Fermentation inoculant for improving puffing performance and nutritional quality of brown rice and application of fermentation inoculant

Abstract

The invention provides a fermentation inoculant for improving puffing performance and nutritional quality of brown rice and application thereof, and belongs to the technical field of food deep processing. The fermentation inoculant for improving the puffing performance and the nutritional quality of the brown rice is composed of bacillus amyloliquefaciens and aspergillus oryzae according to the ratio of (2-3): 1. Through the synergistic effect of the complex microbial inoculants, cellulase, hemicellulase and protease secreted by aspergillus oryzae can break a brown rice bran barrier and degrade macromolecular protein, amylase secreted by bacillus amyloliquefaciens can improve the starch gelatinization efficiency, and meanwhile the content of antinutritional factors is reduced. The final puffed brown rice powder has the characteristics of high expansion rate, loose texture, high nutrition utilization rate, excellent brewing performance and the like, solves the problems of poor puffing performance, low nutrition absorption and easy caking during brewing in traditional brown rice processing, and is suitable for industrial production of instant nutritious food.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of food deep processing, and particularly relates to a fermentation agent for improving the bulking performance and nutritional quality of brown rice and application thereof. BACKGROUND

[0002] Brown rice, as a whole grain after hulling, retains bran, endosperm and germ, and is rich in dietary fiber, vitamins (such as B vitamins and vitamin E), minerals (such as potassium, magnesium and iron) and functional ingredients (such as gamma-aminobutyric acid and polyphenols), and has high nutritional value and health benefits. However, the processing and application of brown rice are limited by its own characteristics, including: The outer layer of brown rice is composed of dense cellulose, hemicellulose and lignin, forming a hard physical barrier, and the starch in the endosperm is tightly wrapped by a protein network, making it difficult for water and steam to penetrate during bulking processing, resulting in low expansion rate, hard texture, and easy occurrence of "undercooked" or local scorched products, and poor palatability. Brown rice contains anti-nutritional factors such as phytic acid and tannin, among which phytic acid can combine with minerals such as calcium, iron and zinc to form insoluble complexes, reducing the bioavailability of minerals; at the same time, the protein and starch in brown rice exist in the form of macromolecules, which limits the play of its nutritional value. After untreated brown rice is ground, due to the hydrophobicity of dietary fiber and the low gelatinization degree of starch, it is easy to form lumps and settle during rehydration, and the taste is rough, which is difficult to meet the convenience requirements of instant food.

[0003] To improve the processing performance of brown rice, the existing technology mostly uses physical or chemical treatment, but single physical treatment cannot completely break down the bran barrier; chemical treatment can easily lead to loss of nutritional ingredients and may also introduce chemical residues, which is not in line with the trend of green processing. Microbial fermentation, as a natural and efficient biological transformation technology, is gradually applied in grain processing. Therefore, it is of important practical value to develop a complex fermentation agent that can synergistically decompose the bran, protein and starch of brown rice, and comprehensively improve the bulking performance, nutritional quality and rehydration performance of brown rice. SUMMARY

[0004] Therefore, the present application aims to provide a fermentation agent for improving the bulking performance and nutritional quality of brown rice and application thereof, which can obtain a brown rice processing product with excellent bulking performance, high nutritional utilization rate and good rehydration performance through fermentation treatment.

[0005] To achieve the above-mentioned application purposes, the present application provides the following technical solutions: A fermentation agent for improving the bulking performance and nutritional quality of brown rice, which is composed of Bacillus amyloliquefaciens and Aspergillus oryzae at a ratio of 2-3:1.

[0006] Preferably, the viable count of the Bacillus amyloliquefaciens is ≥1×109 CFU / g; the viable cell count of the Aspergillus oryzae is ≥1x10 9 CFU / g.

[0007] The application further provides application of the fermentation agent in preparation of the puffed brown rice instant powder.

[0008] The application further provides a preparation method of the puffed brown rice instant powder. The brown rice is soaked and activated after being washed, and then inoculated with the fermentation agent for fermentation; after the fermentation is completed, the fermented brown rice is dried, puffed, and then crushed into powder after being cooled.

[0009] Preferably, after being washed, the brown rice is soaked in distilled water at 30-35 DEG C for 4-6h until the water content of the brown rice is 35%-40%.

[0010] Preferably, the inoculation amount of the fermentation agent is 3-5wt%, and the fermentation is carried out at 30-32 DEG C and under the environment with a relative humidity of 70%-80% for 8-12h.

[0011] Preferably, the water content of the dried fermented brown rice is 12-15%; and the puffing is carried out by extrusion puffing, and the screw rotation speed is 200-250r / min, and the puffing temperature is 150-160 DEG C.

[0012] Preferably, the crushing particle size of the puffed brown rice instant powder is 80-100 meshes.

[0013] Preferably, the method further comprises adding auxiliary materials after the crushing into powder; the auxiliary materials comprise 1-2wt% of soluble dietary fiber and / or nutritional auxiliary materials.

[0014] The application further provides the puffed brown rice instant powder prepared by the preparation method.

[0015] Compared with the prior art, the application has the following beneficial effects: The compound microbial agent can provide sufficient power for puffing through enzyme system cooperation, so that the expansion rate of the brown rice is increased to more than 270%, the texture of the puffed product is loose, the hardness is reduced by more than 50%, the "undercooked" or "burnt" phenomenon is effectively avoided, and the palatability is significantly improved.

[0016] The fermentation-puffing preparation can synergistically degrade phytic acid, tannin and other anti-nutritional factors, reduce the chelation of calcium, iron, zinc and other minerals, and degrade macromolecular proteins and starch into small molecular peptides, amino acids and oligosaccharides, so as to improve the in-vitro digestion rate of the proteins and starch and greatly improve the nutrient absorption efficiency. In addition, the fermentation process can retain or even increase the content of functional components such as gamma-aminobutyric acid and polyphenol, and enhance the health value of the product.

[0017] The solubility of the expanded brown rice instant powder formed after fermentation and expansion is obviously improved, the dispersion time is shortened, the sedimentation rate is reduced, and the viscosity is moderate, solving the problems of traditional brown rice powder, such as easy caking and rough taste, and meeting the convenience demand of instant food. DETAILED DESCRIPTION

[0018] The present application provides a kind of fermentation inoculant for improving the expansion performance and nutritional quality of brown rice, which is composed of Bacillus amyloliquefaciens and Aspergillus oryzae at a ratio of 2-3:1;Preferably, the viable count of Bacillus amyloliquefaciens is ≥1×10 9 CFU / g, and the viable count of Aspergillus oryzae is ≥1×10 9 CFU / g (in terms of spore count). The present application does not have special limitations on the specific sources of Bacillus amyloliquefaciens and Aspergillus oryzae, and commonly used strains in the art can be used. As an implementable way, the preservation number of Bacillus amyloliquefaciens in the present application is CICC 10079, and the preservation number of Aspergillus oryzae is CGMCC No.40917, which can be purchased through market channels.

[0019] The present application also provides the use of the above-mentioned fermentation inoculant in the preparation of expanded brown rice instant powder.

[0020] The present application provides a preparation method of expanded brown rice instant powder, which comprises raw material pretreatment, fermentation, drying after fermentation, expansion and powdering, and the specific steps are as follows: (1) Raw material pretreatment - after washing brown rice, soak and activate it to lay a foundation for fermentation and expansion.

[0021] In the present application, the impurities, broken particles and immature particles of brown rice are preferably removed, and full brown rice is selected, washed and drained of surface moisture; further preferably, the thousand-grain weight of brown rice is ≥25g. The screening step can reduce bacterial contamination, ensure the uniformity of raw materials, and avoid the influence of impurities on the stability of fermentation and expansion.

[0022] In the present application, after washing brown rice, it is soaked in distilled water at 30-35℃ for 4-6h, further preferably in distilled water at 32℃ for 5h, until the moisture content of brown rice is 35%-40%; more preferably, the solid-liquid ratio of brown rice to distilled water is 1:3, and the water is changed 1-2 times during soaking. Moderate water absorption can soften the brown rice skin layer, facilitating subsequent microbial decomposition; at the same time, it activates endogenous enzymes in brown rice, assisting the fermentation process.

[0023] (2) Fermentation stage - inoculate Bacillus amyloliquefaciens and Aspergillus oryzae for fermentation to target improve the expansion potential and nutritional basis.

[0024] In the present application, preferably the inoculation amount of the fermentation agent is 3-5wt%, further preferably the inoculation amount is 4wt%, and the inoculation is stirred uniformly; preferably the fermentation temperature is 30-32℃, and the relative humidity is 70%-80%; preferably the fermentation time is 8-12h, further preferably 10h, and more preferably the fermentation is stirred once every 4h. In the initial stage of fermentation, Aspergillus oryzae rapidly secretes cellulase and hemicellulase, preferentially decomposes cellulose and hemicellulose in the bran of brown rice, breaks the dense physical barrier, makes the structure of the bran loose, creates conditions for the subsequent penetration of enzymes and steam penetration during puffing, and the secreted acid protease can synergistically decompose the protein in the brown rice, converts the macromolecular protein into small molecular peptides and amino acids, and releases the restraint of the protein network on the starch granules. Bacillus amyloliquefaciens can secrete high-activity alpha-amylase and glucoamylase, moderately degrades the starch in the endosperm of brown rice, converts part of the starch into oligosaccharides and glucose, improves the gelatinization efficiency of starch, and provides sufficient power for volume expansion during puffing, at the same time, a small amount of organic acid produced can reduce the pH of the fermentation system to 4.2-4.5, inhibit the pollution of miscellaneous bacteria, and the acidic environment can further promote the activity of cellulase and protease.

[0025] (3) drying after fermentation, controlling the moisture content, and adapting to the puffing requirement.

[0026] In the present application, the fermented brown rice is preferably dried to a moisture content of 12-15%, further preferably 13-14%, and more preferably hot air drying is adopted: the fermented brown rice is spread flat (thickness ≤2cm), placed in a hot air drying box at 40-45℃, and dried to a moisture content of 12%-15%, during which the brown rice is turned over 2-3 times to avoid local over-drying or over-wetting. If the moisture content is too high (>15%), the brown rice is prone to adhere to the screw during puffing, causing local overheating and carbonization, and reducing the puffing rate; if the moisture content is too low (<12%), the raw material is too hard, and insufficient steam is generated during puffing, resulting in a dense and hard product. Low-temperature drying can avoid the destruction of the soluble nutrients produced during fermentation by high temperature.

[0027] (4) in the puffing stage, the porous structure of the brown rice is strengthened, and the brewing performance is improved.

[0028] In the present application, preferably, extrusion puffing is adopted, the screw rotation speed is 200-250r / min, further preferably 220-230r / min, to ensure sufficient shearing and mixing of the raw material; preferably, the puffing temperature is 150-160℃, further preferably the temperature gradient is 80-90℃ in the feeding zone→120-130℃ in the compression zone→150-160℃ in the puffing zone→130-140℃ in the discharge zone, and more preferably the temperature gradient is 85℃ in the feeding zone→125℃ in the compression zone→155℃ in the puffing zone→135℃ in the discharge zone, to avoid local overheating; preferably, the die diameter of the extrusion puffing is 2-3mm, to make the particles after puffing more uniform. The double-screw extrusion puffing machine used in the present application is not particularly limited, and a commonly used type in the art can be adopted.

[0029] (5) Cooling and shaping.

[0030] In the present application, the puffed brown rice is preferably cooled naturally to room temperature (about 25℃) to avoid structure shrinkage and cracking caused by rapid cooling; further preferably, the water content of the puffed brown rice after cooling is ≤5%.

[0031] (6) Grinding to improve the brewing performance.

[0032] In the present application, the grinding particle size of the puffed brown rice is preferably 80-100 mesh; further preferably, the puffed brown rice after cooling is first coarsely ground to 40 mesh to remove a small amount of un-puffed hard core, and then finely ground to 80-100 mesh. Too small particle size (>100 mesh) is easy to agglomerate and clump; too coarse particle size (<80 mesh) has a granular feeling after brewing, and 80-100 mesh can balance the dispersibility and taste.

[0033] (7) Formulation to further improve the brewing performance or to impart more nutritional ingredients.

[0034] In the present application, the following auxiliary materials are preferably added according to the weight of the puffed brown rice: 1-2wt% of soluble dietary fiber, further preferably 1.5wt%, and more preferably selected from one or more of inulin, fructooligosaccharides, and resistant dextrin. Soluble dietary fiber can improve the dispersibility during brewing and avoid sedimentation.

[0035] In the present application, nutritional auxiliary materials are preferably also added, including but not limited to: complex vitamins (vitamin B1, B2, B6, vitamin E), minerals (calcium carbonate, ferrous lactate, zinc gluconate), and plant extracts (green tea extract, gynostemma pentaphyllum polysaccharide), etc.

[0036] As an implementable manner, a three-dimensional mixer (rotation speed 30r / min, mixing time 15min) is used for formulation to ensure uniform dispersion of the auxiliary materials.

[0037] (8) Packaging to ensure shelf life and nutritional stability.

[0038] The puffed brown rice powder of the present application is subjected to puffing treatment, and has low water content after cooling, so it does not need to be sterilized and can be directly packaged.

[0039] The present application also provides a puffed brown rice brewing powder prepared by the above preparation method.

[0040] The technical solutions provided by the present application will be described in detail below in conjunction with examples, but they should not be understood as limiting the scope of protection of the present application.

[0041] Example 1 A fermentation agent for improving the puffing performance and nutritional quality of brown rice, prepared by the following method: Strain selection: Bacillus amyloliquefaciens (CICC 10079) and Aspergillus oryzae (CGMCC No. 40917) were selected.

[0042] Preparation of the bacterial agent: the activated Bacillus amyloliquefaciens and Aspergillus oryzae were mixed at a ratio of 2:1 in terms of viable bacterial count, wherein the viable bacterial count of Bacillus amyloliquefaciens was ≥1.0×10 9 CFU / g, and the viable bacterial count (spore count) of Aspergillus oryzae was ≥1.0×10 9 CFU / g, and the mixture was uniformly mixed and vacuum freeze-dried to prepare the compound fermentation bacterial agent.

[0043] Example 2 A fermentation bacterial agent for improving the puffing performance and nutritional quality of brown rice was prepared by the following method: Strain selection: Bacillus amyloliquefaciens (CICC 10079) and Aspergillus oryzae (CGMCC No. 40917) were selected.

[0044] Preparation of the bacterial agent: the activated Bacillus amyloliquefaciens and Aspergillus oryzae were mixed at a ratio of 3:1 in terms of viable bacterial count, wherein the viable bacterial count of Bacillus amyloliquefaciens was ≥1.0×10 9 CFU / g, and the viable bacterial count (spore count) of Aspergillus oryzae was ≥1.0×10 9 CFU / g, and the mixture was uniformly mixed and vacuum freeze-dried to prepare the compound fermentation bacterial agent.

[0045] Example 3 A preparation method of a puffed brown rice instant powder was as follows: (1) Raw material pretreatment: full brown rice with a thousand-grain weight of 25 g was selected, impurities were removed, and then the brown rice was washed and soaked in distilled water (solid-liquid ratio 1:3) at 30°C for 4 h (moisture content 35%), and the water was replaced once during the soaking.

[0046] (2) Fermentation: the bacterial agent of Example 1 was added at an inoculation amount of 3 wt%, and the mixture was uniformly stirred and then fermented at 30°C and a relative humidity of 70% for 8 h, with stirring every 4 h.

[0047] (3) Drying: the fermented brown rice was spread flat (thickness 2 cm), and hot air drying was performed at 40°C until the moisture content was 12%, with stirring twice during the drying.

[0048] (4) Puffing: a double-screw extrusion puffing machine was used, the screw rotation speed was 200 r / min, the puffing temperature was 150°C (feed zone 80°C→compression zone 120°C→puffing zone 150°C→discharge zone 130°C), and the die diameter was 2 mm.

[0049] (5) Grinding: after the puffed brown rice was naturally cooled to 25°C, the moisture content was ≤5%, and the brown rice was first coarsely ground to 40 mesh (to remove hard cores), and then finely ground to 80 mesh.

[0050] (6) Blending: add 1 wt% inulin, mix for 15 min at 30 r / min using a three-dimensional mixer.

[0051] (7) Packaging: directly package.

[0052] Example 4 A preparation method of a puffed brown rice instant powder, the steps being as follows: (1) Raw material pretreatment: select plump brown rice with a thousand-grain weight of 26 g, wash and soak in distilled water at 32°C (material-to-liquid ratio of 1:3) for 5 h (moisture content of 37%), and change the water once during the soaking.

[0053] (2) Fermentation: add the inoculant of Example 2 at an inoculation amount of 4 wt%, and ferment at 31°C and a relative humidity of 75% for 10 h, with stirring every 4 h.

[0054] (3) Drying: spread the fermented brown rice (thickness of 2 cm), and dry at 43°C with hot air until the moisture content is 13.5%, with stirring 3 times.

[0055] (4) Puffing: screw speed of 225 r / min, puffing temperature of 155°C (feed zone of 85°C→ compression zone of 125°C→ puffing zone of 155°C→ discharge zone of 135°C), and die diameter of 2.5 mm.

[0056] (5) Grinding: after the puffed brown rice is naturally cooled to 25°C, the moisture content is ≤5%, and the brown rice is first coarsely ground to 40 mesh (to remove hard cores), and then classified and ground to 90 mesh after cooling.

[0057] (6) Blending: add 1.5 wt% resistant dextrin and 1 wt% compound vitamin, and mix for 15 min at 30 r / min using a three-dimensional mixer.

[0058] (7) Packaging: directly package.

[0059] Example 5 A preparation method of a puffed brown rice instant powder, the steps being as follows: (1) Raw material pretreatment: select plump brown rice with a thousand-grain weight of 27 g, wash and soak in distilled water at 35°C (material-to-liquid ratio of 1:3) for 6 h (moisture content of 40%), and change the water twice during the soaking.

[0060] (2) Fermentation: add the inoculant of Example 1 at an inoculation amount of 5 wt%, and ferment at 32°C and a relative humidity of 80% for 12 h, with stirring every 4 h.

[0061] (3) Drying: spread the fermented brown rice (thickness of 2 cm), and dry at 45°C with hot air until the moisture content is 15%, with stirring 3 times.

[0062] (4) Expansion: screw rotation speed 250 r / min, expansion temperature 160°C (feed zone 90°C→ compression zone 130°C→ expansion zone 160°C→ discharge zone 140°C), die diameter 3 mm.

[0063] (5) Pulverization: after the expanded brown rice is naturally cooled to 25°C, the water content is ≤5%, and the brown rice is first coarsely pulverized to 40 mesh (hard core is removed), and then is classified and pulverized to 100 mesh after cooling.

[0064] (6) Blending: 2wt% of oligofructose, 1wt% of wolfberry polysaccharide and 0.1wt% of zinc gluconate are added, and a three-dimensional mixer is mixed at 30 r / min for 15 min.

[0065] (7) Packaging: direct packaging.

[0066] Test Example 1 1. Experimental grouping Five groups of parallel tests (each group is repeated three times) are set, and the same brown rice raw material (thousand-grain weight ≥ 25 g) and subsequent expansion parameters (screw rotation speed 250 r / min, expansion temperature 155°C) are used in each group, and only the fermentation treatment is different: Control group 1 (blank group): after the brown rice is soaked and activated (distilled water soaking at 30°C for 5h, water absorption 35%-40%), no inoculant is inoculated, and direct drying (water content 15%), expansion is performed.

[0067] Control group 2 (single Bacillus amyliquefaciens group): Bacillus amyliquefaciens (viable bacterial count ≥1×10 9 CFU / g) is inoculated, the inoculation amount is 4wt%, and the rest of the steps are the same as the method of the present application (soaking, drying, expansion, etc.).

[0068] Control group 3 (single Aspergillus oryzae group): Aspergillus oryzae (viable bacterial count ≥1×10 9 CFU / g) is inoculated, and the rest of the steps are the same as control group 2.

[0069] Experimental group 1: Bacillus amyliquefaciens (viable bacterial count ≥1×10 9 CFU / g): Aspergillus oryzae (viable bacterial count ≥1×10 9 CFU / g) = 1:1, and the rest of the steps are the same as control group 2.

[0070] Experimental group 2: Bacillus amyliquefaciens (viable bacterial count ≥1×10 9 CFU / g): Aspergillus oryzae (viable bacterial count ≥1×10 9 CFU / g) = 2:1, and the rest of the steps are the same as control group 2.

[0071] Experimental group 3: Bacillus amyliquefaciens (viable bacterial count ≥1×10 9CFU / g): Aspergillus oryzae (viable count ≥ 1 x 10 9 CFU / g) = 3: 1, and the remaining steps are the same as those of the control group 2.

[0072] 2, Index detection Expansion rate: Take the puffed samples of each group, measure the volume (V1) by the drainage method, compare the volume of the raw material before puffing (V0), and calculate the expansion rate = (V1 / V0) x 100%.

[0073] Textural properties: The hardness (g), brittleness (g), and chewiness (g-s) were measured by a texture analyzer (TPA mode), and each sample was measured 5 times to take the average value.

[0074] Microstructure: Take the cross-section of the puffed brown rice, after gold spraying treatment, observe the bran and endosperm structure by scanning electron microscope (SEM), and record the number of pores and average pore size (μm).

[0075] 3, Experimental results As shown in Table 1, the expansion rates of experimental group 2 and experimental group 3 were significantly higher than those of the blank group, single strain group, and experimental group 1. This is because the cellulase and hemicellulase secreted by Aspergillus oryzae effectively break the dense structure of the bran, and the amylase secreted by Bacillus amyloliquefaciens improves the starch gelatinization efficiency. The two work together to provide sufficient steam penetration space and expansion power for puffing, and the synergistic effect is optimal at a ratio of 2:1. The hardness of experimental group 2 was reduced by 50.0% compared with the blank group, the brittleness was increased by 73.1%, and the chewiness was reduced by 46.6%, indicating that its palatability was significantly better than that of other groups. This is related to the loose structure of brown rice after fermentation by the compound microbial agent, which reduces the hard texture after puffing. The number of pores and average pore size of experimental group 2 are much higher than those of the blank group, indicating that the bran barrier is effectively destroyed, forming more loose and porous structure, which provides a physical basis for volume expansion during puffing.

[0076] Table 1 Effect of inoculation of different fermentation agents on the expansion performance of puffed brown rice

[0077] Test Example 2 1, Experimental grouping is the same as that of Test Example 1.

[0078] 2, Index detection Anti-nutritional factor content: Phytic acid: The absorbance of the complex formed by phytic acid and iron ions at 510 nm was measured by the ferric chloride colorimetric method, and the content (mg / 100g) was calculated.

[0079] Tannin: The absorbance at 765 nm was measured by the Folin-phenol spectrophotometric method, and the tannin content (mg / 100g) was converted.

[0080] Mineral bioavailability: In vitro simulated gastrointestinal digestion model (artificial gastric juice + artificial intestinal juice) was used. After digestion, centrifugation was performed, and atomic absorption spectrometer was used to determine the content of calcium, iron and zinc in the supernatant. The soluble proportion (%) = (soluble mineral content / total mineral content) x 100%.

[0081] Protein and starch digestibility: Protein in vitro digestion rate: pepsin-trypsin stepwise digestion was used, and Kjeldahl nitrogen determination method was used to determine the content of free amino acids after digestion, and the digestion rate (%) = (total amino acid content after digestion / total protein content) x 100%.

[0082] Starch in vitro digestion rate: α-amylase-glucoamylase digestion was used, and high performance liquid chromatography (HPLC) was used to determine the glucose release amount, and the digestion rate (%) = (total glucose content / total starch content) x 100%.

[0083] Functional ingredient content: γ-aminobutyric acid (GABA): HPLC method (C18 column, mobile phase: 0.1% phosphoric acid aqueous solution-acetonitrile=95:5, detection wavelength 210nm) was used to determine the content (mg / 100g).

[0084] Polyphenol: Folin-phenol method was used to determine the absorbance at 765nm, and the content (mg / 100g) was calculated with gallic acid as standard.

[0085] 3、Experimental results As shown in Table 2, the phytic acid and tannin contents of experimental group 2 and experimental group 3 were significantly lower than those of the blank group and the single strain group. This is because the cellulase and acid protease of Aspergillus oryzae and the amylase of Bacillus amyloliquefaciens synergistically accelerate the degradation of anti-nutritional factors; the solubility of calcium, iron and zinc is significantly higher than that of the blank group, because the reduction of phytic acid and other anti-nutritional factors reduces the chelation of minerals and improves the bioavailability; the protein and starch digestion rates are significantly higher than those of the blank group, which is due to the synergistic effect of the secreted protease and amylase of the compound microbial agent, which promotes the degradation of macromolecular nutrients; the GABA and polyphenol contents are close to those of the blank group and slightly higher, which proves that the fermentation does not destroy the functional ingredients, but rather promotes the release of some ingredients due to enzymatic action.

[0086] Table 2 Effect of inoculation of different fermentation agents on the nutritional quality of puffed brown rice

[0087] Test Example 3 1、The experimental grouping is the same as that of Test Example 1.

[0088] Each group of puffed brown rice was ground to 100 mesh, 1.5wt% inulin was added, and a brewing powder was processed.

[0089] 2、Index detection Solubility: 5g of the brewing powder was weighed and added to 100mL of 37℃ distilled water, stirred for 2min and then centrifuged (3000r / min, 10min). The supernatant was dried and the solubility (%) was calculated as (supernatant dry weight / 5g) x 100%.

[0090] Dispersion: 5g of the brewing powder was poured into 100mL of 37℃ distilled water and the complete dispersion time (s) was recorded. After standing for 30min, the weight of the sediment was measured and the sedimentation rate (%) was calculated as (sediment weight / 5g) x 100%.

[0091] Viscosity: The viscosity (mPa・s) of the solution after brewing was measured using a rotational viscometer (37℃, 60r / min).

[0092] Sensory evaluation: A 10-person professional panel scored the color (1-5 points), mouthfeel smoothness (1-5 points), and caking (1-5 points), with a total score of = color + smoothness + (5-caking points), with a maximum score of 15 points.

[0093] 3. Experimental results As shown in Table 3, the solubility of experimental group 2 and experimental group 3 was significantly higher than that of the blank group, the dispersion time was short, and the sedimentation rate was low. Due to the porous structure after puffing combined with the effect of the adjuvant, the contact area and wetting efficiency of the powder and water were improved; the viscosity was lower than that of the blank group, which avoided the too thick mouthfeel after brewing, while maintaining the appropriate smoothness, which met the mouthfeel needs of instant food; the sensory score was above 13 points, showing uniform color, smooth mouthfeel, and no obvious caking, with excellent comprehensive brewing performance, meeting the needs of consumers for convenience and palatability.

[0094] Table 3 Effect of inoculating different fermentation inoculants on the brewing quality of puffed brown rice powder

[0095] The above only describes the preferred embodiments of the present application, and it should be noted that for ordinary skilled persons in the art, without departing from the principles of the present application, several improvements and refinements can be made, which should also be considered within the scope of protection of the present application.

Claims

1. A fermentation agent for improving the puffing performance and nutritional quality of brown rice, characterized in that, It is composed of Bacillus amyloliquefaciens and Aspergillus oryzae in a ratio of 2-3:

1.

2. The fermentation agent according to claim 1, characterized in that, The viable count of the *Bacillus amyloliquefaciens* is ≥1×10⁻⁶. 9 CFU / g; viable count of the Aspergillus oryzae ≥ 1 × 10⁻⁶ 9 CFU / g.

3. The application of the fermentation agent according to claim 1 or 2 in the preparation of puffed brown rice instant powder.

4. A method for preparing puffed brown rice instant powder, characterized in that, Includes the following steps: After washing the brown rice, soak it to activate it; inoculate it with the fermentation agent described in claim 1 or 2 for fermentation; after fermentation, dry and puff it, cool it and then grind it into powder.

5. The preparation method according to claim 4, characterized in that, After the brown rice is washed, it is soaked in distilled water at 30-35℃ for 4-6 hours until the moisture content of the brown rice is 35%-40%.

6. The preparation method according to claim 4, characterized in that, The inoculum amount of the fermentation agent is 3-5 wt%, and fermentation is carried out at 30-32℃ and 70%-80% relative humidity for 8-12 hours.

7. The preparation method according to claim 4, characterized in that, The moisture content of the dried and fermented brown rice is 12-15%; the puffing is performed by extrusion puffing with a screw speed of 200-250 r / min and a puffing temperature of 150-160℃.

8. The preparation method according to claim 4, characterized in that, The particle size of the puffed brown rice instant powder is 80-100 mesh.

9. The preparation method according to claim 4, characterized in that, It also includes adding excipients after the material is pulverized into powder; the excipients include 1-2 wt% soluble dietary fiber and / or nutritional supplements.

10. The puffed brown rice instant powder prepared by the preparation method according to any one of claims 4-9.

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