terms "comprising", "including", "containing", "have" and "has" are inclusive or open-ended and do not exclude additional, unrecited elements or method steps.

[0031] The parts in the present application are by mass parts unless otherwise specified.

[0032] The "room temperature" in the present application is 20-30℃ unless otherwise specified.

[0033] The α-amylase solution used in the following examples and comparative examples of the present application was prepared by diluting α-amylase with an enzyme activity of 30000 U / g by 20 times.

[0034] The preparation method of the coconut powder used in the following examples and comparative examples of the present application is as follows: 50 g of coconut meat is pulverized, 200 g of coconut juice and 2 g of glycerol monostearate are added, sterilization is performed, high-pressure homogenization is performed, and a centrifugal spray dryer is used for drying treatment to obtain coconut powder with an average particle size of 150 μm.

[0035] The preparation method of the rice powder used in the following examples and comparative examples of the present application is as follows: rice is pulverized to pass through a 100-mesh sieve by using a super micro pulverizer.

[0036] The raw materials used in the following examples and comparative examples of the present application are all commercially available products.

[0037] Example 1

[0038] A coffee-flavored rice powder is composed of the following raw materials in mass fraction:

[0039] Rice powder 67 parts, coffee powder 31 parts, coconut powder 4 parts, yam powder 2.5 parts, milk powder 4 parts, and sodium trimetaphosphate 1.1 parts.

[0040] Preparation of the coffee-flavored rice powder:

[0041] Rice powder is added to 100 parts of water and stirred uniformly, 0.2 parts of an α-amylase solution is added, and enzymatic hydrolysis is performed at 67℃ for 13 min, then sterilization is performed at 95℃ for 2 min, pre-gelatinization is performed at 65℃ for 15 min, and then cooling to room temperature is performed by means of an ice water bath, and the solid phase component is collected to obtain a rice protein extract;

[0042] Coffee powder, yam powder, milk powder, and water are added to the rice protein extract to obtain a liquid phase mixture (water content 57 wt%), homogenization is performed at 30 MPa by using a micro-jet homogenizer, spray drying (inlet temperature 130℃) is performed to obtain a precursor powder with an average particle size of 180 μm, and then the precursor powder is mixed with coconut powder and sodium trimetaphosphate to obtain the coffee-flavored rice powder.

[0043] Example 2

[0044] A coffee-flavored rice powder is composed of the following raw materials in mass fraction:

[0045] Rice powder 55 parts, coffee powder 35 parts, coconut powder 7 parts, yam powder 2 parts, milk powder 4 parts, and sodium trimetaphosphate 0.2 parts.

[0046] Preparation of the coffee-flavored rice powder:

[0047] Rice powder is added to 100 parts of water and stirred uniformly, 0.2 parts of an α-amylase solution is added, and enzymatic hydrolysis is performed at 65℃ for 13 min, then sterilization is performed at 95℃ for 3 min, pre-gelatinization is performed at 65℃ for 18 min, and then cooling to room temperature is performed by means of an ice water bath, and the solid phase component is collected to obtain a rice protein extract;

[0048] A liquid mixture (water content 56wt%) was obtained by adding coffee powder, yam powder, milk powder and water into the rice protein extract, and homogenized at 30Mpa using a microfluidizer. The precursor powder with an average particle size of 180μm was obtained by spray drying (inlet temperature 130℃), and then mixed with coconut powder and sodium trimetaphosphate to obtain the coffee-flavored rice flour.

[0049] Comparative Example 1 (without enzymatic hydrolysis)

[0050] The difference from Example 1 is that the preparation method of the rice protein extract is modified as follows:

[0051] The rice protein extract was obtained by adding rice flour into 100 parts of water, stirring uniformly, pre-gelatinizing at 65℃ for 28min, and then cooling to room temperature by ice water bath, and collecting the solid phase component.

[0052] Comparative Example 2 (complete enzymatic hydrolysis)

[0053] The difference from Comparative Example 1 is that the enzymatic hydrolysis time is modified to 3h.

[0054] Comparative Example 3 (neither enzymatic hydrolysis nor pre-gelatinization)

[0055] A coffee-flavored rice flour is composed of the following raw materials in mass parts:

[0056] 67 parts of rice flour, 31 parts of coffee powder, 4 parts of coconut powder, 2.5 parts of yam powder, 4 parts of milk powder and 1.1 parts of sodium trimetaphosphate.

[0057] Preparation of coffee-flavored rice flour:

[0058] A liquid mixture (water content 57wt%) was obtained by mixing rice flour, coffee powder, yam powder, milk powder and water, and homogenized at 30Mpa using a microfluidizer. The precursor powder with an average particle size of 180μm was obtained by spray drying (inlet temperature 130℃), and then mixed with coconut powder and sodium trimetaphosphate to obtain the coffee-flavored rice flour.

[0059] Comparative Example 4

[0060] The difference from Example 1 is that the addition of coconut powder is omitted and the same mass of rice flour is supplemented.

[0061] Comparative Example 5

[0062] The difference from Example 1 is that the addition of yam powder and milk powder is omitted and the same mass of rice flour is supplemented.

[0063] Effect verification

[0064] (1) Kjeldahl method was used to measure the protein content of the rice protein extract in Example 1 and Comparative Example 1, and the raw material rice flour in Example 1. The test results are shown in Table 1.

[0065] Table 1

[0066] Raw material rice flour Example 1 Comparative Example 1 Protein content (wt%) 7.72 42.37 19.53

[0067] (2) The products of Example 1 and Comparative Examples 1-2 were subjected to a blood sugar level test. The test method was as follows: 90 g of the above rice flour was taken (to test the change in blood sugar after excessive consumption), and was stirred uniformly in 350 mL of hot water at 80°C to obtain a rice brewing liquid; 30 healthy adults were arranged as volunteers, and the volunteers were required to fast for dinner the day before the test, and then the fasting blood sugar of the testers at 7:00 the next morning was measured by finger prick blood sampling, and then the above three rice brewing liquids were uniformly consumed, and 10 people were arranged to consume each rice brewing liquid; starting from the time when each person finished eating, the blood sugar was measured at 30, 60, 120 and 240 min after consumption, respectively; each person repeated the above operation 3 times, and the type of rice brewing liquid consumed was different each time, and the average value was taken. The test results are shown in Table 2.

[0068] Table 2

[0069] Fasting blood glucose 30 min 60 min 120 min 240 min Example 1 4.86 6.41 5.98 5.63 4.97 Comparative Example 1 4.62 7.13 6.34 5.46 4.75 Comparative Example 2 4.89 6.20 6.47 6.05 5.01

[0070] As can be seen from Table 2, the rice brewing liquid of Example 1 has less effect on human blood sugar.

[0071] (3) The products of Example 1 and Comparative Examples 1-5 were subjected to a sensory test. The test method was as follows: 50 g of the above rice flour was taken, stirred in 200 mL of hot water at 80°C for 30 s to obtain a rice brewing liquid, and then provided to 10 volunteers, and the above 6 rice brewing liquids were subjected to sensory evaluation, and the average value was taken; the sensory evaluation standard is shown in Table 3.

[0072] Table 3

[0073]

[0074] The test results are shown in Table 4.

[0075] Table 4

[0076] Aroma Color Taste Example 1 9.2 9.8 8.5 Comparative Example 1 8.6 9.4 8.1 Comparative Example 2 7.9 9.5 7.7 Comparative Example 3 7.8 5.4 6.7 Comparative Example 4 8.8 9.3 7.6 Comparative Example 5 8.7 9.6 7.3

[0077] In Table 4, the reason for the lower score of Comparative Example 3 is that there are still a large amount of lumps in the rice brewing liquid, and the dissolution is not sufficient. As can be seen from Example 1 in Table 4, by pretreating the rice flour raw material, the aroma, color and taste of the brewing liquid can be improved.

[0078] The above described embodiments are only to illustrate the preferred modes of the present application, and are not intended to limit the scope of the present application. Any modification and improvement made by those skilled in the art to the technical solutions of the present application without departing from the design spirit of the present application shall fall within the protection scope of the present application as defined by the claims.

Claims

1. A ready-to-eat nutritious rice flour having coffee flavor, characterized by, The raw materials include, by mass fraction: 55-72 parts of rice powder, 23-35 parts of coffee powder, 3-7 parts of coconut powder, 2-5 parts of yam powder, 2-5 parts of milk powder and 0.2-1.5 parts of emulsifier; The preparation method of the coffee-flavored instant nutritious rice powder is: The rice powder is added into water, and then alpha-amylase is added for enzymatic hydrolysis, sterilization, pre-gelatinization, cooling, and collection of solid phase components to obtain a rice protein extract; The coffee powder, yam powder, milk powder and water are added into the rice protein extract to obtain a liquid mixture, the liquid mixture is spray dried to obtain a precursor powder, and then the precursor powder is mixed with the coconut powder and the emulsifier to obtain the coffee-flavored instant nutritious rice powder. The temperature of the enzymatic hydrolysis is 50-70 DEG C, and the time is 8-15 min; the sterilization is heating at 95-100 DEG C for 1-3 min; and the temperature of the pre-gelatinization is 65-70 DEG C, and the time is 15-20 min.

2. The instant nutritious rice cereal of coffee flavor according to claim 1, characterized by, The preparation method of the coconut powder is as follows: the coconut meat is crushed, coconut juice and glycerol monostearate are added, high-pressure homogenization is performed, and spray drying is performed to obtain the coconut powder.

3. The instant nutritious rice cereal of coffee flavor according to claim 2, characterized by, The mass ratio of the coconut meat, the coconut juice and the glycerol monostearate is 5-10:20-30:0.1-0.3; and the average particle size of the coconut powder is 100-200 mu m.

4. The instant nutritious rice cereal of coffee flavor according to claim 1, characterized by, The raw materials of the coffee-flavored instant nutritious rice powder include, by mass fraction: 67 parts of rice powder, 31 parts of coffee powder, 4 parts of coconut powder, 2.5 parts of yam powder, 4 parts of milk powder and 1.1 parts of emulsifier.

5. The instant nutritious rice cereal of coffee flavor as claimed in claim 1, wherein, The proportion of water in the liquid mixture is 50-60 wt%; the inlet temperature of the spray drying is 110-150 DEG C; and the average particle size of the precursor powder is 100-200 mu m.

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