Low-GI high-dietary-fiber konjac coarse cereal instant food and preparation method thereof

Abstract

The invention belongs to the technical field of foods, and particularly relates to a low-GI high-dietary-fiber konjac coarse cereal instant food and a preparation method thereof. According to the present invention, the low glycemic index raw materials are selected, the konjak rice is adopted as the main material, and various coarse cereals are added as the auxiliary materials, such that the konjak rice flour is processed, can be suitable for special crowds with diabetes mellitus and the like and general crowds, and has characteristics of rich taste and rich aroma. After the raw materials are sequentially fermented and enzymolyzed, the oxidation resistance and caking property of the product are improved, the storage performance is improved, the shelf life is prolonged, and the nutritional value is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of food, and in particular relates to a low-GI high-dietary-fiber konjac and coarse-grain instant food and a preparation method thereof. Background Art

[0002] With the improvement of modern people's living standards and changes in dietary structure, the incidence of chronic metabolic diseases has increased year by year. In particular, diseases closely related to diet, such as obesity, diabetes, and cardiovascular disease, have become a major global public health issue. Studies have shown that the intake of low-glycemic index (Low Glycemic Index, referred to as low GI) foods and high-fiber foods in the diet can help improve blood sugar control, enhance satiety, regulate lipid metabolism, and promote intestinal health. Therefore, the development of functional foods with low GI values ​​and rich in dietary fiber has become a research hotspot in the field of food science and nutrition.

[0003] Instant porridge is a convenient food in modern fast-paced life, and its variety is increasing. Konjac rice is made from konjac flour and micronized powder as main ingredients and is made with a unique process. This product is a low-calorie artificial rice rich in soluble dietary fiber and is an ideal healthy staple food for people with hypertension, high blood sugar, diabetes, and obesity. Konjac rice has low calories, and the glucomannan (water-soluble dietary fiber) in it swells when exposed to water, forming a gel in the stomach, which can significantly prolong the time of fullness, making it increasingly popular in the market.

[0004] However, the primary chemical component of konjac rice is konjac glucomannan, a natural high-molecular-weight polysaccharide with a complex structure. Its backbone is composed of D-glucose and D-mannose polymerized via β-(1→4)-pyranosidic bonds, but its exact structure remains uncertain. While ready-to-eat products made with konjac rice are commercially available, research has shown that long-term storage can affect their stability, leading to decreased quality and a shortened shelf life. Summary of the Invention

[0005] The invention aims to provide a low-GI high-dietary-fiber konjac grain instant food and a preparation method thereof.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] The first aspect of the present invention provides a method for preparing a low GI high dietary fiber konjac grain instant food, comprising the following steps:

[0008] (1) Weigh the following grain raw materials: buckwheat kernels, tricolor quinoa, sorghum rice, red beans, chickpeas, highland barley, red lentils, oat grains, purple glutinous rice, coix seeds, black beans, and konjac rice, clean them, dry them to constant weight, grind and sieve them to obtain mixed powder;

[0009] (2) mixing the mixed powder and water in a mass-to-volume ratio of 1:(15-20), heating to 95-100° C., keeping warm for 80-120 minutes, then cooling to 35-40° C., adding mixed bacteria at a concentration of 0.1-0.2% by weight of the mixed powder, keeping warm and fermenting for 15-20 hours, sterilizing, and cooling to obtain a fermentation product;

[0010] (3) adding 0.1-0.2% of the mixed powder mass of the complex enzyme to the fermentation product, adjusting the pH to 4.0-5.5 with citric acid, performing enzymolysis at 40-50° C. for 40-50 min, inactivating the enzyme, and cooling to obtain a low GI high dietary fiber konjac grain instant food.

[0011] Preferably, the coarse grain raw materials include the following raw materials in percentage by mass: buckwheat kernel 1-5%, tricolor quinoa 1-4%, sorghum rice 1-6%, red bean 1-5%, chickpea 1-7%, highland barley 1-6%, red lentil 1-5%, oat grain 1-8%, purple glutinous rice 1-5%, coix seed 1-7%, black bean 1-5%, and the balance is konjac rice.

[0012] Preferably, the miscellaneous grain raw materials include the following raw materials in percentage by mass: buckwheat kernel 3.30%, tricolor quinoa 3.30%, sorghum rice 3.30%, red bean 3.30%, chickpea 2.20%, highland barley 2.20%, red lentil 2.20%, oat grain 2.20%, purple glutinous rice 3.30%, coix seed 2.20%, black bean 2.20%, and the balance is konjac rice.

[0013] Preferably, the mixed bacteria include Acetobacter pasteurianus and Streptococcus faecalis.

[0014] Preferably, the ratio of the number of live bacteria of Acetobacter pasteurianus and Streptococcus faecalis in the mixed bacteria is 1:(2-3).

[0015] Preferably, the ratio of the number of live bacteria of Acetobacter pasteurianus and Streptococcus faecalis in the mixed bacteria is 1:2.5.

[0016] The invention uses konjac rice as the main raw material, combines it with a composite formula of multiple grains, and introduces a specific microbial fermentation process to carry out targeted degradation of the konjac glucomannan therein. By optimizing the fermentation conditions, the molecular weight of the glucomannan is effectively controlled in the system of the invention, the viscosity is reduced, and a balance is achieved with taste adaptability.

[0017] Preferably, the complex enzyme comprises β-glucanase, α-amylase and pullulanase.

[0018] Preferably, the enzyme activity ratio of β-glucanase, α-amylase and pullulanase in the complex enzyme is 1:(1.2-1.4):(0.5-0.7).

[0019] Preferably, the enzyme activity ratio of β-glucanase, α-amylase and pullulanase in the complex enzyme is 1:1.3:0.6.

[0020] The present invention significantly improves the anti-caking performance of the product through the synergistic treatment of fermentation and enzymatic hydrolysis, and is also beneficial for improving the product's brewing solubility, smooth taste and processing stability.

[0021] The invention provides a low-GI high-dietary-fiber konjac grain instant food prepared by the preparation method.

[0022] Compared with the prior art, the advantages and beneficial effects of the present invention are:

[0023] 1. The present invention provides a low-GI and high-dietary-fiber konjac and coarse-grain instant food, which is made by selecting raw materials with a low glycemic index (GI), using konjac rice as the main ingredient and adding various coarse grains as auxiliary ingredients. The low-GI and high-dietary-fiber konjac and coarse-grain instant food can be applied to special groups such as those suffering from diabetes and the general population, and has a rich taste and strong aroma.

[0024] 2. The present invention uses konjac rice as the main raw material, combines a composite formula of various cereals, and introduces a specific microbial fermentation process to carry out targeted degradation of the konjac glucomannan therein. By optimizing the fermentation conditions, effective control of the molecular weight of the glucomannan is achieved in the system of the present invention, reducing the viscosity while achieving a balance with the taste adaptability.

[0025] 3. The present invention uses fermentation and enzymatic hydrolysis to synergistically process, thereby significantly improving the anti-caking performance of the product during long-term storage. It has strong antioxidant properties and can maintain its taste during long-term storage. It is especially suitable for consumers such as the elderly, fitness enthusiasts, and sub-healthy groups who have high demands for convenient nutritional intake. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic diagram of the basic information of the test report of the low GI high dietary fiber konjac grain instant food prepared in Example 1;

[0027] Figure 2 This is a schematic diagram of the test report results of the low-GI, high-dietary fiber konjac and miscellaneous grains instant food prepared in Example 1. DETAILED DESCRIPTION

[0028] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0029] The raw materials used in the following examples of the present invention are all commercially available commodities:

[0030] Streptococcus faecalis, product number HZB115945, Wuhan Huizao Biotechnology Co., Ltd. Hangzhou Branch.

[0031] Acetobacter pasteurianus, product number HZB171365, Wuhan Huizao Biotechnology Co., Ltd. Hangzhou Branch.

[0032] Lactobacillus rhamnosus, product number: HZB115392, Wuhan Huizao Biotechnology Co., Ltd.

[0033] Lactobacillus acidophilus, HZB111770, Wuhan Huizao Biotechnology Co., Ltd. Hangzhou Branch.

[0034] Lactobacillus delbrueckii, product number HZB139506, Wuhan Huizao Biotechnology Co., Ltd. Hangzhou Branch.

[0035] Lactobacillus plantarum, product number HZB116349, Wuhan Huizao Biotechnology Co., Ltd. Hangzhou Branch.

[0036] Lactobacillus casei, product number HZB116347, Wuhan Huizao Biotechnology Co., Ltd. Hangzhou Branch.

[0037] Lactobacillus bulgaricus, product number HZB116558, Wuhan Huizao Biotechnology Co., Ltd. Hangzhou Branch.

[0038] β-glucanase, Product No. S23089; α-amylase, Product No. S10003; pullulanase, Product No. S10042; cellulase, Product No. S10042; lipase, Product No. S25959; acid protease, Product No. S10012; Shanghai Yuanye Biotechnology Co., Ltd.

[0039] The konjac rice in the following examples and comparative examples was purchased from Huizhou Wangjia Food Co., Ltd.

[0040] Example 1

[0041] This embodiment provides a low GI high dietary fiber konjac grain instant food, the preparation method of which comprises the following steps:

[0042] (1) Weighing a raw material of miscellaneous grains, wherein the raw material of miscellaneous grains comprises the following raw materials in percentage by mass: 3.30% buckwheat kernel, 3.30% tricolor quinoa, 3.30% sorghum rice, 3.30% red bean, 2.20% chickpea, 2.20% highland barley, 2.20% red lentil, 2.20% oat grain, 3.30% purple glutinous rice, 2.20% coix seed, 2.20% black bean, and the balance is konjac rice; washing, drying to constant weight, and grinding through a 60-mesh sieve to obtain a mixed powder;

[0043] (2) Mix the mixed powder and water in a mass volume ratio of 1:16, heat to 100°C, keep warm for 100 minutes, then cool to 37°C to obtain a fermentation material, add mixed bacteria, and the number of viable bacteria in the fermentation material is 10 7 CFU / mL, the mixed bacteria include Acetobacter pasteurianus and Streptococcus faecalis; the ratio of the number of viable bacteria of Acetobacter pasteurianus and Streptococcus faecalis in the mixed bacteria is 1:2.5; the anaerobic fermentation is carried out at room temperature for 18 hours, sterilized, and cooled to obtain a fermentation product;

[0044] (3) Adding 0.16% of the mass of the mixed powder to the fermentation product, the complex enzyme includes β-glucanase, α-amylase and pullulanase; the enzyme activity ratio of β-glucanase, α-amylase and pullulanase in the complex enzyme is 1:1.3:0.6; using citric acid to adjust the pH to 5, enzymatically hydrolyzing at 45°C for 45 minutes, inactivating the enzyme, cooling, and sterilizing to obtain a low GI high dietary fiber konjac grain instant food.

[0045] Example 2

[0046] This embodiment provides a low GI high dietary fiber konjac grain instant food, the preparation method of which comprises the following steps:

[0047] (1) Weighing a raw material of miscellaneous grains, wherein the raw material of miscellaneous grains comprises the following raw materials in percentage by mass: 3.30% buckwheat kernel, 3.30% tricolor quinoa, 3.30% sorghum rice, 3.30% red bean, 2.20% chickpea, 2.20% highland barley, 2.20% red lentil, 2.20% oat grain, 3.30% purple glutinous rice, 2.20% coix seed, 2.20% black bean, and the balance is konjac rice; washing, drying to constant weight, and grinding through a 60-mesh sieve to obtain a mixed powder;

[0048] (2) Mix the mixed powder and water in a mass volume ratio of 1:16, heat to 95°C, keep warm for 80 minutes, then cool to 35°C to obtain a fermentation material, add mixed bacteria, and the number of viable bacteria in the fermentation material is 10 7 CFU / mL, wherein the mixed bacteria include Acetobacter pasteurianus and Streptococcus faecalis; the ratio of the number of live bacteria of Acetobacter pasteurianus and Streptococcus faecalis in the mixed bacteria is 1:2; the mixture is subjected to anaerobic fermentation at room temperature for 20 hours, sterilized, and cooled to obtain a fermentation product;

[0049] (3) Adding 0.1% of the mass of the mixed powder to the fermentation product, the complex enzyme includes β-glucanase, α-amylase and pullulanase; the enzyme activity ratio of β-glucanase, α-amylase and pullulanase in the complex enzyme is 1:1.4:0.5; using citric acid to adjust the pH to 5.5, enzymatic hydrolysis at 40°C for 50 minutes, inactivating the enzyme, cooling, and sterilizing to obtain a low GI high dietary fiber konjac grain instant food.

[0050] Example 3

[0051] This embodiment provides a low GI high dietary fiber konjac grain instant food, the preparation method of which comprises the following steps:

[0052] (1) Weighing a raw material of miscellaneous grains, wherein the raw material of miscellaneous grains comprises the following raw materials in percentage by mass: 3.30% buckwheat kernel, 3.30% tricolor quinoa, 3.30% sorghum rice, 3.30% red bean, 2.20% chickpea, 2.20% highland barley, 2.20% red lentil, 2.20% oat grain, 3.30% purple glutinous rice, 2.20% coix seed, 2.20% black bean, and the balance is konjac rice; washing, drying to constant weight, and grinding through a 60-mesh sieve to obtain a mixed powder;

[0053] (2) Mix the mixed powder and water in a mass volume ratio of 1:16, heat to 100°C, keep warm for 120 minutes, then cool to 40°C to obtain a fermentation material, add mixed bacteria, and the number of viable bacteria in the fermentation material is 10 7 CFU / mL, the mixed bacteria include Acetobacter pasteurianus and Streptococcus faecalis; the ratio of the number of viable bacteria of Acetobacter pasteurianus and Streptococcus faecalis in the mixed bacteria is 1:3; the anaerobic fermentation is carried out at a temperature of 15 hours, sterilized, and cooled to obtain a fermentation product;

[0054] (3) Adding 0.2% of the mass of the mixed powder to the fermentation product, the complex enzyme includes β-glucanase, α-amylase and pullulanase; the enzyme activity ratio of β-glucanase, α-amylase and pullulanase in the complex enzyme is 1:1.2:0.7; using citric acid to adjust the pH to 4.0, enzymatically hydrolyzing at 50°C for 40 minutes, inactivating the enzyme, cooling, and sterilizing to obtain a low GI high dietary fiber konjac grain instant food.

[0055] Comparative Example 1

[0056] The difference between this comparative example and Example 1 is that the ratio of the number of live bacteria of Acetobacter pasteurianus and Streptococcus faecalis in the mixed bacteria is 1:0.5.

[0057] Comparative Example 2

[0058] The difference between this comparative example and Example 1 is that the ratio of the number of live bacteria of Acetobacter pasteurianus and Streptococcus faecalis in the mixed bacteria is 1:4.

[0059] Comparative Example 3

[0060] The difference between this comparative example and Example 1 is that the mixed bacteria include Lactobacillus plantarum and Lactobacillus bulgaricus, and the ratio of the number of live bacteria of Lactobacillus plantarum to Lactobacillus bulgaricus in the mixed bacteria is 1:2.5.

[0061] Comparative Example 4

[0062] The difference between this comparative example and Example 1 is that the mixed bacteria include Lactobacillus rhamnosus and Lactobacillus delbrueckii, and the ratio of the number of live bacteria of Lactobacillus rhamnosus and Lactobacillus delbrueckii in the mixed bacteria is 1:2.5.

[0063] Comparative Example 5

[0064] The difference between this comparative example and Example 1 is that the mixed bacteria include Lactobacillus casei and Lactobacillus acidophilus, and the ratio of the number of live bacteria of Lactobacillus casei to Lactobacillus acidophilus in the mixed bacteria is 1:2.5.

[0065] Comparative Example 6

[0066] The difference between this comparative example and Example 1 is that the mixed bacteria are replaced by Acetobacter pasteurianus.

[0067] Comparative Example 7

[0068] The difference between this comparative example and Example 1 is that the composite enzyme includes cellulase, lipase and acid protease; and the enzymatic activity ratio of cellulase, lipase and acid protease in the composite enzyme is 1:1.4:0.5.

[0069] Comparative Example 8

[0070] The difference between this comparative example and Example 1 is that the complex enzyme is replaced by α-amylase.

[0071] Comparative Example 9

[0072] The difference between this comparative example and Example 1 is that the composite enzyme includes α-amylase and pullulanase; and the enzyme activity ratio of α-amylase to pullulanase in the composite enzyme is 1.4:0.5.

[0073] Comparative Example 10

[0074] The difference between this comparative example and Example 1 is that the low GI high dietary fiber konjac grain instant food is prepared by a method comprising the following steps:

[0075] (1) Weighing a raw material of miscellaneous grains, wherein the raw material of miscellaneous grains comprises the following raw materials in percentage by mass: 3.30% buckwheat kernel, 3.30% tricolor quinoa, 3.30% sorghum rice, 3.30% red bean, 2.20% chickpea, 2.20% highland barley, 2.20% red lentil, 2.20% oat grain, 3.30% purple glutinous rice, 2.20% coix seed, 2.20% black bean, and the balance is konjac rice; washing, drying to constant weight, and grinding through a 60-mesh sieve to obtain a mixed powder;

[0076] (2) The mixed powder and water were mixed in a mass volume ratio of 1:16, heated to 100°C, kept warm for 100 minutes, then cooled to 37°C, kept warm for 18 hours, and cooled to obtain a low GI high dietary fiber konjac grain instant food.

[0077] Performance Testing

[0078] 1. The low GI high dietary fiber konjac grain instant foods prepared in Examples 1-3 and Comparative Examples 1-10 were first concentrated under reduced pressure and then spray-dried to obtain solid powders.

[0079] (1) Color change: Weigh 80 g of solid powder as a sample and spread it flat with a thickness of 3 mm. At a temperature of 40°C, a humidity of 80% RH, and an illumination of 800 Lux, use a colorimeter to regularly measure the L, a*, and b* values ​​of the sample. The color change is quantified according to the formula ΔE = [(Δa) 2 +(Δb) 2 +(ΔL) 2 ] 1 / 2 , test once every 12 hours, and count the time when the change ΔE>2 is noticeable;

[0080] (2) Viscosity Determination: Add 100g of water to 1g of solid powder, stir thoroughly, and measure the viscosity using a viscometer. The unit is mPa·s. Use a No. 4 rotor at 60 rpm. Viscosity = K·average value measured by the digital viscometer. Where K is the viscosity coefficient (K = 100).

[0081] 2. Agglomeration: The low-GI, high-fiber konjac grain instant foods prepared in Examples 1-3 and Comparative Examples 1-10 were sterilized, sealed, and stored at room temperature for 12 months. After opening, the products were gently poured out and the agglomeration observed. 0 - No agglomeration; 1 - Slightly agglomerated, disintegrates upon light touch; 2 - Small lumps that can be broken with slight force; 3 - Large lumps that require vigorous crushing; 4 - Agglomerated.

[0082] 3. The low GI, high dietary fiber, konjac and coarse grain instant foods prepared in Examples 1-3 and Comparative Examples 1-10 were subjected to a taste evaluation. 20 volunteers were selected for scoring, with a male-to-female ratio of 1:1 and an age range of 25-45 years. The overall satisfaction score for the overall taste of the product was 10 points.

[0083] Table 1 Performance test results

[0084]

[0085]

[0086] As shown in Table 1, Examples 1-3 can improve the antioxidant properties of the products by subjecting the cereal raw materials to enzymatic hydrolysis and fermentation, thereby increasing the anti-caking properties and improving the storage stability, which are significantly better than the product in Comparative Example 10 that is not subjected to microbial treatment.

[0087] The instant product prepared by the present invention comprises konjac rice as its main component, which is konjac glucomannan. Existing studies have found that konjac glucomannan with relatively low viscosity has significant preventive and therapeutic effects in enhancing immunity, intestinal health, weight loss, lowering blood sugar and blood lipids, and anti-aging. As shown in Table 1, Examples 1-3 can reduce the viscosity of the konjac glucomannan in the system of the present invention through fermentation and enzymolysis, thereby improving the health benefits of the instant product.

[0088] At the same time, Examples 1-3 of the present invention ferment and enzymatically hydrolyze the coarse grain raw materials, so that the product has a higher sensory evaluation, not only has high nutritional value, but also has a taste that is deeply loved by consumers.

[0089] The above is 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 principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for preparing a low GI high dietary fiber konjac cereal instant food, characterized in that: The following steps are included: (1) Weigh the following grain raw materials: buckwheat kernels, tricolor quinoa, sorghum rice, red beans, chickpeas, highland barley, red lentils, oat grains, purple glutinous rice, coix seeds, black beans, and konjac rice, clean them, dry them to constant weight, grind and sieve them to obtain mixed powder; (2) mixing the mixed powder and water, heating, keeping the temperature, then cooling, adding the mixed bacteria, keeping the temperature and fermenting, sterilizing, and cooling to obtain a fermentation product; (3) adding complex enzyme to the fermentation product, adjusting the pH, performing enzymolysis, inactivating the enzyme after the enzymolysis is completed, cooling, and obtaining a low-GI high-dietary-fiber konjac grain instant food.

2. the preparation method of low GI high dietary fiber konjac coarse grains instant food according to claim 1, is characterized in that, The coarse grain raw materials include the following raw materials in percentage by mass: 1-5% buckwheat kernel, 1-4% tricolor quinoa, 1-6% sorghum rice, 1-5% red bean, 1-7% chickpea, 1-6% highland barley, 1-5% red lentil, 1-8% oat grain, 1-5% purple glutinous rice, 1-7% coix seed, 1-5% black bean, and the balance is konjac rice.

3. the preparation method of low GI high dietary fiber konjac coarse grains instant food according to claim 1, is characterized in that, The mixed bacteria include Acetobacter pasteurianus and Streptococcus faecalis.

4. the preparation method of low GI high dietary fiber konjac coarse grains instant food according to claim 3, is characterized in that, The ratio of the number of live bacteria of Acetobacter pasteurianus and Streptococcus faecalis in the mixed bacteria is 1:(2-3).

5. the preparation method of low GI high dietary fiber konjac coarse grains instant food according to claim 1, is characterized in that, The conditions for heat preservation and fermentation are: heat preservation and fermentation at 35-40℃ for 15-20h.

6. the preparation method of low GI high dietary fiber konjac coarse grains instant food according to claim 1, is characterized in that, The complex enzyme comprises beta-glucanase, alpha-amylase and pullulanase.

7. The preparation method of the low GI high dietary fiber konjac coarse grains instant food according to claim 6, wherein The enzyme activity ratio of beta-glucanase, alpha-amylase and pullulanase in the complex enzyme is 1:(1.2-1.4):(0.5-0.7).

8. The preparation method of low GI high dietary fiber konjac coarse grains instant food according to claim 1, wherein The conditions for enzymatic hydrolysis are: enzymatic hydrolysis at 40-50°C for 40-50 minutes.

9. the preparation method of low GI high dietary fiber konjac coarse grains instant food according to claim 1, is characterized in that, In step (2), the temperature is heated to 95-100° C. and kept warm for 80-120 minutes.

10. A low GI high dietary fiber konjac grain instant food prepared by the preparation method according to any one of claims 1 to 9.

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